This is the personal site of Tom Roelandts. I’m trying to whet your appetite for science with this thing. My education and interests show through, of course, since I focus on stuff that I feel confident writing about. The site used to be solely about the photos, and I still think the thumbnails page is rather cute, but the emphasis has clearly shifted towards the articles lately.

How to Create a Simple Low-Pass Filter?

Normalized windowed-sinc filter

How to create a simple low-pass filter, given a cutoff frequency and a transition bandwidth? A low-pass filter is meant to allow low frequencies to pass, but to stop high frequencies. Theoretically, the ideal (i.e., perfect) low-pass filter is the sinc filter. The sinc function is defined as… read more

Submitted on 15 April 2014

Introducing Clippy!

Clippy

I’ve decided to introduce the world-famous Clippy to improve the interactivity of this site. After all, who am I to doubt the wisdom of Microsoft when they introduced it as the friendly helper that it is, and that already in 1997. You might be skeptical about this, but trust me, it’ll be cool! I haven’t decided yet whether… read more

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Submitted on 1 April 2014

The Clustering Illusion

The clustering illusion is the human tendency to expect random events to appear more regular or uniform than they are in reality, resulting in the assumption that clusters in the data cannot be caused by chance alone. An important example of this is that the stars in the night sky seem clumped together in some regions, while… read more

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Submitted on 5 March 2014

Valentine Filtering

Heart

Happy Valentine’s Day! This is a bit of a trick post; after luring you in with the cute heart, I’ll explain in this article how image filtering can be implemented in frequency space… read more

Submitted on 12 February 2014

Gaussian Noise is Added, Poisson Noise is Applied

Poisson and Gaussian noise, pixel values 0 to 5

There is a fundamental difference between adding Gaussian noise and applying Poisson noise. In practice, people often talk about adding Poisson noise anyway, but this is not accurate. I will be looking at this from the image processing perspective in this article, and I’ll show purely visual examples. An application of this could be… read more

Submitted on 11 January 2014

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