Year after year, the demand for ever-better smartphone photos continues to grow, in particular in the domain of portrait photography. Manufacturers thus use perceptual quality criteria throughout the development of smartphone cameras. This costly procedure can be partially replaced by automated learning-based methods for image quality assessment (IQA). Due to its subjective nature, it is necessary to estimate and guarantee the consistency of the IQA process, a characteristic lacking in the mean opinion scores (MOS) widely used for crowdsourcing IQA. In addition, existing blind IQA (BIQA) datasets pay little attention to the difficulty of cross-content assessment, which may degrade the quality of annotations. This paper introduces PIQ23, a portrait-specific IQA dataset of 5116 images of 50 predefined scenarios acquired by 100 smartphones, covering a high variety of brands, models, and use cases. The dataset includes individuals of various genders and ethnicities who have given explicit and informed consent for their photographs to be used in public research. It is annotated by pairwise comparisons (PWC) collected from over 30 image quality experts for three image attributes: face detail preservation, face target exposure, and overall image quality. An in-depth statistical analysis of these annotations allows us to evaluate their consistency over PIQ23. Finally, we show through an extensive comparison with existing baselines that semantic information (image context) can be used to improve IQA predictions. The dataset along with the proposed statistical analysis and BIQA algorithms are available: https://github.com/DXOMARK-Research/PIQ2023
翻译:年复一年,智能手机拍照的需求不断增长,特别是在肖像摄影领域。因此,制造商在智能手机摄像机的开发过程中使用了感知质量标准。可以通过基于学习的自动化方法进行图像质量评估(IQA),部分替代这种昂贵的过程。由于IQA具有主观性,因此需要估计和保证IQA过程的一致性,这在众包IQA中广泛使用的平均意见分数(MOS)中缺乏。此外,现有的盲IQA(BIQA)数据集在跨内容评估的难度方面给予的关注不足,这可能会降低注释的质量。本文介绍了PIQ23,这是一个面向肖像的IQA数据集,包含5116个由100部智能手机拍摄的50个预定义情景的图像,涵盖了各种品牌、型号和使用情况。该数据集包括各种性别和种族的个人,他们已明确、知情地同意他们的照片被用于公共研究。数据集由30多位图像质量专家进行成对比较(PWC)进行注释,注重三个图像属性:面部细节保留、面部目标曝光和整体图像质量。对这些注释的深入统计分析使我们能够评估它们在PIQ23上的一致性。最后,我们通过与现有基线的广泛比较表明,可以使用语义信息(图像上下文)来改进IQA预测。数据集以及所提出的统计分析和BIQA算法都可获得:https://github.com/DXOMARK-Research/PIQ2023