Correcting exposure retrospectively with Urban Lightscape
On the Dot

The Urban Lightscape photo tool lets you adjust local brightness levels within an image, thus turning a simple snapshot into a real eye-catcher.
You have a great subject and have captured it impeccably in a photograph, but when you open the file on your computer, you notice an overexposed spot that leaves part of the image blurry or difficult to see. Don't panic; try Urban Lightscape [1], a tool that adjusts brightness just in the area that really needs fixing.
Urban Lightscape is available for Windows, Mac, and Linux. License fees are charged for the Windows and Mac versions, but the program is available for free for Linux users who are willing to build it from the source code. Ubuntu users can also obtain Urban Lightscape through a PPA archive [2], which simplifies the installation for non-technical users. All you need is a short excursion to the command line:
$ sudo add-apt-repository ppa:dhor/myway $ sudo apt-get update $ sudo apt-get install urbanlightscape
To run the program, just enter urbanlightscape
at the command line.
Image Formats
The first step is to load your photos. Dragging and dropping from the file manager does not work; the only solution is via the File dialog. There, you have a number of formats from which to choose, including JPEG, PNG, TIFF, and various Windows formats. The formats from Photoshop and RAW files are missing from the selection; however, the All files choice allowed me to load RAW images from a Canon camera.
Getting Started
Once you have the first photo loaded, you can get straight to work. The program impresses with its very simple structure (Figure 1), and you might be surprised by how few controls are in the interface. However, don't worry; you'll have nothing to enable or install later.
You can easily create your first control point by double-clicking on a point of the image that you want to customize. After a moment, you see a control point – a small circle with a serial number (Figure 2) – appear. These control points are similar to the U-point controls in the Nik Collection [3].
Holding down the mouse button after double-clicking lets you modify the control point. Drag the mouse up to increase the brightness; drag the mouse down to make the point and the adjacent area slightly darker (Figure 3). You can then add any number of additional control points to give the image the right balance in terms of brightness (Figure 4).

Smart Distribution
Depending on the nature of the photo, it can make sense to add a relatively large number of control points – in some cases, the desired effect even requires you to do so. The process is not particularly complicated, because you can create a point quite quickly.
It may happen that two adjacent control points brighten up part of the image, but between them lies a region that you want to keep darker. To address this, insert an additional intermediate control point that takes the brightness down a bit. At difficult points of the image, you are likely to produce a jumble of control points quickly.
You have the option of adjusting the control points later on. To do so, use View | Overlay to enable the view showing the numbered control points. Then double-click and hold to change the values, just as you did when creating them. You can also use the mouse in this mode to move the control points. To delete a control point, simply drag it out of the window.
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you've found an article to be beneficial.
News
-
The GNU Project Celebrates Its 40th Birthday
September 27 marks the 40th anniversary of the GNU Project, and it was celebrated with a hacker meeting in Biel/Bienne, Switzerland.
-
Linux Kernel Reducing Long-Term Support
LTS support for the Linux kernel is about to undergo some serious changes that will have a considerable impact on the future.
-
Fedora 39 Beta Now Available for Testing
For fans and users of Fedora Linux, the first beta of release 39 is now available, which is a minor upgrade but does include GNOME 45.
-
Fedora Linux 40 to Drop X11 for KDE Plasma
When Fedora 40 arrives in 2024, there will be a few big changes coming, especially for the KDE Plasma option.
-
Real-Time Ubuntu Available in AWS Marketplace
Anyone looking for a Linux distribution for real-time processing could do a whole lot worse than Real-Time Ubuntu.
-
KSMBD Finally Reaches a Stable State
For those who've been looking forward to the first release of KSMBD, after two years it's no longer considered experimental.
-
Nitrux 3.0.0 Has Been Released
The latest version of Nitrux brings plenty of innovation and fresh apps to the table.
-
Linux From Scratch 12.0 Now Available
If you're looking to roll your own Linux distribution, the latest version of Linux From Scratch is now available with plenty of updates.
-
Linux Kernel 6.5 Has Been Released
The newest Linux kernel, version 6.5, now includes initial support for two very exciting features.
-
UbuntuDDE 23.04 Now Available
A new version of the UbuntuDDE remix has finally arrived with all the updates from the Deepin desktop and everything that comes with the Ubuntu 23.04 base.