Gimp: How to test gamut and correct when out of gamut

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Gimp: How to test gamut and correct when out of gamut

I was using the mosaic filter to make a paper using the exact colors in my palette. However, it threw in another color that I think may be a gradient. However, this particular filter didn't give me the option of adjusting the hue. I asked about it in another forum, and I was told the color was out of gamut. How can I test the gamut in Gimp? What do I need to do to correct the problem when it's the result of a filter short of scrapping the whole thing? Any advice would be greatly appreciated. Thanks!

Kathryn .... links for gamut with gimp

http://ninedegreesbelow.com/photography/conversion-intent-settings.html
scroll down for gimp

http://tinyurl.com/o7sd9v6
a book preview with information ... takes a bit to load because it's huge

http://tinyurl.com/pvllo6m
another book preview

I don't use gimp so haven't actually read the information and there are other links on the site which may lead you to help with gimp

Thank you Susan

Thank you so much, Susan! I've been searching and haven't yet found anything, so these will be a great help!

Joining this thread. smiley

has anyone had any luck activating this G check?

btw, thanks for the links, Susan!

2 of them didn't reveal anything i didn't already know- where to find those settings, how to change the alert color... but i can't activate the checker

and the 1st link - is soooo detailed and the instructions soooo complicated... i don't have a printer and can't work out how to type in specifications for a printer & my monitor ICC... i even installed some AdobeCMYK Colors but it didn't do the trick... and even if i entered all the paramaters, i'd still have to do it all over again for every single item i wanted to check... sooo many boxes to click...

is this really happening? can it really not be done?! i'd like to know i did everything possible, before spending a fortune on PS

Paddy, I'm in the same boat. I've found all the settings and changed the color alert, but I cannot get the checker activated. I also installed some CMYK colors to see if that would activate the checker but it didn't work. I haven't had the time to really look at the first link Susan gave because it is so detailed, but I hope to soon. I really need to get this checker to work, because I have a LINUX operating system and I don't think PS will work on my system. Besides the fact, that I don't want to have to pay for PS smiley

thanks for sharing your pain, Kathryn, i was begining to feel like a fool thinking i'm the only one that doesn't get it smiley and i so understand you! i saw some settings "display/ monitor" & "color management" in ControlPanel, so maybe a solution lies in there...somewhere... smiley

"gimp is dead!
long live the gimp!"

smiley

Hey ladies, I've been super busy lately, but I think I might have some time to look at this issue. Would either of you mind sharing a file that you have so I can see exactly what your talking about?
I've not checked on my system yet, just reading through the forum. (Also wondering if there is a way that we could set a favorite word to be notified of new threads for GIMP?)

Thanks Laura, that would be a big help if you could tell me what I need to do. I have a mosaic page I was doing for the April blog train, but it didn't look right. When I asked for feedback, France told me the yellow was out of gamut. However, I cannot get my Gimp program to alert me when something is out of gamut. Here is the file. Any help you could give me would be very appreciated.

Kathryn, I know older versions of Photoshop (7.0 on up to at least CS4) worked under WINE. Not sure if the cloud-based version does, but I know I used the older ones with WINE. Actually, I'm gonna check WineHQ.

It's a mixed bag. If you get any version, you want CS2, CS6 or CC (and CC is the newest cloud-based version, $10 or $20/mo if you just want access to Photoshop and Lightroom rather than the whole suite). Those are all rated Gold under WINE. Other versions range from uninstallable to variously limited support. The info's here: https://appdb.winehq.org/objectManager.php?sClass=application&iId=17

I'm not sure how to check gamut in GIMP, though, sorry. smiley

Thanks, Holly, I may have to check into that. I'm really happy with GIMP, though, if I can just figure out how to check gamut!

Laura, at this time you can only go to the software specific section and view what is new to the different threads. All of the Gimp threads have Gimp in the title, so it should be easy to see the thread.

Okay, I've found a few things, but may not have a chance to do anything more for a while.

Being Out of Gamut Tutorial - a good description of the issue, though not specific for GIMP.

How to Change RGB to CMYK in Photoshop - more reading at Karen Diamond Designs site.

I then found this page How to convert image to CMYK in GIMP? which talks of Separate+ plugin but it's pretty old, not as old as some, but still before the latest GIMP Update I think.

How to … more at the GIMP Registry forums.
including Colors → Components → Decompose....and select select CMYK for “Color model”. But I'm not sure then how to make the change back to RGB. I tried it a couple of different ways, including selecting layers.

Seems like I found a GIMP Tutorial that told a way to set up the system so that it didn't even try to use colors that would be out of gamut. I may have upgraded my GIMP since then, so I'm not sure...but my Color Management has Display rendering intent set to Perceptual as well as Softproof Rendering intent...and I picked a bold color I don't usually use to "Mark out of gamut colors."

Since I probably won't have more time till late next month, I thought I'd post what I've found so far.

Also in looking around in GIMP, I found a feature that I'd like to read up on...Colors > Map and the features contained there in.

I originally saw this posted in another thread and it might help some of you. There is a free download version of PS CS2 from the adobe website. You can get the info here: http://www.redmondpie.com/download-adobe-photoshop-cs2-for-free-legally-while-you-still-can/

It's definitely not the latest & greatest version but if you wanted something just for some added tools in QC'g your products, it may help. From there, it's super easy to remedy anything that's out of gamut. smiley

@Amanda, thanks for the link, I'll have to check it out.

@Laura, Thanks so much for the links, unfortunately they won't really help me because they are geared for Windows systems and I have a LINUX system. However, I did discover that if I go into Mode and Index my colors according to the palette, then it corrected any gamut issues I had. This will work great for palettes that have been given, such as blog train palettes. Unfortunately, that is not going to be much help in determining if a palette I'm compiling is in gamut smiley

Kathryn, CS2 is one of the Photoshop versions which will work basically flawlessly under WINE, which creates a Windows virtual machine on a Linux box so you can run Windows-only programs on it. It's around a decade old, but it'll still do 85% of what the most current CC version does, just with slightly older versions of the algorithms. It'll definitely help you check gamut, if you want to try it. I used to use Photoshop CS2 under WINE on Ubuntu 10.10 with no issues, though I was using it to do photography editing rather than designing scrap stuff.

Find out about WINE at https://www.winehq.org/--maybe it'll give you some extra options.

Thanks, Holly, I'm familiar with WINE. I'll definitely check out CS2. (It might be nice to have a PS that I can use some of my files with...I haven't been able to find any way to convert style sheets into GIMP smiley ) I'm currently using Ubuntu 14.04, so I'll see if it will work in WINE.

Amanda, thanks for that link. I'd seen it quite awhile back (before getting PSE), but thought it was no longer good. I'm downloading it now - hope it works! If it does, I may put it on my Mac at home and it will be great to check for gamut since that's the bane of my existence right now lol.

-Lisa

Best of luck on it, Kathryn--I'm upgrading my computer in early May (ordering parts on the 1st--so excited at not having to put these off any longer!!) and will probably be setting up a dual-boot system with Ubuntu again myself once the parts arrive.

I appreciated and bookmarked this thread because I've worked primarily in Gimp with occasional help from Paintshop Pro, and never even knew gamut existed before finding this forum, but could tell right away it was the source of some of the problems I run into now and then!

I just upgraded to the newest version of Gimp and they've addressed the gamut issue: https://www.gimp.org/release-notes/gimp-2.10.html

"Color dialogs now have an LCH color selector you can use instead of HSV. The LCH selector also displays out-of-gamut warning."

I have no idea whether they've addressed it well, but thought I'd pass it along smiley