FOURIER TRANSFORM CODING OF IMAGES

The scientific advantages are pointed out from the Fourier transform encoding optical and electron microscope images and source data for computer-plotted Fourier-plane holograms, especially if bit compression ratios may be achieved, with comparable reconstructions, at the level found for the adaptive cosine transform. The relative importance is considered of image reconstruction based on the Fourier phase data alone and on combined phase and amplitude data. It is shown that bit rates as low as 0.3 bit per pixel can be achieved by encoding a combination of the Fourier phase and amplitude data. This is achieved by low-pass filtering together with a clustering procedure in the Fourier plane which seeks out the more important Fourier amplitude coefficients and their associated phases.