A detection system implemented in a vehicle to detect free parking space is disclosed. The system comprises an input unit for imaging perspective view around the vehicle and a processing unit to receive a sequence of images from the at least one image sensor and detect at least one polygon pertaining to a parking slot in at least one image of the sequence of images, transform the at least one image into a bird's-eye-view image using a homography matrix, detect at least one quadrilateral pertaining to a parking slot, transform the bird's-eye-view image comprising the at least one quadrilateral, into corresponding image pertaining to perspective view around the vehicle using an inverse homography matrix, to analyse real world co-ordinates of the parking slot, and determine type of the parking slot by computing real world dimensions based on analysis of the real world co-ordinates of the parking slot.