本論文提出一套特徵圖壓縮方法，以小波轉換減少特徵圖數值分布在空間
上的相關性，降低了壓縮資料的夏農熵，使之後的熵編碼能夠取得更好的壓
縮的效果。在 Resnet-18 於 ImageNet 上的測試，本方法能達到 9.5 的壓縮
率，並同時提升 0.5% 的正確率 。本論文亦提出一套省略部分高頻訊號的
方法，於模型重新訓練時引入可訓練的通道選擇參數，提供省略部分高頻訊
號的依據。於 Resnet-20 於 Cifar-10 上的測試 ，顯示在保有 75%、50%、
25% 高頻訊號的情況下，此方法能達到 11、13、17 的壓縮率。我們
亦進行了對照實驗，比較學習以及固定通道選擇參數的模型表現，證明了學
習通道選擇參數的有效性。最後於 Resnet-18 於 ImageNet 上的測試，在保
有 75%、50%、25% 高頻訊號的情況下，分別達到 11、13、16 的壓
縮率，達到現在最佳方法的水準。

We present a feature map compression method for convolutional neural networks. The proposed method adopts discrete wavelet transform (DWT) in the compression pipeline to achieve a compression rate of 9.5X with 0.5% accuracy gain on ResNet-18. We also propose a mechanism to remove redundant high-frequency components in the feature map, which is achieved by including the channel selection parameters during retraining to provides the guideline for eliminating high-frequency components. Through ablation study we show that the channel selection parameters are effective in improving the performance. With retaining ratio = 0.75, 0.5, and 0.25, our method can further achieve 11X, 13X and 16X compression rates with 0.02% of accuracy gain, and 0.06% and 0.57% of accuracy drop respectively on ResNet-18.

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