I realize this doesn't have much to do with Inkscape but I figured this would be a good place to start.

I am having some REAL big problems coding SVG XML and having it being reproduced in Illustrator as I am expecting. Major problem right now is the feColorMatrix effect. I understand the effect and how the matrix changes the pixels but problem I am having is that when I specify 0.5 as the final output result on any of the color channel rows, Illustrator is not interpreting 0.5 as RGB 127, in other words, 50% the color value. It is more like 0.215 equates to 127 RGB decimal. Here is some code:



As you can see, the first filter retrieves the SourceAlpha which is all black. Then the color matrix takes that and does this on the first row of the matrix:

(a x red) + (b x green) + (c x blue) + (d x alpha) + e = final red output

plugging in the numbers:

(0 x 0) + (0 x 0) + (0 x 0) + (0 x 0) + 0.5 = 0.5

Should be 50% red! Or 127 RGB!!! I did the math and in Illy it is more like 0.215 = 127 = 50% ??????

Interesting problem. I found that Google Chrome's svg renderer has the same problem as you describe. Inkscape however seems to be producing the colors as expected. I just had to remove the feGaussianBlurr element from your filter to get the rest rendering correctly.

The color specifications seems to be an exponential curve. I plotted the output values when specifying .1, .15, .2, .25, etc. and looked at the corresponding RGB decimal value. For example, 0.215 is 127 and 0.5 is 187. Plotting the other decimals shows an exponential curve on a graph. This is very very fishy. Not only is this weird but specifying offset values for the feOffset effect is totally not right either. Am I crazy or is Adobe purposely skewing the values on things that are left up for interpretation in the SVG specifications? Didn't Adobe purchase or obtain EPS and drop it? Probably because it was too open source for them.

I am working out the exponential curve equation now and I'll post the equation when I have it.

Please let me know if there is any more information about this craziness.

Thank you.

Why do you suppose this is? Why is there some kind of color curve in Chrome and Illustrator? Where is the math so I can compensate?

Wow, I finally figured it out after 2 days, 2 sheets of graphing paper and 5 sheets of blank paper with both sides scribbled on. No thanks to ANYTHING or ANYONE on the internet. I couldn't find the solution anywhere.

And you're not going to share what you've discovered? Sounds like a good plan for some bad karma to me .

Sorry, I was going to share but I realized the math still doesn't add up.

I've tried everything. 0.003921568 gives RGB 0 but 0.003921569 gives RGB 13. It is impossible to even specify a value in between that range. Illustrator is wack and so is Chrome and there is no apparent reason why. AI sucks. I'm just going to duplicate the vector and offset that to make the shadow. That way I can control its color and alpha like normal using HEX. Thanks.

This has been answered at Stackoverflow: http://stackoverflow.com/questions/8214924/illustrator-svg-effects-coding-issues