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Transparent palette colour PNG

PostPosted: Tue Oct 22, 2013 4:49 am
by SysOp
Hello again,
Sorry I always come up with new bug reports shortly after a new version is released...

I cannot seem to save transparent palette colour PNG pictures with NeoPaint 5. The option to select the transparent colour is not available under Picture Info like it is when editing a GIF.
When I open a transparent GIF and save it as PNG, a window pops up telling me the alpha channel has to be removed and will be replaced with white :(. Even though of course the picture does not even have an alpha channel. Could you please fix this?
Thanks in advance!

Kind regards,
Jeroen

Re: Transparent palette colour PNG

PostPosted: Tue Oct 22, 2013 11:23 am
by Neosoft Support
We'll see if we can make this more automatic in the future, but in order for GIF images to become transparent PNGs they must first be converted to 32-bit. Here's how to convert a transparent GIF into a transparent PNG:

1. Open the GIF image.

2. Select "Convert to > 16 million Colors + Alpha Channel (32-bit)" from NeoPaint's Picture menu.

3. Select "Save As" from the File menu.

4. Select "PNG" from the "Save as type" box.

5. Save the file.

Once the image is converted to PNG it will use alpha channel* transparency. To define transparent areas of the alpha channel use the "Define transparency" command in the Picture menu. Use the Help button on the Define transparency screen for details on how this feature works.

*An alpha channel is a special mask used to identify which portions of a picture should be transparent (see through) and which portions should be opaque (solid). In addition to completely transparent or completely opaque, an alpha channel can also include partial transparency.

An alpha channel is essentially a grayscale mask containing up to 256 shades of grey. Each pixel in the mask represents a transparency level for the corresponding pixel in the original picture. A mask pixel with a value of zero (black) means the corresponding picture pixel is 100% transparent. A mask pixel with a value of 255 (white) means the corresponding picture pixel is 100% opaque. A mask pixel with a value of 128 (medium grey) means the corresponding picture pixel is 50% transparent.

Re: Transparent palette colour PNG

PostPosted: Tue Oct 22, 2013 11:46 am
by SysOp
Thank you for your reply.

I don't want to convert the pictures to 32-bit colour when it is not required. This will increase the file size to exceed the size of the GIF by far and the time it takes to compress it. In some cases 32-bit pictures are not compatible and sometimes I need palette colours and specific palette's for applications that run in 8 or 4-bit colour modes.
Please do not automatically change the colour depth to 32-bit if that's what you mean!
PNG pictures can have single colour transparency on palette colour pictures and all applications I know support it, including NeoPaint 4.
NeoPaint 5 will even show transparency when a transparent palette colour PNG picture is opened, but it won't save it.

Re: Transparent palette colour PNG

PostPosted: Wed Oct 23, 2013 11:47 am
by Neosoft Support
NeoPaint 5 will even show transparency when a transparent palette colour PNG picture is opened, but it won't save it.


OK, maybe this can be changed in the future. Although, I'm not sure that there is much of an advantage to saving an 8-bit image as a PNG vs saving as a GIF unless you're using the image somewhere that specifically requires PNG. But as far as NeoPaint is concerned the change shouldn't be difficult.