3d Augmented Reality graphics vision

Augmenting Images with Blender 3D 2.9x

augmenting KITTI image with a 3D car

Trying to demonstrate how to do data augmentation on the KITTI stereo dataset, I found myself diving (too deeply) into Blender 3D.

What I set out to do is add a 3D object to an unsuspecting image from the KITTI dataset, to show that one way to get more training data is by synthesizing. I just put a 3D object in front of an image (say a 3D plane with the image as the texture) and done ✅ – I’ve augmented the image. Turns out it needs a bit more of Blender trickery. This is the real reason for this post.

3d Augmented Reality code graphics opencv python video vision

Projector-Camera Calibration – the "easy" way

First let me open by saying projector-camera calibration is NOT EASY. But it’s technically not complicated too.
It is however, an amalgamation of optimizations that accrue and accumulate error with each step, so that the end product is not far from a random guess.
So 3D reconstructions I was able to get from my calibrated pro-cam were just a distorted mess of points.
Nevertheless, here come the deets.

3d Augmented Reality code graphics Mapping opengl programming Tracking video vision

Bootstrapping planar AR and tracking without markers [w/code]

Years ago I wanted to implement PTAM. I was young and naïve 🙂
Well I got a few moments to spare on a recent sleepless night, and I set out to implement the basic bootstrapping step of initializing a map with a planar object – no known markers needed, and then tracking it for augmented reality purposes.

3d Augmented Reality code graphics opencv opengl programming qt Tracking video vision

Augmented Reality on libQGLViewer and OpenCV-OpenGL tips [w/code]

You already know I love libQGLViewer. So here a snippet on how to do AR in a QGLViewer widget. It only requires a couple of tweaks/overloads to the plain vanilla widget setup (using the matrices properly, disable the mouse binding) and it works.

The major problems I recognize with getting a working AR from OpenCV’s intrinsic and extrinsic camera parameters are their translation to OpenGL. I saw a whole lot of solutions online, and I contributed from my own experience a while back, so I want to reiterate here again in the context of libQGLViewer, with a couple extra tips.