Android Camera2 API set custom Brightness, Contrast, Gamma

Question

Since this hasn't clear answer, and stackoverflow hasn't questions / answers about Camera 2 API Gamma, I ask for solution to modify Brightness, Contrast and Gamma using Android Camera 2 API.
My code to get range and step:

Rational controlAECompensationStep = characteristics.get(CameraCharacteristics.CONTROL_AE_COMPENSATION_STEP);
if (controlAECompensationStep != null) {
    compensationStep = controlAECompensationStep.doubleValue();
}

Range<Integer> controlAECompensationRange = characteristics.get(CameraCharacteristics.CONTROL_AE_COMPENSATION_RANGE);
if (controlAECompensationRange != null) {
    minCompensationRange = controlAECompensationRange.getLower();
    maxCompensationRange = controlAECompensationRange.getUpper();
}

My method to set Brightness in percents:

public void setBrightness(int value) {
    int brightness = (int) (minCompensationRange + (maxCompensationRange - minCompensationRange) * (value / 100f));
    previewRequestBuilder.set(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION, brightness);
    applySettings();
}
private void applySettings() {
    try {
        captureSession.setRepeatingRequest(previewRequestBuilder.build(), null, null);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

But this approach doesn't work correctly. Image becomes green, like here.

I described all what I found in documentation (demo .apk included).

You can try Spectaculum, it works with Camera2 API: https://github.com/protyposis/Spectaculum?utm_source=android-arsenal.com&utm_medium=referral&utm_campaign=4529 — Umair Adil, Mar 16 '17 at 12:09
@UmairAdil thank you for response. but it isn't what I actually want. — Volodymyr Kulyk, Mar 16 '17 at 12:37
@VladimirKulyk I have gone through and installed the apk on Nexus 5x device and B+, B- works fine. No green color? — Anurag Singh, Mar 21 '17 at 05:34
@AnuragSingh ok :D looks like I set `AutoWhiteBalance` to `false` if changing B, G or C manually. It makes my preview green. — Volodymyr Kulyk, Mar 21 '17 at 08:07
Sorry I didn't get it. If you need to update apk, please do so? — Anurag Singh, Mar 21 '17 at 09:13
@AnuragSingh this apk is my camera2 test application. I use functionality from it in my current project, where I set `CaptureRequest.CONTROL_AWB_MODE` `CaptureRequest.CONTROL_AWB_MODE_OFF`, than I modify B, G or C and get [green](https://www.dropbox.com/s/xelc71a72qkoipp/20170321_095250.png?dl=0) result. — Volodymyr Kulyk, Mar 21 '17 at 09:20

Volodymyr Kulyk · Accepted Answer · 2017-12-11T12:13:36.140

My mistake was in changing Auto White Balance Mode(AWB) to CONTROL_AWB_MODE_OFF before modifying Brightness(B), Gamma(G) or Contrast(C).
Do not set OFF mode for AWB, use AUTO or other from possible modes.

get current B in percents

public int getBrightnessValue() {
    int absBRange = maxCompensationRange - minCompensationRange;
    int value = getValue(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION);
    return 100 * (value - minCompensationRange) / absBRange;
}

set B in percents

public void setBrightness(int value) {
    int brightness = (int) (minCompensationRange + (maxCompensationRange - minCompensationRange) * (value / 100f));
    previewRequestBuilder.set(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION, brightness);
    applySettings();
 }

set C in percents

//set def channels (used for contrast)
TonemapCurve tc = previewRequestBuilder.get(CaptureRequest.TONEMAP_CURVE);
if (tc != null) {
    channels = new float[3][];
    for (int chanel = TonemapCurve.CHANNEL_RED; chanel <= TonemapCurve.CHANNEL_BLUE; chanel++) {
        float[] array = new float[tc.getPointCount(chanel) * 2];
        tc.copyColorCurve(chanel, array, 0);
        channels[chanel] = array;
    }
}

public void setContrast(int value) {
    final int minContrast = 0;
    final int maxContrast = 1;

    if (channels == null || value > 100 || value < 0) {
        return;
    }

    float contrast = minContrast + (maxContrast - minContrast) * (value / 100f);

    float[][] newValues = new float[3][];
    for (int chanel = TonemapCurve.CHANNEL_RED; chanel <= TonemapCurve.CHANNEL_BLUE; chanel++) {
        float[] array = new float [channels[chanel].length];
        System.arraycopy(channels[chanel], 0, array, 0, array.length);
        for (int i = 0; i < array.length; i++) {
            array[i] *= contrast;
        }
        newValues[chanel] = array;
    }
    TonemapCurve tc = new TonemapCurve(newValues[TonemapCurve.CHANNEL_RED], newValues[TonemapCurve.CHANNEL_GREEN], newValues[TonemapCurve.CHANNEL_BLUE]);
    previewRequestBuilder.set(CaptureRequest.TONEMAP_MODE, CaptureRequest.TONEMAP_MODE_CONTRAST_CURVE);
    previewRequestBuilder.set(CaptureRequest.TONEMAP_CURVE, tc);
    applySettings();
}

private void applySettings() {
    captureSession.setRepeatingRequest(previewRequestBuilder.build(), null, null);
}

G is still in progress.

Code examples above may be not 100% correct, if you have better solutions or found a bug, please let me know ;)

Here I am unable to find `getValue` @`getValue(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION);` ? — Shailendra Madda, Nov 09 '17 at 13:54
@ShylendraMadda `private CaptureRequest.Builder previewRequestBuilder;` `Integer brightness = previewRequestBuilder.get(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION);` — Volodymyr Kulyk, Nov 10 '17 at 07:02
@SumitMarwha look at `//set def channels (used for contrast)` comment and code bellow. — Volodymyr Kulyk, Dec 11 '17 at 12:14
TonemapCurve tc = previewRequestBuilder.get(CaptureRequest.TONEMAP_CURVE); --Getting null in resilt — Sanket990, Mar 18 '19 at 16:16
Volodymyr good code but be aware that posts can move around on stack. You should post your answer and then comment the link to it. It's not "below" anymore. Like this: https://stackoverflow.com/a/42925286/9008140 — John Lord, Nov 24 '20 at 21:43
previewRequestBuilder.get(CaptureRequest.TONEMAP_CURVE) return null, do u know why? — Arsenius, Mar 24 '21 at 08:26

Android Camera2 API set custom Brightness, Contrast, Gamma

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