在触摸相机屏幕时像默认相机一样调整android相机api中的亮度

Question

I am preparing a custom android camera app and wish to adjust the exposure/brightness of the camera on touch event. The default values look a bit darker than the default camera . I tried using whiteBalance(auto) function but it wont help. Was trying it using exposure like

params.setExposureCompensation(params.getExposureCompensation());

            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
                if(params.isAutoExposureLockSupported()) {
                    params.setAutoExposureLock(false);
                }
            }

but i am not understanding the difference between the exposure function's like ,

getExposureCompensation(), getMaxExposureCompensation(),getExposureCompensationStep()

Answer 1

Firstly, you are not actually setting the exposure.

params.setExposureCompensation(params.getExposureCompensation());

sets the exposure to the previous value ie it is never changed. What you need to do is set a value between params.getMinExposureCompensation() and params. getMaxExposureCompensation() params. getMaxExposureCompensation()

Secondly the difference between the exposure functions is clearly explained in the docs

getExposureCompensation

Gets the current exposure compensation index. current exposure compensation index. The range is getMinExposureCompensation() to getMaxExposureCompensation(). 0 means exposure is not adjusted.

getMaxExposureCompensation

Gets the maximum exposure compensation index.(>=0)

getExposureCompensationStep

exposure compensation step. Applications can get EV by multiplying the exposure compensation index and step. Ex: if exposure compensation index is -6 and step is 0.333333333, EV is -2.

Here EV stands for exposure value