End-to-End Single-Frame Image Signal Processing for High Dynamic Range Scenes

Abstract

This paper considers photography of high dynamic range scenes containing mixtures of shadows and highlights on mobile phones. Multi-frame merging constructs a high-quality image at the cost of capturing multiple frames of the same scene. Contrarily, end-to-end optimized image signal processing (E2EISP) produces an enhanced image from a single-frame Bayer array. This paper combines the merits of the two approaches by using labels of high-quality multi-frame merged images to train E2EISP with a novel neural network architecture composed of a multi-head mixture of brightness enhancement for accurately processing shadows/highlights and a multi-head mixture of image processing featured camera settings of white balance and color correction for a proper color generation. We also proposed a combination of supervised, unsupervised, and generative adversarial losses for brightness, edge, and detail enhancement. Experimental results show that the proposed single-frame ISP produces enhanced images and outperforms state-of-the-art methods.