QImage and QPıx cant read this png image but opencv does why ?

RahibeMeryem

Hi,

I encountered a PNG image that neither :

QPixmap qpix(fileName)

nor

QImage photo(fileName);

can read . Both says invalid image.

But I can read with and succesfully convert them to qimage and qpix with opencv with :

cv::Mat cv_image = cv::imread(fileName.toStdString());

Is there any clue why this is happening this png image. Other png images has no problem..

PS: When I convert to image to jpg or export as png again its working.

image is:

mrjj

Hi
The mm.png is actually a jpg file.
It just has the wrong extension.

RahibeMeryem

@mrjj yes you right.. thanks a lot..

PS: QImage and QPixmap should check the file as opencv, it is deciding by their extension I assume.

mrjj

@RahibeMeryem
Hi
Yeah, it can do some guessing looking at the header
but I think it only tries to guess if there is
not extension.