Tuesday, December 10, 2013

Color Film Emulation Added to GIMP!

The now very famous Open Source (free!) GNU Image Manipulation Program (GIMP) has just received a major boost with the addition of color film emulation! It has had B&W film emulation for a number of years, but thanks to GIMP's spin-off project called G'MIC, which appears as a hugely functional plug-in within GIMP, it now performs Color Film Emulation in much the same way as DxO Lab's "FilmPack" product range - that is, it'll take any 8-bit JPEG image file and make it look like specific brands / types of film.

DxO Labs is one step ahead of GIMP, in theory at least, because it has built the very same Film Emulation product into it's super fantastic Raw Data file converter - Optics Pro Ver.9. This means that you can select your film emulation within the Raw File conversion process, which should be much better than either of FilmPack or GIMP's new capabilities, which relies on having a JPEG file already converted, as it will not work with Raw Data. But is it really better? I'll let you decide as best as you can from several conversions I made of this one rather bad picture (I want you to look at the image quality over and above my own so-called artistry). The very first one is or reference - it is a DxO Raw File conversion based solely on my camera body, not FilmPack. As such, it may be the best looking one of the bunch. But the real idea here is to compare how well GIMP's execution of Film Emulation works on an already converted 8-bit JPEG, up against DxO Lab's more direct application of Film Emulation to the Raw File itself.

RAW, Direct Conversion With DxO Optics Pro, Generic - this is the Reference JPEG
RAW, Direct Conversion With DxO Optics Pro, Agfa Vista 200
Reference JPEG, GMIC-GIMP Agfa Vista 200
RAW, Direct Conversion With DxO Optics Pro, Fuji Superia 200
Reference JPEG, GMIC-GIMP Fuji Superia 200
RAW, Direct Conversion With DxO Optics Pro, Kodachrome-64
Reference JPEG, GMIC GIMP Kodachrome 64
RAW, Direct Conversion With DxO Optics Pro, Kodak Ektachrome 100
Reference JPEG, GMIC-GIMP Kodak Ektachrome 100
RAW, Direct Conversion With DxO Optics Pro, Kodak T-Max 100
Reference JPEG, GMIC-GIMP Kodak T-Max 100
RAW, Direct Conversion With DxO Optics Pro, Rollei Ortho 25
Reference JPEG, GMIC-GIMP, Rollei Ortho 25


To my eyes, the similarities are remarkable. The same challenge of Film Emulation is executed here within two totally different products - one you pay a lot for, the other one is free, yet, the overall look of the simulated film types is remarkably similar. This means that both teams really did their homework. I was actually skeptical enough about film emulation that I was expecting to see highly visible differences between the two.

As for which does the job better, I would have to say, as expected, the DxO optics Pro with FilmPack Plug-in has better contrast, texture, and color vibrancy, but not by much. In the B&W examples, I can see almost no difference, and for Agfa Vista 200, I think GIMP actually looks more appealing. There are many other films to choose from in both products, as well as the ability to tweak the end result with both.

One thing to really keep in mind - GIMP is free, and DxO Optics Pro will set you back the price of a new compact digital camera! Also, of you're not into shooting Raw Files - like, if your camera won't do it, or if you're like Ken Rockwell and don't see the point, it's a no-brainer - this wonderful new G'MIC-GIMP Plug-in is free, and it works in Linux (also Windows and Mac). DxO Labs does not sell products that work with Linux.


  1. Nice comparison, I'm glad you like the emulations! :)

    I'm hoping to expand the offerings as soon as I get some more time to build some more.

    1. Patrick - you're the man! Thanks for visiting my Blog. I actually happened across GIMP Magazine, and found your article about this project there. I am truly impressed that you've "nailed it" just as good as DxO FilmPack.

  2. Great job by the GMIC team (as I've come to expect) but also a very useful write-up by the author, Dave Milton.

    I'm an enthusiastic GMIC fan but I cannot but also recommend the film filters provided in digiKam, the open source digital asset management and image editing program. Much like DXO, they work on the 16-bits image right after raw conversion. Although only black & white filters are available, the number of film emulsions emulated is far greater and includes even some IR options.

  3. Thank you Mike. Just a small question - you say digiKam works "on 16-bit... right after RAW conversion"; it seems to me that DxO Optics Pro with their FilmPack plug-in, works the emulations as actually part of the RAW conversion, not afterward. Is that your understanding? If Patrick could build his emulations into UF-RAW instead of G'MIC, that would bring us to the same approach as used by DxO, I think. Any clarifications here Patrick?

    1. From a technical perspective, there is no such thing as image edits as "part of the raw conversion". Although integrated packages sometimes make it look as if they have an immense wealth of editing capability, those edits are really applied to an in-memory, already converted version of the raw which would typically already be structured as a TIFF file anyway.

      Raw conversion is literally thàt: converting a bunch of digital data coming off an image sensor, but not yet an image in its own right, into an editable image which can than be processed further. Typical steps of raw conversion are debayering, application of a tonecurve and gammacurve as well as some preliminary sharpening (although even the latter is already performed on an image held in memory to be quite frank).

      Applications that claim to do everything but the kitchen sink during raw conversion really are comprised of an internal image processing engine tacked onto the raw conversion engine.

      There basically is no difference to separate the steps into two different processing steps, as Udi Fuchs (of UFRaw fame) says: "do one thing but do it extremely well" in true Linux spirit.

      If you therefore take a very competent RAW conversion engine (DCRAW, UFRaw etc.) and generate a 16-bit TIFF file out of that which you then process in a package capable of maintaining that 16-bit colordepth, you are not doing anything different than the integrated convertor/editor suites do - you just save an intermediate TIFF file rather than having it held in the working RAM of your PC.

      Sadly, GIMP cannot deal with the 8-bit yet but the good news is that David's GMIC engine is already fully capable of higher bit-depths and can be employed from the commandline in full 16-bit glory. I'm sure David can elaborate much better than I can as I am but an amateur tinkerer ;-)

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  5. Gimp is really a very good photo editor and there are not any doubts about the vitality of Gimp and I've been using it since a long instance and really very much benefited. So thanks a lot :)

  6. I am french and g'mic user also. I have published a post on my blog here in the same wy of your.: http://photomuz.blogspot.fr/2014/11/simulez-les-films-argentiques-avec.html


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