Volume 14, Number 1

Patch-Based Image Learned Codec using Overlapping

  Authors

Marwa Tarchouli^1,2, Marc Riviere¹, Thomas Guionnet¹, Wassim Hamidouche², Meriem Outtas², and Olivier Deforges², ¹Ateme, France, ²Univ. Rennes, France

  Abstract

End-to-end learned image and video codecs, based on auto-encoder architecture, adapt naturally to image resolution, thanks to their convolutional aspect. However, while coding high resolution images, these codecs face hardware problems such as memory saturation. This paper proposes a patch-based image coding solution based on an end-to-end learned model, which aims to remedy to the hardware limitation while maintaining the same quality as full resolution image coding. Our method consists in coding overlapping patches of the image and reconstructing them into a decoded image using a weighting function. This approach manages to be on par with the performance of full resolution image coding using an endto-end learned model, and even slightly outperforms it, while being adaptable to different memory sizes. Moreover, this work undertakes a full study on the effect of the patch size on this solution’s performance, and consequently determines the best patch resolution in terms of coding time and coding efficiency. Finally, the method introduced in this work is also compatible with any learned codec based on a conv/deconvolutional autoencoder architecture without having to retrain the model.

  Keywords

Auto-encoders, Image compression, Deblocking, block artifacts.