1. A method of detecting trees in an image, the method comprising: providing an input image of an area with trees; receiving at least one dimension related to the trees; applying a two dimensional (2D) high pass filter to the input image to produce a high pass image, wherein the 2D high pass filter is configured to mark objects based on the at least one dimension; producing a processed image by associating a set of pixels in the high pass image with a respective set of grayscale values, the grayscale values selected based on respective magnitudes of color variations around the set of pixels; applying a density operator to the processed image to identify locations with high frequency changes and marking the centers of the locations; defining shapes around the centers of the locations; identifying canopies by grouping two or more shapes; and identifying trees based on at least one of: identifying trees in the high pass image by identifying clusters of marked objects and identified canopies.