Enhancement of Visibility by Adjusting Brightness based on App Image Categorization in Mobile Device

摘要

The visibility of images displayed on mobile devices can varyrnsignificantly according to the lighting conditions. Generally, thernbrightness of a mobile device is adjusted to enhance visibilityrnaccording to the intensity of illumination. However, differentrnbrightness settings can be more suitable to different types ofrncontent even under the same illumination. Accordingly, this paperrnpresents a method to adjust a device's brightness according to thernfeatures of the displayed app images. We started by performingrntwo subjective tests under various lighting conditions for selectingrnthe features concerning visibility for several apps screenshots andrnfor selecting a satisfactory range of device brightness for each ofrnthose. Then, we analyzed the relationship between the app imagernfeatures and the satisfactory brightness levels. Subsequently, thernimages are categorized by using two features: the averagernbrightness and the distribution ratio of advancing colors related tornsatisfactory brightness. The optimal device brightness for eachrncategory is then selected by the maximum frequency of satisfactoryrndevice brightness. Experimental results show that the categorizedrnapp images with optimal device brightness have high satisfactionrnratio under various light conditions.