Quality-guided Skin Tone Enhancement for Portrait Photography
This work addresses the need for more flexible and user-controllable image enhancement in photography, particularly for skin tone adjustments, though it appears incremental as it builds on existing learning-based methods.
The paper tackles the problem of enabling learning-based image enhancement models to adjust images continuously and controllably, rather than producing fixed results, by proposing a quality-guided paradigm that learns distributions of images with various quality ratings, validated through subjective experiments on skin tone adjustment in portrait photography and natural raw images.
In recent years, learning-based color and tone enhancement methods for photos have become increasingly popular. However, most learning-based image enhancement methods just learn a mapping from one distribution to another based on one dataset, lacking the ability to adjust images continuously and controllably. It is important to enable the learning-based enhancement models to adjust an image continuously, since in many cases we may want to get a slighter or stronger enhancement effect rather than one fixed adjusted result. In this paper, we propose a quality-guided image enhancement paradigm that enables image enhancement models to learn the distribution of images with various quality ratings. By learning this distribution, image enhancement models can associate image features with their corresponding perceptual qualities, which can be used to adjust images continuously according to different quality scores. To validate the effectiveness of our proposed method, a subjective quality assessment experiment is first conducted, focusing on skin tone adjustment in portrait photography. Guided by the subjective quality ratings obtained from this experiment, our method can adjust the skin tone corresponding to different quality requirements. Furthermore, an experiment conducted on 10 natural raw images corroborates the effectiveness of our model in situations with fewer subjects and fewer shots, and also demonstrates its general applicability to natural images. Our project page is https://github.com/IntMeGroup/quality-guided-enhancement .