Thresholding video

Applying a threshold filter to a webcam feed is a handy technique to use in computer vision. You'll need this to do some basic blob tracking. This technique is very simple. You compare the brightness of every pixel in the webcam feed to a threshold value. Pixels with a higher brightness get a white color, pixels with a lower brightness will be colored black. The end result is an image that consists solely of black and white pixels.

How to do it...

You'll start by importing the video library. You've learned how to do this in the Using a webcam recipe. Next to our Capture object, we also need integer variables named numPixels and threshold.

import processing.video.*;

Capture webcam;
  
int numPixels;
int threshold;

In the setup() function, we'll start the webcam, just like in the Using a webcam recipe. The numPixels variable will be used to store the total number of pixels from the webcam image. This will be handy if we need to loop through them in the draw() function. We'll...