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
-
openSUSE Joins End of 10
openSUSE has decided to not only join the End of 10 movement but it also will no longer support the Deepin Desktop Environment.
-
New Version of Flatpak Released
Flatpak 1.16.1 is now available as the latest, stable version with various improvements.
-
IBM Announces Powerhouse Linux Server
IBM has unleashed a seriously powerful Linux server with the LinuxONE Emperor 5.
-
Plasma Ends LTS Releases
The KDE Plasma development team is doing away with the LTS releases for a good reason.
-
Arch Linux Available for Windows Subsystem for Linux
If you've ever wanted to use a rolling release distribution with WSL, now's your chance.
-
System76 Releases COSMIC Alpha 7
With scores of bug fixes and a really cool workspaces feature, COSMIC is looking to soon migrate from alpha to beta.
-
OpenMandriva Lx 6.0 Available for Installation
The latest release of OpenMandriva has arrived with a new kernel, an updated Plasma desktop, and a server edition.
-
TrueNAS 25.04 Arrives with Thousands of Changes
One of the most popular Linux-based NAS solutions has rolled out the latest edition, based on Ubuntu 25.04.
-
Fedora 42 Available with Two New Spins
The latest release from the Fedora Project includes the usual updates, a new kernel, an official KDE Plasma spin, and a new System76 spin.
-
So Long, ArcoLinux
The ArcoLinux distribution is the latest Linux distribution to shut down.