Photoprocessing - Brightness and Unsharp Mask
Wilhelm Sanke
sanke at hrz.uni-kassel.de
Thu Jun 1 16:14:32 EDT 2006
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.
Regards,
Wilhelm Sanke
<http://www.sanke.org/MetaMedia>
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