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* Refactor invert.c in farbfeld.5Laslo Hunhold2017-04-14
| | | | | | | | | | | | | I noticed that it would be beneficial to release the invert.c code listing under a very permissive license. I like the style of the "Copy me if you can"-License, but thought that 0BSD would make it even clearer that everyone can do whatever he wants with this code. The code itself was not bad beforehand, but lacked some elementary features like checked flushing at the end and proper error messages. I also reworked the data structures a bit to make it more appealing and clearer where the "guts" of the code are (i.e. in invert()).
* Update and refactor the manpagesLaslo Hunhold2017-04-14
| | | | | | Make them more consistent, and only maintain a list of the conversion tools in farbfeld.5. Refine the wording on the jpg-manpages.
* Use the "row-major" term instead of "row-aligned"FRIGN2016-02-22
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* Move alpha-premultiplication information away from the FORMATFRIGN2016-01-31
| | | | | | and rather define it in the manual. In the end, it doesn't influence the data structure and thus is not part of the FORMAT-specification.
* Back to the roots.FRIGN2016-01-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Talking with even more people and weighing the benefits, I've made the decision to remove color spaces from farbfeld again (as it currently is handled in version 1) and recommend sRGB, not force it. Thing is the following: We are not ready yet for this step. Neither the people working with the images nor the hardware to display extended colors. Using greater colorspaces also removes the "hackability" of farbfeld. As it was previously possible to easily create gradients in plain C, you have to keep multiple things in mind with linear ProPhoto RGB. The first thing is that not all colors are "real", and there are imaginary colors. This doesn't happen with sRGB because all the colors it describes are "real". The second thing is the linear gamma curve, which makes the gradients look perceptually inconsistent. In the interest of creating a good and simple interchange format, we can't only weigh in points of professionals. This little excursion has shown that aiming for the 99% is still the way to go. And as often as you could repeat that sRGB will meet its fate in the future when screens become better, it is surprising how badly the industry has caught up to it. I also must honestly say that we can't solve the color space issue using RGB and should look at other formats to explore (CIELUV, CIELAB), which I will probably give a talk about at slcon3. Before releasing version 2, my aim is to make the I/O a bit more effective (as far as possible) so it's even easier to use. I know people will be pissed off, but fuck it, I'm the maintainer! Live with it.
* Mandate "ProPhoto RGB" color space for farbfeld and handle ICC profilesFRIGN2016-01-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I've literally been thinking about this for quite a while now. The initial motivation behind defaulting to sRGB was the idea that most data on the web was in sRGB anyway. However, my assumption was weakened in the sense that the development is clearly moving towards images with supplied ICC profiles and software slowly catching up to handle this. My tests have shown that more and more people even do that on the web, even though it's been a "tradition" that Photoshop users "Save for Web" and convert the gamut lossy into sRGB to bring a consistent color-"experience" even to those clients not supporting ICC profiles and which always assume sRGB. What made this decision so difficult is that converting to "ProPhoto RGB" requires some advanced knowledge on this topic, however, I came to the conclusion to implement it given the *2ff- and ff2*-tools handle it silently and well in the background, and given the little cms library is actually quite okay to use. When converting from ff to png, a proper "Pro Photo RGB" ICC V4-profile is automatically included in the exported png by ff2png. V4 is not as widespread as V2, but in the worst case (no V4 support somewhere) the colors will just be a little off. As an added bonus, any input files for png2ff which include ICC profiles are also correctly handled and the color space conversions are executed as expected. Accordingly, the FORMAT-specification has been changed. While at it, I added the note on alpha-multiplication. Now the format is very exact and shouldn't leave any ambiguities. jpeg supports ICC profiles as well, but I hadn't had the chance to look into it (not as trivial as PNG probably, help appreciated :)), so I'm always assuming sRGB here. Rationale --------- It is not obvious why one would go through the lenghts of supporting this big-gamut colorspace and not just stick with sRGB. In 99% of the cases, there's no reason to do that, but with even more extreme developments in the OLED-sector and other advances display hardware is slowly getting more powerful than sRGB, asking for color information which is suitable for the task and actually uses the full potential. The decision in this regard was not difficult in farbfeld because we always use 16-Bit anyway and won't have to fear posterization in a big- gamut color-space.
* Add short note on alpha-premultiplicationFRIGN2016-01-15
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* farbfeld.5: exit() -> returnFRIGN2016-01-05
| | | | | Now that we're in main, we don't need to exit(). Also, we should return 0 at the end, thanks Hiltjo!
* Update example in farbfeld.5FRIGN2016-01-05
| | | | | We were close to a full program anyway, so I just completed the code so you can study and run it easily.
* Fix bugs in farbfeld(5)-exampleFRIGN2016-01-05
| | | | | | | | 1) We forgot to write the header out again (no changes, but else the format would have obviously been broken) 2) The order of 'size' and 'count' was wrong in the fread- and fwrite- calls inside the loops, and the checks were failing. now this is fixed.
* Fix markup-error in farbfeld.5FRIGN2016-01-04
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* Add farbfeld(5) manpageFRIGN2016-01-04