How to compare 2 QImages

Question

How can we compare two QImages ?

I have 2 QImages as below with some actual data in it:

QImage image_1;  
QImage image_2;

If I do a if(image_1 == image_2) & this returns true then does it mean the that the 2 QImages are pixel to pixel same?

Or does it mean that they are equal in sizes?
Or does it mean something completely different?

Note:
My requirement is to confirm that the QImages are pixel to pixel same.
Please suggest if there is a way to do that kindo of comparasion.

It is usually good idea to read the docs before asking... And if not clear or if docs not found, ask away, buy explain that in the question. — hyde, Dec 18 '17 at 22:04

score 4 · Accepted Answer · answered Dec 18 '17 at 21:55

If I do a if(image_1 == image_2) & this returns true then does it mean the that the 2 QImages are pixel to pixel same?

Yes, same pixels: http://doc.qt.io/qt-5/qimage.html#operator-eq-eq

We have equal operator described as:

bool QImage::operator==(const QImage &image) const Returns true if this image and the given image have the same contents; otherwise returns false.

The comparison can be slow, unless there is some obvious difference (e.g. different size or format), in which case the function will return quickly.

How to compare 2 QImages

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