Android Camera2 API 设置自定义亮度、对比度、伽玛

Question

因为 hasn't clear answer, and Whosebug hasn't questions / answers about Camera 2 API Gamma, I ask for solution to modify Brightness, Contrast and Gamma using Android Camera 2 API.
我的代码得到 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();
}

我设置亮度百分比的方法：

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();
    }
}

但是这种方法不能正常工作。图片变成green, like .

我描述了我在 documentation 中找到的所有内容（包括演示 .apk）。

Answer 1

我的错误是在修改亮度 (B)、伽玛 (G) 或对比度 (C) 之前更改了 Auto White Balance Mode(AWB) to CONTROL_AWB_MODE_OFF。
不要为 AWB 设置 OFF 模式，使用 AUTO 或其他可能的模式。

以百分比形式获取当前 B

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

将 B 设置为百分比

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

以百分比形式设置 C

//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还在进行中

上面的代码示例可能不是 100% 正确，如果您有更好的解决方案或发现错误，请告诉我 ;)

Android Camera2 API 设置自定义亮度、对比度、伽玛

Android Camera2 API set custom Brightness, Contrast, Gamma

android

android-camera

android-camera2