说明：  通过设置不同的gamma值，可以达到对图像亮度的调整，gamma值小于1时变暗，大于1时变亮。直方图及其标定
(By setting different gamma values, you can adjust the brightness of the image. When the gamma value is less than 1, it becomes dark, and when it is greater than 1, it becomes bright. Histogram and its calibration)