We propose a practical near real-time compression-based class-associative multiple target detection technique for color images. The size of the color images is reduced to its utmost ratio to speed up the processing time and to increase the storage capacity of the recognition system. A fringe-adjusted joint transform correlation technique is employed to successfully detect the compression-based multiple targets in colored images. In addition, to eliminate the false alarms and zero-order terms due to multiple desired and undesired objects in an input scene, we have used the shifted phase-encoded and the reference phase-encoded techniques. The performance of detecting the class-associative multiple targets for large compression ratios (up to 94%) and under strong noisy conditions (Gaussian and salt and pepper noises) is assessed through many computer simulations experiments. Furthermore, detecting small targets or even a small part of a target is presented for images occluded up to 90%.
In this paper, designs of ultra-fast all-optical based Terahertz-optical-asymmetric-demultiplexer (TOAD)-based
devices are reported. Using TOAD switches, adders/subtracters units are demonstrated. The high speed is achieved due to the use of the nonlinear optical materials and the nonbinary modified signed-digit (MSD) number representation. The proposed all-optical circuits are compared in terms of numbers TOAD switches, optical amplifiers and wavelength converters.
Most of the algorithm proposed for face recognition involve considerable amount of computations and hence they
cannot be used on devices constrained with limited memory. In this paper, we propose a novel solution for efficient face
recognition for systems which are charactered with small memory devices and
demand fast performance. By dividing the face images into components, the scheme finds the discriminant phases of the
Fourier transform of these components of face images. The discriminant phases are found by using linear discriminant
analysis (LDA) to obtain a system that matches the criteria imposed by devices of limited memory and requiring fast
recognition. Note that since the effects of face variation within an image are reduced when the image is divided into
components, then the performance of the system is enhanced. Compared to spatial domain analysis, it will be shown that
the use of component in the frequency domain produces better recognition performance. A thorough study and
comprehensive experiments relating time consumption and computational complexity versus system performance are
presented. The proposed technique increases the face recognition rate and at the same time achieves substantial saving in
the computational time, when compared to other known systems. The experimental results reveal that a recognition rate
of ≥99% is achieved, when applied to two independent and well known databases.
Being a popular choice among the biometric features, the fingerprint has long been used for identification and
verification purposes by security agencies. In this paper, additional images are included in the input joint images in a
joint transform correlator (JTC) to achieve a fast real-time fingerprint verification. In the proposed scheme, in addition
to the reference and the target image, the input joint image has a complementary reference image and a complementary
target image. At the correlation output of the JTC, the cross-correlation peak value between the reference and the
complementary target image and the cross-correlation peak value between the complementary reference and the target
images are used as the criteria to perform the recognition of the target in the input scene. It will be shown that these two
cross-correlation peak values will be zero if and only if the input target matches the reference image. The scheme is
employed to verify binary characters and binarized fingerprint images.
Simple grating filters such as rectangular and triangular ones are used in a two non-conventional real-time joint-transform correlation (JTC) architectures to eliminate the spatial light modulators (SLM) at the Fourier planes of a conventional JTC. In the first one, the grating filter is used along with a heterodyning and one-dimensional optical scanning techniques to capture the cross-correlation functions of the input images without major processing. This significantly reduces the time processing needed for real-time applications by eliminating the drawbacks of the non-ideal characteristics of the SLMs. In the second technique, the one-dimensional optical scanning is eliminated to achieve a faster (but a little bit more complicated) processing.
In this paper, we are proposing more efficient one-step negabinary signed-digit algorithms for the addition/subtraction operations. It is shown that by using digits grouping of the negabinary signed-digits, a huge reduction of the number of the symbolic substitution computation rules involved in the arithmetic computations will be achieved. Further, to increase the information storage density, one-step trinary negabinary (using base = -3) and negabinary quaternary (using base = -4) signed-digit will be proposed. The proposed algorithms are very suitable for optical implementation. Various holographic and nonholographic methods based on symbolic substitution content addressable memory (CAM) are suggested for optoelectronic implementation. Among them, the method of joint spatial encoding technique and incoherent optical correlator to act as as shared CAM will be presented.
A novel analytical approach is proposed for an accurate estimation of a broad range of Gaussian laser beam diameters. The new approach is used to study the performance of most recently proposed periodic and aperiodic rulings. Further, for spot-size measurement applications, which range from very small to very large beam diameters, a new single aperiodic exponential ruling is proposed.
A novel technique that employs phase encoding for the reference image and nonlinear Fourier plane apodization for optimizing the detection performance for multiple target detection is proposed. The proposed reference phase-encoded JTC overcomes false target detection by eliminating the false correlation peaks while alleviating the effects of noise and other artifacts in just one-step thus ensuring higher processing speed. Also, this technique yields only one peak per target instead of a pair of peaks produced by alternate JTCs. An all-optical implementation for the reference phase-encoded JTC technique is proposed and computer simulation results are presented.
Parallel one-step addition (subtraction), multiplication, and division is proposed to perform the computation of complex functions such as the square root, logarithm, exponential, and other related operations. An optoelectronic correlator based architecture is suggested for implementing the proposed modified singed-digit (MSD) number system representations based. We utilized the symbolic substitution technique to reduce the number of the computation rules involved.
One-step parallel addition and parallel multiplication operations using quaternary signed-digit numbers are proposed with symbolic substitution algorithm using optical cascaded correlation.
The spot size measurement of a Gaussian laser beam is extended to wide dynamic range through the formulation of a novel exponential grating. It is found that the exponential grating provides accurate measurement for both extremely small and large Gaussian beam diameters and proves to be superior to Ronchi, triangular, and sinusoidal rulings.
By combining two powerful optical computing techniques, namely, optical symbolic substitution (OSS) and polarization-encoded optical shadow-casting (POSC), an optical morphological hit-or-miss transformation is demonstrated and used in the recognition of perfect and imperfect shapes.
Rotation-invariant image sharpening schemes based on Roberts operators, difference operators, Laplacian, and high-frequency emphasis are realized using optical symbolic substitution. Symbolic systems based on both optical content-addressable memory and phase-only holograms are considered for these image enhancement schemes.
By combining two powerful optical computing techniques, namely, optical symbolic
substitution (OSS) and polarization-encoded optical shadow-casting (POSC), morphological or
shape transformation operations are demonstrated. Accordingly, erosion, dilation, opening, and
closing operations are realized using both OSS and POSC schemes. These morphological
operations are used for noise removal in binary images.
The architectural relationship between two powerful optical computing techniques namely, symbolic substitution and optical shadow-casting is discussed. A common basis for both the techniques are devel oped and their roots are traced back to fundumental principles of logic design. It has been shown that both shadow-casting and symbolic substitution based optical computing operations can be expressed as a logical sum of product expression.
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