Re: still the same bug

[Geert Jordaens <geert.jordaens@xxxxxxxxxx>]

I once wrote a path for it, this included the possibility of disabling the histogram correction (by setting the values out of range).
It seems that a more recent patch reversed this option.
Probably the out of range option was not the best way of implementing it, however the function does make sense
for line-art and B&W photo's see bug #72862.

Revision 16861 - (view) (annotate) - [select for diffs]

2005-03-11  Sven Neumann  <sven@xxxxxxxx>

	* plug-ins/common/despeckle.c: test intensity against white and
	black level, not only the red channel. Improved border behavior.
	Iterate over the pixels row-by-row, instead of jumping through the
	data column-wise.

...

Revision 15374 -
2004-10-30  Sven Neumann  <sven@xxxxxxxx>

	* plug-ins/common/despeckle.c: applied a patch from Geert Jordaens
	that improves the Despeckle algorithm. See bug #72862.

Right now I don't have the tme to followup a bug report or create a complete patch.

          for (v = ymin; v < ymax; v++)
            {
              gint off2 = v * width * bpp;

              for (u = xmin, off2 += xmin * bpp; u < xmax; u++, off2 += bpp)
                {
                  guchar value = pixel_luminance (src + off2, bpp);

/*                if (value < black_level) Allow no histogram correction on line art or b&w*/
                  if (value < black_level && filter_type & FILTER_ADAPTIVE)
                    {
                      hist0++;
                    }

/*                else if (value > white_level) Allow no histogram correction on line art or b&w*/
                  else if (value > white_level && filter_type & FILTER_ADAPTIVE)
                    {
                      hist255++;
                    }
                  else
                    {
                      buf[count]  = src + off2;
                      ibuf[count] = value;
                      count++;
                    }
                }
            }



Geert Jordaens

Luis A. Florit wrote:

Pals,

    I reported this bug in this list some time ago, and got no
answer (I think), and the 2.3.16 version still has the same bug:
The despeckle plugin shifts the image one pixel to the right,
and one to the bottom. Consequently, it is essentially useless.
If you draw in the middle of a white background a black cross
like this:

 x
xxx
 x

and run the despeckle plugin with radius 1, you get this asymmetric
output:

 x
xxx
 xx

    Thanks,

        Luis.

_______________________________________________
Gimp-developer mailing list
Gimp-developer@xxxxxxxxxxxxxxxxxxxxxx
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


  

_______________________________________________
Gimp-developer mailing list
Gimp-developer@xxxxxxxxxxxxxxxxxxxxxx
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer