Feature request: Indexed PNG with lowered bit-depth option, allow alternative alpha options, or disabling it.

[kevincrans]

I want the exported image to have the same palette benefits as the editor: indexed and less bit-depth.
Idk about how bits alpha can be altered for indexed png, but first color of bmp palette is sometimes interpreted as an alpha, so why not with png.
I wrote a whole story of a feature request, but I think this is big enough of a request.

[steffest]

I think what you request is already there in development.

You can preview that on the dev version on https://dpaint.app/dev/ (which can be bit rough around the edges)

[kevincrans]

Oh my god, so awesome!
Foolish of me.
And Gif is there as well! (I originally wanted to ask)

[kevincrans]

@steffest
It works, but just so you know, this is how it looks in Safari tho:

But the palettes are also gone besides the drop down menu, so I think something is being reworked.

[kevincrans]

I can't save transparency, it becomes black.
Can this be set to read from the first color of the palette? (in case it isn't black)
I'm keeping this open, just in case one of us else misses something.

[steffest]

Yup, You caught the dev version in a re-construction phase.
https://www.stef.be/dpaint/dev/ should be more usable now.

The save dialog has been revamped.

And Indexed-PNG should keep transparent pixels now if there are any.
(and yes, it will map those to the first color of the saved palette)
Please note that choosing this option (8-bit PNG) doesn't auto-convert the image to max 256 colours, you have to do that yourself, allowing for more control in that process, for example to determine where the threshold is to map half-transparent pixel to full or not transparent.

Trying to save an image with more than 256 colors will display this error message.

Saving as GIF is somewhat implemented but needs a bit more care to make it robust.
I'll keep this ticket open until I complete some more test and have a more sturdy GIF export.

[kevincrans]

That's great!
I've created a 216 websafe palette, convertible to the 9-bit Atari, but now I know to use 256 instead of Full.

However, I set it to use current palette, I don't know if it sorts it, but the blacks got removed to alpha when saving png, while the black value was in the end (I made the 1st value an unused gray AFTER applying the palette).
Can this be fixed, or is this a format's limit? (I could make the blacks gray)
Edit: Gif saves fine, but doesn't open fine