最近作Android下图像处理方面的工做，Android下获得的图像其编码格式为YUV，图像处理须要RGB格式，须要进行转换。下面给出遇到的两类YUV格式转换RGB的代码。html
第一种：YUV420SP转RGBandroid
遇到的YUV420SP是这种格式：NV21: YYYYYYYY VUVU 函数
void YUV420SP2RGB(char *rgbBuf, char *yuv420sp, int width, int height)
{
int frameSize = width * height;
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);
}
}
}
int convert_yuv_to_rgb_pixel(int y, int u, int v)
{
unsigned int pixel32 = 0;
unsigned char *pixel = (unsigned char *)&pixel32;
int r, g, b;
r = y + (1.370705 * (v-128));
g = y - (0.698001 * (v-128)) - (0.337633 * (u-128));
b = y + (1.732446 * (u-128));
if(r > 255) r = 255;
if(g > 255) g = 255;
if(b > 255) b = 255;
if(r < 0) r = 0;
if(g < 0) g = 0;
if(b < 0) b = 0;
pixel[0] = r ;
pixel[1] = g ;
pixel[2] = b ;
return pixel32;
}
int convert_yuv_to_rgb_buffer(unsigned char *yuv, unsigned char *rgb, unsigned int width, unsigned int height)
{
unsigned int in, out = 0;
unsigned int pixel_16;
unsigned char pixel_24[3];
unsigned int pixel32;
int y0, u, y1, v;
for(in = 0; in < width * height * 2; in += 4)
{
pixel_16 =
yuv[in + 3] << 24 |
yuv[in + 2] << 16 |
yuv[in + 1] << 8 |
yuv[in + 0];
y0 = (pixel_16 & 0x000000ff);
u = (pixel_16 & 0x0000ff00) >> 8;
y1 = (pixel_16 & 0x00ff0000) >> 16;
v = (pixel_16 & 0xff000000) >> 24;
pixel32 = convert_yuv_to_rgb_pixel(y0, u, v);
pixel_24[0] = (pixel32 & 0x000000ff);
pixel_24[1] = (pixel32 & 0x0000ff00) >> 8;
pixel_24[2] = (pixel32 & 0x00ff0000) >> 16;
rgb[out++] = pixel_24[0];
rgb[out++] = pixel_24[1];
rgb[out++] = pixel_24[2];
pixel32 = convert_yuv_to_rgb_pixel(y1, u, v);
pixel_24[0] = (pixel32 & 0x000000ff);
pixel_24[1] = (pixel32 & 0x0000ff00) >> 8;
pixel_24[2] = (pixel32 & 0x00ff0000) >> 16;
rgb[out++] = pixel_24[0];
rgb[out++] = pixel_24[1];
rgb[out++] = pixel_24[2];
}
return 0;
}
使用时，调用convert_yuv_to_rgb_buffer（）这个函数就能够了。关于这个函数的参数解释以下：
yuv：YUV422数据的起始地址编码
rgb：转换后的数据的起始地址spa
width：摄像头采集数据时所设置的图片宽度（如：320）.net
height：摄像头采集数据时所设置的图片高度（如：240）code
参考：orm
1. http://developer.android.com/reference/android/graphics/ImageFormat.htmlhtm
2. http://www.cnblogs.com/lknlfy/archive/2012/04/09/2439508.htmlblog
3. http://www.ztyhome.com/android-camera-yuv420/