1、Mat转byte

private static int[] mat2RGB(Mat src) {
	int width = src.cols();
	int height = src.rows();
	int dims = src.channels();
	byte[] data = new byte[width * height * dims];
	src.get(0, 0, data);
	int[] pixels = new int[width * height];

	BufferedImage bi = new BufferedImage(width,height,BufferedImage.TYPE_INT_ARGB);
	int r = 0, g = 0, b = 0;
	int index = 0;
	for(int row = 0; row < height; row++) {
		for(int col = 0; col < width; col++) {
			index = row * width * dims + col * dims;
			if(dims == 3) {
				b = data[index]&0xff;
				g = data[index+1]&0xff;
				r = data[index+2]&0xff;
				pixels[row * width + col] = ((255&0xff) << 24) | ((r&0xff) << 16) | ((g&0xff) << 8) | (b&0xff);
			}else if(dims == 1) {
				b = data[index]&0xff;
				pixels[row * width + col] = ((255&0xff) << 24) | ((b&0xff) << 16) | ((b&0xff) << 8) | (b&0xff);
			}
		}
	}
	return pixels;
}

2、int[]转byte[]

private static byte[] rgbToGray(int[] argb, int width, int height) {
	int yIndex = 0;
	int index = 0;
	byte[] gray = new byte[width * height];

	for(int j = 0; j < height; ++j) {
		for(int i = 0; i < width; ++i) {
			int R = (argb[index] & 16711680) >> 16;
			int G = (argb[index] & '\uff00') >> 8;
			int B = argb[index] & 255;
			int Y = (66 * R + 129 * G + 25 * B + 128 >> 8) + 16;
			gray[yIndex++] = (byte)(Y < 0 ? 0 : (Y > 255 ? 255 : Y));
			++index;
		}
	}

	return gray;
}

经过测试，每帧运行速度比原来提高了0.75