Object Detection and Segmentation — Beyond "What Is This?"
Classifying a whole image as "cat" is only the beginning of computer vision. Real applications need to know where the cat is, how many objects there are, and sometimes exactly which pixels belong to each one. Object detection and segmentation answer those harder questions, and they power self-driving cars, medical imaging, and photo editing. This post covers the main vision tasks beyond classification and how they build on the CNN foundation.
Real vision needs more than 'what is this?' — the task hierarchy runs classification → detection (bounding boxes) → semantic segmentation (per-pixel) → instance segmentation. How one-stage (YOLO) vs two-stage detectors and encoder-decoders (U-Net) build on the CNN backbone, powering self-driving and medical imaging.