Several recent works have empirically observed that Convolutional Neural Nets
(CNNs) are (approximately) invertible. To understand this approximate
invertibility phenomenon and how to leverage it more effectively, we focus on a
theoretical explanation and develop a mathematical model of sparse signal
recovery that is consistent with CNNs with random weights. We give an exact
connection to a particular model of model-based compressive sensing (and its
recovery algorithms) and random-weight CNNs. We show empirically that several
learned networks are consistent with our mathematical analysis and then
demonstrate that with such a simple theoretical framework, we can obtain
reasonable re- construction results on real images. We also discuss gaps
between our model assumptions and the CNN trained for classification in
practical scenarios.

论文讨论卷积神经网络近似可逆性及其在稀疏信号恢复方面的数学模型，并给出一种精确的模型基础压缩感知与其恢复算法和随机权重 CNN 的连接。作者通过实验得出多个学习网络与数学分析一致，以简单的理论框架合理地重构实际图片。同时，作者也探讨了我们的模型假设与实际场景分类训练的 CNN 之间的差距。