CHANNEL PRUNING VIA GRADIENT OF MUTUAL INFORMATION FOR LIGHTWEIGHT CONVOLUTIONAL NEURAL NETWORKS

Channel pruning for light-weighting networks is very effective in reducing memory footprint and computational cost. Many channel pruning methods assume that the magnitude of a particular element corresponding to each channel reflects the importance of the channel. Unfortunately, such an assumption does not always hold. To solve this problem, this paper proposes a new method to measure the importance of channels based on gradients of mutual information. The proposed method computes and measures gradients of mutual information during back-propagation by arranging a module capable of estimating mutual information. By using the measured statistics as the importance of the channel, less important channels can be removed. Finally, the fine-tuning enables robust performance restoration of the pruned model. Experimental results show that the proposed method provides better performance with smaller parameter sizes and FLOPs than the conventional schemes.