Identification of factors related to the enhancement of image-quality for subjective image-quality assessment model based on psychological measurement

The purpose of this study is to identify the physical factors affecting image-quality for a comprehensive enhancement in subjective image-quality assessment by human being. In recent years, digital cameras have become extremely popular because they enable image recording with very high fidelity and are affordably priced. However, in subjective image-quality assessment by human, one does not always consider that images with high fidelity are of high quality. In this study, a psychological experiment was performed as the first step to develop a subjective image-quality assessment model that considers kansei of human being by using conjoint method. We particularly focused on the identification of physical factors without depending on a scene. The results of this experiment showed that “luminance” and “contrast” may contribute to an enhancement in the image-quality assessment, regardless of the type of scene used. It was also suggested that human memory, in which the colors preferred by the individual are retained, also plays a major role in a subjective image-quality assessment.