My original objective is to find the least cost path between two points. I am planning to do it with the "Cost Path" function of ArcGIS. Therefore, I have to construct a cost surface map for traversing through different land use types. I have an ArcGIS map service like the one below which I want to assign a specific cost. My idea is to convert each attribute of this map -which is quite distinguishable from each other- into a different raster file. Any ideas how could I do that or other recommendations to address my main goal?