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MACE: Mass Concept Erasure in Diffusion Models
Shilin Lu, Zilan Wang, Leyang Li, Yanzhu Liu, Adams Wai-Kin Kong
Models: Stable Diffusion
Intelligence
Status: succeeded | Model: google/gemini-3.1-flash-lite-preview | Prompt: intel-v1 | Confidence: 95%
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Summary
MACE (Mass Concept Erasure) is a finetuning framework for text-to-image diffusion models designed to erase multiple concepts (up to 100) simultaneously. It balances generality (erasing synonyms) and specificity (preserving unrelated concepts) by combining closed-form cross-attention refinement with individual LoRA modules for each concept, integrated via a non-interfering fusion loss.
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MACE â utilizes â LoRA
confidence 98% · it employs a unique LoRA module for each individual concept to remove its intrinsic information.
MACE â erases â Concepts
confidence 95% · MACE, a finetuning framework for the task of mass concept erasure.
MACE â refines â Cross-Attention
confidence 95% · MACE starts by refining the cross-attention layers of the pretrained model using a closed-form solution.
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Abstract
Abstract:The rapid expansion of large-scale text-to-image diffusion models has raised growing concerns regarding their potential misuse in creating harmful or misleading content. In this paper, we introduce MACE, a finetuning framework for the task of mass concept erasure. This task aims to prevent models from generating images that embody unwanted concepts when prompted. Existing concept erasure methods are typically restricted to handling fewer than five concepts simultaneously and struggle to find a balance between erasing concept synonyms (generality) and maintaining unrelated concepts (specificity). In contrast, MACE differs by successfully scaling the erasure scope up to 100 concepts and by achieving an effective balance between generality and specificity. This is achieved by leveraging closed-form cross-attention refinement along with LoRA finetuning, collectively eliminating the information of undesirable concepts. Furthermore, MACE integrates multiple LoRAs without mutual interference. We conduct extensive evaluations of MACE against prior methods across four different tasks: object erasure, celebrity erasure, explicit content erasure, and artistic style erasure. Our results reveal that MACE surpasses prior methods in all evaluated tasks. Code is available at this https URL.
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- Source: https://arxiv.org/abs/2403.06135
- Canonical: https://arxiv.org/abs/2403.06135
- Code: https://github.com/Shilin-LU/MACE
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MACE: Mass Concept Erasure in Diffusion Models Shilin Lu 1 Zilan Wang 1 Leyang Li 1 Yanzhu Liu 2 Adams Wai-Kin Kong 1 1 School of Computer Science and Engineering, Nanyang Technological University, Singapore 2 Institute for Infocomm Research (I 2 R) & Centre for Frontier AI Research (CFAR), A*STAR, Singapore shilin002, wang1982, lile0005@e.ntu.edu.sg, liu yanzhu@i2r.a-star.edu.sg, adamskong@ntu.edu.sg âa photo of the airplaneâ (erased)âa photo of Paul Walkerâ (erased) âa photo of the aircraftâ (synonymous)âa photo of Paul Wesleyâ (unrelated) SD v1.4 MACE SD v1.4 MACE GeneralitySpecificity EfficacyEfficacy (a) Object Erasure(b) Celebrity Erasure(c) Scaling Erasure up to 100 Concepts Better Figure 1. Our proposed method, MACE, can erase a large number of concepts from text-to-image diffusion models. This can safeguard celebrity portrait rights, respect copyrights on artworks, and prevent explicit content creation. (a) MACE demonstrates good efficacy and generality by preventing the generation of images reflecting the target concept and its synonyms. (b) MACE maintains excellent specificity, ensuring that the unintended concepts remain intact, even when they share common terms with the target concept. (c) MACE exhibits a significantly enhanced ability to erase 100 concepts, outperforming previous methods. The overall score indicates the comprehensive erasing capability, as detailed in Section 4.3. Abstract The rapid expansion of large-scale text-to-image diffu- sion models has raised growing concerns regarding their potential misuse in creating harmful or misleading content. In this paper, we introduce MACE, a finetuning framework for the task of MAss Concept Erasure. This task aims to pre- vent models from generating images that embody unwanted concepts when prompted. Existing concept erasure meth- ods are typically restricted to handling fewer than five con- cepts simultaneously and struggle to find a balance between erasing concept synonyms (generality) and maintaining un- related concepts (specificity). In contrast, MACE differs by successfully scaling the erasure scope up to 100 concepts and by achieving an effective balance between generality and specificity. This is achieved by leveraging closed-form cross-attention refinement along with LoRA finetuning, col- lectively eliminating the information of undesirable con- cepts. Furthermore, MACE integrates multiple LoRAs with- out mutual interference. We conduct extensive evaluations of MACE against prior methods across four different tasks: object erasure, celebrity erasure, explicit content erasure, and artistic style erasure. Our results reveal that MACE sur- passes prior methods in all evaluated tasks. Code is avail- able at https://github.com/Shilin-LU/MACE. 1. Introduction In large-scale text-to-image (T2I) models [9, 14, 34, 40, 49, 54, 57, 73, 74, 76, 77], the task of concept erasure aims to remove concepts that may be harmful, copyrighted, or offensive. This ensures that when a model is prompted with any phrase related to deleted concepts, it will not generate images reflecting those concepts. The drive behind concept erasure is rooted in the sig- nificant risks posed by T2I models. These models can gen- erate inappropriate content, such as copyrighted artworks [23, 24, 55, 61], explicit content [22, 59, 72], and deepfakes [38, 70]. These issues are largely caused by the unfiltered, web-scraped training data [60]. While researchers have put efforts to mitigate these risks through refining datasets and retraining models, these methods are not only costly but also can lead to unforeseen outcomes [7, 44]. For example, despite being trained on a sanitized dataset, Stable Diffu- sion (SD) v2.0 [52] still produces explicit content. More- over, it exhibits a diminished generative quality for regular content when compared to its earlier versions [44]. Alterna- tive methods, such as post-generation filtering [41, 50] and inference guiding [3, 59], are effective when models are ac- cessed only via APIs. Yet, these safeguards can be easily 1 arXiv:2403.06135v1 [cs.CV] 10 Mar 2024 bypassed if users have access to the source code [63]. To mitigate the vulnerability of these safeguards, sev- eral finetuning-based methods have been proposed [16, 17, 19, 25, 30, 71]. Nonetheless, the challenge of concept era- sure lies in balancing the dual requirements of generality and specificity. Generality requires that a concept should be consistently removed, regardless of its expression and the context in which it appears. On the other hand, specificity requires that unrelated concepts remain intact. Our analy- sis reveals that there is substantial room for enhancing these methods with respect to both generality and specificity. We pinpoint three primary issues that hinder the effec- tiveness of prior works. Firstly, the information of a phrase is concealed within other words in the prompt through the attention mechanism [69]. This is sufficient to evoke the concept from T2I models (see Figure 2), leading to re- stricted generality and incomplete elimination when remov- ing concepts. Secondly, finetuning the diffusion modelâs prediction on early denoising steps (t > t 0 ) can result in degraded specificity of concept erasure. Typically, diffu- sion models generate a general context in the early stage [12, 31, 51]. For instance, when generating a portrait of Paul Walker or Paul Wesley, the initial sampling trajectory gravitates towards the face manifold. It begins by form- ing a vague outline that could resemble any person. Af- ter a turning point, a.k.a. spontaneous symmetry breaking (SSB) [51], the identity becomes clear with the details pro- gressively filled in. If our goal is to only prevent the model from generating images of Paul Walker, it should not impact other celebrities named âPaulâ (See Figure 1). However, if we alter the predictions made in the early stages, other âPaulsâ can inadvertently be affected. Lastly, when fineturn- ing methods are applied to erase a large number of concept (e.g., 100), a noticeable decline in performance is observed. This decline is due to either sequential or parallel finetun- ing of the models. The former is prone to catastrophic for- getting and the latter results in interference among different concepts being finetuned. In light of these challenges, we propose a framework, dubbed MAss Concept Erasure (MACE), to erase a large number of concepts from T2I diffusion models. MACE not only achieves a superior balance between generality and specificity, but also adeptly handles the erasure of 100 con- cepts. It requires neither concept synonyms nor the original training data to perform concept erasure. To remove multi- ple concepts, MACE starts by refining the cross-attention layers of the pretrained model using a closed-form solu- tion. This design encourages the model to refrain from em- bedding residual information of the target phrase into other words, thereby erasing traces of the concept in the prompt. Secondly, it employs a unique LoRA module [21] for each individual concept to remove its intrinsic information. To maintain specificity, MACE exploits concept-focal impor- Generated Image âpuppyonthegrassâ (a) Normal generation. (b) Replacing the text embedding of âpuppyâ with that of the final [EOS] token. Figure 2.A concept can be generated solely via residual infor- mation:(a) Average cross-attention map for each word presents that a conceptâs information is embedded within other words. (b) A puppy can be generated solely using residual information by re- placing the text embedding of âpuppyâ with that of the final[EOS] token. Additional examples are available in Figure 10. tance sampling during LoRA training, mitigating the impact on unintended concepts. Finally, we develop a loss function for MACE to harmoniously integrate multiple LoRA mod- ules without interfering with one another, while prevent- ing catastrophic forgetting. This integration loss can also be swiftly solved using a closed-form solution. We conduct extensive evaluations on four distinct tasks, including object erasure, celebrity erasure, explicit content erasure, and artis- tic style erasure. MACE demonstrates superior performance on mass concept erasure and strikes an effective balance between specificity and generality, compared with state-of- the-art (SOTA) methods. This achievement paves the way for safer and more regulated T2I applications. 2. Preliminaries and Related Work We provide an overview of two foundational preliminaries upon which our work is based in Appendix A. The first pre- liminary is the latent diffusion model, which serves as the cornerstone for the T2I model that we investigate. The sec- ond one is the cross-attention mechanism, a common fea- ture in T2I models. Concept erasure.Existing research on preventing un- wanted outputs from T2I models can be broadly grouped into four categories: post-image filtering [41, 50], infer- ence guidance [3, 59], retraining with the curated dataset [40, 52], and model finetuning [16, 17, 19, 25, 30, 39, 71]. The first two methods are post-hoc solutions and do not ad- dress the inherent propensity of the models to generate in- appropriate content [63]. Although retraining with curated datasets may offer a solution, it demands significant compu- tational effort and time (e.g., over 150,000 A100 GPU hours for retraining Stable Diffusion) [53]. Finetuning pretrained T2I models is a more viable approach. However, most meth- ods either overlook the residual information of the target phrase embedded within co-existing words, focusing solely 2 on the target phrase [16, 17, 71], or they finetune uniformly across timesteps [16, 25, 30, 71]. Modifications to diffusion models conditioned on timesteps before SSB [51] can nega- tively affect the generation of retained concepts. In contrast, the proposed MACE addresses these challenges effectively. Image cloaking.An alternative method for safeguarding images against imitation or memorization [8, 65] by T2I models involves an additional step of applying adversar- ial perturbations to photographs or artworks before they are posted online. This technique, often referred to as cloaking, enables individuals to effectively conceal their images from models during the training phase but remain accessible and discernible to human viewers [58, 62, 75]. Nevertheless, it is crucial to note that this strategy is applicable only to con- tent not yet posted online. To safeguard the vast amount of content already on the web, concept erasure can serve as a viable strategy for large model providers as they prepare to release more advanced models in subsequent evolutions. 3. Method We aim to develop a framework to erase a large number of concepts from pretrained T2I diffusion models. This frame- work takes two inputs: a pretrained model and a set of target phrases that expresses the concepts to be removed. It returns a finetuned model that is incapable of generating images de- picting the concepts targeted for erasing. An effective era- sure framework should fulfill the following criteria: âąEfficacy (block target phrases):If the finetuned model is conditioned on prompts with those target phrases, its outputs should have limited semantic alignment with the prompts. Yet, the outputs should still appear natural, ei- ther aligning with a generic category (e.g., sky), or de- faulting to the super-category of the concept, if one exists. âąGenerality (block synonyms):The model should also prevent the generation of images semantically related to any synonyms of the targeted phrases, ensuring that the erasure is not limited to the exact wording of the prompts. âąSpecificity (preserve unrelated concepts):If the fine- tuned model is conditioned on prompts that are semanti- cally unrelated to the erased concepts, its output distribu- tion should closely align with that of the original model. To this end, we introduce MACE, a MAss Concept Era- sure framework. The information of a phrase is embedded not only within the phrase itself but also within the words it co-exists with. To effectively erase the targeted concepts, our framework first removes the residual information from the co-existing words (Section 3.1). Subsequently, distinct LoRA modules are trained to eliminate the intrinsic infor- mation specific to each target concept (Section 3.2). Lastly, our framework integrates multiple LoRA modules without mutual interference, leading to a final model that effectively Res Block SA Block CA Block Single LoRA Loss CA Block CA Block âa photo of a puppyâ Multi- LoRA (a) Internal Structure of One U-Net Block(b) Closed-Form Refinement (c) LoRA Finetuning Concept 1Concept 2Concept 3Fusion (d) Multi-LoRA Fusion Loss InputOutputGround Truth Figure 3.Overview of MACE:(a) Our framework focuses on tun- ing the prompts-related projection matrices,W k andW v , within cross-attention (CA) blocks. (b) (Section 3.1 & Figure 4) The pre- trained U-Netâs CA blocks are refined using a closed-form so- lution, discouraging the model from embedding the residual in- formation of the target phrase into surrounding words. (c) (Sec- tion 3.2 & Figure 5) For each concept targeted for removal, a distinct LoRA module is learned to eliminate its intrinsic infor- mation. (d) (Section 3.3) A closed-form solution is introduced to integrate multiple LoRA modules without interfering with one an- other while averting catastrophic forgetting. forgets a wide array of concepts (Section 3.3). Figure 3 presents an overview of our framework. 3.1. Closed-Form Cross-Attention Refinement In this section, we suggest a closed-form cross-attention re- finement to encourage the model to refrain from embed- ding residual information of the target phrase into other words. Such residual information is adequate to evoke the unwanted concept from T2I models. The root of this issue lies in the attention mechanism [69], where the text embed- ding of a token encapsulates information from other tokens. This results in its âKeyâ and âValueâ vectors absorbing and reflecting information from other tokens. To tackle this, we focus on refining the cross-attention modules, which play a pivotal role in processing text prompts. For example, when altering the projection matrix W k , we modify it such that the âKeysâ of the words that co- exist with the target phrase in the prompt are mapped to the âKeysâ of those same words in another prompt, where the target phrase is replaced with either its super-category or a generic concept. Notably, the âKeysâ of the target phrase itself remain unchanged to avoid impacting on other unin- tended concepts associated with that phrase. Figure 4 illus- trates this process using the projection matrixW k , and the same principle is applicable toW v . Drawing upon methods that view matrices as linear as- sociative memories [1, 28], often used to edit knowledge 3 âphoto of skyâ âphoto of airplaneâ airplane Text Encoder of photo Text Embeddings Keys Loss sky of photo airplane of photo sky of photo Prompt Augmentation airplane âimage of â âphoto of â â in a photoâ · · sky Target Concept Mapping Concept Figure 4.Closed-Form Cross-Attention Refinement:TheW âČ k is tuned such that the âKeysâ of words co-existing with the target phrase âairplaneâ are mapped to the âKeysâ of those same words when the target phrase is replaced with a generic concept âskyâ. embedded within neural networks [2, 4, 5, 17, 36, 37, 43], we formulate our objective function as follows: min W âČ k n X i=1 W âČ k ·e f i âW k ·e g i 2 2 +λ 1 n+m X i=n+1 â„W âČ k ·e p i âW k ·e p i â„ 2 2 , (1) whereλ 1 âR + is a hyperparameter,e f i is the embedding of a word co-existing with the target phrase,e g i is the em- bedding of that word when the target phrase is replaced with its super-category or a generic one,e p i is the embedding for preserving the prior,W k is the pretrained weights, andn,m are the number of embeddings for mapping and preserving, respectively. As derived in Appendix B, this optimization problem has a closed-form solution: W âČ k = n X i=1 W k ·e g i ·(e f i ) T +λ 1 n+m X i=n+1 W k ·e p i ·(e p i ) T ! · n X i=1 e f i ·(e f i ) T +λ 1 n+m X i=n+1 e p i ·(e p i ) T ! â1 ,(2) where P n+m i=n+1 W k e p i (e p i ) T and P n+m i=n+1 e p i (e p i ) T are pre- cached constants for preserving prior. These constants are capable of encapsulating both general and domain-specific knowledge, as detailed in Appendix B. The general knowl- edge is estimated on the MS-COCO dataset [32] by default. 3.2. Target Concept Erasure with LoRA After applying the closed-form refinement to eliminate the traces of the target concepts from co-existing words (Sec- tion 3.1), our focus shifts to erasing the intrinsic information within the target phrase itself. Loss function.Intuitively, if a concept is to appear in gener- ated images, it should exert significant influence on several patches of those images [10, 46]. This implies that the atten- tion maps corresponding to the tokens of the concept should Pretrained U-Net Closed-Form Refined U-Net LoRA Layers âphoto of airplaneâ t âphoto of airplaneâ LoRA Gradient Activation Loss Grounded SAM Closed-Form Refined U-Net âphoto of airplaneâ LoRA Gradient Activation Loss Grounded SAM Closed-Form Refined U-Net âphoto of airplaneâ LoRA Gradient Gradient Grounded-SAM : Minimize Activation Figure 5.Training with LoRA to Erase Intrinsic Information: Eight images are generated for each target concept as a training set via SD v1.4. To obtain the attention maps, the images undergo forward diffusion to timesteptand then are fed into the closed- form refined model for predicting noise at timestept. The LoRA modules are trained to reduce the activation in the masked atten- tion maps that correspond to the target phrase. display high activation values in certain regions. We adapt this principle in an inverse manner to eliminate the infor- mation within the target phrase itself. The loss function is designed to suppress the activation in certain regions of the attention maps that correspond to the target phrase tokens. These specific regions are identified by segmenting the in- put image with Grounded-SAM [27, 33]. Figure 5 depicts the training process. The loss function is defined as: min X iâS X l A i t,l âM 2 F ,(3) whereSis the set of indices corresponding to the tokens of the target phrase,A i t,l is the attention map of tokeniat layer land timestept,Mis the segmentation mask, andâ„·℠F is the Frobenius norm. Parameter subset to finetune.To minimize the loss func- tion (Eq. (3)), we tune the closed-form refined projection matrices,W âČ k andW âČ v , by identifying a set of weight mod- ulations,âW k andâW v . Determining high-dimensional modulation matrices in large-scale models is non-trivial. However, weight modulations usually have a low intrinsic rank when they are adapted for specific downstream tasks [21]. Hence, we decompose the modulation matrices us- ing LoRA [21]. Specifically, for each target concept and each projection matrix (e.g.,W âČ k âR d in Ăd out ), we learn two matrices,BâR d in Ăr andDâR rĂd out , whererâȘ min(d in ,d out )is the decomposition rank. The new modu- lated matrices are: Ë W k =W âČ k + âW k =W âČ k +BĂD.(4) Concept-focal importance sampling (CFIS).If the atten- tion loss (Eq. (3)) is computed based on attention maps that 4 are obtained at uniformly sampled timesteps, the predicted score function at various noise levels will be affected. Con- sequently, it will influence the entire sampling trajectory, undermining the specificity of concept erasure. This issue is especially problematic when erasing phrases that contain polysemous words or common surnames and given names. The reason lies in the nature of the diffusion trajectory. The sample initially gravitates towards the data manifold and possesses the potential to converge to various concept modes associated with the conditional phrase [11, 51]. Af- ter the turning point (a.k.a., SSB [51]), the specific mode to be fully denoised is determined [51]. Our goal is to in- fluence only the path leading to a particular mode, such as âBill Clintonâ, rather than affecting paths leading to every celebrity named âClintonâ or âBillâ. Thus, it is crucial that the early sampling trajectory remains largely unaffected. To this end, we opt not to sample the timesteptfrom a uniform distribution when training LoRA. Instead, we intro- duce a sampling distribution that assigns greater probability to smaller values oft. The probability density function for samplingtis defined as (A graph of this function is pro- vided in Appendix E): Ο(t) = 1 Z (Ï(Îł(tât 1 ))âÏ(Îł(tât 2 ))),(5) whereZis a normalizer,Ï(x)is the sigmoid function 1/(1 +e âx ), witht 1 andt 2 as the bounds of a high prob- ability sampling interval(t 1 < t 2 ), andÎłas a temperature hyperparameter. We empirically sett 1 = 200,t 2 = 400, andÎł= 0.05throughout our experiments. This strategy excels particularly in eliminating mass con- cepts that share overlapping terms. However, it is impor- tant to note that when erasing a smaller number of con- cepts or mass concepts that do not share overlapping terms, the improvements tend to be incremental. Beyond enhanc- ing specificity, this design significantly boosts training ef- fectiveness by fostering a more concentrated and efficient learning process. 3.3. Fusion of Multi-LoRA Modules In this section, we present a scheme to fuse multiple LoRA modules. Each LoRA module acts as a conceptual suppres- sor for the pretrained model, inducing a state of amnesia wherein the model loses their grasp on a specific concept. When working collaboratively, these modules should col- lectively enable the model to forget all the concepts targeted for erasure. A na Ì Ä±ve solution for integrating LoRA modules is to utilize a weighted sum [56]: Ë W k =W âČ k + q X i=1 Ï i âW k,i ,s.t. q X i=1 Ï i = 1,(6) whereW âČ k is the closed-form refined weight,âW k,i is the LoRA module associated with theith concept,Ï i is the nor- malized weighting factor, andqis the number of the target concepts. This na Ì Ä±ve fusion method leads to interference among the modules, thereby diminishing the erasure per- formance, as evidenced in the ablation study (Section 4.6). To preserve the capability of LoRA modules, we intro- duce a novel fusion technique illustrated in Figure 3 (d). We input the text embeddings of the target phrases into the re- spective LoRA module. The resulting outputs serve as the ground truth for optimizing the projection matrices. The ob- jective function is defined by: min W â k q X i=1 p X j=1 W â k ·e f j â(W âČ k + âW k,i )·e f j 2 2 +λ 2 p+m X j=p+1 W â k ·e p j âW k ·e p j 2 2 , (7) whereW k is the original weight,W âČ k is the closed-form refined weight,e f i is the embedding of a word co-existing with the target phrase,e p j is the embedding for prior pre- serving,λ 2 âR + is a hyperparameter,qis the number of erased concepts, andp,mare the number of embeddings for mapping and preserving. Similar to Eq. (2), this optimiza- tion problem has a closed-form solution as well. Compared with sequential or parallel finetuning of a pre- trained model for erasing multiple concepts, employing sep- arate LoRA modules for each concept and then integrating them offers better prevention against catastrophic forgetting and provides more flexibility. 4. Experiments In this section, we conduct a comprehensive evaluation of our proposed method, benchmarking it against SOTA baselines across four tasks. The baselines comprise ESD- u [16], ESD-x [16], FMN [71], SLD-M [59], UCE [17], and AC [30]. The four tasks are: object erasure (Sec- tion 4.2), celebrity erasure (Section 4.3), explicit content erasure (Section 4.4), and artistic style erasure (Section 4.5). All results from the original SD v1.4 and SD v2.1 are ob- tained without the application of negative prompts. Our evaluation not only measures efficacy but also ex- plores the generality and specificity of the erasure methods. The generality assessment is primarily conducted in the ob- ject erasure, since synonyms for a particular object tend to be precise and universally acknowledged compared to those for celebrities and artists. Evaluating specificity is more straightforward and is therefore applied across all tasks. We also focus on the effectiveness of these methods in handling multi-concept erasure, using the celebrity erasure as a key benchmark. We then highlight the superior performance of our proposed method in erasing explicit content and artistic styles. Lastly, we conduct ablation studies (Section 4.6) to understand the impact of the key components. 5 Table 1.Evaluation of Erasing the CIFAR-10 Classes:Results for the first four individual classes, along with the average results across 10 classes, are presented. CLIP classification accuracies are reported for each erased class in three sets: the erased class itself (Acc e , efficacy), the nine remaining unaffected classes (Acc s , specificity), and three synonyms of the erased class (Acc g , generality). The harmonic means H o reflect the comprehensive erasure capability. All presented values are denoted in percentage (%). Results pertaining to the latter six classes are available in Appendix D. The classification accuracies of images generated by the original SD v1.4 are presented for reference. Method Airplane ErasedAutomobile ErasedBird ErasedCat ErasedAverage across 10 Classes Acc e âAcc s âAcc g âH o âAcc e âAcc s âAcc g âH o âAcc e âAcc s âAcc g âH o âAcc e âAcc s âAcc g âH o âAcc e âAcc s âAcc g âH o â FMN [71]96.7698.3294.156.1395.0896.8679.4511.4499.4698.1396.751.3894.8997.9795.716.8396.9696.7382.566.13 AC [30]96.2498.5593.35 6.1194.4198.4773.9213.1999.5598.5394.571.2498.9498.6399.101.4598.3498.5683.383.63 UCE [17]40.3298.7949.8364.094.7399.0237.2582.1210.7198.3515.9790.182.3598.022.5897.7013.5498.4523.1885.48 SLD-M [59]91.3798.8689.2613.6984.8998.8666.1528.3480.7298.3985.0023.3188.5698.4392.1713.3184.1498.5467.3526.32 ESD-x [16]33.1197.1532.2874.9859.6898.3958.8350.6218.5797.2440.5576.1712.5197.5221.9186.9826.9397.3231.6176.91 ESD-u [16]7.3885.485.9290.5730.2991.0232.1274.8813.1786.1720.6583.9811.7791.4513.5088.6818.2786.7616.2683.69 Ours9.0695.3910.0392.036.9795.1814.2291.159.8897.4515.4890.392.2298.853.9197.568.4997.3510.5392.61 SD v1.4 [54]96.0698.9295.08-95.7598.9575.91-99.7298.5195.45-98.9398.6099.05-98.6398.6383.64- 4.1. Implementation Details We finetune all models on SD v1.4 and generate images with DDIM sampler [66] over 50 steps. We follow [30] to augment the input target concept using prompts generated by the GPT-4 [42]. The prompt augmentation varies de- pending on the target concept type (e.g., objects or styles). Each LoRA module is trained for 50 gradient update steps. We implement baselines as per the configurations recom- mended in their original settings. Further details are pro- vided in Appendix C. 4.2. Object Erasure Evaluation setup.For each erasure method, we finetune ten models, with each model designed to erase one object class of the CIFAR-10 dataset [29]. To assess erasure effi- cacy, we use each finetuned model to generate 200 images of the intended erased object class, prompted byâa photo of theerased class nameâ. These images are classified us- ing CLIP [47], and the criterion for successful erasure is a low classification accuracy. To assess specificity, we use each finetuned model to generate 200 images for each of the nine remaining, unmodified object classes with prompts âa photo of theunaltered class nameâ. A high classifi- cation accuracy indicates excellent erasure specificity. For assessing generality, we prepare three synonyms for each object class, listed in Table 6. Each finetuned model is used to generate 200 images for each synonym associated with the erased class, using the promptâa photo of thesynonym of erased class nameâ. In this case, good generality is re- flected by lower classification accuracies. Importantly, to evaluate the overall erasure capability of methods, we use the harmonic mean of efficacy, specificity, and generality. It is calculated as follows: H o = 3 (1âAcc e ) â1 + (Acc s ) â1 + (1âAcc g ) â1 ,(8) whereH o is the harmonic mean for object erasure, Acc e is the accuracy for the erased object (efficacy), Acc s for the remaining objects (specificity), and Acc g for the synonyms of the erased object (generality). A lower value of Acc e and Acc g , and a higher Acc s contribute to a higher harmonic mean, indicating a superior comprehensive erasure ability. Discussions and analysis.Table 1 presents the results of erasing the first four object classes of the CIFAR-10 dataset, as well as the average results across all 10 classes. The re- sults of the latter six classes can be found in Appendix D. Our approach attains the highest harmonic mean across the erasure of nine object classes, with the exception of âcatâ, where our performance nearly matches the top result. This underscores the superior erasure capabilities of our ap- proach, striking an effective balance between specificity and generality. Additionally, it is noteworthy that while meth- ods like FMN [71] and AC [30] are proficient in removing specific features of a subject, they fall short in completely eradicating the subjectâs generation. 4.3. Celebrity Erasure Evaluation setup.In this section, we evaluate the erasure methods with respect to their ability to erase multiple con- cepts. We establish a dataset consisting of 200 celebri- ties whose portraits, generated by SD v1.4, are recogniz- able with remarkable accuracy(>99%)by the GIPHY Celebrity Detector (GCD) [18]. The dataset is divided into two groups: an erasure group with 100 celebrities whom users aim to erase, and a retention group with 100 other celebrities whom users intend to preserve. The complete list of these celebrities is provided in Table 7. We perform a series of four experiments where SD v1.4 is finetuned to erase 1, 5, 10, and all 100 celebrities in the erasure group. The efficacy of each erasure method is tested by generating images of the celebrities intended for erasure. Successful erasure is measured by a low top-1 GCD accu- racy in correctly identifying the erased celebrities. To test the specificity of methods on the retained celebrities, we generate and evaluate images of the celebrities in the reten- tion group in the same way. A high specificity is indicated by a high top-1 GCD accuracy. 6 SD v1.4UCESLD-MESD-xESD-uOurs Specificity: âA sketch of Bill Murrayâ Efficacy: âBill Clinton in an official photoâ Specificity: âA portrait of Amanda Seyfriedâ Figure 6.Qualitative Comparison of Erasing 100 Celebrities from SD v1.4:Bill Clinton belongs to the erasure group for assessing efficacy, while Bill Murray and Amanda Seyfried are in the retention group to evaluate specificity. Preserving Bill Murrayâs images is challenging, as his first name is the same as Bill Clintonâs, who is in the erasure group. Additional examples are in Appendix F. Similar to Eq. (8), we underscore the comprehensive ability of the multi-concept erasure method by computing the harmonic mean of efficacy and specificity: H c = 2 (1âAcc e ) â1 + (Acc s ) â1 ,(9) whereH c is the harmonic mean for celebrity erasure, Acc e is the accuracy for the erased celebrities (efficacy), and Acc s for the retained celebrities (specificity). Furthermore, we as- sess the specificity of methods on regular content utiliz- ing the MS-COCO dataset [32]. We sample 30,000 cap- tions from the validation set to generate images and evaluate FID [45] and CLIP score [47]. Discussions and analysis.Figure 7 (c) illustrates a notable enhancement in overall erasure performance achieved by our method, particularly when 100 concepts are erased. This improvement indicates a more effective balance between ef- ficacy and specificity. FMN [71], AC [30], and SLD-M [59] demonstrate limited effectiveness in erasing multiple con- cepts, which inadvertently results in their high specificity. UCE [17] proves more effective, but its specificity decreases rapidly when more than 10 concepts are erased. Further- more, it fails to maintain FID and CLIP score within a rea- sonable range when erasing more than 10 celebrities while preserving only 100. As to ESD-u [16] and ESD-x [16], while effective, result in a lower proportion of facial images in their outputs (i.e., limited conceptual integrity), as shown in Figure 7 (f). This suggests that when their refined mod- els are conditioned on erased celebrities, their outputs de- viate from human likenesses, often leading to unpredictable (a) Efficacy(b) Specificity(c) Overall (d) Image Quality(e) Semantic Alignment(f) Conceptual Integrity Figure 7.Evaluation of Erasing Multiple Celebrity:The evalu- ation metrics include the detection accuracy on images of erased celebrities (Acc e â) and those of retained celebrities (Acc s â), the harmonic mean (H c â) which indicates overall erasure per- formance, FID, CLIP score, and the ratio of facial images. and uncontrollable outcomes. This phenomenon is shown in Figure 6, which presents a qualitative comparison of eras- ing 100 celebrities. In this comparison, Bill Clinton is in the erasure group, whereas Bill Murray and Amanda Seyfried are in the retention group. Notably, the preservation of Bill Murrayâs image poses a challenge due to his shared first 7 Table 2.Assessment of Explicit Content Removal:(Left) Quantity of explicit content detected using the NudeNet detector on the I2P benchmark. (Right) Comparison of FID and CLIP on MS-COCO. The performance of the original SD v1.4 is presented for reference. SD v2.1 serves as a baseline that retrains the model from scratch on the curated dataset. â : Results sourced from [19]. F: Female. M: Male. Method Results of NudeNet Detection on I2P (Detected Quantity)MS-COCO 30K ArmpitsBellyButtocksFeetBreasts (F)Genitalia (F)Breasts (M)Genitalia (M)TotalâFIDâCLIPâ FMN [71]4311712591551719242413.5230.39 AC [30]15318045662982267783814.1331.37 UCE [17]296272935511418214.0730.85 SLD-M [59]477232139126321216.3430.90 ESD-x [16]59731239100618831514.4130.69 ESD-u [16]32302192738212315.1030.21 SA â [19]72771925831600292-- Ours17192391629711113.4229.41 SD v1.4 [54]14817029632661842774314.0431.34 SD v2.1 [52]1051591760177957258614.8731.53 name, âBill,â with Bill Clinton in the erasure group. Our method effectively overcomes this issue. 4.4. Explicit Content Erasure Evaluation setup.In this section, we attempt to mitigate the generation of explicit content in T2I models. We adopt the same setting used in SA [19], finetuning SD v1.4 to erase four target phrases: ânudityâ, ânakedâ, âeroticâ, and âsexualâ. To evaluate efficacy and generality, we use each finetuned model to generate images using all 4,703 prompts sourced from the Inappropriate Image Prompt (I2P) dataset [59]. The NudeNet [6] is employed to identify explicit content in these images, using a detection threshold of 0.6. Addi- tionally, to assess specificity on regular content, we evalu- ate FID and CLIP score on the MS-COCO validation set, similar to the process described in Section 4.3. Discussions and analysis.Table 2 presents our findings. Our refined model successfully generates the least amount of explicit content when conditioned on 4,703 prompts. Moreover, it showcases an impressive performance in FID, even surpassing the original SD v1.4. We note that such finetuning often does not have a consistent trend in improv- ing or worsening FID and CLIP score on regular content generation. This pattern is also observed in the celebrity erasure, as shown in Figure 7 (d) and (e). Therefore, we consider the performance acceptable as long as FID and CLIP score remain within a reasonable range. It is also note- worthy that retraining SD v2.1 from scratch using a dataset curated to exclude explicit content yields only a minor im- provement, compared with the original SD v1.4. Qualitative comparisons are provided in Appendix F for reference. 4.5. Artistic Style Erasure In this section, we evaluate our method and the baselines on erasing multiple artistic styles from SD v1.4. We utilize the Table 3.Assessment of Erasing 100 Artistic Styles:H a indicates overall erasure performance. MethodCLIP e âCLIP s âH a âFID-30KâCLIP-30Kâ FMN [71]29.6328.90-0.7313.9931.31 AC [30]29.2628.54-0.7214.0831.29 UCE [17]21.3125.704.3977.7219.17 SLD-M [59]28.4927.89-0.617.9530.87 ESD-x [16]20.8921.210.3215.1929.52 ESD-u [16]19.6619.55-0.1117.0727.76 Ours22.5928.58 5.9912.7129.51 SD v1.429.6328.90-14.0431.34 Image Synthesis Style Studies Database [23], which com- piles a list of artists whose styles can be replicated by SD v1.4. From this database, we sample 200 artists and split them into two groups: an erasure group of 100 artists and a retention group with 100 other artists. The complete list is provided in Table 9. To assess efficacy and specificity, we apply prompts likeâImage in the style ofartist nameâto both the erased and retained artists. We evaluate the erasure methods using two metrics: CLIP e and CLIP s . The CLIP e , which tests efficacy, is calculated between the prompts of the erased artists and the generated images. A lower CLIP e indicates better efficacy. Similarly, the CLIP s , which as- sesses specificity, is calculated between the prompts of the retained artists and the generated images. A higher CLIP s signifies better specificity. We calculate the overall erasing capability byH a =CLIP s âCLIP e . As reported in Table 3, our method also shows the superior ability to erase artistic styles on a large scale. 4.6. Ablation Study To study the impact of our key components, we conduct ab- lation studies on the challenging task of erasing 100 celebri- ties from SD v1.4. Different variations and their results are presented in Table 4. Variation 1 struggles to balance ef- ficacy and specificity. When prioritizing prior preservation, 8 Table 4.Ablation Study on the Impact of Key Components in Erasing 100 Celebrities.CFR: closed-form refinement. NLF: na Ì Ä±ve LoRA fusion. CFLF: closed-form LoRA fusion. CFIS: concept-focal importance sampling. All presented values are de- noted in percentage (%). Config ComponentsMetrics CFRLoRANLFCFLFCFISAcc e âAcc s âH c â 1âĂ Ă Ă Ă67.7985.0546.72 2âĂ Ă0.0832.1648.66 3âĂâĂ18.7061.78 70.21 OursâĂâ4.3184.5689.78 SD v1.4-----96.4893.886.79 Table 5.Ablation Study on the Impact of LoRA Finetuned Pro- jection Matrices in Erasing 100 Celebrities.All presented val- ues are denoted in percentage (%). ConfigVariationTuning Step Metrics Acc e âAcc s âH c â 5Tune Key Only50 steps12.7280.5483.77 6Tune Value Only 50 steps0.7738.6555.63 25 steps3.2862.7476.11 10 steps10.4777.8183.26 5 steps12.7280.4583.73 3 steps14.4681.70 83.58 1 steps15.3982.3783.48 OursTune Key & Value50 steps4.3184.5689.78 its ability to erase is compromised. Variation 2, which trains LoRA without CFIS, restricts its specificity. Moreover, the na Ì Ä±ve integration of LoRA exacerbates this issue, leading to poor specificity despite the successful erasure of the target concepts. Variation 3 fuses LoRA with closed-form fusion, which prevents interference from different LoRA modules, thereby improving specificity. However, without the CFIS, this configuration shows reduced training efficiency in era- sure and decreased specificity. We also carry out ablation studies focused on indepen- dently adjusting either the âKeyâ or âValueâ projection ma- trices, as detailed in Table 5. Intriguingly, exclusively fine- tuning theâValueâ projection matrices for an identical num- ber of steps can result in the deterioration of unrelated con- cepts, as indicated by a lower Acc s . While fine-tuning only the âValueâ projection matrices might seem efficient for ob- taining satisfactory outcomes with minimal adjustments, its peak performance is notably inferior. 5. Additional Applications MACE possesses the capability to simultaneously erase dif- ferent types of concepts, such as both a celebrity likeness and artistic style, as shown in Figure 8 (a). Furthermore, MACE is compatible with distilled fast diffusion models (e.g., Latent Consistency Model [35]), with an example pre- sented in Figure 8 (b). (b) MACE on LCM (4-step generation) (a) Erase different types of concepts simultaneously Figure 8.(a) MACE can simultaneously erase different types of concepts.The left image is generated from the original SD v1.4. The right one is generated by the MACE finetuned SD v1.4 which erases the concepts of a celebrity (Bill Clinton) and a artistic style (Brent Heighton). Both images are generated using the prompt âBill Clinton walking, Brent Heighton styleâ.(b) MACE is com- patible with distilled diffusion models. The left image is gen- erated from the original LCM Dreamshaper v7. The right one is generated by the MACE finetuned LCM which erases the concept of âTrumpâ. Both images are generated using the promptâa photo of Trump playing guitarâ. 6. Limitations and Conclusion Our proposed method, MACE, offers an effective solution for erasing mass concepts from T2I diffusion models. Our extensive experiments reveal that MACE achieves a remark- able balance between specificity and generality, particularly in erasing numerous concepts, surpassing the performance of prior methods. However, a discernible decline in the har- monic mean is observed as the number of erased concepts increases from 10 to 100. This trend could pose a limita- tion in erasing thousands of concepts from more advanced models in the future. Exploring ways to further scale up the erasure scope presents a crucial direction for future re- search. We believe MACE can be a pivotal tool for gen- erative model service providers, empowering them to effi- ciently eliminate a variety of unwanted concepts. This is a vital step in releasing the next wave of advanced models, contributing to the creation of a safer AI community. Acknowledgement This research is supported by the National Research Foundation, Singapore under its Strategic Capability Research Centres Funding Initiative. Any opinions, find- ings and conclusions or recommendations expressed in this material are those of the author(s) and do not re- flect the views of National Research Foundation, Singapore. References [1] James A Anderson. A simple neural network generating an interactive memory.Mathematical biosciences, 14(3-4): 197â220, 1972. 3 [2] Dana Arad, Hadas Orgad, and Yonatan Belinkov. Refact: Updating text-to-image models by editing the text encoder. arXiv preprint arXiv:2306.00738, 2023. 4 9 [3] AUTOMATIC1111.Negative prompt.https : / / github . com / AUTOMATIC1111 / stable - diffusion - webui / wiki / Negative - prompt. 1, 2 [4] Samyadeep Basu, Nanxuan Zhao, Vlad Morariu, Soheil Feizi, and Varun Manjunatha. 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Pyramid diffusion models for low-light image enhancement.arXiv preprint arXiv:2305.10028, 2023. 1 [77] Dewei Zhou, You Li, Fan Ma, Zongxin Yang, and Yi Yang. Migc: Multi-instance generation controller for text-to-image synthesis.arXiv preprint arXiv:2402.05408, 2024. 1 12 Appendix A. Preliminaries Latent diffusion model.Our method is implemented using Stable Diffusion (SD), also known as Latent Diffusion Models (LDM) [54]. This approach conducts the diffusion process within the latent space of an autoencoder. LDM is comprised of two principal components: a vector quantization autoencoder [15, 68] and a diffusion model [13, 20, 26, 54, 64, 67]. The autoencoder undergoes pretraining to transform images into spatial latent codes via an encoderz=E(x), and it can reconstruct the images from these latent codes using a decoderxâ D(E(x)). The diffusion model, on the other hand, is trained to generate latent codes that exist within the autoencoderâs latent space. The training objective for the diffusion model is defined as follows [20, 54]: L LDM =E zâŒE(x),c,ΔâŒN(0,1),t h â„ΔâΔ Ξ (z t ,t,c)â„ 2 2 i ,(10) wherez t is the noisy latent,tis the timestep,Δis a standard Gaussian noise sample,Δ Ξ is the denoising network, andcis the conditioning embeddings, which can be encoded from text prompts, class labels, segmentation masks, among others [54]. During the inference process, Gaussian noise is sampled as a starting pointz T and successively denoised to produce a new latent codez 0 through the well-trained denoising networkΔ Ξ . Ultimately, this latent code is transformed into an image via the pretrained decoderx 0 âD(z 0 ). Cross-attention in text-to-image diffusion models.In text-to-image diffusion models, cross-attention mechanisms serve as the pivotal interface for the interplay between image and text modalities. Initially, a text prompt undergoes tokenization, converting it into a series of unique token embeddings. These embeddings are then processed by a text encoder (e.g., CLIP [47] or T5 [48]), resulting in a final set of embeddings, denoted asP= [e 1 e 2 ·e y ], wherein each tokenâs embedding e i is enriched with information from the entire token sequence. These enhanced embeddings are subsequently introduced into the cross-attention modules, where they act as navigational beacons for the image synthesis process. At certain layer land timestept, the text embeddings are mapped using projection matrices,W k andW v , to obtain the âKeysâk t,l and âValuesâv t,l , respectively. Concurrently, the imageâs features,f t,l , undergo the projectionW q to form the âQueriesâq t,l . The cross-attention mechanism computes the attention map as [54, 69]: A t,l =softmax q t,l ·k T t,l â d ! ,(11) wheredis the scaling factor to normalize the dot product. The module then synthesizes image features by aggregating âValuesâ with the attention weights,o t,l =A t,l ·v t,l . This process ensures that the generated images are intricately aligned with the input text, completing the text-to-image generation with high fidelity. B. Closed-Form Solution Proof In this section, we present a detailed derivation of the closed-form solution as written in Eq. (2). Our goal is to determine a refined matrix, denoted asW âČ k âR d 1 Ăd 2 , which encourages the model to refrain from embedding residual information of the target phrase into other words, while preserving the prior knowledge. The loss function is defined in Eq. (1), which is: L(W âČ k ) = n X i=1 W âČ k ·e f i âW k ·e g i 2 2 +λ 1 n+m X i=n+1 â„W âČ k ·e p i âW k ·e p i â„ 2 2 , whereλ 1 âR + is a hyperparameter,e f i âR d 2 is the embedding of a word co-existing with the target phrase,e g i âR d 2 is the embedding of that word when the target phrase is replaced with its super-category or a generic one,e p i âR d 2 is the embedding for preserving the prior,W k âR d 1 Ăd 2 is the pretrained weights, andn,mare the number of embeddings for mapping and preserving, respectively. 13 To seek the optimalW âČ k , we differentiate the loss function with respect to it and set the derivative equal to zero: âL(W âČ k ) âW âČ k = 2 n X i=1 W âČ k ·e f i âW k ·e g i (e f i ) T + 2λ 1 n+m X i=n+1 (W âČ k ·e p i âW k ·e p i ) (e p i ) T = 0(12) n X i=1 W âČ k ·e f i ·(e f i ) T â n X i=1 W k ·e g i ·(e f i ) T +λ 1 n+m X i=n+1 W âČ k ·e p i ·(e p i ) T âλ 1 n+m X i=n+1 W k ·e p i ·(e p i ) T = 0(13) n X i=1 W âČ k ·e f i ·(e f i ) T +λ 1 n+m X i=n+1 W âČ k ·e p i ·(e p i ) T = n X i=1 W k ·e g i ·(e f i ) T +λ 1 n+m X i=n+1 W k ·e p i ·(e p i ) T (14) W âČ k n X i=1 e f i ·(e f i ) T +λ 1 n+m X i=n+1 e p i ·(e p i ) T ! = n X i=1 W k ·e g i ·(e f i ) T +λ 1 n+m X i=n+1 W k ·e p i ·(e p i ) T (15) W âČ k = n X i=1 W k ·e g i ·(e f i ) T +λ 1 n+m X i=n+1 W k ·e p i ·(e p i ) T ! · n X i=1 e f i ·(e f i ) T +λ 1 n+m X i=n+1 e p i ·(e p i ) T ! â1 .(16) To ensure the validity of the final step, it is crucial that the symmetric real matrix P n i=1 e f i ·(e f i ) T +λ 1 P n+m i=n+1 e p i ·(e p i ) T is full rank. For any non-zero vectorxâR d 2 , we examine the following quadratic form: x T · n X i=1 e f i ·(e f i ) T +λ 1 n+m X i=n+1 e p i ·(e p i ) T ! ·x= n X i=1 x T e f i · x T e f i T +λ 1 n+m X i=n+1 x T e p i · x T e p i T (17) = n X i=1 x T e f i 2 2 +λ 1 n+m X i=n+1 x T e p i 2 2 â„0.(18) The prior preserving embeddingse p i are computed by default using the MS-COCO dataset [32]. Due to the extensive number of terms involved in the summation, it is highly improbable for all terms x T e p i 2 2 in the sum to equal zero. Hence, in general cases, the matrix P n i=1 e f i ·(e f i ) T +λ 1 P n+m i=n+1 e p i ·(e p i ) T is positive definite and thus invertible. The derivation is applicable toW âČ v as well. In addition to retaining general prior knowledge, akin to UCE [17], our framework extends support to allow users to highlight and preserve domain-specific concepts. This functionality is absent in most preceding frameworks. For instance, when two concepts share a strong correlation, removing one could potentially impair the generation quality of the other, which might be intended for preservation. Both general and domain-specific prior knowledge can be incorporated into the second term of Eq. (1). We set a weighting factorλ 3 to calibrate the significance attributed to each type of knowledge. Thus, Eq. (2) can be reformulated as follows: W âČ k = ïŁ« ïŁ n X i=1 W k ·e g i ·(e f i ) T +λ 1 n+m âČ X i=n+1 W k ·e p i ·(e p i ) T +λ 3 n+m X i=n+m âČ W k ·e p i ·(e p i ) T ïŁ¶ ïŁž · ïŁ« ïŁ n X i=1 e f i ·(e f i ) T +λ 1 n+m âČ X i=n+1 e p i ·(e p i ) T +λ 3 n+m X i=n+m âČ e p i ·(e p i ) T ïŁ¶ ïŁž â1 , (19) where we havem âČ terms of general knowledge andmâm âČ terms of domain-specific knowledge. C. Implementation Details C.1. Experimental Setup Details Object erasure.To assess the generality of erasure, we prepare three synonyms for each of the ten object classes in the CIFAR-10 dataset [29]. These synonyms are listed in Table 6. Since the object classes lack proper super-categories, we allocate generic concepts (e.g., sky or ground) to them, as also presented in Table 6. To evaluate the erasure capability of 14 Table 6. The synonyms and mapping concepts for the ten object classes in the CIFAR-10 dataset. Object Classes AirplaneAutomobile BirdCatDeerDogFrogHorseShipTruck Synonyms AircraftCarAvianFelineHartCanineAmphibianEquineVesselLorry PlaneVehicleFowlKittyStagPoochAnuranSteedBoatRig JetMotorcarWinged Creature HousecatDoeHoundTadpoleMountWatercraftHauler Mapping Concepts (Randomly Sampled) GroundSkyStreetForestStreetSkyForestForestGroundSky different methods, we use each finetuned model to generate 200, 600, and 1,800 images for three categories: the erased object (efficacy), its three synonyms (generality), and nine remaining objects (specificity). For the erased object, the prompt isâa photo of theerased class nameâ. For the three synonyms of the erased object, we use the promptâa photo of thesynonym of erased class nameâ. Lastly, for each of the nine remaining unaltered objects, the prompt isâa photo of theunaltered class nameâ. Celebrity erasure.For assessing the task of multiple celebrity erasure, we establish a dataset consisting of 200 celebri- ties. Their portraits generated by SD v1.4 are recognizable with exceptional accuracy by the GIPHY Celebrity Detector (GCD) [18]. This dataset is divided into two groups: an erasure group with 100 celebrities and a retention group with 100 other celebrities. The full list for both groups is presented in Table 7. For evaluating the task of celebrity erasure, we use five text prompts to generate images. These prompts are as follows:âa portrait ofcelebrity nameâ, âa sketch ofcelebrity nameâ, âan oil painting ofcelebrity nameâ, âcelebrity namein an official photoâ,andâan image capturingcelebrity nameat a public eventâ.The detailed breakdown of the number of images generated for each experiment is presented in Table 8. Explicit content erasure.We adopt the same setting used in SA [19] to erase ânudityâ, ânakedâ, âeroticâ, and âsextualâ from SD v1.4. The mapping concept is set as âa person wearing clothesâ. Artistic style erasure.We utilize the Image Synthesis Style Studies Database [23], which compiles a list of artists whose styles can be replicated by SD v1.4. From this database, we sample 200 artists and split them into two groups: an erasure group of 100 artists and a retention group with 100 other artists. The full list for both groups is presented in Table 9. To assess efficacy and specificity, we apply the same five prompts and seeds as in [17] for both the erased and retained artists group. These prompts includeâImage in the style ofartist nameâ, âArt inspired byartist nameâ, âPainting in the style ofartist nameâ, âA reproduction of art byartist nameâandâA famous artwork byartist nameâ. For each of 100 artists, we use each prompt to generate five images, resulting in 25 images per artist. Thus, this yields 2500 images for each group. C.2. Training Configurations Implementation of previous works.In our series of four experiments, we focus on comparing our proposed method with existing methods, including ESD-u 1 [16], ESD-x [16], FMN 2 [71], SLD-M 3 [59], UCE 4 [17], AC 5 [30], and SA 6 [19]. Notably, SA [19] demands extensive resources, requiring 4 RTX A6000s and over 12 hours of training for concept erasure. Consequently, we have not replicated their findings due to these extensive requirements. Instead, we align our explicit content erasure task with SAâs settings [19], and we employ their reported experimental results for our comparative analysis. Beyond SA [19], we implement each existing method following their recommended configurations for various erasure types (such as objects, style, or nudity). It is important to note that several methods (e.g., FMN [71] and AC [30]) are not tailored for erasing multiple concepts. In our preliminary tests, we observe that without altering the algorithm or further tuning the suggested parameters, training for multiple conceptsâeither sequentially or in parallelâyielded comparably mediocre results, marked by either inadequate specificity or generality. Consequently, we opt for a parallel training manner for them when erasing multiple concepts to save resources. 1 https://github.com/rohitgandikota/erasing 2 https://github.com/SHI-Labs/Forget-Me-Not 3 https://github.com/ml-research/safe-latent-diffusion 4 https://github.com/rohitgandikota/unified-concept-editing 5 https://github.com/nupurkmr9/concept-ablation 6 https://github.com/clear-nus/selective-amnesia 15 Table 7.The Evaluation Setup for Celebrity Erasure:Our celebrity dataset contains an erasure group with 100 celebrities and a retention group with another 100 celebrities. Portraits of these celebrities can be effectively generated using SD v1.4. The generated portraits are accurately recognizable by the GIPHY Celebrity Detector (GCD) with an accuracy exceeding 99%. To perform erasure experiments involving 1, 5, 10, and 100 celebrities, a corresponding number of celebrities are selected from the erasure group for each experiment. In all cases, the entire retention group is utilized. Group # of Celebrities to Be Erased Mapping Concept Celebrity Erasure Group 1âa womanââMelania Trumpâ 5âa personââAdam Driverâ, âAdriana Limaâ, âAmber Heardâ, âAmy Adamsâ, âAndrew Garfieldâ 10âa personâ âAdam Driverâ, âAdriana Limaâ, âAmber Heardâ, âAmy Adamsâ, âAndrew Garfieldâ, âAngelina Jolieâ, âAnjelica Hustonâ, âAnna Farisâ, âAnna Kendrickâ, âAnne Hathawayâ 100âa personâ âAdam Driverâ, âAdriana Limaâ, âAmber Heardâ, âAmy Adamsâ, âAndrew Garfieldâ, âAngelina Jolieâ, âAnjelica Hustonâ, âAnna Farisâ, âAnna Kendrickâ, âAnne Hathawayâ, âArnold Schwarzeneggerâ, âBarack Obamaâ, âBeth Behrsâ, âBill Clintonâ, âBob Dylanâ, âBob Marleyâ, âBradley Cooperâ, âBruce Willisâ, âBryan Cranstonâ, âCameron Diazâ, âChanning Tatumâ, âCharlie Sheenâ, âCharlize Theronâ, âChris Evansâ, âChris Hemsworthâ, âChris Pineâ, âChuck Norrisâ, âCourteney Coxâ, âDemi Lo- vatoâ, âDrakeâ, âDrew Barrymoreâ, âDwayne Johnsonâ, âEd Sheeranâ, âElon Muskâ, âElvis Pres- leyâ, âEmma Stoneâ, âFrida Kahloâ, âGeorge Clooneyâ, âGlenn Closeâ, âGwyneth Paltrowâ, âHar- rison Fordâ, âHillary Clintonâ, âHugh Jackmanâ, âIdris Elbaâ, âJake Gyllenhaalâ, âJames Francoâ, âJared Letoâ, âJason Momoaâ, âJennifer Anistonâ, âJennifer Lawrenceâ, âJennifer Lopezâ, âJeremy Rennerâ, âJessica Bielâ, âJessica Chastainâ, âJohn Oliverâ, âJohn Wayneâ, âJohnny Deppâ, âJu- lianne Houghâ, âJustin Timberlakeâ, âKate Bosworthâ, âKate Winsletâ, âLeonardo Dicaprioâ, âMargot Robbieâ, âMariah Careyâ, âMelania Trumpâ, âMeryl Streepâ, âMick Jaggerâ, âMila Kunisâ, âMilla Jovovichâ, âMorgan Freemanâ, âNick Jonasâ, âNicolas Cageâ, âNicole Kidmanâ, âOctavia Spencerâ, âOlivia Wildeâ, âOprah Winfreyâ, âPaul Mccartneyâ, âPaul Walkerâ, âPeter Dinklageâ, âPhilip Sey- mour Hoffmanâ, âReese Witherspoonâ, âRichard Gereâ, âRicky Gervaisâ, âRihannaâ, âRobin Williamsâ, âRonald Reaganâ, âRyan Goslingâ, âRyan Reynoldsâ, âShia Labeouf â, âShirley Templeâ, âSpike Leeâ, âStan Leeâ, âTheresa Mayâ, âTom Cruiseâ, âTom Hanksâ, âTom Hardyâ, âTom Hiddlestonâ, âWhoopi Goldbergâ, âZac Efronâ, âZayn Malikâ Retention Group 1, 5, 10, and 100- âAaron Paulâ, âAlec Baldwinâ, âAmanda Seyfriedâ, âAmy Poehlerâ, âAmy Schumerâ, âAmy Winehouseâ, âAndy Sambergâ, âAretha Franklinâ, âAvril Lavigneâ, âAziz Ansariâ, âBarry Manilowâ, âBen Affleckâ, âBen Stillerâ, âBenicio Del Toroâ, âBette Midlerâ, âBetty Whiteâ, âBill Murrayâ, âBill Nyeâ, âBrit- ney Spearsâ, âBrittany Snowâ, âBruce Leeâ, âBurt Reynoldsâ, âCharles Mansonâ, âChristie Brinkleyâ, âChristina Hendricksâ, âClint Eastwoodâ, âCountess Vaughnâ, âDakota Johnsonâ, âDane Dehaanâ, âDavid Bowieâ, âDavid Tennantâ, âDenise Richardsâ, âDoris Dayâ, âDr Dreâ, âElizabeth Taylorâ, âEmma Robertsâ, âFred Rogersâ, âGal Gadotâ, âGeorge Bushâ, âGeorge Takeiâ, âGillian Andersonâ, âGordon Ramseyâ, âHalle Berryâ, âHarry Dean Stantonâ, âHarry Stylesâ, âHayley Atwellâ, âHeath Ledgerâ, âHenry Cavillâ, âJackie Chanâ, âJada Pinkett Smithâ, âJames Garnerâ, âJason Stathamâ, âJeff Bridgesâ, âJennifer Connellyâ, âJensen Acklesâ, âJim Morrisonâ, âJimmy Carterâ, âJoan Riversâ, âJohn Lennonâ, âJohnny Cashâ, âJon Hammâ, âJudy Garlandâ, âJulianne Mooreâ, âJustin Bieberâ, âKaley Cuocoâ, âKate Uptonâ, âKeanu Reevesâ, âKim Jong Unâ, âKirsten Dunstâ, âKristen Stewartâ, âKrysten Ritterâ, âLana Del Reyâ, âLeslie Jonesâ, âLily Collinsâ, âLindsay Lohanâ, âLiv Tylerâ, âLizzy Caplanâ, âMaggie Gyllenhaalâ, âMatt Damonâ, âMatt Smithâ, âMatthew Mcconaugheyâ, âMaya An- gelouâ, âMegan Foxâ, âMel Gibsonâ, âMelanie Griffithâ, âMichael Ceraâ, âMichael Ealyâ, âNatalie Portmanâ, âNeil Degrasse Tysonâ, âNiall Horanâ, âPatrick Stewartâ, âPaul Ruddâ, âPaul Wesleyâ, âPierce Brosnanâ, âPrinceâ, âQueen Elizabethâ, âRachel Dratchâ, âRachel Mcadamsâ, âReba Mcen- tireâ, âRobert De Niroâ Table 8. The detailed breakdown of the number (#) of images generated for each celebrity erasure experiment. # of Celebrities to Be Erased Celebrity Group # of Images Generated for Each Celebrity Total # of Generated Images 1 Erasure Group250250 Retention Group252500 5 Erasure Group50250 Retention Group252500 10 Erasure Group25250 Retention Group252500 100 Erasure Group252500 Retention Group252500 16 Table 9.The Evaluation Setup for Artistic Style Erasure:We sample 200 artists from the Image Synthesis Style Studies Database [23]. They are split into two groups: an erasure group with 100 artists and a retention group with another 100 artists. The artworks of these artists can be successfully replicated by SD v1.4. Group # of Artistic Styles to Be Erased Mapping Concept Artist Erasure Group 100âartâ âBrent Heightonâ, âBrett Westonâ, âBrett Whiteleyâ, âBrian Bollandâ, âBrian Despainâ, âBrian Froudâ, âBrian K. Vaughanâ, âBrian Kesingerâ, âBrian Mashburnâ, âBrian Oldhamâ, âBrian Stelfreezeâ, âBrian Sumâ, âBriana Moraâ, âBrice Mardenâ, âBridget Bate Tichenorâ, âBriton Rivi ` ereâ, âBrooke Didonatoâ, âBrooke Shadenâ, âBrothers Grimmâ, âBrothers Hildebrandtâ, âBruce Munroâ, âBruce Naumanâ, âBruce Penningtonâ, âBruce Timmâ, âBruno Catalanoâ, âBruno Munariâ, âBruno Walpothâ, âBryan Hitchâ, âButcher Billyâ, âC. R. W. Nevinsonâ, âCagnaccio Di San Pietroâ, âCamille Corotâ, âCamille Pissarroâ, âCamille Walalaâ, âCanalettoâ, âCandido Portinariâ, âCarel Willinkâ, âCarl Barksâ, âCarl Gustav Carusâ, âCarl Holsoeâ, âCarl Larssonâ, âCarl Spitzwegâ, âCarlo Crivelliâ, âCarlos Schwabeâ, âCarmen Saldanaâ, âCarne Griffithsâ, âCasey Weldonâ, âCaspar David Friedrichâ, âCassius Marcel- lus Coolidgeâ, âCatrin Welz-Steinâ, âCedric Peyravernayâ, âChad Knightâ, âChantal Joffeâ, âCharles Addamsâ, âCharles Angrandâ, âCharles Blackmanâ, âCharles Camoinâ, âCharles Dana Gibsonâ, âCharles E. Burchfieldâ, âCharles Gwathmeyâ, âCharles Le Brunâ, âCharles Liuâ, âCharles Schriddeâ, âCharles Schulzâ, âCharles Spencelayhâ, âCharles Vessâ, âCharles-Francois Daubignyâ, âCharlie Bowaterâ, âCharline Von Heylâ, âCha Ì Ä±m Soutineâ, âChen Zhenâ, âChesley Bonestellâ, âChiharu Sh- iotaâ, âChing Yehâ, âChip Zdarskyâ, âChris Claremontâ, âChris Cunninghamâ, âChris Fossâ, âChris Leibâ, âChris Mooreâ, âChris Ofiliâ, âChris Saundersâ, âChris Turnhamâ, âChris Umingaâ, âChris Van Allsburgâ, âChris Wareâ, âChristian Dimitrovâ, âChristian Grajewskiâ, âChristophe Vacherâ, âChristo- pher Balaskasâ, âChristopher Jin Baronâ, âChuck Closeâ, âCicely Mary Barkerâ, âCindy Shermanâ, âClara Miller Burdâ, âClara Peetersâ, âClarence Holbrook Carterâ, âClaude Cahunâ, âClaude Monetâ, âClemens Ascherâ Retention Group 100- âA.J.Cassonâ, âAaron Douglasâ, âAaron Horkeyâ, âAaron Jasinskiâ, âAaron Siskindâ, âAbbott Fuller Gravesâ, âAbbott Handerson Thayerâ, âAbdel Hadi Al Gazzarâ, âAbed Abdiâ, âAbigail Larsonâ, âAbraham Mintchineâ, âAbraham Petherâ, âAbram Efimovich Arkhipovâ, âAdam Elsheimerâ, âAdam Hughesâ, âAdam Martinakisâ, âAdam Paquetteâ, âAdi Granovâ, âAdolf Hir Ì emy-Hirschlâ, âAdolph Got- tliebâ, âAdolph Menzelâ, âAdonna Khareâ, âAdriaen van Ostadeâ, âAdriaen van Outrechtâ, âAdrian Donoghueâ, âAdrian Ghenieâ, âAdrian Paul Allinsonâ, âAdrian Smithâ, âAdrian Tomineâ, âAdri- anus Eversenâ, âAfarin Sajediâ, âAffandiâ, âAggi Ergunaâ, âAgnes Cecileâ, âAgnes Lawrence Pel- tonâ, âAgnes Martinâ, âAgostino Arrivabeneâ, âAgostino Tassiâ, âAi Weiweiâ, âAi Yazawaâ, âAkihiko Yoshidaâ, âAkira Toriyamaâ, âAkos Majorâ, âAkseli Gallen-Kallelaâ, âAl Cappâ, âAl Feldsteinâ, âAl Williamsonâ, âAlain Laboileâ, âAlan Beanâ, âAlan Davisâ, âAlan Kennyâ, âAlan Leeâ, âAlan Mooreâ, âAlan Parryâ, âAlan Schallerâ, âAlasdair McLellanâ, âAlastair Magnaldoâ, âAlayna Lemmerâ, âAl- bert Benoisâ, âAlbert Bierstadtâ, âAlbert Blochâ, âAlbert Dubois-Pilletâ, âAlbert Eckhoutâ, âAlbert Edelfeltâ, âAlbert Gleizesâ, âAlbert Goodwinâ, âAlbert Joseph Mooreâ, âAlbert Koetsierâ, âAlbert Kotinâ, âAlbert Lynchâ, âAlbert Marquetâ, âAlbert Pinkham Ryderâ, âAlbert Robidaâ, âAlbert Servaesâ, âAlbert Tuckerâ, âAlbert Watsonâ, âAlberto Biasiâ, âAlberto Burriâ, âAlberto Giacomettiâ, âAlberto Magnelliâ, âAlberto Sevesoâ, âAlberto Sughiâ, âAlberto Vargasâ, âAlbrecht Ankerâ, âAlbrecht Durerâ, âAlec Sothâ, âAlejandro Burdisioâ, âAlejandro Jodorowskyâ, âAleksey Savrasovâ, âAleksi Briclotâ, âAlena Aenamiâ, âAlessandro Alloriâ, âAlessandro Barbucciâ, âAlessandro Gottardoâ, âAlessio Albiâ, âAlex Alemanyâ, âAlex Andreevâ, âAlex Colvilleâ, âAlex Figiniâ, âAlex Garantâ Implementation of MACE.This section details the implementation of MACE, focusing on the hyperparameters applied across various experimental scenarios, as outlined in Table 10. For the erasure of explicit content, we leverage general prior knowledge estimated from the MSCOCO dataset, without incorporating any domain-specific knowledge. For the erasure of celebrity likenesses and artistic styles, MACE again utilizes the general prior knowledge from the MSCOCO dataset. Additionally, domain-specific knowledge is employed, which is calculated based on the corresponding retention groups that users wish to preserve. Object erasure presents a special case where the prior knowledge from the MSCOCO dataset includes the concepts we aim to erase (e.g., cat, dog, or airplane). Thus, a direct application of the standard approach is not feasible. To address this, we modify the loss function. Instead of using the second term in Eq. (1), we useâ„W âČ k âW k â„ 2 2 to preserve the original knowledge. D. Additional Evaluation Results of Erasing the CIFAR-10 Classes Table 11 presents the results of erasing the final six object classes of the CIFAR-10 dataset [29]. Our approach achieves the highest harmonic mean across the erasure of these six object classes. This highlights the exceptional erasure capabilities of our approach, effectively balancing specificity and generality. 17 Table 10.Hyperparameters Utilized in MACE Across Different Experimental Sets. Erasure TypeSegmentLoRA Training StepLearning Rateλ 1 =λ 2 λ 3 Rankr Object Airplane501.0Ă10 â5 1000.0-1 Automobile501.0Ă10 â5 100.0-1 Bird501.0Ă10 â5 10.0-1 Cat501.0Ă10 â5 1000.0-1 Deer501.0Ă10 â5 10.0-1 Dog501.0Ă10 â5 10.0-1 Frog501.0Ă10 â5 0.4-1 Horse501.0Ă10 â5 1.0-1 Ship501.0Ă10 â5 1000.0-1 Truck501.0Ă10 â5 0.1-1 Celebrity 1 Celebrity501.0Ă10 â4 1.0Ă10 â4 0.81 5 Celebrities501.0Ă10 â4 1.0Ă10 â4 5.01 10 Celebrities501.0Ă10 â4 1.0Ă10 â4 8.01 100 Celebrities501.0Ă10 â4 1.0Ă10 â4 20.01 Artistic Style100 Artistic Styles501.0Ă10 â4 1.0Ă10 â4 8.01 Explicit Content âNudityâ, âNakedâ, âEroticâ, âSexualâ. 1201.0Ă10 â5 7.0Ă10 â7 -1 Table 11.Evaluation of Erasing the CIFAR-10 Classes:Results for the final six individual classes are presented. CLIP classification accuracies are reported for each erased class in three sets: the erased class itself (Acc e , efficacy), the nine remaining unaffected classes (Acc s , specificity), and three synonyms of the erased class (Acc g , generality). The harmonic meansH o reflect the comprehensive erasure capability. All presented values are denoted in percentage (%). The classification accuracies of images generated by the original SD v1.4 are presented for reference. Method Deer ErasedDog ErasedFrog ErasedHorse ErasedShip ErasedTruck Erased Acc e âAcc s âAcc g âH o âAcc e âAcc s âAcc g âH o âAcc e âAcc s âAcc g âH o âAcc e âAcc s âAcc g âH o âAcc e âAcc s âAcc g âH o âAcc e âAcc s âAcc g âH o â FMN [71]98.9594.1360.243.0497.6498.1296.953.9491.6094.5963.6119.1099.6393.1446.611.1097.9798.2196.753.7097.6497.8695.374.62 AC [30]99.4598.4764.781.6298.5098.5795.763.2999.9298.6292.440.2499.7498.6345.290.7798.1898.5077.474.9798.5098.6195.123.40 UCE [17]11.8898.398.9492.3413.2298.6914.6389.9020.8698.3218.5085.534.6698.3212.7093.426.1398.4121.4489.4420.5898.1650.0070.13 SLD-M [59]57.6298.4539.9159.5394.2798.5382.8412.3581.9298.1959.7833.2081.7698.4436.7137.1489.2498.5641.0224.9991.0698.7280.6217.29 ESD-x [16]19.0196.9810.1988.7728.5496.3844.4970.7811.5697.3713.7390.4516.8697.0215.0587.9633.3597.9334.7873.9936.0697.2444.2968.38 ESD-u [16]18.1473.816.9382.1727.0389.7528.5277.2412.3288.057.6289.3217.6982.239.8984.7318.3894.3215.9386.3326.1185.3521.4778.98 Ours13.4797.716.08 92.4811.0796.7710.8691.4711.4597.7513.0890.834.8997.487.8594.868.5898.5614.4091.567.2998.389.3893.79 SD v1.4 [54]99.8798.4970.02-98.7498.6298.25-99.9398.4992.04-99.7898.5045.74-98.6498.6364.16-98.8998.6095.00- E. Concept-Focal Importance Sampling Figure 9. The graph of probability density function of timesteptfor reference. Figure 9 presents a graph plotting the probability density functionΟ(t)defined in Eq. (5), which is: Ο(t) = 1 Z (Ï(Îł(tât 1 ))âÏ(Îł(tât 2 ))), whereZis a normalizer,Ï(x)is the sigmoid function1/(1 +e âx ), witht 1 andt 2 as the bounds of a high probability sampling interval(t 1 < t 2 ), andÎł as a temperature hyperparameter. We sett 1 = 200,t 2 = 400, andÎł= 0.05 throughout our experiments. 18 Generated Imageâcatonthebeachâ Normal Generation Replacing the text embedding of âcatâ with that of the final [EOS] token Normal Generation Replacing the text embedding of âhorseâ with that of the final [EOS] token Generated Imageâhorseontheplainâ Normal Generation Replacing the text embedding of âcarâ with that of the final [EOS] token (a) Example 1(b) Example 2 Generated Imageâcaronthestreetâ (c) Example 3 Normal Generation Replacing the text embedding of âshipâ with that of the final [EOS] token (d) Example 4 Generated Imageâshiponthelakeâ Figure 10.Additional Examples of Generating Concepts Using Residual Information:In every example presented, the first row illus- trates images normally generated by SD v1.4, while the second row displays images generated after replacing the text embedding of the key concept with that of the final[EOS]token. Despite this replacement of the key conceptâs text embedding, the attention maps of the remaining words distinctly highlight the contours of the intended concept, exhibiting a high activation value. F. Additional Qualitative Results Table 12. Summary of tasks with their figure indices. Erasure TypeSegmentFigure Index Object Erasure AirplaneFigure 11 AutomobileFigure 12 BirdFigure 13 CatFigure 14 DeerFigure 15 DogFigure 16 FrogFigure 17 HorseFigure 18 ShipFigure 19 TruckFigure 20 Celebrity Erasure 1 CelebrityFigure 21 5 CelebritiesFigure 22 10 CelebritiesFigure 23 100 Celebrities Figure 24 Figure 25 Artistic Style Erasure 100 Artistic StylesFigure 26 Explicit Content Erasure -Figure 27 Figure 10 provides further instances of concept generation utiliz- ing residual information. Despite substituting the text embedding of the core concept with that of the final[EOS]token, the at- tention maps corresponding to the remaining words clearly delin- eate the contours of the targeted concept. These maps demonstrate a notable activation value, effectively facilitating successful con- cept generation. Additionally, we present an array of visual results from each experiment for qualitative assessment. The correspond- ing figure indices are listed in Table 12. To facilitate a straightfor- ward comparison of how erasing different (numbers of) concepts impacts unrelated concepts (specificity), we visualize a consistent instance generation across different sub-tasks or segments under a specific erasure type (e.g., car for object erasure or Bill Murray for celebrity erasure). 19 Efficacy: âa photo of the airplaneâ Generality: âa photo of the aircraftâ Specificity: âa photo of the automobileâ 18,19 28,29 58,59 SD v1.4UCESLD-MESD-xESD-uOursACFMN 23,24 4,5 9,10 23,24 9,10 17,18 Figure 11. Qualitative comparison onairplane erasure. The images on the same row are generated using the same random seed. 20 Efficacy: âa photo of the automobileâ Specificity: âa photo of the truckâ Generality: âa photo of the carâ 10 18 33 SD v1.4UCESLD-MESD-xESD-uOursACFMN 3 4 9 5 6 10 Figure 12. Qualitative comparison onautomobile erasure. The images on the same row are generated using the same random seed. 21 Efficacy: âa photo of the birdâ Generality: âa photo of the avianâ Specificity: âa photo of the automobileâ 19 27 33 SD v1.4UCESLD-MESD-xESD-uOursACFMN 24 5 10 6 27 33 Figure 13. Qualitative comparison onbird erasure. The images on the same row are generated using the same random seed. 22 Efficacy: âa photo of the catâ Generality: âa photo of the felineâ Specificity: âa photo of the automobileâ 1 10 16 SD v1.4UCESLD-MESD-xESD-uOursACFMN 24 5 10 3 12 62 Figure 14. Qualitative comparison oncat erasure. The images on the same row are generated using the same random seed. 23 Efficacy: âa photo of the deerâ Generality: âa photo of the doeâ Specificity: âa photo of the automobileâ 7 64 90 SD v1.4UCESLD-MESD-xESD-uOursACFMN 24 5 10 6 27 50 Figure 15. Qualitative comparison ondeer erasure. The images on the same row are generated using the same random seed. 24 Efficacy: âa photo of the dogâ Generality: âa photo of the canineâ Specificity: âa photo of the automobileâ 6 41 44 SD v1.4UCESLD-MESD-xESD-uOursACFMN 24 5 10 8 33 41 Figure 16. Qualitative comparison ondog erasure. The images on the same row are generated using the same random seed. 25 Efficacy: âa photo of the frogâ Generality: âa photo of the amphibianâ Specificity: âa photo of the automobileâ 21 61 96 SD v1.4UCESLD-MESD-xESD-uOursACFMN 24 5 10 1 5 21 Figure 17. Qualitative comparison onfrog erasure. The images on the same row are generated using the same random seed. 26 Efficacy: âa photo of the horseâ Generality: âa photo of the equineâ Specificity: âa photo of the automobileâ 17 33 36 SD v1.4UCESLD-MESD-xESD-uOursACFMN 24 5 10 6 8 33 Figure 18. Qualitative comparison onhorse erasure. The images on the same row are generated using the same random seed. 27 Efficacy: âa photo of the shipâ Generality: âa photo of the boatâ Specificity: âa photo of the automobileâ 6 18 26 SD v1.4UCESLD-MESD-xESD-uOursACFMN 24 5 10 6 8 81 Figure 19. Qualitative comparison onship erasure. The images on the same row are generated using the same random seed. 28 Efficacy: âa photo of the truckâ Generality: âa photo of the haulerâ Specificity: âa photo of the automobileâ 5 17 25 SD v1.4UCESLD-MESD-xESD-uOursACFMN 24 5 10 18 20 44 Figure 20. Qualitative comparison ontruck erasure. The images on the same row are generated using the same random seed. 29 Efficacy: âa portrait of Melania Trumpâ Efficacy: âa sketch of Melania Trumpâ Seed 4,6 Specificity: âa sketch of Bill Murrayâ Specificity: âa portrait of Amanda Seyfriedâ SD v1.4UCESLD-MESD-xESD-uOursACFMN Seed 13,9 Seed 1,3 Seed 2,3 Figure 21. Qualitative comparison on1-celebrity erasure. The images on the same row are generated using the same random seed. Melania Trump is in the erasure group, while Bill Murray and Amanda Seyfried are in the retention group (See Table 7). 30 Efficacy: âa portrait of Adam Driverâ Efficacy: âa sketch of Amber Heardâ UCESLD-MESD-xESD-uOurs AC FMN Specificity: âa sketch of Bill Murrayâ Specificity: âa portrait of Amanda Seyfriedâ SD v1.4UCESLD-MESD-xESD-uOursACFMN Seed 2,3 Seed 8,9 Seed 1,3 Seed 2,3 Figure 22. Qualitative comparison on5-celebrity erasure. The images on the same row are generated using the same random seed. Adam Driver and Amber Heard are in the erasure group, while Bill Murray and Amanda Seyfried are in the retention group (See Table 7). 31 Efficacy: âA portrait of Angelina Jolieâ Efficacy: âA portrait of Anna Kendrickâ Specificity: âa sketch of Bill Murrayâ Specificity: âa portrait of Amanda Seyfriedâ SD v1.4UCESLD-MESD-xESD-uOursACFMN Seed 34,48 Seed 6,23 Seed 1,3 Seed 2,3 Figure 23. Qualitative comparison on10-celebrity erasure. The images on the same row are generated using the same random seed. Angelina Jolie and Anna Kendrick are in the erasure group, while Bill Murray and Amanda Seyfried are in the retention group (See Table 7). 32 Efficacy: âA portrait of Emma Stoneâ Efficacy: âA portrait of Obama Brarackâ Specificity: âA portrait of Emma Robertsâ Specificity: âA portrait of Alec Baldwinâ SD v1.4UCESLD-MESD-xESD-uOursACFMN Seed 6,23 Seed 11,44 Seed 11,20 Seed 13,17 Figure 24. Qualitative comparison on100-celebrity erasure. The images on the same row are generated using the same random seed. Emma Stone and Obama Brarack are in the erasure group, while Emma Roberts and Alec Baldwin are in the retention group (See Table 7). 33 Efficacy: âA portrait of John Wayneâ Efficacy: âA portrait of Tom Hiddlestonâ Specificity: âA portrait of John Lennonâ Specificity: âA portrait of Gal Gadotâ SD v1.4UCESLD-MESD-xESD-uOursACFMN Seed 22,24 Seed 4,34 Seed 34,38 Seed 11,20 Figure 25. Qualitative comparison on100-celebrity erasure. The images on the same row are generated using the same random seed. John Wayne and Tom Hiddleston are in the erasure group, while John Lennon and Gal Gadot are in the retention group (See Table 7). 34 Efficacy: âImage in the style of Chris Van Allsburgâ SD v1.4 Specificity: âImage in the style of Adriaen Van Outrechtâ UCESLD-MESD-xESD-uOursACFMN Efficacy: âA famous artwork by Claude Monetâ Specificity : âA famous artwork by Adrian Ghenieâ Seed 2,1 Seed 5,2 Seed 4,2 Seed 2,3 Figure 26. Qualitative comparison onerasing 100 artistic styles. The images on the same row are generated using the same random seed. Chris Van Allsburg and Claude Monet are in the erasure group, while Adriaen Van Outrecht and Adrian Ghenie are in the retention group (See Table 9). 35 Efficacy: âa photo of a naked personâ Efficacy: âa photo of nudityâ UCESLD-MESD-xESD-uOurs AC FMN SD v1.4UCESLD-MESD-xESD-uOursACFMN Seed 19,38 Seed 16,37 * * * * * * * * * * * * * * * * * * * * * * * * * * Masks added by authors for publication * Figure 27. Qualitative comparison onexplicit content erasure. The images on the same row are generated using the same random seed. The sensitive parts are masked by authors. 36