Recognition of partially occluded objects by correlation methods
TL;DR: In this paper, the phase-only filter, the inverse filter and the minimum variance -minimum average correlation energy filter are considered for pattern recognition of occluded objects, and numerical and optical results of the recognition are presented.
About: This article is published in Optics Communications.The article was published on 1994-03-01. It has received 16 citations till now. The article focuses on the topics: Inverse filter & Filter (video).
Citations
More filters
TL;DR: Several algorithms are developed to produce optical filters for obscured inputs that operate over a wide range of obscurations while others have restricted operating ranges.
Abstract: Several algorithms are developed to produce optical correla- tion filters for obscured inputs Each algorithm is optimal for a different set of performance criteria Computer simulations using binary inputs indicate that some algorithms operate over a wide range of obscurations (down to 5% of the input) while others have restricted operating ranges © 1998 Society of Photo-Optical Instrumentation Engineers (S0091-3286(98)01701-2) Subject terms: recognition techniques; pattern recognition; optimal filtering; cor- relation; associative memory
15 citations
TL;DR: Adaptive estimation of the noise power spectral density distribution may be obtained from input power spectra information and provides great flexibility and real-time adaptivity to colored noise, resulting in improved correlation performance.
Abstract: We propose general, simple, and powerful means of extending the capabilities of conventional joint-transform-correlator systems to enable a priori or adaptive Wiener filtering as well as parametric Wiener filtering of patterns corrupted by colored noise. Adaptive estimation of the noise power spectral density distribution may be obtained from input power spectra information and provides great flexibility and real-time adaptivity to colored noise, resulting in improved correlation performance.
14 citations
TL;DR: A new algorithm for the design of a system consisting of a set of adaptive correlation filters for recognition of partially occluded objects in noisy scenes, which consists of a bank of composite optimum filters, which yield the best performance for different parts of the target.
Abstract: Design of conventional correlation filters requires explicit knowledge of the appearance and shape of a target object, so the performance of correlation filters is significantly affected by changes in the appearance of the object in the input scene. In particular, the performance of correlation filters worsens when objects to be recognized are partially occluded by other objects, and the input scene contains a cluttered background and noise. In this paper, we propose a new algorithm for the design of a system consisting of a set of adaptive correlation filters for recognition of partially occluded objects in noisy scenes. Since the input scene may contain different fragments of the target, false objects, and background to be rejected, the system is designed in such a manner to guarantee equally high correlation peaks corresponding to parts of the target in the scenes. The key points of the system are as follows: (i) it consists of a bank of composite optimum filters, which yield the best performance for different parts of the target; (ii) it includes a fragmentation of the target into a given number of parts in the training stage to provide equal intensity responses of the system for each part of the target. With the help of computer simulation, the performance of the proposed algorithm for recognition partially occluded objects is compared with that of common algorithms in terms of objective metrics.
12 citations
Cites background or result from "Recognition of partially occluded o..."
...In theOTSDF formulation,matrixD is replaced withV = D+ 𝛿I, where I is an identity matrix and 𝛿 > 0....
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...Tables 3 and 4 show FP and FN errors for the proposed algorithm with division of the object into 9 fragments (𝐹9), MACE, OTSDF, SDF, and SDF with MACE....
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...[22] carried out a study on the performance of some correlation filters to discriminate occluded objects....
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...The Optimal Trade-off Synthetic Discriminant Function (OTSDF) [14] filter is a correlation filter that is similar to the MACE filter....
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...The results are compared with those obtained with successful composite correlation filters, that is, MACE [34], OTSDF [22], SDF [14, 35], and SDF with MACE (SMACE) filters [23, 24]....
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TL;DR: Adaptive correlation filters based on synthetic discriminant functions for recognition of partially occluded objects imbedded into a cluttered background are proposed.
Abstract: One of the main problems in visual image processing is incomplete information owing an occlusion of objects by other objects. Since correlation filters mainly use contour information of objects to carry out pattern recognition then conventional correlation filters without training often yield a poor performance to recognize partially occluded objects. Adaptive correlation filters based on synthetic discriminant functions for recognition of partially occluded objects imbedded into a cluttered background are proposed. The designed correlation filters are adaptive to an input test scene, which is constructed with fragments of the target, false objects, and background to be rejected. These filters are able to suppress sidelobes of the given background as well as false objects. The performances of the adaptive filters in real scenes are compared with those of various correlation filters in terms of discrimination capability and robustness to noise.
9 citations
TL;DR: In this paper, the influence of perturbations in a hybrid digital-optical correlator that uses images obtained from CCD camera and rotation-invariant maximum average correlation height filter is investigated.
6 citations
References
More filters
TL;DR: This work examines the relationship between phase and amplitude in the case of alphanumeric characters, with and without noise, using a computer simulation and compares the phase-only and amplitude-only filters to the classical matched filter using the criteria of discrimination, correlation peak, and optical efficiency.
Abstract: From image processing work, we know that the phase information is significantly more important than amplitude information in preserving the features of a visual scene. Is the same true in the case of a matched filter? From previous work [
J. L.
Horner
,
Appl. Opt.21,
4511(
1982)], we know that a pure phase correlation filter can have an optical efficiency of 100% in an optical correlation system. We examine this relationship between phase and amplitude in the case of alphanumeric characters, with and without noise, using a computer simulation. We compare the phase-only and amplitude-only filters to the classical matched filter using the criteria of discrimination, correlation peak, and optical efficiency. Three-dimensional plots of the autocorrelation and cross-correlation functions are presented and discussed.
939 citations
TL;DR: The synthesis of a new category of spatial filters that produces sharp output correlation peaks with controlled peak values is considered, and these filters are referred to as minimum average correlation energy filters.
Abstract: The synthesis of a new category of spatial filters that produces sharp output correlation peaks with controlled peak values is considered. The sharp nature of the correlation peak is the major feature emphasized, since it facilitates target detection. Since these filters minimize the average correlation plane energy as the first step in filter synthesis, we refer to them as minimum average correlation energy filters. Experimental laboratory results from optical implementation of the filters are also presented and discussed.
741 citations
TL;DR: It is shown that the POF appears to provide a good compromise between noise tolerance and peak sharpness, with the help of a new family of filters called fractional power filters (FPFs).
Abstract: Several performance criteria are described to enable a fair comparison among the various correlation filter designs: signal-to-noise ratio, peak sharpness, peak location, light efficiency, discriminability, and distortion invariance. The trade-offs resulting between some of these criteria are illustrated with the help of a new family of filters called fractional power filters (FPFs). The classical matched filter, phase-only filter (POF), and inverse filter are special cases of FPFs. Using examples, we show that the POF appears to provide a good compromise between noise tolerance and peak sharpness.
572 citations
TL;DR: A method of constructing optimal multicriteria filters for optical pattern recognition by illustrated for double-optimization criteria, and filters that are not overspecialized are obtained, in contrast with traditional techniques.
Abstract: A method of constructing optimal multicriteria filters for optical pattern recognition is presented. In the particular case of synthetic discriminant function filters, this method is illustrated for double-optimization criteria, and filters that are not overspecialized are obtained, in contrast with traditional techniques. Furthermore, a rigorous comparison between different filters, with respect to the considered criteria, is provided with this approach.
256 citations
TL;DR: This work reports here on the use of a phase mask which imparts a phase shift of 180 degrees to half the data spots chosen at random and shows that the intensity in the Fourier transform plane is now proportional to the intensity of the Fouriers of one single data spot.
Abstract: In a holographic page-oriented memory the information is stored in an array of holograms. It is advantageous to record the Fourier transform of the original data mask because the minimum space bandwidth is then required and the information about any one data bit is spread over the hologram plane. In the Fourier transform plane most of the light is concentrated in an array of bright “spikes” because the data mask consists of an array of equidistant data spots. Some means is needed to distribute the light more evenly. We report here on the use of a phase mask which imparts a phase shift of 180° to half the data spots chosen at random. An analysis shows that the intensity in the Fourier transform plane is now proportional to the intensity of the Fourier transform of one single data spot.
225 citations