| Popis: |
Photospace data previously measured on large image sets have shown that a high percentage of camera phone pictures are taken under low-light conditions. Corresponding image quality measurements linked the lowest quality to these conditions, and subjective analysis of image quality failure modes identified image blur as the most important contributor to image quality degradation. Camera phones without flash have to manage a trade-off when adjusting shutter time to low-light conditions. The shutter time has to be long enough to avoid extreme underexposures, but not short enough that hand-held picture taking is still possible without excessive motion blur. There is still a lack of quantitative data on motion blur. Camera phones often do not record basic operating parameters such as shutter speed in their image metadata, and when recorded, the data are often inaccurate. We introduce a device and process for tracking camera motion and measuring its Point Spread Function (PSF). Vision-based metrics are introduced to assess the impact of camera motion on image quality so that the low-light performance of different cameras can be compared. Statistical distributions of user variability will be discussed. |
