A new section of the image processing series is now up – [corner detection](http://www.parallelpoints.com/node/56/)
# Detecting corners
Let’s use a corner detector as an example. [Corner detection](http://en.wikipedia.org/wiki/Corner_detection) is an important image processing task: corners are good things to track over several frames of an image sequence. Once you’ve tracked them you can infer 3-d positions for them.
OK, I started out on [Scilab](http://www.scilab.org/), but got frustrated! It’s too different to [Matlab](http://www.mathworks.com/products/matlab/) – which has its flaws, but at least I’m familiar with them. I’m always going to be annoyed by the 1-based indexing of Matlab, but I’ve learned to deal with it.
Thanks to [Ignacio Segura](http://www.isegura.es/blog/stop-spam-your-site-being-invisible-honeytrap-drupal-comments-form) I have a new anti-spambot measure. Users won’t notice it (unless they browse with CSS turned off, or other such unusualness). Hopefully this will mean that a) I don’t have to “disapprove” loads of comment span every day, and b) I can allow anonymous commenting without having to approve it before it becomes visible.
Thanks to Ioannis for the stimulus – I’ve [compared a Sobel edge detector with a very simple edge detector](http://parallelpoints.com/node/50)…