PHOTOREALISTIC OBJECT RECONSTRUCTION USING VOXEL COLORING AND ADJUSTED IMAGE ORIENTATIONS

In this paper we present a voxel-based 3D reconstruction technique to compute photo realistic volume models from multiple color images. Visibility information is the key requirement for photorealistic reconstructions. In order to get the full visibility information item buffers are created for each image. In the item buffers each pixel is assigned the ID of the closest voxel it corresponds to. All scene points are projected into every image and if the ID stored in the pixel is the same as the voxel’s ID, they are checked for photo consistency. This way only visible (non-occluded) voxels are considered. Voxels are labelled either opaque and assigned a color value or transparent and carved away until no non-photo consistent voxel exists. Due to the missing of control points on the object, the images undergo a process of relative orientation in a free network using manually measured tie points. With these image orientations and a previously calibrated camera, the scene points are projected in a high accurate way, minimizing projection errors. This way objects are modelled where the application of control points is either impossible (e.g. in microscopic images) or uneconomical. Experimental results show that the combination of photogrammetric methods and shape from photo consistency techniques yield more accurate results since camera errors are taken into consideration and images are assigned individual orientation data.