Sectional techniques for 3D imaging of microscopic and macroscopic objects

The confocal sectional 3D reconstruction method requires a special hardware which can analyze only small microscopic samples. A non-confocal sectional method called “shape-from-focus” is presented. This non-confocal method is capable of forming three-dimensional reliefs of both the microscopic and macroscopic samples without any special hardware and thus the financial requirements of the presented non-confocal method are minimum in comparison with the confocal method. Although the both these two methods are based on the same principle stemming from processing a series of digital images (optical sections), there is a striking difference between them. The present paper compares both these methods, discusses their advantages and disadvantages, specifies their limits and illustrates their particular properties by means of real microscopic and macroscopic 3D reconstructions. The main interest is focused on the non-confocal “shape-from-focus” method that is not so widely known as the confocal method and for this reason the “shape-from-focus” method is discussed in more details providing technical suggestions for attaining 3D projections of high quality.