A Comparison of Kekre's Fast Search and Exhaustive Search for Various Grid Sizes Used for Colouring a Greyscale Image

There are various techniques using various colour spaces that can be used to colour a greyscale image such as those described in [1], [2], [3] and [4]. In this paper we focus on the procedure described in [4] extended to seven different colour spaces – RGB, LUV, YCgCb, YCbCr, YUV, XYZ and YIQ. We also vary the grid (pixel window) sizes used in the aforementioned procedure and apply both the exhaustive search (ES) algorithm as well as Kekre’s Fast Search (KFS) algorithm to find the mapping with the least mean squared error and compare the results obtained across grid sizes.