Showing papers by "Javier Garcia published in 1995"
TL;DR: An additional degree of freedom is introduced to fractional-Fourier-transform systems by use of anamorphic optics and preliminary results show preliminary results that demonstrate the proposed theory.
Abstract: An additional degree of freedom is introduced to fractional-Fourier-transform systems by use of anamorphic optics. A different fractional Fourier order along the orthogonal principal directions is performed. A laboratory experimental system shows preliminary results that demonstrate the proposed theory. Applications such as anamorphic fractional correlation and multiplexing in fractional domains are briefly suggested.
43 citations
TL;DR: It is shown that for many practical cases the phase information part of the color code is sufficient for obtaining good results and an implementation based on a liquid-crystal television panel that works in a phase-modulation mode is suggested.
Abstract: The common multichannel system for recognizing colored images is replaced by a color-encoded single-channel system. Amethod inspired by the Munsell color system is used for encoding the different colors as phase and amplitude functions. It is shown that for many practical cases the phase information part of the color code is sufficient for obtaining good results. An implementation based on a liquid-crystal television panel that works in a phase-modulation mode is suggested. Computer simulations that demonstrate the capabilities of the suggested method are given as well as a comparison with previously published multichannel performance.
26 citations
TL;DR: In this paper, a new criterion for locating the expansion center of circular harmonic filters is presented, which consists in the use of the information provided by both the circular harmonic energy map and the peak to correlation energy map of the object to be detected.
22 citations
TL;DR: An optoelectronic processor in which detail enhancement results from the digitally calculated difference between an original input image and its low-pass filtered version, and it is shown that the normalized difference between the morphological white and black top hats enhances bright and dark image details analogously to the rank-order unsharp masking.
Abstract: In all-optical processors, enhancement of image details is the result of high-pass filtering. We describe an optoelectronic processor in which detail enhancement results from the digitally calculated difference between an original input image and its low-pass filtered version. The low-pass filtering is realized through the rank-order median and the morphological opening and closing operations calculated by use of the optical convolver. It is shown that the normalized difference between the morphological white and black top hats enhances bright and dark image details analogously to the rank-order unsharp masking.
19 citations
TL;DR: A flexible hybrid opto-electronic processor for rank-order and morphological filtering is presented, based on the shadow-casting convolver architecture, and the threshold decomposition concept, which provides the possibility of programming the input image and structuring element at video rate.
17 citations
08 Mar 1995
TL;DR: In this paper, a radial stretching of the phase only filter depending on the energy angular distribution of the target spectrum is used to perform shift and scale invariant pattern recognition, and the complex conjugate of a basic size target Fourier transform and the cumulative energy angular distributions are calculated.
Abstract: A radial stretching of the phase only filter depending on the energy angular distribution of the target spectrum is used to perform shift and scale invariant pattern recognition. The complex conjugate of a basic size target Fourier transform and the cumulative energy angular distribution are calculated. Then the radially stretched filter providing the same energy contribution to the correlation peak independent on the target size is prepared and used in a conventional correlator, with spherical-wave illumination. The maximum scale ratio of recognizable objects equals 1:1.5. Computer simulations and experimental results, showing the performance of the filter are presented.
1 citations