Field extraction method, terminal device and program product

The invention discloses a field block extraction method, terminal equipment and a program product. The method comprises the following steps: acquiring an orthoimage of a region needing mapping; cultivated land in the orthoimage is recognized, and the outer contour of each cultivated land is obtained; all the outer contours are traversed, and the intersected outer contours are merged and retracted inwards until any two outer contours are not overlapped; the outer contours are enlarged according to set pixels, all the enlarged outer contours are traversed, and the contour pixels of all the disjoint field parcels are scaled to half of the set pixels; a ridge area contour is obtained; and extracting the center line of the contour of the ridge region to obtain a closed contour, namely the outer contour of the field. According to the method, automatic extraction of the ridge center line in the terrestrial topographic map is realized, and the problems of mutual independence of fields in a current intelligent recogni