# Interactive Widgets This page provides an overview of the interactive widgets currently available with the course notes. Select a widget to open it in a new page. ## Image formation and optical systems - PSF and MTF — dual view — Explore a point spread function and its modulation transfer function side by side. - Thin lens sandbox — Experiment with image formation using a thin lens. - Image sequence stepper — Step through an image sequence or load your own images. - Convolution scrubber — Explore the convolution operation interactively. - 2D FFT drawing tool — Draw a 2D signal and inspect its Fourier transform. - Dirac approximation and Fourier series — Explore the Dirac approximation and its Fourier-series representation. - DFT and cyclic extension — Explore periodicity, leakage, zero-padding, and 2D convolution with padding. - How a Fresnel lens is constructed — Follow the construction of a refractive Fresnel lens. ## Light fields and directional imaging - Light field explorer — Inspect microlens-array measurements, sub-aperture views, and digital refocusing. - Camera light field and ray diagram — Connect camera rays to light-field integration and virtual refocusing. - Central display pixel detection — Simulate coded measurements and recover central display-pixel positions. - Schlieren and angular filter — Explore how an angular filter converts ray deflections into image brightness.