Comment # 20 on bug 1206322 from Petr Gajdos

(In reply to Dominique Leuenberger from comment #3)
> (In reply to Petr Gajdos from comment #2)
> > Let's try to remove GraphicsMagick again: bug 1206322
> 
> That's ambitious:

Yes, it was ambitious, even if I think only five packages really BuildRequires
it: inkscape, scribus, octave, wt and pdf2djvu and requirements are optional in
all of them. I think it is doable, but I am not sure how much time would this
require in case we want to keep all the functionality [bug 1206322 comment 20].

(In reply to Dirk Weber from comment #19)
> $ gm compare -metric PAE ./85-1_tw.png montage1.png
> Image Difference (PeakAbsoluteError):
>            Normalized    Absolute
>           ============  ==========
>      Red: 0.2149691005    14088.0
>    Green: 0.1889066911    12380.0
>     Blue: 0.1703669795    11165.0
>    Total: 0.2149691005    14088.0
> $ gm compare -metric PAE ./86-1_tw.png montage2.png
> Image Difference (PeakAbsoluteError):
>            Normalized    Absolute
>           ============  ==========
>      Red: 0.1409323262     9236.0
>    Green: 0.1148699168     7528.0
>     Blue: 0.0963302052     6313.0
>    Total: 0.1409323262     9236.0
> 
> ImageMagick-7.1.0.55-1.1.i586
> GraphicsMagick-1.3.38-1.6.i586
> 
> I am afraid I can not judge these results. 
> I do not know whether these are precise operations which always have to 
> give the same results or whether they are fuzzy operations and the result 
> can e.g. depend on the used floating point unit,
> like x87 or SSE2, and it is normal to have a deviation when an image
> "montaged" on one type
> of fp-unit is compared to one "montaged" on another type of fp-unit even
> when both are actually valid results.

Thank you Dirk for your evaluation.

I really do not think testing ImageMagick with GraphicsMagick and vice versa is
a good idea; the problem, if any at all (reading previous comments), can be in
either of them and I am almost convinced who will have to tackle these
potential issues down. But ok, I understand you guys want me to have a nice
hackweek, right ;)?