BITRATE-PERFORMANCE OPTIMIZED MODEL TRAINING FOR THE NEURAL NETWORK CODING (NNC) STANDARD

In August 2022, ISO/IEC MPEG published the first international standard on compression of neural networks, namely Neural Network Coding (NNC, MPEG-7 part 17). It compresses neural networks to about 5% to 15% in size at virtually no performance loss. In NNC, the model weights are usually quantized and then encoded into the bitstream using DeepCABAC entropy coding. In order to improve the coding efficiency, this paper presents new training strategies for optimized model weights considering the quantization and entropy coding process of NNC, by making the training process bitrate- and quantization-aware. With this bitrate-performance optimized training the bitrate can be further reduced by more than 25% on average for state-of-the-art image classification models.