On Thu, Oct 9, 2008 at 1:43 PM, Alexandre Prokoudine
> On Mon, Oct 6, 2008 at 9:13 AM, Stephen DeLear wrote:
>> operation_class->name        = "sdv-unsharp-mask";
>> and leave the standard unsharp mask.
>> The current unsharp mask uses radius, amount and threashold. The new one
>> uses scale and standard deviation.  The function it is performing an unsharp
>> mask but it's done the equivalent of going from Farenhight to Kelvin without
>> telling anyone.  This results in somebody using one image editor not being
>> able to spec actions for somebody using a different editor.  This can be a
>> big deal where multiple photographers are trying to produce a consistent
>> output (for example a primary and secondary shooter at a wedding).
> Ah, I see what you mean. That's a question to author of the GEGL op then.

The names of properties of GEGL operations are as far as I am
concerned API, when creating a user interface in a photo manipulation
application like GIMP, f-spot or other applications on top it would be
the responsibility of the programmer to map the scientific terms used
to describe the properties to sliders that maybe uses terms more
useful to a casual non expert image processing person. Using the
standard deviation instead of an approximate radius of the gaussian
blur is much more mathematically correct and is also the way the SVG
1.2 filter specification specifies the parameters for a gaussian blur.

/Øyvind K.
«The future is already here. It's just not very evenly distributed»
                                                 -- William Gibson
http://pippin.gimp.org/                            http://ffii.org/
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