图片格式的识别

/识别图片格式

QString getImgFmt(constQString&imagePath)
{
QFile imageFile(imagePath);
if(!imageFile.open(QIODevice::ReadWrite)){
return QString();
}
QByteArrayba =imageFile.readAll();

QString imgFmt =QString();
if(0x424D== ((ba[0]& 0xff)<< 8| (ba[1]& 0xff))){
imgFmt.append("bmp");
}
else if(0x8950== ((ba[0]& 0xff)<< 8| (ba[1]& 0xff))){
imgFmt.append("png");
}
else if(0xFFD8== ((ba[0]/&0xff)<< 8| (ba[1]& 0xff))){
imgFmt.append("jpg");
}

return imgFmt;
}


int main()
{
QString path_0("D:\\workspace\\aaa.bmp");
int bmpDepth =getBmpBitDepth(path_0);

QString path_1("D:\\workspace\\tray.png");
int pngDepth =getPngBitDepth(path_1);

QString path_2("D:\\workspace\\1111.png");
int jpegDepth =getJpegBitDepth(path_2);

QString fmt =getImgFmt(path_2);
printf("fmt=%s\n",fmt.toStdString().c_str());
}