I have an application where I’m trying to automate taking a melting point. I have a small capillary tube that contains a small amount of a chemical I want to take the melting point. The microprecessor controls heating the tube and I get the temperature from an LM-35 connected to the ADC. I want to use the camera to compare a snapshot of the tube (with chemical) before melting - basically a small tube with some powder inside - usually white. So the 1st image is the un-melted sample - call it image1. The tube is heated and another snapshot is taken - image2. I want to compare the two using image2.get_similarity(image1) and use the value as a trigger to decide if the sample has melted. Image2 will be the same as Image1 (a value for similarity close to 1) until the sample begins to melt. When it melts the sample will turn into a liquid and the similarity value should change to something much less than 1.
The program runs fine but the similarity values are always 1 even when I hold up something completely different in front of the camera (like a pencil).
So I must not be using “get_similarity” correctly.