Optical and electronic design of a hybrid digital-optical correlator system

Birch, Philip; Claret-Tournier, Frederic; Budgett, David; Young, Rupert; Chatwin, Christopher R.

doi:10.1117/1.1428293

Cited by 17 publications

(6 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Young and his co-workers in 1993 outlined an opticaldigital hybrid correlator system that allows the potential for a multikilohertz reference template search on data acquired at video rates [5][6][7][8]. In this hybrid digital-optical correlation approach, the input data is digitally Fourier transformed and is multiplied with the digitally presynthesized distortion-invariant filters, and the product function is displayed over an electrically addressed spatial light modulator (SLM).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of perturbations in a hybrid digital-optical correlator

Bhagatji

Nishchal

Beri

et al. 2007

Optics and Lasers in Engineering

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

“…Pattern recognition using optical techniques, one of the most important and promising applications, has generated considerable amount of interest in the optics community for last few decades [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. As a result, optical correlator systems have now been started appearing in the market place [15].…”

Section: Introductionmentioning

confidence: 99%

Influence of perturbations in a hybrid digital-optical correlator

Bhagatji

Nishchal

Beri

et al. 2007

Optics and Lasers in Engineering

View full text Add to dashboard Cite

“…Young and his co-workers in 1993 outlined an optical-digital hybrid correlator system that allows the potential for a multikilohertz reference template search on data acquired at video rates [24][25][26][27] . In this hybrid approach, the input data is digitally Fourier transformed and multiplied with the digitally pre-synthesized distortion-invariant filters.…”

Section: Introductionmentioning

confidence: 99%

A hybrid digital-optical correlator for automatic target recognition

2007

View full text Add to dashboard Cite

Detection of rotationally distorted targets is a challenging task in pattern recognition applications. Recently, we proposed and implemented a wavelet-modified maximum average correlation height (MACH) filter for in-plane and out-of-plane rotation invariance in hybrid digital-optical correlator architecture. Use of wavelet transform improved the performance of the MACH filter by reducing the number of filters required for identifying a rotated target and enhancing the correlation peak intensity significantly. The output of a hybrid digital-optical correlator contains two autocorrelation peaks and a strong dc. To capture a desired single autocorrelation peak a chirp function with the wavelet-modified MACH filter was used. The influence of perturbations in hybrid digital-optical correlator has also been studied. Perturbations include, the effect of occlusion on input target, the effect of additive and multiplicative noise and their combined effect on input target, and the effect of occlusion of product function to be optically processed for obtaining the correlation outputs. The present paper reviews investigations on the hybrid digital-optical correlation scheme with special reference to the work carried out at the Photonics Division, IRDE Dehradun.

show abstract

“…Current image correlation techniques rely upon digital signal processing (DSP) elements, which are often too slow for target intercept applications because the data is compared serially. A holographic optical correlator (HOC) (10,11) offers parallel database searches much faster than DSP, but its potential has been limited by architectural constraints.…”

Section: Introductionmentioning

confidence: 99%

Shared-hardware alternating operation of a superparallel holographic optical correlator and a superparallel holographic RAM

Andrews

Shahriar²,

Tripathi³

et al. 2004

SPIE Proceedings

View full text Add to dashboard Cite

For practical pattern recognition and tracking systems, it is often useful to have a high-speed random access memory (RAM), which complements a holographic correlator. Recently, we have demonstrated a super-parallel holographic optical correlator, which uniquely identifies N images from a database using only 2 N number of detector elements. In this paper, we show how this correlator architecture, operated in reverse, may be used to realize a super-parallel holographic random access memory. We present preliminary results establishing the feasibility of the super-parallel holographic random access memory, and show that essentially the same set of hardware can be operated either as the super-parallel holographic optical correlator or as a super-parallel holographic random access memory, with a minor reorientation of some of the elements in real time. This hybrid device thus eliminates the need for a separate random access memory for a holographic correlator based target recognition and tracking system.

show abstract

Optical and electronic design of a hybrid digital-optical correlator system

Cited by 17 publications

References 10 publications

Influence of perturbations in a hybrid digital-optical correlator

Influence of perturbations in a hybrid digital-optical correlator

A hybrid digital-optical correlator for automatic target recognition

Shared-hardware alternating operation of a superparallel holographic optical correlator and a superparallel holographic RAM

Contact Info

Product

Resources

About