This function perform a binary map of given saliency map

binaryMap = obj.computeBinaryMap(saliencyMap)

Input

• saliencyMap the saliency map obtained through one of the specialized algorithms, single matrix.

Output

• binaryMap the binary map, uint8 matrix with either 0 or 255 values.

This is obtained in this way: In a first step, to improve the definition of interest areas and facilitate identification of targets, a segmentation by clustering is performed, using K-means algorithm. Then, to gain a binary representation of clustered saliency map, since values of the map can vary according to the characteristics of frame under analysis, it is not convenient to use a fixed threshold. So, Otsu's algorithm is used, which assumes that the image to be thresholded contains two classes of pixels or bi-modal histograms (e.g. foreground and back-ground pixels); later on, the algorithm calculates the optimal threshold separating those two classes, so that their intra-class variance is minimal.