Pictures, Photographs or images are the second most important data after documents. For professional photographers, documents are secondary. Handling of images in Linux is very simple matter with a variety of open source programs and all are absolutely free. Image organizers, in Linux are far more superior to any other comparable system. Unfortunately there is no comprehensive guide at one place for the beginner or new user. Over years I have been trying various image processing software and here I have attempted to include as many as possible. These can be installed on Ubuntu and its derivatives and all Linux systems (with ‘apt-get’ command or Ubuntu Software Center or Synaptic Package Manager) or by downloading from the source given at the wiki page.

Photo editing and image manipulation Linux softwares

Inkscape is the general standard for creating and editing SVGs. It is an Open Source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format. Inkscape supports many advanced SVG features (markers, clones, alpha blending, etc.) and great care is taken in designing a streamlined interface. It is very easy to edit nodes, perform complex path operations, trace bitmaps and much more. (Its official Website is inkscape dot org.)

GIMP, or GNU Image Manipulation Program is similar to Proprietary Adobe Photoshop. Used for the retouching of images, and creating raster graphics (PNG, JPEG). GIMP can also be used to create animations (GIF) with the help of GIMP Animation Package (GAP). It also works for artists with GIMP Paint Studio (GPS) plug in. It can be installed directly from terminal by using the command "sudo apt-get install gimp". Do not forget to install the Ex foundry Scripts (as macros are called in gimp) by running the command “sudo apt-get install gimp-plugin-registry". All without quoutes.

UFRaw is a good Open Source software to process digital raw images. Digital Camera captures an image by recording all the data in a format called ‘raw’. When we choose the camera to save in JPEG format, it actually processes the raw data and saves the image directly in raw format on the camera. Since the camera works with a small processor and of fixed guess work, its result is not optimized. It would be a good idea to capture image in raw format and process the data on computer.

Darktable is another raw image processor but I have dealt with it under organizers.

Hugin, is good option to create one big panoramic image by stiching together several smaller images. Hugin can also correct the perspective of an image besides many other features. No landscape photographer can do without this software. It can be installed directly from terminal by using the command "sudo apt-get install hugin"

QGis, can create GIS maps’ layers: topographic background, shaded relief, states/provinces polygons, rivers/lakes/coasts, urban areas, etc. PNG or SVG.

Blender, is for the creation and editing of 3D images, so is POV-Ray, which is also a free 3D ray tracer.

Image compression software

Image processing programs like gimp or ufraw do offer to save image in compressed formats but their compression is nothing to carry home about. Ordinarily jpeg image saved at 95% shall be perfect balance between quality and size. Specialized softwares do a better job and should be used while storing the images to save the space.

JPEG files can be compressed without loss in quality, using jpegtran -optimize. Even though compression is slower, it does result in a smaller file. Jpegtran is part of libjpeg. A package called littleutils contains a script called opt-jpg that automates JPEG optimization, using jpegtran as the underlying engine.

PNG files: There are a variety of tools to compress PNGs without any loss of quality:

PngCrush can be used to remove all the information about gama, white balance etc. An example:

pngcrush -rem gAMA -rem cHRM -rem iCCP -rem sRGB InputFile.png OutputFile.png

OptiPNG usually outputs smaller files than pngcrush, as the latter retains more information in the file to strictly follow the PNG specification.

AdvDef can be used after either of above two programs to further optimize the compression.

For quick compression, we can use OptiPNG without any option at all like this:

optipng file.png

If time is at our disposal (i.e. an overnight operation) following string of commands are recommended for optimum results:

optipng -o7 file.png
advdef -z4 file.png
pngout /ks file.png
deflopt file.png

Experimenting with these programs shall reveal as to what combination produces the best result. Links to its wiki page contains link to official web page also. For technical reasons, direct link has not been given.

Organizing and viewing the images

Managing the images is the most daunting task. After a while the images multiply and we are unable to find the image when we want to see it.

XNViewMP is the best choice among image viewers and exif data editors. The  versatility of this software is amazing. It can seamlessly take through drive after drive and folder after folder to organize file by editing exif/xmp/iptc meta data and to organize files as per requirement. It can also edit meta data across a batch of files including raw images. Unfortunately it’s Linux edition is seven years old while Window edition has been updated just 48 days ago. Let’s hope that new edition will around soon. (Official website is xnview dot com) It has to downloaded as deb file from its website.

Darktable is another graphic rich image organizer cum raw image processor. However I could not use it as it frequently crashed on my system. ( 2.4 Gz Dual core with 3 GB RAM). But it is worth a try. Another problem is that it saves numerous xmp files across all the folders which looks very cluttered but perhaps there may be an option in Preferences.

Fspot, Shotwell, gThumb are three other most popular image viewers/organizer for Gnome desktop and in all probability one of these would be installed with Ubuntu or any of its derivatives. Eye of Gnome is another less popular but Gnome Official image organizer. Gwenview would be the popular and recently updated viewer/organizer for KDE desktop.

A comparison of various other image viewers and organizers can be seen at this wiki page.

Phatch is a batch file processor which can make routine changes like water-marking or editing exif data on a multiple of files. The best part is that it can save the changes in a script file so that same script/file can be loaded and applied to different batches of file over and over again.

© Sandeep Bhalla