ARGB1555内部存储空间的大小与ARGB转换方式

ARGB1555一个像素点为16位，ARGB8888一个像素点为32位，存储空间理论上同一幅图像是两倍关系。

unsigned int ARGB1555toARGB8888(unsigned short c)

{

unsigned int a = c&0x8000, r = c&0x7C00, g = c&0x03E0, b = c&0x1F;

unsigned int rgb = (r << 9) | (g << 6) | (b << 3);

return (a*0x1FE00) | rgb | ((rgb >> 5) & 0x070707);

}