Image processing with Go
Programming Snapshot – Go
© Lead Image © Martin Malchev, 123RF.com
Go comes with an image-processing toolkit right out of the box. In this month's column, Mike Schilli explains how to walk through a photo's pixels to detect the foreground by comparing values against a threshold and shows how to manipulate the original by creating a nice looking silhouette.
Until recently, my headshot at the end of every "Programming Snapshot" article showed a much younger version of myself, dating back 15 years, so I grudgingly shot a new one the other day. While doing this, the idea occurred to me to try out my new favorite language Go's suitability for image processing. How hard could it be to generate an artful silhouette of the person shown in the photo?
Of course, with some Gimp skills this could be done quite quickly. However, what is far more interesting is the question of how an image processing program walks through the pixels of Figure 1 and finds out which of them actually belong to the person (the foreground) and which to the lighter background. When a foreground pixel is found, the algorithm can then go ahead and set it to black, which in the digital world means it has its red, green, and blue channels set to 0,0,0. Easy enough, right?
Finding the Foreground
With a light background and a significantly darker object in the foreground, the program in Listing 1 [1] simply finds all pixels whose brightness lies below a previously defined threshold value and blacks them out completely. The Darken() function accepts a draw.Image type structure from line 9, including the width and height of the image in the width and height parameters in pixels.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
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
-
So Long, ArcoLinux
The ArcoLinux distribution is the latest Linux distribution to shut down.
-
What Open Source Pros Look for in a Job Role
Learn what professionals in technical and non-technical roles say is most important when seeking a new position.
-
Asahi Linux Runs into Issues with M4 Support
Due to Apple Silicon changes, the Asahi Linux project is at odds with adding support for the M4 chips.
-
Plasma 6.3.4 Now Available
Although not a major release, Plasma 6.3.4 does fix some bugs and offer a subtle change for the Plasma sidebar.
-
Linux Kernel 6.15 First Release Candidate Now Available
Linux Torvalds has announced that the release candidate for the final release of the Linux 6.15 series is now available.
-
Akamai Will Host kernel.org
The organization dedicated to cloud-based solutions has agreed to host kernel.org to deliver long-term stability for the development team.
-
Linux Kernel 6.14 Released
The latest Linux kernel has arrived with extra Rust support and more.
-
EndeavorOS Mercury Neo Available
A new release from the EndeavorOS team ships with Plasma 6.3 and other goodies.
-
Fedora 42 Beta Has Arrived
The Fedora Project has announced the availability of the first beta release for version 42 of the open-source distribution.
-
Dash to Panel Maintainer Quits
Charles Gagnon has stepped away as maintainer of the popular Dash to Panel Gnome extension.