1. A three-dimensional image processing system for use in a network environment comprising a three-dimensional image processing device including means for acquiring image data used in three-dimensional image production based on instructions from control computers, means for subjecting the image data to pre-processing to incorporate it into three-dimensional voxels, means for operating on the three-dimensional voxel image element values using object parameters that designate the color, opacity and space domain of the multiple objects that constitute the specimen so at to produce a single three-dimensional data construct, and means for operating on the three-dimensional data construct using projection processing parameters to construct three-dimensional images; multiple control computers each including means for designating image data used in three-dimensional image production, means for designating object parameters that designate the color, opacity and space domain of the multiple objects that constitute the specimen, means for setting projection processing parameters for constructing three-dimensional images from three-dimensional data, means for relaying these instructions to the three-dimensional image processing device, and means for displaying the three-dimensional images produced by the three-dimensional image processing device, and network means for connecting said three-dimensional image processing device and said control computers.