8. NumPy¶

The Image class covers the per-pixel work the camera already knows how to do – thresholds, blob finding, edge detection, and the rest of the image library. The numpy module covers everything else: ADC readings and other buffers of plain numbers, math that runs across a whole buffer at once, and per-pixel transforms the image library has not already built in.

Enter the ndarray, a single class that holds a packed block of equally typed numbers. Everything else in numpy is a math function that operates on an ndarray. Adding two arrays together, summing one of them, taking a sine of every element – each is a single library call that processes the whole buffer in one go, much faster than the equivalent Python for loop.

Concepts