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Physical Sciences and Mathematics Commons

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Selected Works

Professor Philip Ogunbona

Digital

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Articles 1 - 4 of 4

Full-Text Articles in Physical Sciences and Mathematics

Cmos Sensor Cross-Talk Compensation For Digital Cameras, Wanqing Li, Philip Ogunbona, Yu Shi, Igor Kharitonenko Sep 2012

Cmos Sensor Cross-Talk Compensation For Digital Cameras, Wanqing Li, Philip Ogunbona, Yu Shi, Igor Kharitonenko

Professor Philip Ogunbona

This paper presents two algorithms for removing the cross-talk effect in CMOS sensor based color-imaging systems. The algorithms work on the Bayer raw data and have low computational complexity. Experimental results on Macbeth color chart and real images demonstrated that both algorithms can effectively eliminate the cross-talk effect and produce better quality images with conventional color interpolation and correction algorithms designed for CCD image sensors. Complexity of the algorithms is also analyzed.


A Secure And Flexible Authentication System For Digital Images, Takeyuki Uehara, Reihaneh Safavi-Naini, Philip Ogunbona Sep 2012

A Secure And Flexible Authentication System For Digital Images, Takeyuki Uehara, Reihaneh Safavi-Naini, Philip Ogunbona

Professor Philip Ogunbona

Authentication of image data is a challenging task. Unlike data authentication systems that detect a single bit change in the data, image authentication systems must remain tolerant to changes resulting from acceptable image processing or compression algorithms while detecting malicious tampering with the image. Tolerance to the changes due to lossy compression systems is particularly important because in the majority of cases images are stored and transmitted in compressed form, and so it is important for verification to succeed if the compression is within the allowable range. In this paper we consider an image authentication system that generates an authentication …


Digital Watermarks For Copyright Protection, Nicholas Paul Sheppard, Reihaneh Safavi-Naini, Philip Ogunbona Sep 2012

Digital Watermarks For Copyright Protection, Nicholas Paul Sheppard, Reihaneh Safavi-Naini, Philip Ogunbona

Professor Philip Ogunbona

It is feared that the ease with which digital media can be copied will lead to a proliferation of copyright infringement. One proposed technical solution is digital watermarking, which embeds a hidden signal into host data that can be used in a variety of protocols that attempt to either prevent or deter copyright infringement. In this paper, we give a brief overview of digital watermarking and discuss some of the issues involved in providing effective digital watermarking systems for deterring copyright infringement.


A 96 X 64 Intelligent Digital Pixel Array With Extended Binary Stochastic Arithmetic, Tarik Hammadou, Magnus Nilson, Amine Bermak, Philip Ogunbona Sep 2012

A 96 X 64 Intelligent Digital Pixel Array With Extended Binary Stochastic Arithmetic, Tarik Hammadou, Magnus Nilson, Amine Bermak, Philip Ogunbona

Professor Philip Ogunbona

A chip architecture that integrates an optical sensor and a pixel level processing element based on binary stochastic arithmetic is proposed. The optical sensor is formed by an array of fully connected pixels, and each pixel contains a sensing element and a Pulse Frequency Modulator (PFM) converting the incident light to bit streams of identical pulses. The processing element is based on binary stochastic arithmetic to perform signal processing operations on the focal plane VLSI circuit. A 96 x 64 CMOS image sensor is fabricated using 0.5pm CMOS technology and achieves 29 x 29pm pixel size at 15% fill factor.