RSS/Atom feed Twitter
Site is read-only, email is disabled
  1. Chat
  2. Useful links
  3. Polls

Featured content

How do I restrict GIMP's palette to 16 - 235?

This discussion is connected to the gimp-user-list.gnome.org mailing list which is provided by the GIMP developers and not related to gimpusers.com.

This is a read-only list on gimpusers.com so this discussion thread is read-only, too.

2 of 2 messages available
Toggle history

Please log in to manage your subscriptions.
How do I restrict GIMP's palette to 16 - 235? DJ 17 May 03:57
  How do I restrict GIMP's palette to 16 - 235? saulgoode@flashingtwelve.brickfilms.com 17 May 06:19
DJ
2007-05-17 03:57:45 UTC (over 17 years ago)

How do I restrict GIMP's palette to 16 - 235?

Hi,

I am creating a menu for a DVD. How do I restrict GIMP's palette to 16 - 235, as mentioned in the reference at the link below?

[ref: http://people.csail.mit.edu/tbuehler/video/titles.html]

Just thought I'd mention there is a GIMP script to aid in the creation of buttons and xml required by dvdauthor.

[ref: http://registry.gimp.org/plugin?id=4609]

And good sites on fixing up old photos with GIMP? Most of the photos are black and white. I've googled, but nothing really stands out, and was wondering if any GIMP user has come across a site that has helped them in a similar process and learning curve.

Mostly, I am doing Layers -> Color -> Levels, and clicking Auto. Or, adding a Duplicate layer and changing the Mode to Multiply. I tug, pull, and click the sliders and buttons on the Color's Levels tool, as well as the Curves tool, but I'd like to have more of an understanding of taking an old photo from point A to point B.

Last, any suggestions, or gotcha's, when using GIMP to "cleanup" photos' for dvd-slideshow?

A good trick, from reading the archives, is to save your work in XCF and use ImageMagick to convert from XCF to JPG.

Thank you.

saulgoode@flashingtwelve.brickfilms.com
2007-05-17 06:19:47 UTC (over 17 years ago)

How do I restrict GIMP's palette to 16 - 235?

Quoting DJ :

I am creating a menu for a DVD. How do I restrict GIMP's palette to 16 - 235, as mentioned in the reference at the link below?

[ref: http://people.csail.mit.edu/tbuehler/video/titles.html]

Your first option is to scale the range of output colors so they fit within the range 16-235. This can be accomplished using the "Levels" tool and setting the output range of each of the three color channels to have a lower limit of 16 and an upper limit of 235 (I would recommend saving these settings so you don't need to re-enter them each time). This will result in some degree of color shift for all pixels.

You might prefer to just clip any colors which are outside the NTSC-recommended range so that they fall within the 16-235 range. This can be accomplished by creating two new layers above your original -- one of the layers should be filled with "NTSC black" (HTML=0x101010) and set to "Lighten only" mode; the other layer should be filled with "NTSC white" (HTML=0xebebeb) and set to "Darken only" mode.

Another alternative would be to provide some "smooth" color adjustment (using the Curves tool, again with the channels handled separately) which would provide something of a compromise between the previous two options - retaining much of the pre-existing NTSC-safe colors but still exhibiting some contrast variation for the unsafe one.