Re: [Gimp-developer] gimp.org tutorials

[Elle Stone <ellestone ninedegreesbelow com>]

On 09/24/2015 03:42 PM, Pat David wrote:
> All,
>
> I am still trudging through the list of tutorials from the old site and
> (slowly) migrating them one at a time to the new infrastructure.

That's a hugely impressive amount of hard work you've been doing.

> I've noticed a couple of things, though.  Many of these tutorials are a)
> copyrighted without notice of a more permissive licensing, and b) really
> out of date.

> So the question is, what should I do with them?  My first inclination is to
> keep them and migrate them, but possibly to not link to them any longer?
> This way the URI is consistent and stil working, but the pages won't be
> reachable except through their direct url.

This seems like a good option. Dead links make a website look bad, and 
someone who reaches such a link won't know why the article is missing.

If this route is taken, it might be nice to put links to updated/more 
accurate articles at the top (if available), along with an explanation 
of why the tutorial was "retired" (copyright, out of date, wrong 
information, etc).

> Another option is to simply not migrate some of them, given their copyright
> limitations.
>
> I am slowly trying to replace older tutorials with new ones that will be
> free of the copyright issues, but it's slower going than moving the
> website. :)
>
> Also, I've included the complete list of tutorials, in case anyone wants to
> point out some that we definitely won't need or care about migrating.

"Out of date" and "restrictrive or unclear copyrights" are two serious 
issues, it seems to me. Another issue is "technically incorrect 
information".

> http://www.gimp.org/tutorials/Color2BW/index.html
> 
http://www.gimp.org/tutorials/Digital_Black_and_White_Conversion/index.html

The above two articles contain technically incorrect information. In 
particular, the described procedures for converting from LAB Lightness 
to black and white produce an image with tonality that doesn't have 
anything whatsoever to do with the tonality of the LAB Lightness channel 
of the original color image 
(http://ninedegreesbelow.com/photography/lab-lightness-to-black-and-white-gimp28.html).

Similar comments apply to the articles' respective discussions of 
obtaining Luminance/Luminosity using GIMP 2.8.

Part of the problem is from limitations imposed by GIMP 2.8's 8-bit 
integer processing, which makes it impossible to obtain RGB Luminance 
and LAB Lightness wihtout also posterizing the RGB data. And any mention 
of "technically" or "mathematically" incorrect shouldn't be read to 
imply "aesthetically wrong".

It would be nice if officially hosted GIMP tutorials could be modified 
to include notes about "technically correct" vs "what can actually be 
done using GIMP 2.8".

Best,
Elle