The rc-convex hull conjecture for hole-free digital pictures

Let $(X,c_2,c_1)$ be a digital picture with no hole, and let $H_{rc}(X)$ denote its rc-convex hull. Rc-convex hull conjecture. The digital picture $(H_{rc}(X),c_2,c_1)$ is a set of largest cardinality in the homotopy type of $(X,c_2,c_1)$. This conjecture asks whether the rc-convex hull always gives a largest representative within the homotopy type for hole-free digital pictures with adjacency pair $(c_2,c_1)$; the supplied text does not indicate whether it has been resolved.