为了解决超高分辨率CCD成像系统焦平面测光时间过长的问题，提出了一种焦平面测光的加速方法。该方法使用像素合并技术提高像素读取速度，将当前积分时间和系统最小积分时间的比值作为像素合并的行数，使用成像系统的最小积分时间成像，读出合并图像并计算其灰度直方图和灰度均值，为后续自动曝光算法提供依据。该方法在对积分时间和像素读出时间显著压缩的同时不影响图像平均灰度和直方图分布的获取。经实验，该方法可将测光时间缩短到一般情况的30%以下，可广泛应用在超高分辨率CCD成像系统的焦平面测光过程中，以此来提高自动曝光控制的速度。

To solve the problem of long focal-plane-light-measuring time in ultra-high resolution CCD imaging system, an acceleration method is proposed. Pixel binning technology is adopted in this method to speed up the pixel output rate, the ratio of current integration time to minimum integration time is used as binning number of rows. In the light measuring period, the system uses the minimum integration time to expose the CCD, read out binned the pixel charge packets and calculate the average gray level and histogram for the auto exposure control arithmetic to use. This method can significantly reduce both integration time and pixel readout time, and maintain the original average gray level and histogram. The experiment results prove the performance of this method by compressing the light measuring time to 30% below. This method can be widely used in ultra-high resolution CCD light measuring process.