[Gimp-print-devel] Another dark tint improvement

[Thomas T. <tt...@bi...>]

I believe I found the cause of the wedge problem: the value of bk gets
too high. The extra if in the following snippet makes the wedge look
beautiful. Photos come out very nicely as well, both in ordered dither
(199*199 matrix) and Floyd-Steinberg. Still using 0.1 and 0.699 for
dither_set_black_lower and -_upper, respectively.

	  if (bk > 0)
	    {
	      if ( bk >= 32000 )
	        bk = 32000;
	      bk = bk * bk / 65536;
	      c -= (d->k_clevel * bk) /128;
	      m -= (d->k_mlevel * bk) /128;
	      y -= (d->k_ylevel * bk) /128;


I'm wondering if we cannot make processing more efficient by changing
the:

if (black != NULL)

near the beginning of the main loop in

if ((black != NULL) & (k != 0))

This would skip the black generating process for bright colors and
white.


I'll put the latest patched version in print/Matgen. I'm not too happy
about the 32000 limit for bk above, but it works. 64K did have some
effect, but not enough.


Thomas