Android 如何把图片的rgb原始数据转为yuv原始数据
最近在做Android上图片编辑的软件,我用Android自带的Bitmap.getPixels()函数获得了图片原始数据的数组int[] data.
这个整形数组每一个int就代表图像一个像素的argb,也就是获得的原始数据为ARGB24格式。现在要把这个整形数组转为YUV420格式的数组。找了网上的资料,几天都没搞出来,只找到了YUV420转为RGB24的函数(在后面附上)。我现在的需求类似这个函数,只是要把RGB24转YUV420而已,函数的原型为public void decodeRGB24(byte[] rgbBuf, byte[] yuv420sp, int width, int height) { ... }.哪位高手指教一下啊,不胜感激啊。。。
附上YUV420转为RGB24的函数:
public void decodeYUV420SP(byte[] rgbBuf, byte[] yuv420sp, int width, int height) {
final int frameSize = width * height;
if (rgbBuf == null)
throw new NullPointerException("buffer 'rgbBuf' is null");
if (rgbBuf.length < frameSize * 3)
throw new IllegalArgumentException("buffer 'rgbBuf' size "
+ rgbBuf.length + " < minimum " + frameSize * 3);
if (yuv420sp == null)
throw new NullPointerException("buffer 'yuv420sp' is null");
if (yuv420sp.length < frameSize * 3 / 2)
throw new IllegalArgumentException("buffer 'yuv420sp' size " + yuv420sp.length
+ " < minimum " + frameSize * 3 / 2);
int i = 0, y = 0;
int uvp = 0, u = 0, v = 0;
int y1192 = 0, r = 0, g = 0, b = 0;
for (int j = 0, yp = 0; j < height; j++) {
uvp = frameSize + (j >> 1) * width;
u = 0;
v = 0;
for (i = 0; i < width; i++, yp++) {
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;
}
y1192 = 1192 * y;
r = (y1192 + 1634 * v);
g = (y1192 - 833 * v - 400 * u);
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;
rgbBuf[yp * 3] = (byte)(r >> 10);
rgbBuf[yp * 3 + 1] = (byte)(g >> 10);
rgbBuf[yp * 3 + 2] = (byte)(b >> 10);
}
}
}