what is the best way to get the resolution of the various formats of images?

opengpu2

opengpu2

@opengpu2 i now simply use:
QPixmap pixmap(path);
int w = pixmap.width();
int h = pixmap.height();

but i found that sometimes i can't open some image file....eg.i can open some TGA, but failed to get the w and h of some TGA...they return 0....that file can be open with Photoshop.....

opengpu2

the width and height is not 0...
but i tried QPixmap, QImage....they both return 0 when i call .width(), .height()