| 摘要 |
A scene illumination system is provided that produces spatially uniform or controlled brightness levels for machine vision applications. The system includes a camera, multiple light sources that preferentially illuminate different regions within the camera's field-of-view, and a processing unit coupled to the camera and light sources. Focal regions of the light sources within the camera's field-of-view are sampled to determine average regional brightness and compared to target brightness levels. The processing unit controls the light sources to increase or decrease illumination levels to converge toward the target brightness levels within the field-of-view. This modulation of the light sources may be repeated with successive video images until target brightness levels are achieved. Once achieved, the iterative feedback control may be locked-in for some applications, while for others, the iterative process may continue periodically or continuously to account for different scenes or changes in lighting conditions. |
