初来贵坛 拜拜山头 最近搞安森美的图像sensor不知道在哪个论坛，哪个板块讨论的人比较多

Auto Exposure
The integrated automatic exposure control (AEC) is responsible for ensuring that
optimal settings of exposure and gain are computed and updated every other frame.
AEC can be enabled or disabled by R0x3100[0]. When AEC is disabled (R0x3100[0] = 0),
the sensor uses the manual exposure value in the coarse and fine integration time registers
and the manual gain value in the gain registers. When AEC is enabled
(R0x3100[0]=1), the target luma value is set by AE_LUMA_TARGET_REG (R0x3102). For
AR0144, this target luma has a default value of 0x0500. The luma target maximum auto
exposure value is limited by R0x311C; the minimum auto exposure is limited by
R0x311E. These values are in units of line-times. The minimum value for register 0x311E
is 1 line. The exposure control measures current scene luminosity by accumulating a
histogram of Gr pixel values while reading out a frame. It then compares the current
luminosity to the desired output luminosity. Finally, the appropriate adjustments are
made to the exposure time and gain.

自动曝光
        集成的自动曝光控制AEC 确保了  “最佳曝光设置”和 “计算和更新每帧的增益”
R0x3100[0]  开/关 AEC功能。
0：关
        sensor使用手动曝光值，通过 coarse and fine integration time registers
                  使用手动增益，通过增益寄存器
1：开
        通过设置AE_LUMA_TARGET_REG (R0x3102) 寄存器，设置目标luma value （亮度值）
             默认的目标luma data=0x0500
        R0x311C 设置 maximum auto exposure 目标luma value
        R0x311E  设置the minimum auto exposure 目标luma value  最小为1
        这些值以行数为单位？

当读出一帧时，曝光控制 通过累计Gr像素值的直方图 来测量当前场景的亮度，
然后比较当前亮度和目标亮度，最后再做适量的配置来设置曝光时间和曝光增益。

搞不懂上面哪个luma target max/min的含义，这个明明时亮度，为啥和行数扯上关系