RAW Images

Done using GIMP 2.10.24 on Kubuntu Linux 20.04 LTS

RAW images are images that have been minimally processed from a camera sensor or other scanner. There is not a single format for RAW, each camera manufacturer defines its own format, and some of them have multiple formats, such as Kodak with 5 formats and Canon with three. Any digital camera will take RAW photos, but consult your owners manual for details. Android phones can also take RAW images along with the usual JPEG images. The benefit from shooting RAW is that you can fix over- and under-exposed images better working with the unprocessed data. When trying to fix this in JPEG images you may find that you are throwing off other parts of the picture. So why doesn’t everyone shoot RAW all of the time? The biggest reason is the files sizes are much larger. If you are taking holiday snaps on your cell phone, this can be an issue. And to be fair, for most people most of the time, cell phone photos are good enough, and in the last few years cell phone cameras have gotten quite good. So if you are generally happy with the JPEG photos your phone or digital camera give you, I am not going to suggest you need to change. I don’t personally bother to shoot RAW because the JPEGs on my Android are good enough for my purposes. But if you were a professional photographer and making a living from your photography you would probably be shooting RAW most of the time because it gives you the best control over the final results.

There are a number of free and open source applications that can edit RAW images. They include:

  • Darktable As the name suggests, this is something that gives you similar functionality to a Light Table, used in photo processing.
  • dcraw is designed as a Windows program and works from the command line! But it can also run in Linux
  • Krita is a popular drawing program and editor for raster images. It can open RAW images, but is not really designed for processing them
  • RAWTherapee is a pretty full-featured photo processor.
  • digiKam is similar to Darktable, but is a favorite among KDE users. This is the program I have been using for the last few years to help manage my photo collection.
  • ImageMagick is a software suite that edits many image formats, including most RAW formats. It is cross-platform, and has been a favorite many users over the years.
  • Shotwell is similar to darktable and digiKam, but where digiKam is a KDE program, Shotwell is is Gnome program.

There are other programs as well, and this Wikipedia page has a good list of them, both the free and open source programs and the various proprietary programs like Adobe Lightroom and Adobe Photoshop. But of course my focus is always on free and open source software, so I won’t say any more about proprietary programs. But as you look a the list, you might see that GIMP is not on the list. And that is because GIMP does not (as I write this) support RAW images. But all is not lost. If you dig into the technical details (and this is a good write-up from Kat Landreth) no photo editor edits RAW images directly. Instead, what they do is first convert the file into a format like TIFF. And you can do the same thing using a number of tools. But the two I want to focus on here are Darktable and RAWTherapee, because they integrate with GIMP in a way that makes it work pretty well. So I am not saying this is the only way to do it, but it is a way I have seen a number of GIMP experts recommend it. And the plug-ins for both were built in to GIMP by the GIMP development team to help bring this functionality into GIMP, which makes either a pretty good choice. The comparison is that RAWTherapee has more features and can do more than Darktable, but Darktable is more user-friendly and better suited to beginners. They are both good solutions

Step one is of course to install either Darktable or RAWTherapee, which I did using my Package Manager (Muon on my Kubuntu 20.04 desktop). Note that both programs are cross-platform applications that also run on Windows and Mac computers, so go to their web sites for more info if you run one of those other operating systems. And to continue my practice of using public domain image sites, I found one for RAW images. Signatureedits.com offers public domain photos in raw format at https://www.signatureedits.com/free-raw-photos/. Their license states:

All raw files published on Signature Edits can be used for free. You can use them for commercial and noncommercial purposes. You do not need to ask permission from or provide credit to the photographer or Signature Edits, although it is appreciated when possible.

More precisely, Signature Edits grants you an irrevocable, nonexclusive, worldwide copyright license to download, copy, modify, distribute, perform, and use raw files from Signature Edits for free, including for commercial purposes, without permission from or attributing the photographer or Signature Edits. This license does not include the right to compile photos from Signature Edits to replicate a similar or competing service, or to misrepresent the authorship of these photos as your own original work.

https://www.signatureedits.com/raw-files-license/

This seems like a good license to me, since I have no intention of compiling photos to create a competing service, and obviously I did just link to them (optional, of course), because I always credit the original creator. The file I downloaded is “_signature edits free raws _Photodesk 5.NEF”. *.NEF tells me that this photo is in the Nikon RAW image format. So I have an image downloaded, and I went to GIMP to open it, but all I got was the sad trombone. (OK, there actually was not an audio sound effect, just an error message.) I tried a different image, same result. A little Google searching showed me a lot of people are having this problem. Michael Davies said that he thought RAWTherapee worked better with GIMP in Linux, but it didn’t for me. I tried uninstalling Darktable and just leaving RAWTherapee in place, and it still didn’t work. Then, just to check, I tried in Windows, and it worked just the way it should. Well, I guess that is good to know.

The image I downloaded is this, but note this is not the original RAW image, which would not work in any case on my Web page.

PNG derived from original RAW image without editing

This is a PNG image I made. So how did I manage that? Well, with the image downloaded, I could open it up directly in RAWTherapee. From there, I could save it as a *.tif file (aka TIFF), and that I could open in GIMP. Then in GIMP it was just the usual process of exporting the image as a PNG image and uploading it to my site.

So in the end you have a few ways to do this. If you have a Windows computer, you can open a RAW image in GIMP, and it will take a minute and the image will open in (for instance) Darktable. There you can make your edits. and when you are finished you just close Darktable. Again, there is a brief pause, but then the image will open in GIMP. I made a change in Darktable to brighten up the image by adjusting the RGB curve, and then in GIMP I re-scaled the image to 480×318, and exported it as a PNG file.

PNG derived from original RAW image brightened

The thing I would keep in mind is that by the time you read this the situation may be completely different. I struck out using GIMP 2.10.24 on Kubuntu 20.04. But maybe the next version of GIMP will fix this, or maybe it would work better in Fedora, or whatever. I just hope I have given you enough information to work out how you will do it if you need to edit RAW images.

Now, despite the potential advantages of working with RAW images, I suspect I will stick to JPEG photos in the photos I take. And many of the photos I want to edit are old photos I scanned in from pictures and slides I took years ago. So that leads me to my next topic, scanning in old photos. And from there we can do a dive into editing and fixing old photos. ¡Vamos!

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