Android Camera2 API 设置自定义亮度、对比度、伽玛

Posted 2023-04-17

【中文标题】Android Camera2 API 设置自定义亮度、对比度、伽玛

【英文标题】：Android Camera2 API set custom Brightness, Contrast, Gamma

【发布时间】：2017-08-06 00:29:28

【问题描述】：

由于 this 没有明确的答案，并且 *** 没有关于 Camera 2 API Gamma 的问题/答案，我要求使用android Camera 2 API 修改亮度、对比度和 Gamma 的解决方案。 我获取 range 和 step 的代码：

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，就像here。

---

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

【问题讨论】：

你可以试试 Spectaculum，它适用于 Camera2 API：github.com/protyposis/…

@UmairAdil 感谢您的回复。但这不是我真正想要的。

@VladimirKulyk 我已经在 Nexus 5x 设备和 B+ 上安装了 apk，B- 工作正常。没有绿色？

@AnuragSingh ok :D 如果手动更改 B、G 或 C，我将 AutoWhiteBalance 设置为 false。它使我的预览变成绿色。

对不起，我没明白。如果您需要更新apk，请这样做？

【参考方案1】：

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

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获取当前 B 的百分比

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

---

以百分比设置 B

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仍在进行中。

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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 ;)

【讨论】：

这里找不到getValue@getValue(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION);?

@ShylendraMadda private CaptureRequest.Builder previewRequestBuilder; Integer brightness = previewRequestBuilder.get(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION);

如何获取通道数组进行对比

@SumitMarwha 看看//set def channels (used for contrast) 的评论和下面的代码。

TonemapCurve tc = previewRequestBuilder.get(CaptureRequest.TONEMAP_CURVE); --在resilt中获取null