Range-Limited Scaling Issues.

I haven't tested every single module, but blur for sure, does not scale properly below a certain setting. Has anyone/everyone else had problems with range limiting controls and realizing that the scaling is completely out the window below 100ths of a unit ? Or, is this just a problem with the preview area, and if so, is that a known problem and on the fix-it-like-months-ago-already list ?

jffe

Added : It occured to me that "scaling" is really only part of the issue, and might not be the best term to use when referring to my problem. I use a lot of range limiting in filters, and range limiting blur, then dropping the value below 1/10th of a blur unit, and the scaling then, is not correct to my eyes. Not correct meaning ? In the preview area, it literally seems to go back and forth, and sometimes just not change at all. You can duplicate the problem, by range-limiting a blur to 0.01, then setting it for 0.01 out in the presets area, then move it up to 0.1, I see no change usually, or try 0.05 it looks as blurry as if I had set it for 1.0 and that doesn't make any sense to me scale-wise. If it just has an absolute lower limit of 0.01, then why is it possible to set it lower in theory ? I dunno, try it out, and let me know if it's just me, or if you see the lack of change too.

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Vladimir Golovin wrote: However, due to technical reasons the actual blur radius cannot be lower than one pixel. In such cases, FF produces the resulting image by interpolating between the original unblurred picture and 1-pixel blur.

Seems logical. Maybe that should also go into the help file?

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Vladimir Golovin wrote: Radius is measured as a percentage of the global parameter Size. For example, if Size is set to 600 pixels, and Radius is set to 10, the actual blur radius will be 60 pixels.

----Well, that's not the kind of scaling I meant, but it might explain what I was seeing. I never changed the Size, pixels, I just range limited the blur to the lowest possible setting (0.01) internally, then lowered it below 1.0 on the slider control, and it wasn't behaving as I would've expected to see. Setting both internal and external amounts of blur to 0.01 shows what looks like about (a non changable) 0.01 does. So I guess I'm wondering if that is the absolute lowest amount of blur you can give something (0.01), and if so, why it can be set to lower when it doesn't actually scale down any lower. Hopefully that makes my question clearer. Thanks.

jffe

Thanks crapa, that could very well explain why I was unable to see it at 600 X 600. If FF can confirm that, then I'll consider this one answered, and poor crapa gets to write another wiki entry (he needs a raise soon ha-ha).

jffe

Update: Everything I wrote above on interpolation is incorrect.

I checked the actual code, and the situation is as follows:

All blur-based components use actual sub-pixel blur radius. Since the kernel coverage area (radius*2) cannot be lower than 1 pixel, the Radius of 0 corresponds to the actual coverage (or diameter) of 1 pixel.