这个比较麻烦,png图片是采用的LZ77方式压缩的,这需要你自己来解压
CxImage is a C++ class to load, save, display, transform BMP, JPEG, GIF, PNG, TIFF, MNG, ICO, PCX, TGA, WMF, WBMP, JBG, J2K images.
http://www.xdp.it/cximage/