星迹—iStar的博客

/**
     * 把资源图片转为灰度图
     * @param resID 资源ID
     * @return
     */
    public Bitmap convertGrayImg(int resID) {
        Bitmap src=((BitmapDrawable) getResources().getDrawable(resID)).getBitmap();

        int w=src.getWidth(),h=src.getHeight();
        int[] pix = new int[w * h];
        src.getPixels(pix, 0, w, 0, 0, w, h);

        int alpha=0xFF<<24;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                // 获得像素的颜色
                int color = pix[w * i + j];
                int red = ((color & 0x00FF0000) >> 16);
                int green = ((color & 0x0000FF00) >> 8);
                int blue = color & 0x000000FF;
                color = (red + green + blue)/3;
                color = alpha | (color << 16) | (color << 8 ) | color;
                pix[w * i + j] = color;
            }
        }
        Bitmap result=Bitmap.createBitmap(w, h, Config.RGB_565);
        result.setPixels(pix, 0, w, 0, 0,w, h);
        return result;
    }