Transparent PNG files issue

[Paultx]

I created a PNG file with a transparent background, to have only the text to be applied wherever I want.



Like this.



Then I decided to test the same PNG in negative and used Image > Negative (invert image) > All channels.

The result was that IrfanView made everything negative in a way that turned the black text into white, as expected. But it didn't preserve the transparent part of the image and turned it into orange, probably because I set IV's main window color to blue.




So, when I applied the PNG turned negative by IV to the same image, this was the result.



I thought IV would preserve the transparent areas of the image and convert only the rest.

I don't know if it is a bug, the result of a wrong setting or anything else, so I came here to ask for your help. TIA.


Versions

IrfanView 4.57 32-bit

Windows 10 Pro 20H2 19042.870 64-bit

[Bhikkhu Pesala]

Probably not a bug because the IrfanView edit window only supports 24-bit without alpha transparency. If you save the negative as a new transparent image, to use the Image overlay feature, that should work.