duncan­lock­.net

Compressing Limited Colour PNG images

Most of the .PNG files on this site are the ‘blueprint’ style diagrams, like this one:

Blueprint style diagram showing an optical microscope. The sample inside is magnified in a bubble to 2500 times
Figure 1. This illustration is a large 5.6MB SVG file, mostly because of the very detailed paisley pattern that I used. Exported to PNG - and then compressed using the process below, you can get this down to 118.5kB.

I create these in Inkscape as vector .SVG files & export them to bitmap .PNG files. I then re-compress them, to ensure that the image files that are used on the live website are as small & quick to load as possible.

As these diagrams have a fairly limited colour palette, I can get lots of extra compression by reducing the colour depth of the final .PNG files from the default 32bit (millions of colours) to 8bit (256 colours) - without any …

Continue reading “How I compress PNG files on this website”

reddit bots diagram
Figure 1. How much does a software bot weigh, anyway? Heavily modified & adapted from the original public domain robot on openclipart, posted by johnny_automatic.

reddit, the insanely popular internet community, had 71,435,935 unique visitors last month, with over 2,360,783 people logged in [1].

I say people - but it turns out that not all the denizens of reddit are human. There are also bots. Lots and lots of bots. How many? No-one really knows. [2]

This is an interesting and somewhat shadowy facet of the otherwise very public reddit community, so I thought I’d take a closer look…​

What is a reddit bot?

A reddit bot is no different from any other user, as far as reddit is concerned. The only difference is that rather than a human logging in to upvote cat pictures and …

Continue reading “A Marvellous & Incomplete Compendium of reddit Automatons & Bots”

As I mentioned previously, this site was put together using Pelican - a static site generator, written in Python.

Blueprint style diagram showing a brown Pelican
Figure 1. Pelecanus Occidentalis - the Brown Pelican. Original clipart Flying Pelican from OpenClipart, by molumen, Public Domain. More on Pelican, the bird.

Static site generators take your content, pour it into your templates and output the result as static pre-generated HTML, CSS, JS & image files. You can then just upload the resulting folder of output to your server and you’re done. All you need on the server is a web server of some sort, like Apache or Nginx - anything really - all it’s doing is serving static pages.

The huge advantage of this setup is simplicity:

  1. You can write your content in Markdown [1], reStructuredText [2] or AsciiDoc [3] - all simple text formats, designed to facilitate writing and get out of …
Continue reading “How I built this website, using Pelican: Part 1 - Setup”