how to use wolfram mathematica for data science

I ignore the case of over 70,000 pixels, as I don’t want an alarm when someone turns off the office lights and the entire image changes. If the size of the biggest change is more than 1,000 pixels, then we will call that an intruder event, and we will use the SendMail command to send me email to tell me about it together with the highlighted changed image. Now I can create a function that tests and acts on the result of the scene changes. Had the coffee cup been removed or another added, we would see a second smaller component listed as well.

In this case there has been one scene change of over 37,000 pixels. Secondly, we can use it as a measure of the amount that has changed. I will use it to darken the rest of the image by 75% and add a white line around the edge of the changed area. We can use this simplified scene-change image in two important ways.įirstly, we can use it to highlight what has changed in an image. So let’s put those steps together into a function. This is all we need to detect an intruder. Now we clump together these differences by filling in gaps of 10 pixels or less.

I have applied this to the maximum difference out of all the color channels, since we want a change in color to be as important as an overall change in brightness. I don’t care how different they are, so I will apply a threshold. This image is black where there was no difference between the images. As a quick way to deal with that, I first blur both images slightly. My camera isn’t very good, so there is a bit of noise.

ImageDifference gives us a pixel-by-pixel absolute difference between the two images. Let’s get some test images using the webcam on my laptop.Īnd again, but with a couple of seconds to hide from the camera: Time to build some office security using Mathematica Home Edition!įirst, I am going to make use of an imminent new Mathematica command CurrentImage, which will import a real-time image from a video device. Ever since I wrote the “ Doing Spy Stuff with Mathematica” blog post, I have had a feeling that I am being watched.

How to use wolfram mathematica for data science