1. A computer implemented method for detecting an object in a scene comprising the steps of: capturing imagery of the scene proximate a platform; producing a depth map from the imagery, wherein each pixel in the depth map includes associated 3D position data; tessellating the depth map into a number of patches; classifying the plurality of patches as threat patches; projecting said threat patches into a pre-generated vertical support histogram to facilitate selection of said projected threat patches having a score value within a sufficiency criterion; grouping said selected patches having said score value using a plane fit to obtain a region of interest; and processing said region of interest to detect said object.