A system comprising: a computer processor configured to: receive a two dimensional aerial digital image of an area of a refinery; (110, 120) generate zoomed-in images of the aerial digital image of the area of the refinery; (120, 410, 600) first, identify one or more circular tanks in the zoomed-in images of the refinery using a Hough transform; (130, 320) second, identify one or more vegetation areas in the zoomed-in images of the refinery by checking each pixel in the digital image to determine if a color channel corresponding to vegetation colors dominates; (140, 420, 430, 440, 450) third, identify one or more process areas in the zoomed-in images of the refinery using edge patterns that are computed by determining the respective concentration of edges in a sub-image block, followed by removing sub-image blocks with insignificant density so as to obtain the process areas; (150, 550, 560) fourth, assume any remaining areas in the area of the refinery are as building areas; mark the identified circular tanks, the vegetation areas, the process areas, and the building areas in the digital image; concatenate the zoomed-in and segmented sub-image blocks by stitching adjacent zoomed-in and segmented sub-image blocks together, thereby placing the zoomed-in and segmented sub-image blocks according to an initial order and locations of the zoomed-in and segmented sub-image blocks, such that a single image of the entire refinery is formed; (160, 840) draw polygons around the marked circular tanks, vegetation areas, process areas, and building areas and identify and segment the building areas as the areas that remain after the polygons are drawn around the tank, vegetation, and process areas in a second digital image; (160, 860) and display the second digital image on a computer display device. receive a two dimensional aerial digital image of an area of a refinery; (110, 120) generate zoomed-in images of the aerial digital image of the area of the refinery; (120, 410, 600) first, identify one or more circular tanks in the zoomed-in images of the refinery using a Hough transform; (130, 320) second, identify one or more vegetation areas in the zoomed-in images of the refinery by checking each pixel in the digital image to determine if a color channel corresponding to vegetation colors dominates; (140, 420, 430, 440, 450) third, identify one or more process areas in the zoomed-in images of the refinery using edge patterns that are computed by determining the respective concentration of edges in a sub-image block, followed by removing sub-image blocks with insignificant density so as to obtain the process areas; (150, 550, 560) fourth, assume any remaining areas in the area of the refinery are as building areas; mark the identified circular tanks, the vegetation areas, the process areas, and the building areas in the digital image; concatenate the zoomed-in and segmented sub-image blocks by stitching adjacent zoomed-in and segmented sub-image blocks together, thereby placing the zoomed-in and segmented sub-image blocks according to an initial order and locations of the zoomed-in and segmented sub-image blocks, such that a single image of the entire refinery is formed; (160, 840) draw polygons around the marked circular tanks, vegetation areas, process areas, and building areas and identify and segment the building areas as the areas that remain after the polygons are drawn around the tank, vegetation, and process areas in a second digital image; (160, 860) and display the second digital image on a computer display device.