Question Background and transparency in my PNG files?

[Oblivion77]

Hello everyone



Years ago, i made som pictures in MS Paint and saved them as PNG.



I was now wondering, if the pictures have a background or any transparency.



The files are bit depth 24.

They do not have any tRNS chunks.

They do not have any bKGD chunks.



I used the TweakPNG tool to view the file chunks.



So it is safe to say, that my pictures do not have any background or transparency?



Is there other indicators, for if the pictures have transparency or a background?



Thanks in advance for answering!



Best regards

Emil

 

[jojesa]

Those MS Paint pictures will have a white background.

 

[Oblivion77]

Those MS Paint pictures will have a white background.

But there is no bKGD chunk. So the background and picture, everything is just merged together?

 

[jojesa]

Paint does not follow PNG specs when handling png files.
When you save a png file (with or without bKGD chunk ) using Paint it will change the color space and save the image as color-type 6 (6 bytes).
This makes the image invalid to some programs , even though the bKGD chunk is in the image data, since the bKGD chunk only have 1-byte data.
Many apps can dig the image data and ignore the bad bKGD chunk, and properly render the PNG image.

 

[Oblivion77]

This makes the image invalid to some programs , even though the bKGD chunk is in the image data, since the bKGD chunk only have 1-byte data.

But if there is a bKGD chunk, software like TweakPNG would still show it?

 

[jojesa]

No idea, have not used TweakPNG .

 

[Oblivion77]

No idea, have not used TweakPNG .

Is there other software you would suggest, that can show if there is a bKGD or tRNS chunk?

 

[jojesa]

Try opening them in Microsoft Paint 3D then export file to png.