Group channel pruning and spatial attention distilling for object detection

Due to the over-parameterization of neural networks, many model compression methods based on pruning and quantization have emerged. They are remarkable in reducing the size, parameter number, and computational complexity of the model. However, most of the models compressed by such methods need the support of special hardware and software, which increases the deployment cost. Moreover, these methods are mainly used in classification tasks, and rarely directly used in detection tasks. To address these issues, for the object detection network we introduce a three-stage model compression method: dynamic sparse training, group channel pruning, and spatial attention distilling. Firstly, to select out the unimportant channels in the network and maintain a good balance between sparsity and accuracy, we put forward a dynamic sparse training method, which introduces a variable sparse rate, and the sparse rate will change with the training process of the network. Secondly, to reduce the effect of pruning on network accuracy, we propose a novel pruning method called group channel pruning. In particular, we divide the network into multiple groups according to the scales of the feature layer and the similarity of module structure in the network, and then we use different pruning thresholds to prune the channels in each group. Finally, to recover the accuracy of the pruned network, we use an improved knowledge distillation method for the pruned network. Especially, we extract spatial attention information from the feature maps of specific scales in each group as knowledge for distillation. In the experiments, we use YOLOv4 as the object detection network and PASCAL VOC as the training dataset. Our method reduces the parameters of the model by 64.7 % and the calculation by 34.9%.Comment: Appl Intel

얼굴 표정 인식, 나이 및 성별 추정을 위한 다중 데이터셋 다중 도메인 다중작업 네트워크

학위논문(석사)--서울대학교 대학원 :공과대학 전기·정보공학부,2019. 8. Cho, Nam Ik.컨볼 루션 뉴럴 네트워크 (CNN)는 얼굴과 관련된 문제를 포함하여 많은 컴퓨터 비전 작업에서 매우 잘 작동합니다. 그러나 연령 추정 및 얼굴 표정 인식 (FER)의 경우 CNN이 제공 한 정확도는 여전히 실제 문제에 대해 충분하지 않습니다. CNN은 얼굴의 주름의 두께와 양의 미묘한 차이를 발견하지 못했지만, 이것은 연령 추정과 FER에 필수적입니다. 또한 실제 세계에서의 얼굴 이미지는 CNN이 훈련 데이터에서 가능할 때 회전 된 물체를 찾는 데 강건하지 않은 회전 및 조명으로 인해 많은 차이가 있습니다. 또한 MTL (Multi Task Learning)은 여러 가지 지각 작업을 동시에 효율적으로 수행합니다. 모범적 인 MTL 방법에서는 서로 다른 작업에 대한 모든 레이블을 함께 포함하는 데이터 집합을 구성하는 것을 고려해야합니다. 그러나 대상 작업이 다각화되고 복잡해지면 더 강력한 레이블을 가진 과도하게 큰 데이터 세트가 필요할 수 있습니다. 따라서 원하는 라벨 데이터를 생성하는 비용은 종종 장애물이며 특히 다중 작업 학습의 경우 장애가됩니다. 따라서 우리는 가버 필터와 캡슐 기반 네트워크 (MTL) 및 데이터 증류를 기반으로하는 다중 작업 학습에 기반한 새로운 반 감독 학습 방법을 제안한다.The convolutional neural network (CNN) works very well in many computer vision tasks including the face-related problems. However, in the case of age estimation and facial expression recognition (FER), the accuracy provided by the CNN is still not good enough to be used for the real-world problems. It seems that the CNN does not well find the subtle differences in thickness and amount of wrinkles on the face, which are the essential features for the age estimation and FER. Also, the face images in the real world have many variations due to the face rotation and illumination, where the CNN is not robust in finding the rotated objects when not every possible variation is in the training data. Moreover, The Multi Task Learning (MTL) Based based methods can be much helpful to achieve the real-time visual understanding of a dynamic scene, as they are able to perform several different perceptual tasks simultaneously and efficiently. In the exemplary MTL methods, we need to consider constructing a dataset that contains all the labels for different tasks together. However, as the target task becomes multi-faceted and more complicated, sometimes unduly large dataset with stronger labels is required. Hence, the cost of generating desired labeled data for complicated learning tasks is often an obstacle, especially for multi-task learning. Therefore, first to alleviate these problems, we first propose few methods in order to improve single task baseline performance using gabor filters and Capsule Based Networks , Then We propose a new semi-supervised learning method on face-related tasks based on Multi-Task Learning (MTL) and data distillation.1 INTRODUCTION 1 1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2.1 Age and Gender Estimation . . . . . . . . . . . . . . . . . . 4 1.2.2 Facial Expression Recognition (FER) . . . . . . . . . . . . . 4 1.2.3 Capsule networks (CapsNet) . . . . . . . . . . . . . . . . . . 5 1.2.4 Semi-Supervised Learning. . . . . . . . . . . . . . . . . . . . 5 1.2.5 Multi-Task Learning. . . . . . . . . . . . . . . . . . . . . . . 6 1.2.6 Knowledge and data distillation. . . . . . . . . . . . . . . . . 6 1.2.7 Domain Adaptation. . . . . . . . . . . . . . . . . . . . . . . 7 1.3 Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2. GF-CapsNet: Using Gabor Jet and Capsule Networks for Face-Related Tasks 10 2.1 Feeding CNN with Hand-Crafted Features . . . . . . . . . . . . . . . 10 2.1.1 Preparation of Input . . . . . . . . . . . . . . . . . . . . . . 10 2.1.2 Age and Gender Estimation using the Gabor Responses . . . . 13 2.2 GF-CapsNet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.2.1 Modification of CapsNet . . . . . . . . . . . . . . . . . 16 3. Distill-2MD-MTL: Data Distillation based on Multi-Dataset Multi-Domain Multi-Task Frame Work to Solve Face Related Tasks 20 3.1 MTL learning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.2 Data Distillation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 4. Experiments and Results 25 4.1 Experiments on GF-CNN and GF-CapsNet . . . . . . . . . . . . . . 25 4.2 GF-CNN Result . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.2.1 GF-CapsNet Results . . . . . . . . . . . . . . . . . . . . . . 30 4.3 Experiment on Distill-2MD-MTL . . . . . . . . . . . . . . . . . . . 33 4.3.1 Semi-Supervised MTL . . . . . . . . . . . . . . . . . . . . . 34 4.3.2 Cross Datasets Cross-Domain Evaluation . . . . . . . . . . . 36 5. Conclusion 38 Abstract (In Korean) 49Maste

Shortcut-V2V: Compression Framework for Video-to-Video Translation based on Temporal Redundancy Reduction

Video-to-video translation aims to generate video frames of a target domain from an input video. Despite its usefulness, the existing networks require enormous computations, necessitating their model compression for wide use. While there exist compression methods that improve computational efficiency in various image/video tasks, a generally-applicable compression method for video-to-video translation has not been studied much. In response, we present Shortcut-V2V, a general-purpose compression framework for video-to-video translation. Shourcut-V2V avoids full inference for every neighboring video frame by approximating the intermediate features of a current frame from those of the previous frame. Moreover, in our framework, a newly-proposed block called AdaBD adaptively blends and deforms features of neighboring frames, which makes more accurate predictions of the intermediate features possible. We conduct quantitative and qualitative evaluations using well-known video-to-video translation models on various tasks to demonstrate the general applicability of our framework. The results show that Shourcut-V2V achieves comparable performance compared to the original video-to-video translation model while saving 3.2-5.7x computational cost and 7.8-44x memory at test time.Comment: to be update

Model Compression Techniques in Biometrics Applications: A Survey

The development of deep learning algorithms has extensively empowered humanity's task automatization capacity. However, the huge improvement in the performance of these models is highly correlated with their increasing level of complexity, limiting their usefulness in human-oriented applications, which are usually deployed in resource-constrained devices. This led to the development of compression techniques that drastically reduce the computational and memory costs of deep learning models without significant performance degradation. This paper aims to systematize the current literature on this topic by presenting a comprehensive survey of model compression techniques in biometrics applications, namely quantization, knowledge distillation and pruning. We conduct a critical analysis of the comparative value of these techniques, focusing on their advantages and disadvantages and presenting suggestions for future work directions that can potentially improve the current methods. Additionally, we discuss and analyze the link between model bias and model compression, highlighting the need to direct compression research toward model fairness in future works.Comment: Under review at IEEE Journa

DeepFake detection based on high-frequency enhancement network for highly compressed content

The DeepFake, which generates synthetic content, has sparked a revolution in the fight against deception and forgery. However, most existing DeepFake detection methods mainly focus on improving detection performance with high-quality data while ignoring low-quality synthetic content that suffers from high compression. To address this issue, we propose a novel High-Frequency Enhancement framework, which leverages a learnable adaptive high-frequency enhancement network to enrich weak high-frequency information in compressed content without uncompressed data supervision. The framework consists of three branches, i.e., the Basic branch with RGB domain, the Local High-Frequency Enhancement branch with Block-wise Discrete Cosine Transform, and the Global High-Frequency Enhancement branch with Multi-level Discrete Wavelet Transform. Among them, the local branch utilizes the Discrete Cosine Transform coefficient and channel attention mechanism to indirectly achieve adaptive frequency-aware multi-spatial attention, while the global branch supplements the high-frequency information by extracting coarse-to-fine multi-scale high-frequency cues and cascade-residual-based multi-level fusion by Discrete Wavelet Transform coefficients. In addition, we design a Two-Stage Cross-Fusion module to effectively integrate all information, thereby greatly enhancing weak high-frequency information in low-quality data. Experimental results on FaceForensics++, Celeb-DF, and OpenForensics datasets show that the proposed method outperforms the existing state-of-the-art methods and can effectively improve the detection performance of DeepFakes, especially on low-quality data. The code is available here

The Emerging Trends of Multi-Label Learning

Exabytes of data are generated daily by humans, leading to the growing need for new efforts in dealing with the grand challenges for multi-label learning brought by big data. For example, extreme multi-label classification is an active and rapidly growing research area that deals with classification tasks with an extremely large number of classes or labels; utilizing massive data with limited supervision to build a multi-label classification model becomes valuable for practical applications, etc. Besides these, there are tremendous efforts on how to harvest the strong learning capability of deep learning to better capture the label dependencies in multi-label learning, which is the key for deep learning to address real-world classification tasks. However, it is noted that there has been a lack of systemic studies that focus explicitly on analyzing the emerging trends and new challenges of multi-label learning in the era of big data. It is imperative to call for a comprehensive survey to fulfill this mission and delineate future research directions and new applications.Comment: Accepted to TPAMI 202