ImageProcessing.java

package com.hmkcode.android.vo;

public abstract class ImageProcessing {

	private static int decodeYUV420SPtoRedSum(byte[] yuv420sp , int width , int height) {
		if (yuv420sp == null) {
			return 0;
		}
		
		final int frameSize = width * height;
		int sum = 0;
		
		for (int j = 0 , yp = 0 ; j < height ; j++) {
			int uvp = frameSize + (j >> 1) * width;
			int u = 0;
			int v = 0;
			for (int i = 0 ; i < width ; i++, yp++) {
				int y = (0xff & ((int) yuv420sp[yp])) - 16;
				if (y < 0) {
					y = 0;
				}
				if ((i & 1) == 0) {
					v = (0xff & yuv420sp[uvp++]) - 128;
					u = (0xff & yuv420sp[uvp++]) - 128;
				}
				int y1192 = 1192 * y;
				int r = (y1192 + 1634 * v);
				int g = (y1192 - 833 * v - 400 * u);
				int b = (y1192 + 2066 * u);

				if (r < 0) {
					r = 0;
				}
				else if (r > 262143) {
					r = 262143;
				}
				
				if (g < 0) {
					g = 0;
				}
				else if (g > 262143) {
					g = 262143;
				}
				
				if (b < 0) {
					b = 0;
				}
				else if (b > 262143) {
					b = 262143;
				}

				int pixel = 0xff000000 | ((r << 6) & 0xff0000) | ((g >> 2) & 0xff00) | ((b >> 10) & 0xff);
				int red = (pixel >> 16) & 0xff;
				sum += red;
			}
		}
		return sum;
	}

	public static int decodeYUV420SPtoRedAvg(byte[] yuv420sp , int width , int height) {
		if (yuv420sp == null) {
			return 0;
		}
		final int frameSize = width * height;
		int sum = decodeYUV420SPtoRedSum(yuv420sp, width, height);
		return (sum / frameSize);
	}
}