1. A computer implemented method for shape based image analysis of linear objects, the method comprising: receiving at least one image of the linear objects, wherein the at least one image of the linear object corresponds to a linear object of interest, wherein the linear object is an object comprising at least a portion of the object with a linear and a finite length in the at least one image; extracting, homogeneous blobs from the at least one image using a blob extractor having polygonal contours; classifying the extracted polygonal contours by identifying a quadrilateral resembling contour based on shape of each blob of the homogeneous blobs using a trapezium classifier, wherein the classified quadrilateral-resembling contour is identified as candidate trapeziums having at least one pair of parallel edges; clustering, the candidate trapeziums based on spatial orientation and alignment of medial axes of the candidate trapezium and sorting the candidate trapeziums based on height of the candidate trapeziums to obtain longer trapeziums; detecting the linear objects of interest from the longer trapeziums based on context information, wherein the context information is a cross arm associated with each of the linear objects of interest, wherein the cross arm is detected based on the extracted polygonal contours, height of the longer trapeziums and angle of intersection of the cross arm with the detected linear objects of interest; and classifying the detected linear objects of interest as damaged based on at least one of height of the detected linear objects and inclination of the detected linear objects with respect to ground.