US Patent 11301712 Pointer recognition for analog instrument image analysis

Systems and processes for identifying a pointer in an image of an analog instrument are provided herein. An instrument contour in the image corresponding to the analog instrument may be identified. A plurality of candidate pointer contours in the image may be identified and screened using one or more geometric property screening techniques including an evaluation of a geometric area, a distance parameter, and/or a gravity center of the plurality of candidate pointer contours. Principal component analysis (PCA) may be performed to select an identified pointer contour from among the reduced plurality of candidate pointer contours. A linear regression model may be applied to pixel points in the contour area of the identified pointer contour and a slope and angle of an associated pointer represented by the identified pointer contour may be determined based on an output of the linear regression model.