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The 8-bit color limitation issue is well-known and has been for a long time. The solution is GEGL (http://en.wikipedia.org/wiki/GEGL http://en.wikipedia.org/wik

by samdk 16y ago

The 8-bit color limitation issue is well-known and has been for a long time. The solution is GEGL (http://en.wikipedia.org/wiki/GEGL http://en.wikipedia.org/wiki/GEGL), which has been under development for a (very) long time now and is partially implemented in GIMP 2.6, the latest stable version. It is a problem, but it's important to put it into perspective: almost all monitors display 32-bit color (EDIT: or less) anyway, so if you're doing work targeted at a computer screen, it probably doesn't matter anyway. If you need to do work at color depths higher than 8 bits per pixel (that is, if you're doing serious print work) then yes, you need to be aware of these limitations. If you're almost everyone else it's probably not an issue. (I don't mean to imply that it's not a problem at all, but I think it's important to keep it in perspective.) For the people here asking whether GIMP is good enough for what you're doing: Ars Technica did an excellent review of GIMP 2.6 about a year ago (EDIT: 2 years, but it's still the same major version). It's long, but well-worth reading and will answer your questions. It's written from the perspective of a professional who uses Photoshop, but does an excellent job of remaining balanced. This quote summarizes the review (and also my opinion) pretty nicely, I think: I may seem to skew negative since I talk so much about what's missing, but it's hard to dwell on what a program does well and not sound like a fawning idiot. Most people who sit down to get image editing work done with GIMP will not be disappointed. There is a ton of room for advanced work here. It can be found here: http://arstechnica.com/open-source/reviews/2009/01/gimp-2-6-review.ars http://arstechnica.com/open-source/reviews/2009/01/gimp-2-6-... While I don't follow it closely enough to really discuss GIMP's current development status, development does seem to have slowed significantly (purely from a user's perspective) in recent years. This is a real shame, since I think that for the most part it's an excellent program and in general I much prefer to work in GIMP over Photoshop. For all of its many flaws, I think it's a fantastic piece of software.

w1ntermute 16y ago
> Ars Technica did an excellent review of GIMP 2.6 about a year ago. From the article, seems like it was 2 years ago: "Last updated January 13, 2009". Might seem like an insignificant detail, but 2 years is an eternity in OSS. Are you sure things haven't changed significantly since that review?
- samdk 16y ago
  Agh. Here's me still thinking it's still 2010. Yeah, unfortunately things really haven't changed since the review: we're still on the same major version (2.6) that we were when the review was published. (Hence the comment at the end about development seeming to have slowed a ton.)
  - nailer 16y ago
    Yes. I used GIMP exclusively between 1999 and about 2009. There was always something coming in the next version that would fix GIMP. Color profiling, single window, better text tools, etc. They never did. GIMP doesn't even bother subscribing to GNOME's HIG. It's cast adrift in the world of Linux, and after a decade of using it I'm now happily on Pixelmator on OS X.
    - unwind 16y ago
      As far as I know (and I've lurking on the gimp developer list for 10+ years), GIMP has never been a GNOME application. So, from that point of view, there's no particular reason to expect it to conform to GNOME's human-interface guidelines, is there?
      - mgkimsal 16y ago
        It uses the same crappy GTK file mgt widget design philosophy as GNOME. http://en.wikipedia.org/wiki/GTK%2B http://en.wikipedia.org/wiki/GTK%2B GTK is the GIMP toolkit, and GTK is run by the GNOME foundation. There's quite a bit of relationship between GTK/GIMP/GNOME, even if it may be mostly historical these days. I've always considered GIMP to be a GNOME app, and most people I know have.
        mgedmin 16y ago
        When the GNOME project was founded, they looked around for a widget toolkit, and found Gtk+, that was created for GIMP at that point.
      - 16y ago
juiceandjuice 16y ago
Actually most monitors are 18-24 bits. Tons of cheap TN panels are actually 6 bits with dithering to emulate a 24 bit panel. There are 10 bit and extended gamut panels, however.
bobds 16y ago
>> almost all monitors display 32-bit color anyway Actually, I was surprised to find out that this is not the case. "The inexpensive twisted nematic display is the most common consumer display type." "Also, most TN panels represent colors using only 6 bits per RGB color, or 18 bit in total, and are unable to display the 16.7 million color shades (24-bit truecolor) that are available from graphics cards." http://en.wikipedia.org/wiki/TFT_LCD#Twisted_nematic_.28TN.29 http://en.wikipedia.org/wiki/TFT_LCD#Twisted_nematic_.28TN.2...
- Groxx 16y ago
  Any idea how most modern CRTs handle color? I'm not seeing anything specific on Wikipedia's CRT page...
  - ondra 16y ago
    CRTs will show what the RAMDAC on the video card feeds them. They shouldn't have limitations like this.
julian37 16y ago
> so if you're doing work targeted at a computer screen, it probably doesn't matter anyway Actually, it matters regardless of output device. With higher bit depths, less rounding errors accumulate over time as the image is processed, for example when effects are applied, yielding higher overall output quality. Here is an example, although after many iterations quality loss can be much more dramatic than visible in that picture: http://www.photoshopessentials.com/essentials/16-bit/page-3.php http://www.photoshopessentials.com/essentials/16-bit/page-3....
- machrider 16y ago
  Yes. It matters a great deal if you're trying to recover information from underexposed or nearly overexposed regions of an image. Adjusting the levels of an image is something photographers do all the time, and having 14bits per channel allows you to do it without producing a grainy-as-hell image. Throwing away almost half of the information on the initial import is unforgivable and relegates GIMP to being merely a toy.
  - wazoox 16y ago
    Oh please stop the flame, this is ridiculous. Photoshop didn't support 16 bits before CS, in 2003. Did it prevent people to use it ? Would you say that all magazine covers were "child play" before then?
    - dagw 16y ago
      Not true. Photoshop has had support for 16 bits since at least version 3. What CS brought was full 16 bit support for all layer adjustments and painting features. Before that 16 bit was only supported by a subset of the available editing options.
      - davidw 16y ago
        Still though, the sniffy "merely a toy" is kind of over the top. Are automobiles merely toys because they don't have the range, passenger capacity and speed of a Boeing 747? How about motor scooters? And bicycles? The Gimp is not as good as Photoshop. Is it good enough for many uses? Sure.
damncabbage 16y ago
Even if you don't care about the GIMP/Photoshop comparison, make sure to check it out if you're a GIMP user. It has a bunch of little tips as to how to get photo and retouching done with GIMP; I've used GIMP for years now, but had never realised what Selective Gaussian Blur was really useful for. (These sorts of tutorials are very thin on the ground on the GIMP side, and this provides some real examples of how to more-or-less pull off the effects Photoshop tutorials tend to talk about.)
- pbhjpbhj 16y ago
  >never realised what Selective Gaussian Blur was really useful for This is probably the filter I use most - basically it smooths colours that are close positionally and colourwise to avoid graininess. A good way to clean up images quickly though it can look unnatural if done too much. I often use a little SGB and then a little Unsharp Mask when touching up images for low-res or online output. I'm not professionally trained but do use this for commercial purposes and have for some time.

by samdk 16y ago

w1ntermute 16y ago

> Ars Technica did an excellent review of GIMP 2.6 about a year ago. From the article, seems like it was 2 years ago: "Last updated January 13, 2009". Might seem like an insignificant detail, but 2 years is an eternity in OSS. Are you sure things haven't changed significantly since that review?

samdk 16y ago
Agh. Here's me still thinking it's still 2010. Yeah, unfortunately things really haven't changed since the review: we're still on the same major version (2.6) that we were when the review was published. (Hence the comment at the end about development seeming to have slowed a ton.)
- nailer 16y ago
  Yes. I used GIMP exclusively between 1999 and about 2009. There was always something coming in the next version that would fix GIMP. Color profiling, single window, better text tools, etc. They never did. GIMP doesn't even bother subscribing to GNOME's HIG. It's cast adrift in the world of Linux, and after a decade of using it I'm now happily on Pixelmator on OS X.
  - unwind 16y ago
    As far as I know (and I've lurking on the gimp developer list for 10+ years), GIMP has never been a GNOME application. So, from that point of view, there's no particular reason to expect it to conform to GNOME's human-interface guidelines, is there?
    - mgkimsal 16y ago
      It uses the same crappy GTK file mgt widget design philosophy as GNOME. http://en.wikipedia.org/wiki/GTK%2B http://en.wikipedia.org/wiki/GTK%2B GTK is the GIMP toolkit, and GTK is run by the GNOME foundation. There's quite a bit of relationship between GTK/GIMP/GNOME, even if it may be mostly historical these days. I've always considered GIMP to be a GNOME app, and most people I know have.
      - mgedmin 16y ago
        When the GNOME project was founded, they looked around for a widget toolkit, and found Gtk+, that was created for GIMP at that point.
    - 16y ago

juiceandjuice 16y ago

Actually most monitors are 18-24 bits. Tons of cheap TN panels are actually 6 bits with dithering to emulate a 24 bit panel. There are 10 bit and extended gamut panels, however.

bobds 16y ago

>> almost all monitors display 32-bit color anyway Actually, I was surprised to find out that this is not the case. "The inexpensive twisted nematic display is the most common consumer display type." "Also, most TN panels represent colors using only 6 bits per RGB color, or 18 bit in total, and are unable to display the 16.7 million color shades (24-bit truecolor) that are available from graphics cards." http://en.wikipedia.org/wiki/TFT_LCD#Twisted_nematic_.28TN.29 http://en.wikipedia.org/wiki/TFT_LCD#Twisted_nematic_.28TN.2...

Groxx 16y ago
Any idea how most modern CRTs handle color? I'm not seeing anything specific on Wikipedia's CRT page...
- ondra 16y ago
  CRTs will show what the RAMDAC on the video card feeds them. They shouldn't have limitations like this.

julian37 16y ago

> so if you're doing work targeted at a computer screen, it probably doesn't matter anyway Actually, it matters regardless of output device. With higher bit depths, less rounding errors accumulate over time as the image is processed, for example when effects are applied, yielding higher overall output quality. Here is an example, although after many iterations quality loss can be much more dramatic than visible in that picture: http://www.photoshopessentials.com/essentials/16-bit/page-3.php http://www.photoshopessentials.com/essentials/16-bit/page-3....

machrider 16y ago
Yes. It matters a great deal if you're trying to recover information from underexposed or nearly overexposed regions of an image. Adjusting the levels of an image is something photographers do all the time, and having 14bits per channel allows you to do it without producing a grainy-as-hell image. Throwing away almost half of the information on the initial import is unforgivable and relegates GIMP to being merely a toy.
- wazoox 16y ago
  Oh please stop the flame, this is ridiculous. Photoshop didn't support 16 bits before CS, in 2003. Did it prevent people to use it ? Would you say that all magazine covers were "child play" before then?
  - dagw 16y ago
    Not true. Photoshop has had support for 16 bits since at least version 3. What CS brought was full 16 bit support for all layer adjustments and painting features. Before that 16 bit was only supported by a subset of the available editing options.
    - davidw 16y ago
      Still though, the sniffy "merely a toy" is kind of over the top. Are automobiles merely toys because they don't have the range, passenger capacity and speed of a Boeing 747? How about motor scooters? And bicycles? The Gimp is not as good as Photoshop. Is it good enough for many uses? Sure.

damncabbage 16y ago

Even if you don't care about the GIMP/Photoshop comparison, make sure to check it out if you're a GIMP user. It has a bunch of little tips as to how to get photo and retouching done with GIMP; I've used GIMP for years now, but had never realised what Selective Gaussian Blur was really useful for. (These sorts of tutorials are very thin on the ground on the GIMP side, and this provides some real examples of how to more-or-less pull off the effects Photoshop tutorials tend to talk about.)

pbhjpbhj 16y ago
>never realised what Selective Gaussian Blur was really useful for This is probably the filter I use most - basically it smooths colours that are close positionally and colourwise to avoid graininess. A good way to clean up images quickly though it can look unnatural if done too much. I often use a little SGB and then a little Unsharp Mask when touching up images for low-res or online output. I'm not professionally trained but do use this for commercial purposes and have for some time.