如何使用OpenCV在Android中调整图像亮度？

我创建了一个在 Android 中调整亮度的示例图像。我使用Bitmap来调整亮度，但是运行时间很长。相反，我想使用 OpenCV 在 Android 中设置图像亮度。

这是我的示例代码，但它只改变图像的颜色：

Bitmap bmp = BitmapFactory.decodeResource(getResources(),
            R.drawable.a001);
int width = bmp.getWidth();
int height = bmp.getHeight();
Mat mRgba = new Mat(width, height, CvType.CV_8UC1);
Utils.bitmapToMat(bmp, mRgba);
Mat mRay = new Mat();
Imgproc.cvtColor(mRgba, mRay, Imgproc.COLOR_BGRA2RGB, 4);
Utils.matToBitmap(mRay, bmp);
mImageview_01.setImageBitmap(bmp);

[Update]我尝试添加代码，但出现错误

Bitmap bmp = BitmapFactory.decodeResource(getResources(),
            R.drawable.a001);
int width = bmp.getWidth();
int height = bmp.getHeight();
Mat mRgba = new Mat(width, height, CvType.CV_8UC1);
Utils.bitmapToMat(bmp, mRgba);
Mat mRay = new Mat();
Imgproc.cvtColor(mRgba, mRay, Imgproc.COLOR_BGRA2RGB, 4);
/*
* Use Adaptive Thresholding on the grayscaled Mats crop -> threshed Mat
* src, Mat dst, double maxValue, int adaptiveMethod, int thresholdType,
* int blockSize, double C
*/
Imgproc.adaptiveThreshold(threshed, threshed, 255,
            Imgproc.ADAPTIVE_THRESH_GAUSSIAN_C, Imgproc.THRESH_BINARY_INV, 15, 8);
Utils.matToBitmap(mRay, bmp);
mImageview_01.setImageBitmap(bmp);

[Error]

CvException [org.opencv.core.CvException: /home/reports/ci/slave_desktop/50-SDK/opencv/modules/imgproc/src/thresh.cpp:796: error: (-215) src.type() == CV_8UC1 in function void cv::adaptiveThreshold(cv::InputArray, cv::OutputArray, double, int, int, int, double)

请查看我正在尝试做的事情的示例here http://shaikhhamadali.blogspot.com/2013/07/set-brightness-of-imageincreasedecrease.html.

有许多快速且简单的方法来调整位图亮度，例如色彩矩阵 https://developer.android.com/reference/android/graphics/ColorMatrix or 渲染脚本 https://developer.android.com/guide/topics/renderscript/compute。但如果你仍然考虑使用OpenCV就是这个方法 ：

private Bitmap changeBrightness(Bitmap bmp, int value){
    Mat src = new Mat(bmap.getHeight(),bmap.getWidth(), CvType.CV_8UC1);
    Utils.bitmapToMat(bmap,src);
    src.convertTo(src,-1,1,value);
    Bitmap result = Bitmap.createBitmap(src.cols(),src.rows(), Bitmap.Config.ARGB_8888);
    Utils.matToBitmap(src,result);
    return result;
}