Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

We demonstrate the validity of wavelet-based processing for recognition and classification of three-dimensional phase objects. One Fresnel digital hologram of each of the three-dimensional (3-D) phase objects to be classified is recorded. The electronic holograms are processed digitally to permit 3-D object information to be retrieved as two-dimensional digital complex images. We use a Mexican-hat wavelet-matched filter (WMF) to enhance the correlation peak and discriminate between the objects. The WMF performs a wavelet transform (WT) to enhance the significant features of the images and the correlation of the WT coefficients thus obtained. We compare the feasibility of a WMF-based object classifier with the matched-filter-based classifier to classify our four 3-D phase objects in a 3-D scene into TRUE or FALSE classes with minimal error. © 2006 Optical Society of America.

Electronics

School of Electronics Engineering

Chennai Campus

World University root node

Applied Optics

Recognition and classification of three-dimensional phase objects by digital Fresnel holography

We propose and demonstrate a digital holographic technique for 3D object recognition and classification. One Fresnel digital hologram of each of the 3D objects to be classified is recorded. The electronic holograms are processed digitally to retrieve 3D object information as 2D digital complex images. We use this method to classify four physical objects in a 3D scene into two classes. Results are presented from an experiment to demonstrate the proof of the concept. © 2005 Elsevier B.V. All rights reserved.

Optics Communications

Three-dimensional object recognition from digital Fresnel hologram by wavelet matched filtering

We propose and demonstrate a technique based on digital holography for three-dimensional (3D) object recognition. In our method, the complex wavefront of the 3D object to be recognized is recorded as a Fresnel hologram using a CCD camera. A two step numerical reconstruction process, retrieval of complex wavefront recorded on the CCD plane and propagation of wavefront to the object plane, gives a complex valued two-dimensional (2D) image, which contains information regarding the amplitude and phase of the object wavefront in a 2D plane. The encoding of 3D object information as 2D digital image enables the use of various image-processing techniques for the post processing of the data. We use a Mexican hat wavelet matched filter (WMF) to discriminate between two different objects. WMF performs wavelet transform (WT) to enhance significant features of the images and the correlation of the so obtained WT coefficients in a single step. Digital wavelet matched filtering improves the discrimination capability and results in sharper correlation peaks as compared to classical matched filtering. As compared to many of the 3D recognition techniques based on the processing of 2D perspectives, our system has lesser complexity at the implementation and operational levels.