ITT-4.1

ARCHITECTURES FOR GENERALIZED 2D FIR FILTERING USING SEPARABLE FILTER STRUCTURES
Michael S Andrews (LOGIC Devices, Inc.)

The problem of generalized 2D FIR filtering for large filter kernel sizes can be computationally prohibitive when required in real-time, such as with video applications. In this paper, we describe architectures and design methods for generalized 2D FIR filtering employing LOGIC Devices' LF33xx (HV Filter) family of devices. The LF33xx family of devices is designed to perform dimensionally separate filtering (row/column) along orthogonal axes (horizontal direction and vertical direction for video applications). Additionally, we will briefly review 2D filter design and kernel separability theory.

ITT-4.2

Segmentation of Non-Rigid Bodies in Affine Motion : A New Framework
Sangeeta Narang (IBM - Solutions Research Center, New Delhi, INDIA), Naresh K Narang (All India Radio, New Delhi), Kanad K Biswas (Indian Institute of Technology, New Delhi, INDIA)

In this paper a new technique for partitioning a non-rigid body (human body), when it is in affine motion is presented. The technique is based on finding the contour in the "modified difference frame". These contours can then be used in identifying the regions of interest. Results show that the technique eliminates a lot of stationary regions and thus can reduce the amount of computational time required for the processing of the image. It reduces significantly the total bit rate required for transmission. It also provides an algorithm for contour tracing using extended boundary concept and contour compression by contour merging.

ITT-4.3

Wireless MPEG-4 Video on Texas Instruments DSP Chips
Madhukar Budagavi (DSP Soulutions R&D Center, Texas Instruments), Wendi Rabiner (Massachusetts Institute of Technology), Jennifer Webb, Raj Talluri (DSP Soulutions R&D Center, Texas Instruments)

Technology has advanced in recent years to the point where multimedia communicators are beginning to emerge. These communicators are low-power, portable devices that can transmit and receive multimedia data through the wireless network. Due to the high computational complexity involved and the low-power constraint in wireless applications, these devices require the use of processors that are powerful and are at the same time very power-efficient. In order to facilitate interoperability, it is important that these devices use standardized compression and communication algorithms. As a first step in implementing multimedia terminals, Texas Instruments (TI) has demonstrated real-time MPEG-4 video decoding (simple profile) on a TMS320C54x, TI's low power, high performance DSP chip. In addition, TI has outlined a system-level solution to transmitting video across wireless networks, including channel coding and communication protocols.

ITT-4.4

JOINT MPEG-2 CODING FOR MULTI-PROGRAM BROADCASTING OF PER-RECORDED VIDEO
Irene Koo, Panos Nasiopoulos, Rabab K Ward (The University of British Columbia)

We developed a cost-effective operational system suitable for digital TV, video on demand, and high definition TV broadcast over satellite networks with limited bandwidth. This MPEG-2 based system is easy to implement and allows the joint video coding of multiple video programs. Compared to present broadcast operation and for the same level of picture quality, our system greatly increases the number of video streams transmitted in each channel. As a result, either a large number of transponders can be freed up to carry real-time broadcasting or the level of the transmitted picture quality can be significantly increased. By switching from tape storage to video server technology, the need for numerous (expensive) playback VTR systems at the headend is eliminated. In addition, the majority of the complete MPEG-2 encoders are replaced by much less complex MPEG-2 transcoders. All this means significant savings for the broadcast stations. In addition to the gain in bandwidth and the reduction in cost, our system speeds up the encoding process by six folds.

ITT-4.5

FPGA Implementation of Adaptive Temporal Kalman Filter for Real Time Video Filtering
Robert D Turney (CORE Solutions Group, Xilinx Inc.), Ali M Reza, Justin G Delva (Department of Electrical Engineering and Computer Science, University of Wisconsin-Milwaukee)

Filtering noise in real-time image sequences is required in some applications like medical imaging. The optimum approach in this case is in the form of adaptive 3-D spatial- temporal filter, which is generally very complex and prohibitive for real-time implementation. Independent processing of the image sequences, in spatial and temporal domains can resolve some of these implementation difficulties. Some of the existing spatial filters can easily be modified for real-time implementation. Adaptive temporal filters, however, are more involved. In this paper, an adaptive temporal filter is proposed that lend itself to hardware implementation for real-time temporal processing of image sequences. The proposed algorithm is based on adaptive Kalman filtering which is relatively simple and effective in its performance. Adaptation in this case is with respect to motion in the image sequence as well as variation of noise statistics. An efficient hardware implementation of this algorithm, based on FPGA technology, is proposed.

ITT-4.6

Programmable DSP Platform for Digital Still Cameras
Klaus Illgner, Hans-Georg Gruber, Pedro Gelabert, Jie Liang, Youngjun Yoo, Wissam Rabadi, Raj Talluri (Texas Instruments)

This paper presents a programmable DSP platform for Digital Still Cameras based on the Texas Instruments TMS320C54x family. One major advantage of this platform is that, after capturing an image from a CCD sensor, processing the raw image, and compressing the image for storage is performed on the Digital Signal Processor (DSP). This provides a short shot-to-shot delay and a high degree of flexibility. The system realized also allows instant viewing and selective storing of captured images. This paper outlines the various processing stages necessary to take the raw CCD data and produce a JPEG compressed bit stream and highlighting the advantages of DSPs for this application. The programmable nature of this platform allows for the exploration of different image processing and compression techniques. The low power nature of the digital signal processor provides long battery life.

ITT-4.7

A Robust Sequential Approach for the Detection of Defective Pixels in an Image Sensor
Yap-Peng Tan, Tinku Acharya (Intel Corporation)

Large image sensors usually contain some defects. Defects are pixels with abnormal photo-responsibility. As a result they often generate outputs different from their adjacent pixel outputs and seriously degrade the visual quality of the captured images. However, it is not economically feasible to produce sensors with no defects for rendering images. A limited number of defects are usually allowed in an image sensor as long as the defective outputs can be corrected with post signal processing techniques. In this paper we present a robust sequential approach for detecting sensor defects from a sequence of images captured by the sensor. With this approach no extra non-volatile memory is required in the sensor device to store the locations of sensor defects. In addition, the detection and correction of image defective outputs can be performed efficiently in a computer host. Experimental results of this approach are reported in the paper.

ITT-4.8

Adaptive Coding of Hyperspectral Imagery
Glen P Abousleman (Motorola, Systems Solutions Group)

Two systems are presented for compression of hyperspectral imagery. These systems utilize adaptive classification, trellis-coded quantization, and optimal rate allocation. In the first system, DPCM is used for spectral decorrelation, while an adaptive wavelet-based coding scheme is used for spatial decorrelation. The second system uses DPCM in conjunction with an adaptive DCT-based coding scheme. In each system, entropy-constrained trellis-coded quantization (ECTCQ) is used to quantize the transform coefficients. Entropy-constrained codebooks are designed for generalized Gaussian distributions by using a modified version of the generalized Lloyd algorithm. The wavelet-based system compresses an AVIRIS hyperspectral test sequence at 0.118 bits/pixel/band, while retaining an average peak signal-to-noise ratio (PSNR) of 41.24 dB. The DCT-based system achieves the same bit rate with an average PSNR of 40.72 dB.

ITT-4.9

Temporally Scalable Motion Compensated Adaptive Temporal Subband Coding of Video
Lowell L Winger (University of Ottawa), Anastasios N Venetsanopoulos (University of Toronto)

It has been asserted that temporal subband coding (TSB) is inferior to predictive coding for regionally motion compensated (e.g. block-based MC) temporally scalable compressed video \cite{conklin}. There are two major disadvantages of TSB coding: temporal filtering distortions, and `open-loop' predictive coding of covered and uncovered regions. The `open-loop' structure of TSB coding, however, affords two major advantages not enjoyed by MCP coding: simple optimal bit-allocation, non-existence of quantization error feedback. A new adaptive temporal subband (TSB) \/ motion compensated predictive (MCP) coder is proposed. Hierarchical variable-sized block-matched regions with low predictive error are TSB coded, while poorly predicted regions are `open-loop' MCP coded. Simulation results demonstrate that the adaptive coder substantially improves the temporal scalability of TSB coding, retains an advantageous `open-loop' structure and provides comparable or superior PSNR to both MCP and TSB coding at MPEG-1 quality bitrates.

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Last Update: February 4, 1999 Ingo Höntsch