Region of Interest (ROI)

A Region of Interest is a sub-region of an image — typically a rectangle, ellipse, polygon, or arbitrary maskLoading... — that scopes which pixels an analysis engine acts on. Pixels inside the ROI are processed normally; pixels outside are excluded from the engine's computation, leaving them unchanged in the output. ROIs are drawn manually (operator outlines a tumor region), computed automatically (a ClassifierLoading... produces a tissue-class mask used as ROI), or imported from co-registered annotations. Once defined, an ROI propagates through subsequent engines that accept an ROI parameter — a single ROI definition scopes the entire downstream chain.