Subjective quality feedback by actual human viewers is crucial for reliable evaluation of various solutions and configurations for video processing or encoding. However, it is generally a time consuming and expensive process. Therefore, in many cases evaluation of video quality is done using objective measures, which may be poorly correlated with actual subjective results. In order to address this issue, we have developed VISTA (VIsual Subjective Testing Application), an easy to use application for visually comparing pairs of video sequences played synchronously side by side, and a user interface for indicating the relative subjective quality of the two video sequences. In addition, we developed a system for automating the evaluation process called Auto-VISTA. The system receives as input guidelines for the required testing session, prepares the content to be compared, launches the app in a crowdsourcing Internet marketplace (such as Amazon Mechanical Turk), and performs collection and analysis of the results. Thus, obtaining large scale subjective feedback becomes cheap and accessible, which in turn allows for fast and reliable evaluation cycles of different video encoding and processing solutions, or tuning various configurations and settings for a given solution.
|