On Wed, Nov 21, 2012 at 7:29 AM, Matt Feifarek <[email protected]> wrote:
> On Mon, Nov 19, 2012 at 3:13 PM, johannes hanika <[email protected]> wrote:
>>
>> - use the bilateral filter denoise module, set the rgb sliders to
>> something proportional to your whitebalance coefficients, and radius
>> to something like 7-10 (7.5 and rgb = 1.5 * wb coeff yielded the best
>> results for a 5dm2 iso3200 iirc). you can also try to go a little
>> lower with the green (as it has two pixels in the bayer pattern).
>
>
> Wow! That's excellent results. Bilateral filter denoise seems to work very
> well, but is unfortunately very slow (and somewhat crashy in 1.1). But I'm
> excited to get some guidance on how to use this module other than trial and
> error.
>
> A few questions, if I may:
>
> First, "whitebalance coefficients": Dt's gui has rgb, in the case of my
> sample image, at rgb(1.930, 1.000, 1.820). Within the denoise module, I have
> r,g,b sliders, who are by default at 0.005, each with a tooltip of "how much
> to blur red" etc. The maximum range of each of these sliders is to .1000.
> (What are those units? pixels? factors?)
that's range sigma. this bilateral filter is a 5d gaussian blur with 5
standard deviations sigma_x, sigma_y (spatial sigmas) and the range
sigmas sigma_{r,g,b}. the first two we keep in sync, so that's only
exposed as a single radius. so the first two units are pixels, the
other three are color differences in linear camera raw rgb.
> So if I do as you suggest, 1.5* wb coeff, I get values WAY too large for the
> range of 0-0.1. So I don't understand your instruction.
ah, sorry. i was off by a factor of 1000 or so. the important bit is the ratio.
> Third, "a little lower with the green"... a little lower what? multiplier?
> noise blur? wb coefficient?
with the green slider in the bilateral denoise module.
-jo
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