Haar features

Haar features are simple patterns used in image analysis to identify objects, like faces, by detecting contrast differences. They work by comparing the brightness in adjacent regions—such as light and dark areas—within an image. For example, a Haar feature might look for darker eyes compared to lighter cheeks. These features are computed quickly using an efficient method called integral images, enabling rapid scanning of an image for specific patterns. In facial recognition, Haar features help algorithms find characteristic features like the eyes, nose, and mouth by highlighting contrast variations that define these parts.