PyQt QImage cna't copy, crash without error code

[darrenleeleelee1]

@KroMignon I change but still crash...What is the different between arr and arr.data?

[KroMignon]

@darrenleeleelee1 said in PyQt QImage cna't copy, crash without error code:

What is the different between arr and arr.data?

arr is an instance of numpy.ndarray type, according to your code!
And arr.data is the data buffer according to numpy documentation ==> https://numpy.org/doc/stable/reference/generated/numpy.ndarray.html

I think it would be great if you first explain what you want to do.
Perhaps you should take a look at this python script which converts numpy.ndatarray to QImage and vice versa:
https://kogs-www.informatik.uni-hamburg.de/~meine/software/vigraqt/qimage2ndarray.py

[darrenleeleelee1]

@KroMignon I saw this before, but I don't know how to apply to uint16.

[KroMignon]

@darrenleeleelee1 said in PyQt QImage cna't copy, crash without error code:

I saw this before, but I don't know how to apply to uint16.

Which version of Qt-Libs are you using?
Format_Grayscale16 is only support starting from Qt 5.13 (cf. QImage.Format)

Because of this note from documentation:

Constructs an image with the given width , height and format , that uses an existing memory buffer, data . The width and height must be specified in pixels, data must be 32-bit aligned, and each scanline of data in the image must also be 32-bit aligned.

Perhaps you should specify the number of bytes per line, like this:

qimage = QtGui.QImage(arr.data, arr.shape[1], arr.shape[0], arr.shape[1]*2, QtGui.QImage.Format_Grayscale16)

[darrenleeleelee1]

@KroMignon said in PyQt QImage cna't copy, crash without error code:

arr.shape[1]*2

sorry, I read through the QImage API, but I don;t get why I need to add this.
After I add this it seems can work.

[KroMignon]

@darrenleeleelee1 said in PyQt QImage cna't copy, crash without error code:

sorry, I read through the QImage API, but I don;t get why I need to add this.

Then you don't read carefully ;)
The point is when you only specify width and height: The width and height must be specified in pixels, data must be 32-bit aligned, and each scanline of data in the image must also be 32-bit aligned.

To avoid this, you can use width, height and scanline length in bytes, which is pixel_per_line x pixel_size:

• pixel_per_line is arr.shape[1]
• pixel_size is uint16 which are 2 bytes

==> scanline_size = arr.shape[1]*2

After I add this it seems can work.

Great

[darrenleeleelee1]

@KroMignon @J-Hilk @JonB @jsulm thanks all u guys!