cog_contour             Compute Contour-Based Center of Gravity (COG)
cog_potential           Compute Potential Energy-Based Center of
                        Gravity (COG)
cog_stroke              Compute Stroke-Based Center of Gravity (COG)
draw_contour            Visualize Contour-Based Region and Center of
                        Gravity (COG)
draw_potential          Visualize Potential-Based Center of Gravity
                        (COG) and Potential Field
draw_stroke             Visualize Stroke Region and Center of Gravity
                        (COG)
img_A                   Example Image A
img_B                   Example Image B
