Linux Photo Tools (The H)

[Posted June 8, 2011 by corbet]

Here's a lengthy survey of photo processing tools (some proprietary) on The H. "If you are prepared to deal with multiple user interfaces and software handling concepts, you will be able to produce professional looking results by using clever combinations of appropriate tools. This is a tried and trusted approach for many Linux users, who are familiar with using collections of individual tools that each perform one specific task particularly well. The choice of efficient photo workflow tools for Linux is not as wide as it is for Windows, but there is nevertheless a good selection of powerful programs available for importing, viewing and geotagging your images, as well as for performing a multitude of other tasks."

Linux Photo Tools (The H)

Posted Jun 8, 2011 15:05 UTC (Wed) by knobunc (guest, #4678) [Link] (6 responses)

I'm still looking for a way to do face detection and recognition under Linux.

OpenCV looks promising, but I've never managed to scrounge the time and inclination to try it since it provides hooks, but no UI for it.

Linux Photo Tools (The H)

Posted Jun 8, 2011 15:12 UTC (Wed) by milliams (guest, #71641) [Link]

I believe that the new DigiKam (2.0) will provides it when it is released (http://adityabhatt.wordpress.com/2010/05/19/yet-another-g...).

Linux Photo Tools (The H)

Posted Jun 8, 2011 23:52 UTC (Wed) by endecotp (guest, #36428) [Link] (4 responses)

Using OpenCV for face tracking is apparently not difficult:

http://www.statusq.org/archives/2011/05/15/3407/

Linux Photo Tools (The H)

Posted Jun 8, 2011 23:59 UTC (Wed) by knobunc (guest, #4678) [Link] (3 responses)

Yeah, tracking is good. But I want recognition (so that I don't have to say who is in the pictures).

Linux Photo Tools (The H)

Posted Jun 9, 2011 15:35 UTC (Thu) by dashesy (guest, #74652) [Link] (2 responses)

Face recognition is a much more difficult problem than tracking, and is generally known as cognition.

First, the image should be registered (you may avoid this if you have a very good quality image with enough resolution and the person has not moved her face in an awkward angle)
Second, features are extracted (to reduce the dimension); you may want to get some heuristic approach for this, or rely on a statistical approaches or on some eigenvalue decomposition, or wavelet transformed (thus reduced) feature space, or a combination.
Third, you have to perform steps 1 and 2 for a set of people you are interested in, and record the features in a database
Fourth, when you have a test image (to recognize the face) you can again perform the first two steps then compare the result against your database.
If your feature extraction is hierarchical with low-to-high (fast-to-slow, coarse-to-fine) approach then recognition may be fast enough to be practical.

Now, with OpenCV you can do all of the above!
And if you have an Intel CPU you can get the best from OpenCV using IPP.

Linux Photo Tools (The H)

Posted Jun 9, 2011 16:55 UTC (Thu) by knobunc (guest, #4678) [Link] (1 responses)

If you have any good pointers for books or articles or documentation explaining OpenCV to a relative lay person that would be great.

I followed the DigiKam lead and found libface that may do some of what I want. I had to fix a couple of bugs in the sample code, so I haven't managed to see how good the software is at recognizing people yet.

Linux Photo Tools (The H)

Posted Jun 9, 2011 18:25 UTC (Thu) by dashesy (guest, #74652) [Link]

It might be a good idea to read the first few chapters from the classical Learning OpenCV, and that is more than enough because more likely no body needs all the features. Since the notation and class hierarchy is more important I found the cheat sheet more useful :) I have done pattern matching (not for face actually) and cannot tell anything regarding the performance of libface. Since there are many ways to extract the features you should find one that meets your needs regarding the speed and quality.

Linux Photo Tools (The H)

Posted Jun 8, 2011 16:33 UTC (Wed) by smokeing (guest, #53685) [Link] (4 responses)

Gimp with ufraw plugin?? I have 26G of .pef images processed this way since 2007, and counting.

Linux Photo Tools (The H)

Posted Jun 9, 2011 12:52 UTC (Thu) by epa (subscriber, #39769) [Link] (3 responses)

I'd like to use the GIMP, but for photos that need special treatment - underexposed ones where you need to boost the light in the shadows, or overexposed ones where you need to rescue detail from highlights - it is invaluable to have a tool that works in 16-bit colour space. I've found Raw Therapee to work reasonably well, although it is still in development and can crash.

Once any exposure and contrast problems have been fixed, it's fine to save in 8-bit RGB.

Linux Photo Tools (The H)

Posted Jun 9, 2011 15:46 UTC (Thu) by dashesy (guest, #74652) [Link] (1 responses)

Isn't GEGL (already in GIMP) what you are looking for? I just wish for a qtpsgui plug-in for GIMP and nothing would be more perfect :)

Linux Photo Tools (The H)

Posted Jun 13, 2011 14:07 UTC (Mon) by epa (subscriber, #39769) [Link]

I thought GEGL was still work in progress, with most of the GIMP being limited to 8-bit channels? The GIMP 2.6 release notes talk about "a tentative integration of GEGL, the graph based image processing library that will eventually bring high bit-depth and non-destructive editing to GIMP". I believe that the 2.6 series is still the current stable version.

Linux Photo Tools (The H)

Posted Jun 9, 2011 22:05 UTC (Thu) by n8willis (subscriber, #43041) [Link]

The UFRaw plugin actually does all of the raw adjustment/correction in UFRaw, then saves it (optionally exporting it directly to the extant GIMP session), so all of the processing is performed in the image's full bit-depth. Or to put it another way, UFRaw is a separate app; it's just linked in to GIMP's menus with the plugin.

On another note, they also should have looked at Rawstudio, which is quite mature. And possibly Darktable, which is newer.

Nate