Here is the latest mtPaint:
http://www.btinternet.com/~mark.tyler4/ ... 02.tar.bz2
This release adds support for loading and saving PNG files with a transparency index. An optional zoom grid has been added. The save image window has been improved. Partial French and Portuguese translations have been added. A bug with the painting tool has been fixed.
mtPaint 2.02 now available
- BarryK
- Puppy Master
- Posts: 9392
- Joined: Mon 09 May 2005, 09:23
- Location: Perth, Western Australia
- Contact:
Hi Mark,
I was just thinking about transparency in mtPaint a few days ago.
back in the days when I used Windows, I used to like the Software602
shareware office suite.
It has a paint program, and in the menu it had an entry "Choose color for transparency" -- then a little pointer icon would appear, and I would click over
the color that I wanted to be transparent, and that was it.
That works for GIF.
But PNG, does it assign an actual color as transparent, or is it a different
mechanism?
Transparency in mtPaint has not been so seamless.
For example, I opened a XPM image with one transparent "color" (a "None"
entry), did nothing, just saved it as a GIF, thinking that the transparency
would be preserved, but it wasn't.
... I guess this is because they are two different things? The XPM transparency
is not one of the colors?
Note, Puppy uses the full GIF library with LZW compression.
I thought that the LZW patent had expired, maybe it has in most places in
the world, but I recently read something about it fully expiring in
August 2006. Anyway we are using LZW!
I was just thinking about transparency in mtPaint a few days ago.
back in the days when I used Windows, I used to like the Software602
shareware office suite.
It has a paint program, and in the menu it had an entry "Choose color for transparency" -- then a little pointer icon would appear, and I would click over
the color that I wanted to be transparent, and that was it.
That works for GIF.
But PNG, does it assign an actual color as transparent, or is it a different
mechanism?
Transparency in mtPaint has not been so seamless.
For example, I opened a XPM image with one transparent "color" (a "None"
entry), did nothing, just saved it as a GIF, thinking that the transparency
would be preserved, but it wasn't.
... I guess this is because they are two different things? The XPM transparency
is not one of the colors?
Note, Puppy uses the full GIF library with LZW compression.
I thought that the LZW patent had expired, maybe it has in most places in
the world, but I recently read something about it fully expiring in
August 2006. Anyway we are using LZW!
Barry,
Until version 2.02 transparency was only available with XPM files. The transparency in 2.02 is just for PNG files - I haven't spent any time working on GIF transparency as I feel its a less important file format than PNG these days.
The system of transparency I have used for PNG files in v2.02 is a very basic colour indexing system where a single colour is treated as transparent (RGB images or indexed palette images). The PNG format also allows for multiple colour transparencies and even full alpha channel transparency but I feel this is a little complex for a program like mtPaint (it would require a lot of new code and changes to the UI).
You can load a PNG file with an alpha channel but mtPaint regards a pixel as either fully transparent or fully opaque (it chops it at 50%).
If you load an XPM file into mtPaint and then save it as a PNG it should retain the transparency, as should doing this in reverse with an indexed palette PNG file saved as XPM.
You can pick the colour via the Preferences->Files section or by using the 'Save as' window.
I hope this new feature is helpful - let me know if there are any problems.
Until version 2.02 transparency was only available with XPM files. The transparency in 2.02 is just for PNG files - I haven't spent any time working on GIF transparency as I feel its a less important file format than PNG these days.
The system of transparency I have used for PNG files in v2.02 is a very basic colour indexing system where a single colour is treated as transparent (RGB images or indexed palette images). The PNG format also allows for multiple colour transparencies and even full alpha channel transparency but I feel this is a little complex for a program like mtPaint (it would require a lot of new code and changes to the UI).
You can load a PNG file with an alpha channel but mtPaint regards a pixel as either fully transparent or fully opaque (it chops it at 50%).
If you load an XPM file into mtPaint and then save it as a PNG it should retain the transparency, as should doing this in reverse with an indexed palette PNG file saved as XPM.
You can pick the colour via the Preferences->Files section or by using the 'Save as' window.
I hope this new feature is helpful - let me know if there are any problems.