Photoprocessing - Brightness and Unsharp Mask
katir at hindu.org
Sat Jun 3 06:19:02 CDT 2006
You people all amaze me... are there no limits? (smile)
Question (duh type): are these filters limited to image data that is
an exact square? (implied by "3X3" "7X7")
Or, would a "filter" that supports 7 X 7 also handle an image that
was, for example, 345 pixels wide and 500 pixels tall? I assume the
answer is yes, but wanted to check.
This is a fairly standard size for me, so 3 X 3 is too small. I'm not
too concerned about a slow speed, as there are contexts where Adobe
tools just are not available. One would just start a batch process
and switch to other tasks and come back...
it would be interesting if this whole thing could run without a GUI
on a web server as a faceless processor.... that could have major
implications for web apps where users upload source images, the rev
processor goes to work and the CGI incorporates downsized images back
to some web pages or image repository directory ... I would
certainly put this to use almost immediately. Quality is the big
issue for some potential uses, not for others.
But there we go again asking for the cheese in the moon: linux
versions needed -- Fedora Core 3 is the OS on our new web server ....
I doubt if Adobe offers 8FB filters that would run on Linux....
On Jun 01, 2006, at 10:14 AM, Wilhelm Sanke wrote:
> Just found out where to place the "Bias" or "Shift" factor - an
> additional color value needed especially for relief-type filters -
> in Chipp's *no-external* script.
> Unfortunately, adding this factor in the script that uses the DLL
> is not possible (it will will produce deviating results) as the
> factor has to be processed *inside* the equation for producing the
> new color values, meaning the bias factor cannot be added to the
> imagedata *after* the DLL has been used.
> Execution time for the new no-external script (in my modified
> version of Chipp's paradigmatic original - that takes care of the
> yellow-color shift and substitutes the use of arrays by direct
> addressing of imagedata, which in this case leads to a considerable
> speed gain) is about 10 seconds on a WindowsXP computer with 2
> GHz. This is of course very much slower than with a DLL or
> equivalent external for MacOS, but at any rate it may serve as an
> interim solution for the use of matrix filters with a size of 3 X 3
> inside Metacard/Revolution.
> The results of the use of 3 X 3-matrix filters with the new script
> in Revolution are absolutely identical to the use of equivalent
> filters in Photoshop and PaintPaint Pro. I tested this with a
> number of filters in all three applications.
> Probably next week I will upload an new version of my
> "ImageFilterDemo" stack containing the new script and a number of
> additional useful filters.-
> I repeat my requests - meanwhile supported by Richard Gaskin and
> probably others - for a DLL (and equivalent external on MacOS) for
> the use of 7 X 7-matrix filters - which of course include smaller
> settings like 3 X 3 filters - inside Revolution and the extra
> option for the use of Photoshop-compatible filters of the "8FB" type.
> Wilhelm Sanke
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