GNOME Bugzilla – Bug 161573
Newsprint line spot function malfunctionining
Last modified: 2005-06-21 22:13:47 UTC
Create a new image, fill it with white to black blend so that Newsprint has something to do. Run filters->distorts->newsprint Choose "line" as the spot function for any color. it all goes fine up to here. change the cell size (bigger values make it easier to spot the malfunctioning) The problem can be seen in the preview now. If the filter is applied it spoils the image. However, if you apply undo, and rerun the filter with the same parameters it works fine. I do not remember this bug earlier - I suppose it has been the ading of the preview that triggered it.
I can reproduce this.
I can see absolutely no difference in the output after running interactively and with last_vals.
More detailed recipe: 1) Start GIMP. 2) Create new image in default size. 3) Fill image with black-white gradient from left to right. 4) Start "Newsprint" 5) Change spot function for Red from Round to Line. 6) Increase Cell size from 10 to 15. (You now see the problem.) 7) Press OK. 8) Undo 9) Do "Repeat Newsprint". (You now see what it ought to look like.) The key thing is changing the cell size.
Turns out that the code included some "optimizations" that went badly wrong when the newsprint() function is executed more than once (as in previewing). Fixed in both branches. 2005-06-21 Bill Skaggs <weskaggs@primate.ucdavis.edu> * plug-ins/common/newsprint.c: remove "optimization" that interacts badly with preview; fixes bug #161573.