What is a Point spread function in image processing?

A Point Spread Function (PSF) in image processing describes how a point source of light is represented in an image. It characterizes the response of an imaging system to a point input, reflecting the system’s resolution and ability to reproduce fine details. The shape and spread of the PSF can indicate the quality of the imaging system, with a narrower PSF generally indicating better resolution. PSFs are crucial for tasks like deconvolution, where they help to restore images that have been blurred by the optical system.