Creation of a computer representation of a three-dimensional object surface is described. The viewing cones for camera positions at which images of the object were taken are determined and the intersection of these viewing cones is used to define an initial three-dimensional space within which the object surface lies. This initial space is divided into voxels. Each non-occluded voxel is checked for photoconsistency by comparing the colors (or average colors) of the pixel patches in the images to which that voxel projects. Photo-inconsistent voxels are removed. A voxel may be determined to be photo-inconsistent if there exists no set of photoconsistent pixel regions or the pixel patches do not share a color value range. The pixel patch into which each voxel projects in a further image may be compared with the stored color for that voxel and any photo-inconsistent voxels removed. This process can then be repeated for further images.