1. An output display device coupled to a computer which includes a processor with at a memory storing instructions for displaying a segmented digital volume representing a sample of a porous media comprising: a) voxels representing pore space derived from segmentation of a 3D grey scale digital image; b) voxels representing at least one solid material phase derived from segmentation of the 3D grey scale digital image; and c) converted voxels representing structural features not fully resolved in the 3D grey scale digital image or the direct segmentation thereof, wherein the structural features are cracks or conduits unresolved in the 3D grey-scale digital image and contributing pore space connectivity present in the porous media not accounted for in a preliminary segmentation of the 3D grey-scale digital image, and the converted voxels represent additional pore space, wherein: the placement of the converted voxels is derived from additional processing steps using data from the 3D grey-scale digital image and one or more segmented volumes derived therefrom; and the volume of converted voxels in place is solved to satisfy a criteria relation representative of the sample and independent of the 3D grey-scale image.