http://softpixel.com/~cwright/programming/colorspace/yuv/
http://mgggopssl.egloos.com/1013338
http://blog.naver.com/morpheuz82?Redirect=Log&logNo=130027942184
http://en.wikipedia.org/wiki/YCbCr
http://en.wikipedia.org/wiki/YUV
http://www.mikekohn.net/stuff/image_processing.php#yuv422torgb
http://www.conv2.com/spboard/board.cgi?id=faq&action=view&gul=114&page=3&go_cnt=0
RGB888 ->RGB555
#define RGB15(r, g, b) ( ((r>>3)<<10) | ((g>>3)<<5) | (b>>3) ) // 5:5:5 mode
#define R555(p) ( (BYTE) ( (p>>11) ) )
#define G555(p) ( (BYTE) ( (p>>5)&63 ) )
#define B555(p) ( (BYTE) ( (p)&31 ) )RGB888 -> RGB565
#define RGB16(r, g, b) ( ((r>>3)<<11) | ((g>>2)<<5) | (b>>3) ) // 5:6:5 mode
#define R565(p) ( (BYTE) ( (p>>11) <<3) )
#define G565(p) ( (BYTE) ( (p>>5)&63 <<2) )
#define B565(p) ( (BYTE) ( (p)&31 <<3) )ARGB8888 -> ARGB1555
#define ARGB1555(a,r,g,b) ( (a<<15) | ((r>>3)<<10) | ((g>>3)<<5) | (b>>3) )ARGB8888 -> ARGB4444
#define ARGB4444(a,r,g,b) ( ((a>>4)<<12) | ((r>>4)<<8) | ((g>>4)<<4) | (b>>4) )RGB 5:6:5 or 5:5:5 --> 5:6:5 or 5:5:5
#define RGB555_BYTE(r,g,b) ( ((r)<<10) | ((g)<<5) | (b) ) // 5:5:5
#define RGB565_BYTE(r,g,b) ( ((r)<<11) | ((g)<<5) | (b) ) // 5:6:5