arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2304.02012cs.CVcs.AIcs.LG

EGC:基于扩散能量模型的图像生成与分类

EGC: Image Generation and Classification via a Diffusion Energy-Based Model

The University of Hong Kong(香港大学);ByteDance Inc.(字节跳动公司)

Qiushan Guo, Chuofan Ma, Yi Jiang, Zehuan Yuan, Yizhou Yu, Ping Luo

AI总结:

本文提出基于扩散能量模型的 EGC,通过前向输出联合分布、反向边缘化标签去噪,首次用单组网络参数同时实现高质量图像生成和优越的图像分类及对抗鲁棒性。

摘要:

使用同一组网络参数学习图像分类和图像生成是一个具有挑战性的问题。近期先进的方法往往在一个任务上表现良好,而在另一个任务上表现不佳。本文引入了一种基于能量的分类器和生成器,即 EGC,它能够使用单个神经网络在两个任务上都取得优越的性能。与给定图像输出标签(即条件分布 $p(y|\mathbf{x})$)的传统分类器不同,EGC 的前向传播是一个输出联合分布 $p(\mathbf{x},y)$ 的分类器,从而在其反向传播中通过边缘化标签 $y$ 实现图像生成。具体做法是:在前向传播中,给定含噪图像估计能量和分类概率;在反向传播中,利用估计得到的得分函数进行去噪。在 ImageNet-1k、CelebA-HQ 和 LSUN Church 上,EGC 取得了与最先进方法相比具有竞争力的生成结果,同时在 CIFAR-10 上取得了优越的分类精度和对对抗攻击的鲁棒性。本文是首次成功尝试使用单组网络参数同时在两个任务上表现出色。我们相信 EGC 弥合了判别式学习与生成式学习之间的差距。

英文摘要:

Learning image classification and image generation using the same set of network parameters is a challenging problem. Recent advanced approaches perform well in one task often exhibit poor performance in the other. This work introduces an energy-based classifier and generator, namely EGC, which can achieve superior performance in both tasks using a single neural network. Unlike a conventional classifier that outputs a label given an image (i.e., a conditional distribution $p(y|\mathbf{x})$), the forward pass in EGC is a classifier that outputs a joint distribution $p(\mathbf{x},y)$, enabling an image generator in its backward pass by marginalizing out the label $y$. This is done by estimating the energy and classification probability given a noisy image in the forward pass, while denoising it using the score function estimated in the backward pass. EGC achieves competitive generation results compared with state-of-the-art approaches on ImageNet-1k, CelebA-HQ and LSUN Church, while achieving superior classification accuracy and robustness against adversarial attacks on CIFAR-10. This work represents the first successful attempt to simultaneously excel in both tasks using a single set of network parameters. We believe that EGC bridges the gap between discriminative and generative learning.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑