The Image Quality Index tool shows a numeric value (and visually in the full version of Zephyr) the quality of the input pictures. You can simply drag and drop the pictures into the quality index window, and the score will be automatically computed. Higher score means higher quality. Please note that this score is computed per picture: it does not use any 3D information or of workspace information - this will simply compute which areas of the picture are well in focus and potentially with a high density of keypoints. A high-score picture does not automatically means that a picture has been shot correctly, however a low-score picture should be discarded (in green are shown the better areas). Double click each line to open the visual mode.