Stijn Oomes

Visual geometry of a sphere

When you look at the photo above, what sizes do you think those 5 spheres have?

If I tell you that the sheet of paper on the right is an A4. And the photo is taken in my office with the camera lying flat on the edge of my desk. Do your estimates change?

Neural networks make me uncomfortable

The main problem I have with neural networks for computer vision is that they do not give me understanding. Even the best network, that has a 99.91% accuracy on the MNIST handwritten digits dataset, can not give me any insight. It does not allow me to observe how it actually performs its classification.

Diagonals of an ellipse

I have been watching Norman Wildberger’s videos on all things mathematics for about 10 years. To say that I have learned a lot is the understatement of the decade.

His most recent video is a recorded talk from July this year titled “How Chromogeometry transcends Klein’s Erlangen Program for Planar Geometries”. It is fascinating throughout but my interest was piqued when at 25:13 he starts talking about ellipses.

Understanding events

I am building systems that can understand what they see. In this day and age, the necessary hardware is easily accessible since a digital camera and a computer can now be purchased for well under € 100. It is the software that is the real challenge.

Solving correspondence

A major assumption in modern computer vision is that you have to track points on surfaces in order to see in 3D. You can use 2 images from 2 static cameras (“stereo”), or 2 images from 1 moving camera (“motion”).Continue reading “Solving correspondence”

Internal inertial sensors

One pleasant surprise for computer vision on a mobile device is that we can detect the 3D orientation of the camera from other sensors. An iPhone has an accelerometer and a gyroscope (among complementary sensors not discussed here).Continue reading “Internal inertial sensors”

Mobile AR is a 3D revolution

What components do you need to get Augmented Reality (AR) technology running on your mobile phone? Continue reading “Mobile AR is a 3D revolution”

Virtual furniture at the right scale

Our imagination is a powerful cognitive skill. When I walked into the living room of my new apartment, I experienced a rectangular empty space with a dusty concrete floor and hollow sounding acoustics. But in my mind I was already furnishing and decorating. I imagined a blue carpet on the floor, the walls lined with bookcases, a large table on the far end, and a comfortable couch near the window.Continue reading “Virtual furniture at the right scale”

Upgrading vision system OVS-0

I am right-eyed. A phenomenon also called “master eye” or “ocular dominance”.

So my left eye is the lazy one. And I don’t think it was properly treated when I was growing up. What I remember is that I saw double while reading: two images floating on top of each other. I could not fuse the two images into one “percept” of the book in front of me. I could accomplish that fusion easily for normal objects that were further away than the words on a page at arm’s length.

Interview with newspaper “Het Parool”

Here is an interview that journalist Jim Jansen of the newspaper Het Parool had with me. He wanted to know how scientists spend their Summer holiday. It is in Dutch though, but I added a translation in English.Continue reading “Interview with newspaper “Het Parool””