Transparent/Alpha pixels set to black when saving a PNG

keta

Posts: 7

1 year ago

Occasionally when saving a PNG with transparency/alpha pixels, the pixels that have less than 1.0f alpha will be set to black when saving.

It happens enough to where I now check the saved PNG to ensure that the image has the proper alpha before closing the image in Pixelmator.

This is happening in Pixelmator 3.5 Crayon (and prior) running on OS X 10.11.5.

Steps to reproduce:

1. start new image
2. paint a solid color and then a color with < 1.0f alpha transparency
3. save as PNG and close
4. reopen PNG
5. CMD+S to save as PNG until it happens (1 in 10?)

Here is what it looks like when saved with the issue: http://i.imgur.com/xVAFNv5.png

Thanks for checking this out and resolving this frustrating issue!
Sebastiaan

Posts: 3541

1 year ago

Thanks for pointing us on this keta.

Can you by any chance send us your mac specs, just in case?
keta

Posts: 7

1 year ago

Here's a pic of my specs: http://i.imgur.com/Q6Te03m.png

Let me know if you need more info.
keta

Posts: 7

1 year ago

Were you able to confirm this issue as a Pixelmator bug? Also, the issue occurs on OS X 10.11.6 as well.
scastria

Posts: 2

1 year ago

PLEASE FIX THIS!! I have had this problem for years. It happens about 40% of the time. I have better luck recreating this bug when I try to save on top of a file that already exists. Pixelmator asks if I want to overwrite, I say yes, and then I usually get a black background PNG instead of transparent. Also, it could be my imagination but I also seem to have better luck recreating this bug if I DO NOT type the filename by hand, but instead select a file that already exists making pixelmator change the filename field to that of the selected file. I then click save and I get confirmation to overwrite and then I usually get the bad PNG image.

PLEASE FIX!!
scastria

Posts: 2

1 year ago

The OSX version does not seem to matter as I have had this issue for years.
Fritsl

Posts: 1

1 month ago

Using Pixelmator to create PNG's for Game design ("Sprites"), this is a big issue, please fix, Pixelmator is useless with default Black Alpha.

Photoshop is default White btw, but that can be changed via plugins.

(EDIT: The transparent is "Transparent", but the "color" of it is Black, so when third party SW (Game Engines) scale a PNG with transparency, it antialiases the edges towards black - when it comes from Pixelmator)

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