In general, adjacent pixels of a 3-D image have very similar values of intensity and depth and some of them even have
the exactly same values of them each other. In other words, a 3-D image has a spatial redundancy in intensity and depth
data. This spatial redundancy can be represented with the run-length encoding method, which has been used for data
reduction of the conventional 2-D images. Also, when these redundancies are expanded by line scale, the values of the
line have similar value of the previous line.
Recently, N-LUT method to dramatically reduce the number of pre-calculated interference patterns required for
generation of digital holograms was proposed. In this method, the fringe patterns for other object points on each image
plane can be obtained by simply shifting this pre-calculated PFP according to the displaced location values from the
center to those points and adding them together. Accordingly, CGH pattern for arbitrary line is shifted with amount of
discretization step for the direction of next line, same images for arbitrary line are generated in the next line. And then
differences between two lines are occurred, these differences are compensated in CGH pattern using the N-LUT method.
Accordingly, in this paper, a new approach for fast computation of CGH patterns for the 3-D image by taking into
account of the line-redundancy between lines of the 3-D image is proposed. Some experiments with a test 3-D object are
carried out and the results are compared to those of the conventional methods.