‘Urban Lightscape’ is a simple yet an effective image enhancer that lets you adjust brightness settings and add artificial lighting to your photos with ease. It’s an open source application, runs in MS Windows, Mac OS X and GNU/Linux (including packages for Ubuntu), though the GNU/Linux users get to use it for free but for other platforms you’ll have to buy it (the developers give you 21 days of trail period and also supports working with Adobe Photoshop as a plugin as well).
With ‘Urban Lightscape’, you can use your mouse to select different areas of your images and then can use the built in tools (the tool-bar windows are movable too) to:
*. Adjust Green, Red and Green color settings.
*. Change artificial lighting setting (Brightness, Smoothness, Tolerance, Blacks, Whites and the Spreads).
*. Zoom in and out.
*. Restore the tools to their default settings.
*. Save images into PNG, JPEG, BMP, TIFF, PNM, PCX and XPM formats.
*. Supports opening multiple images using tabbed windows.
If interested, you can install ‘Urban Lightscape’ in Ubuntu 12.04 Precise Pangolin, 11.10 Oneiric Ocelot, 11.04 Natty Narwhal, 10.10 and 10.04 by using a PPA provided by ‘Dariusz Duma’ (thank you!).
For that, open your Terminal and enter the below commands.
sudo apt-add-repository ppa:dhor/myway
sudo apt-get update
sudo apt-get install urbanlightscape
As for using the mouse for ‘marking’ areas, please refer to its manual (it’s pretty well written and won’t take more than few seconds).
For downloading it manually, please visit this page. Good luck.