Composite Video Signal Research Articles

Adaptive video enhancement using neural network

This paper proposes an adaptive video enhancement method for digitally converted analog video. Analog video often has cross-luma artifacts and blurring artifacts by incorrect separation of a composite video signal. Even digital televisions suffer from these artifacts if high definition contents are converted from composite video contents. In order to reduce these artifacts, we trace signal patterns of artifacts and suppress them by using an adaptive linear filter. Moreover, to restore blurred edges of video, we adopt a neural network filter, in which weight coefficients are trained with artifact-free video. Experiments using a number of video sequences show the effectiveness of the proposed algorithm.

Edge-Based 3D Y/C Separation Using Wavelet Transform and Motion Compensation

We propose new 3D adaptive Y/C separation algorithm for the composite video signal decoding. The exact calculation of the similarity is one of the key issues for the Y/C separation. We propose new approaches for the composite video signal decoding: 1) the use of the wavelet transform of the composite video signal for effective similarity computation, 2) an edge-based separation by using the composite video signal directly for sharp-edged results, 3) a simple motion-compensated similarity computation between frames. Also, the proposed algorithm has an adaptive architecture with which multiplication coefficients are adjusted by the similarity values between two pixels in lines of a field, two consecutive fields, and two consecutive frames. In case of comb failure, the proposed scheme resorts to the traditional band-pass filtering method. The experimental results show that the proposed method provides better performance than that of the conventional Y/C separation algorithms.

A TV sign image expander with built-in closed caption decoder

A low cost TV set top box capable of expanding sign images and decoding closed caption data is described. Its internal architecture mainly consists of video decoder/encoder, 256 Kbytes of video memories, an infrared receiver and an FPGA based video processing unit. The FPGA implements a 27 MHz 8 bits microcontroller, an image expander, an on screen display unit, a 12C interface plus other control logic. The image expander uses a fixed 2/spl times/2 bilinear interpolation coupled with a nearest neighborhood input selection to simplify the hardware that allows 9 image scaling factors ranging from 1/spl times/1 to 2/spl times/2. The sign image that can be expanded is of the maximum size of 128/spl times/128 pixels or approximately 1/25 of the entire TV screen. This video processing unit can also decode both Thai and English caption codes inserted in the vertical blanking interval of the incoming composite video signal and display their Thai-English colored fonts in 32/spl times/16 dot matrix forms.

Design and implementation of a novel sync processing system for composite video signals

Sync processing will continue to be a mandatory block for future fully digital multimedia terminals, to offer a compatible analog video input. Conventional sync processing circuits employ a sync slicer combined with a PLL (phase locked loop) for line frequency filtering. The PLL is used for historical reasons and for ease of implementation, which however fundamentally limits the performance. This paper presents the prototype realization of a novel sync processing system, which offers a performance that is impossible with PLL-based solutions. It avoids any recursive processing blocks, is based on a free running clock system, and still delivers an orthogonal output pixel pattern. This paper concentrates on the prototypical implementation on a FPGA board and a synthesized design on a 0.35 /spl mu/m CMOS technology. Compared with state of the art PLL technology, the FGPA prototype demonstrates impressively the improved picture stability with all sources, especially with noisy and unstable analog signals.

0.8 μm cmos implementation of weighted-order statistic image filter based on cellular neural network architecture

In this paper, a very large scale integration chip of an analog image weighted-order statistic (WOS) filter based on cellular neural network (CNN) architecture for real-time applications is described. The chip has been implemented in CMOS AMS 0.8 /spl mu/m technology. CNN-based filter consists of feedforward nonlinear template B operating within the window of 3 /spl times/ 3 pixels around the central pixel being filtered. The feedforward nonlinear CNN coefficients have been realized using programmable nonlinear coupler circuits. The WOS filter chip allows for processing of images with 300 pixels horizontal resolution. The resolution can be increased by cascading of the chips. Experimental results of basic circuit building blocks measurements are presented. Functional tests of the chip have been performed using a special test setup for PAL composite video signal processing. Using the setup real images have been filtered by WOS filter chip under test.

Plasma Position Measurements in a Tokamak with an Iron Core Transformer

Two simple methods of estimating the plasma position in a large-aspect-ratio, low-βp tokamak with an iron core transformer are demonstrated: a magnetic diagnostic method and an optical method. The magnetic diagnostic method utilizes an array of magnetic pickup coils to measure the poloidal magnetic field produced by the plasma current. To include the effects of toroidicity and an iron core transformer, the correction factor was calculated with the magnetic material (or iron core) inside the calculation domain and incorporated in the analysis. The evolution of horizontal and vertical displacement of the plasma center obtained in this way is used to control the KAIST-Tokamak plasmas. To compare the plasma position estimated using the magnetic pickup coils, a simple optical method is also demonstrated on KAIST-TOKAMAK using a composite video signal from a charge-coupled device (CCD) camera. The two results are in good agreement.

Modulation of conventional TV signals in all-digital CATV network head ends

In this paper, a new digital intermediate frequency modulator for conventional TV signals using digital signal processing is presented. A composite colour video signal and two associated audio signals are converted into a digital composite TV signal with spectrum at intermediate frequency. The modulator is designed for the high quality requirements that exist in professional equipment for CATV head ends. The architecture of the digital modulator shown is optimized for an implementation with ASICs. The signal processing with reduced complexity is described in detail, the structures and the design of the filters are illustrated and the simulated results are presented.

A Color Coordinate Normalizer Chip

The use of multispectral images of the same object considerably increases the opportunity for unique selection of features. The use of color information has been receiving growing attention. This paper presents the design and VLSI implementation of a new ASIC, which performs real-time conversion of the raw RGB data into the rgb normalized color coordinates. The high speed of operation is achieved by pipelining the data in a vector fashion. Eight-bit color images have been used, since this resolution is adequate for encoding the composite video signal without noticeable degradation. The inputs to the circuit are the RGB data obtained from a color sensor and digitized through three flash ADCs. The design has been implemented using the CADENCE VLSI CAD tool. The die size dimensions for the core of the chip are 1.87 mm × 1. 80 mm e 3. 37 mm2, for a DLM, 0.7 mm, N-well, CMOS technology and its maximum frequency of operation is 30 MHz. The ASIC is intended to be used in real-time pattern recognition applications, such as robotics, military systems, food, printing, pharmaceutical and agricultural industries. Real-time techniques are important not only in terms of improving productivity, but also in reducing operator errors associated with visual feedback delays.

Spatiotemporal spectral coding of stereo image sequences

This paper presents a new compression scheme for interlaced stereoscopic sequences which differentiates between a region of fixation and a peripheral area, and thereby compacts the stereoscopic information into the spectral space of a monocular video channel. Spectral compression is achieved by avoiding transmitting high-frequency information over the entire images, but only within and around the region where the observer acuity is the highest. The proposed approach consists of decomposing the left and right fields of the stereoscopic pairs into low-pass and high-pass components. High-frequency components are then limited to a fixation region, thus allowing a reduction of their spectral extent. A composite video signal is then formed by positioning the different components into the available spectral space through filtering and modulation. The approach is compatible with the NTSC standard in the sense that the same color subcarrier and the same spectral region are used for the chrominance components. Strategies are proposed for the estimation of the fixation region, based upon a psychophysical study on visual strategies during depth discrimination tasks.

Multirate digital filter design for a PAL TV modulator

This paper develops a multirate digital filter design for the vestigial sideband (VSB) modulator required in the analog TV transmission systems, like PAL. The modulator takes as the input the composite video signal digitized at 13.5 MHz sample rate and the output is a VSB signal modulated to the usual 38.9 MHz IF picture carrier frequency and sampled at 121.5 MHz rate. The design is based on a complex baseband VSB filter running at the input sampling rate, digital multirate techniques for increasing the sampling rate by a factor of nine, and a combination of multirate techniques and digital mixing to translate the signal to the 38.9 MHz picture carrier frequency.

Chapter 1 Video Basics: Use of Camera and Monitor Adjustments

This chapter discusses the practical aspects of adjusting the video camera and the monitor to prevent the loss of specimen image gray-level information, a subject that is often treated in a most cursory fashion in the owners manuals for cameras and monitors. The problem one faces in coordinating camera and monitor adjustments is that there are too many interacting variables and no standard against which to evaluate the performance of the system. One can vary the intensity of the optical image on the photosensitive surface of the camera, camera settings, and monitor settings. All three appear interactive and can be used individually to seemingly optimize the quality of the image to some extent. When done in a haphazard fashion, empirical “knob twiddling” opens the real possibility of loosing specimen information, typically in the brightest and/or darkest portions of the image. The chapter also reviews, in a simplified fashion, a few aspects of the monochrome composite video signal, produced by tube-type cameras and conventional charge-coupled device (CCD) cameras.

Performance evaluation of a second generation metaphase finder for chromosome-based radiation dosimetry.

To be useful, a metaphase chromosome finder must be able to quickly identify chromosome spreads, rank them in terms of analysability and relocate them for visual examination at high magnification. In addition, the system should use state-of-the-art technology which is commercially available at competitive prices. The metaphase finder described here uses an 8-bit CCD camera (640 × 480 pixel resolution) and an Olympus BX-50 microscope with a × 20 apochromat objective. The camera composite video signal is connected to an image processing card (Matrox “COMET” card) for a final image resolution of 2.4 × 2.4 μm (5.8 μm2) per pixel for a 100 × 80 μm field of view. The microscope stage movements and focusing are under software control (illumination and filter selection are manual). Miniature motors (MicroMo 1616 series) and reduction gearboxes were retrofitted to a standard Olympus microscope stage and to the fine focus control shaft.

Low-cost acquisition of video images simultaneously with 240 electrophysiological signals

We developed a low-cost system for simultaneous collection and storage of physiological and video signals. The system samples and multiplexes up to 240 low-bandwidth analog channels with a camera video signal, and outputs a standard composite video signal containing analog and video data. The combined signals can be stored on video tape or can be digitized by an inexpensive framegrabber. The circuitry separates horizontal synchronizing pulses from a camera output; the pulses increment a counter that sequentially selects each electrophysiological channel on a sample-and-hold multiplexer. The intensity of each horizontal scan line from the multiplexer output represents the amplitude of one sample of each physiological channel. This signal is then multiplexed with the video signal, such that a portion of each video horizontal line represents the physiological data. The combined output is stored together, providing a means for synchronizing the two signals during analysis. The design allows easy coordination of electrophysiological events with video images from a standard video camera, avoiding the necessity for separate analog to digital circuitry for physiological and video signal storage on computer media, as well as the need for complex synchronization of the data from different media.

Component video signal-to-noise ratio analysis of FM and AM television system

The objective signal-to-noise performance of component colour video signals is analysed in this paper for FM and AM-VSB video transmission systems. In the analysis, the effect of splitting the composite video signal into its components, by subcarrier demodulation and colour decoding, is taken into consideration. The effect of non linearity of the display is also included in the analysis. An expression for objective component signal-to-noise ratio is derived for both the transmission systems. A relationship between the conventional composite video SNR and the component video SNR is established. Effective noise transfer, between the input and various stages of video signal processing, is discussed in detail. Noise spectral density analysis, for fully saturated primary colours, is evaluated quantitatively for a PAL-I video system. Finally, SNR performance of various hues at constant luminance is evaluated, and the results obtained are compared with the subjective noise visibility tests first carried out in 1957.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A PC-controlled multiple window display card for TV

The development of a personal computer (PC)-controlled multiple window display card for television is described. A digital encoder card for converting the red, green and blue (RGB) signals from the PC to a composite video signal (CVBS) is designed and developed. This digital encoder card accepts the RGB analog signals from the computer VGA display adaptor card and converts them into a PAL or NTSC format composite video signal. A chroma keying circuitry, to enable an additional video signal to be displayed with the encoded CVBS signal on a television screen in a picture-in-picture format is also included.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Development of a crosstalk measurement type three-dimensional digital color decoder

A three-dimensional digital color decoder system that converts composite NTSC or PAL video signals into cross color-free high picture quality digital video signals is described. In this system, the Y/C crosstalk is measured by means of three-dimensional filters which the authors have devised to adaptively control the three-dimensional Y/C separation filters. The algorithm is realized as hardware, and the picture quality is improved by a rank of 1.5 at a slight distance of 4H over the conventional three-dimensional digital color decoders when various composite color video signals including still images, slowly moving images, and moving circular zone plates are input. >

The Design Challenges of Full-Motion Video for PC-Compatible Computer Systems

In this article full-motion video applications for PC-compatible computer systems are divided into three subdivisions, according to functionality and application. The issues of the decoding and encoding of composite video signals, and of the keying and overlay of video signals originating from natural sources and signals synthesized by computer graphical means, are discussed as they relate to PC-compatible personal computer systems. The problems presented by the combination of interlaced and noninterlaced video signals, and by the requirements for color-space conversion, are reviewed. A brief discussion of compression schemes for the computerized handling of motion video is offered, followed by a review of design issues relating to image-processing structures and image-capture hardware.

ICs for digital image transmission

The digital image transmission IC digitizes and compresses picture signals from a camera for transmission over a twisted paired cable, allowing easy and inexpensive application in household video monitoring systems. Three types of integrated circuits have been developed. An encoder IC which subjects the digitized video signals to data compression and sends and receives control signals; a decoder IC that receives video data from the encoder IC and outputs composite analog video signals; and a hybrid IC which integrates an encoder IC with the majority of its peripheral circuits (including A/D conversion circuits and memory). The main specifications of the three ICs are indicated. >

Development of CD-graphics decoder

A CD-G (compact disc-graphics) decoder was developed by integrating all subcode signal processing sections (except V-RAM) required to configure a CD-G system on a single chip, including an integrated RGB (red, green, blue) encoder. The integrated digital RGB encoder allows the LSI to output analog composite video signals. This made it possible to reduce the required number of chips and external components compared to conventional decoders and resulted in further simplification of the CD-G system configuration. By taking advantage of the know-how gained through the development of the LSI described, the authors expect to reach even higher cost-performance levels in future LSI development projects. >

A single chip multistandard video encoder

A single-chip multistandard encoder (MSE) has been developed for multimedia and computer applications. The MSE is a highly integrated mixed signal CMOS IC which serves as a color encoder and a graphic DAC at the same time. All processing steps are carried out digitally, making any filter or color adjustment obsolete. It delivers an analog composite video signal and an S-VHS signal (chroma and luma separated) which can be fed directly into a 75 Omega video input (e.g. SCART) of a connected device. In addition, it includes three digital-to-analog converters (DACs) for the digital input signals which also can directly drive 75 Omega loads. The composite signals can be coded as PAL, NTSC (National Television System Committee), or SECAM or, in a special mode, a NTSC with 4.43 MHz color subcarrier frequency. The chip requires a digital component input signal that is 3-b*8-b RGB (red, green, blue) (true color) or YUV format.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>