In this report, fuzzy correlation of color-histograms is proposed for the similarity measure between the color contents of images. By employing a weighted algorithm on the process of calculating the peak value of the correlation, it oers the flexibility to adapt to an image and its best matching images with partial color distortion or local color characters. Experimental examples demonstrate the ectiveness of the proposed method in its application to the retrieval of color images of interest specified by their color content.

Shape description matrix (SDM) describing regional pixel distribution characteristics of images is defined, with both radial and angular distribution messages taken into account to offer a comprehensive and exact description of the shape characteristics even upon a blurred edge. Using this SDM, a general color histogram (GCH) is developed. Both theoretical and experimental results show that the GCH can be applied to color-image retrievals and recognitions with a high efficiency.

An algorithm with non-linear weight factors in the summation process for fuzzy correlation of color his-tograms is presented, in which non-linear weights are assigned to some characteristic colors of interest. Experimental results show that this can improve the retrieval of color images with partial aberrations or with local color characters.

The use of a laser diode in a joint transform correlator (JTC) is proposed. Effects of temporal coherence, spatial coherence, astigmatism, and elliptical beams are analyzed. Laser diodes can be used in JTC, and also can be used for the correlation process in a Vander Lugt correlator and reading a hologram. Even a light-emitting diode (LED) may be used for the purposes mentioned, if its exit facet is sufficiently small. Two methods for correcting a laser diode beam using a cylindrical lens or a pair of cylindrical lenses are also reviewed. A corrected laser diode can be used in JTC to totally eliminate the effect of astigmatism.

A method for amplitude adjustment is proposed in this paper for the first time to improve the quality of binary images obtained from kinoforms by Iterative Fourier Transform Algorithm (IFTA). By setting the amplitude of the "zero" area in a binary image to a low but non-zero amplitude, their phase is involved in the iteration, which results in an increase of the freedom degree in the design of kinoforms, and an improvement of the quality of the reconstructed binary images. Quantitative illustrations and discussions of the improvement effect are given from simulation results.