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[Synfig-devl] [ synfig-Bugs-1801391 ] Color dialog and RGB composite values don't show same values
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From: SourceForge.net <no...@so...> - 2007-09-25 09:00:26
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Bugs item #1801391, was opened at 2007-09-24 19:56 Message generated for change (Comment added) made by dooglus You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=757416&aid=1801391&group_id=144022 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None Status: Open Resolution: None Priority: 3 Private: No Submitted By: Genete (genete) Assigned to: Nobody/Anonymous (nobody) Summary: Color dialog and RGB composite values don't show same values Initial Comment: The color dialog shows three sliders from 0 to 100. If I convert a Color parameter into its RGB components (composite) they don't show the same values. For example RGB = 0.5, 0.5, 0.5 in the color dialog then the composite RGB values gives RGB = 0.217638, 0.217638, 0.217638. Also the HTML code (I guess hexadecimal value for RGBA in a 00 -- FF range) correspond to the RGB values for the composited ones and not for the decimal numerical values of the color dialog. Reading about RGB in Wikipedia I see that there is a non linear correspondence between the diplayed color by the computer and the RGB values then there is a non linearity due to gamma correction. See: http://en.wikipedia.org/wiki/RGB_color_model#Nonlinearity But if it is in that way, it is confusing if you are using the composited values to fine tuning the color. Maybe it is not a bug, but it is confusing that color dialog and composited RGB values don't show the same values. Carlos ---------------------------------------------------------------------- >Comment By: dooglus (dooglus) Date: 2007-09-25 11:00 Message: Logged In: YES user_id=1546005 Originator: NO http://dooglus.rincevent.net/synfig/colors.png shows screen shots - the colors are darker with 'visually linear' enabled. And less linear? The left hand 40% looks black on my display in the 'linear' screen shot. ---------------------------------------------------------------------- Comment By: dooglus (dooglus) Date: 2007-09-25 10:58 Message: Logged In: YES user_id=1546005 Originator: NO Looking at the wikipedia article, isn't synfig backwards, making the colors even less linear than they were before? If asking a monitor for 0.5 really gives 0.22, then we should be asking for more than .5 when the user sets the color to 50 (out of 100) in linear mode, right? In Synfig's visually linear mode, if I ask for color 50,50,50, I get composites of 0.218, 0.218, 0.218, which my monitor will display as something like 0.1, 0.1, 0.1? ---------------------------------------------------------------------- Comment By: dooglus (dooglus) Date: 2007-09-25 09:41 Message: Logged In: YES user_id=1546005 Originator: NO I've looked at it, and I'm tending to think it's OK how it is, but that it needs documenting better. Maybe a FAQ entry will be enough for now. The color dialog shows color numbers between 0 and 100, and you have the option of having these be visually linear or not. If you convert colors into their composite parts, you see real numbers, between 0.0 and 1.0, which show the underlying representation. You could also split it into YUV and see a different set of components. As it stands, there's no way to use addition or scaling on the composite parts of a color to make it "twice as bright" (visually), since the arithmetic will be done on the non-visually-linear numbers. Leave the bug open for now I think, to remind that it needs thinking about? ---------------------------------------------------------------------- Comment By: Genete (genete) Date: 2007-09-25 07:13 Message: Logged In: YES user_id=1874777 Originator: YES Ah! I see. Sorry for boring you. Close it once you look at it ... tomorrow. ---------------------------------------------------------------------- Comment By: dooglus (dooglus) Date: 2007-09-25 02:19 Message: Logged In: YES user_id=1546005 Originator: NO If you don't want visually linear colors, uncheck file > setup > misc > visually linear colors. You're probably right about the composite display though - perhaps they should show the visually adjusted numbers as well if that feature (the default) is enabled. I'll look at it tomorrow. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=757416&aid=1801391&group_id=144022 |
