TV Picture Quality Research Articles

36.3: A Dynamic Contrast Enhancement Method for TV Picture Quality Improvement

36.3: A Dynamic Contrast Enhancement Method for TV Picture Quality Improvement

画像の処理と符号化 フルーエンシ補間によるテレビ映像高精細化処理のハードウェア実装法

画像の処理と符号化 フルーエンシ補間によるテレビ映像高精細化処理のハードウェア実装法

Effects of Stereo and Motion Manipulations on Measured Presence in Stereoscopic Displays

Methods of assessing presence, a sense of ‘being there’ within a displayed virtual environment, include post-test subjective measures, discrimination tests, and monitoring reflexive responses. Each is limited—either they do not provide a measure of temporal variation, are not feasible with current display technology or are overly content-specific. A measure of presence derived from the method of continuous evaluation (ITU-R, Recommendation BT.500-7, revised, “Methodology for the subjective assessment of the quality of television pictures”, 1995) has been used to overcome these limitations. The results of two experiments are presented. Those of the first experiment established that the methodology is usable under the optimal viewing conditions for the 20 inch stereoscopic TV display upon which our stimuli were presented. It compares within-subject variation on continuous TV picture quality ratings under two viewing conditions—at six picture heights in the light (standard for quality evaluations) and at two picture heights in the dark (optimal stereo TV viewing). The second experiment investigated the effects of manipulations of the visual parameters of stereo, scene motion, and observer-based motion on participants' presence evaluations within edited sections of a stereoscopic film. The results provide support for theories predicting that the extent of sensory information available to a participant is one of the factors determining presence.

New method of in-service fault localisation in passive optical subscriber loops

A new method of detecting fibre breaks in a passive optical subscriber network without interruption to nonaffected customers is demonstrated. For these live measurements, an optical frequency domain reflectometry technique (OFDR) is used. No separate wavelength or additional components in the network are required. An integration facility on the AM/VSB TV-transmission system, without affecting TV-picture quality, is realised.

Improving TV picture quality with linear-median type operations

The FMH filter concept for video signal processing which combines the features of linear and median filters is introduced. In FMH (FIR median hybrid) filters, the overall output is the median calculated over the outputs of FIR subfilters, and the central input sample, the number of values to be sorted, is independent of the filter size; only the size of the FIR subfilters is altered. The noise reduction properties of FMH filters are similar to those of median filters. Applications within the field of digital enhanced TV, EDTV, and HDTV are presented with emphasis on noise suppression and image coding. >

A TV Ghost Canceller Using a CCD Transversal Filter

A system study has been conducted on a transversal filter ghost canceller to achieve system optimization, and an LSI CCD transversal filter for use in the ghost canceller was developed. Furthermore, a practical model of the ghost canceller was constructed on a trial basis. The results of field tests made on the test equipment showed that this system could improve TV picture quality by more than one grade in a five grade subjective evaluation and that the ghost canceller would be useful in practical applications.

A Simple Family of Digital Filters for a Binary Hierarchy

The concept of a binary hierarchy or family of TV picture quality levels is described. A family of digital filters designed for such a binary hierarchy is introduced. The main advantage provided by these filters is that they can be used to perform most up-conversion and down-conversion processes while utilizing essentially the same hardware components, the same boards, and the same layout. The filter's function is changed by means of wire jumpers and external control signals. The family concept can be extended to more complex filters. The use of these filters in the Digital Hierarchy Demonstrations is described.

Apparent improvement of TV picture quality through narrow pupils independent of overall quantal flux reduction.

Apparent improvement of TV picture quality through narrow pupils independent of overall quantal flux reduction.

Study of Noise in Television Broadcast Equipment

Noise* is a source of impairment in any form of information transmission system. In a television picture it is the fluctuating granular structure resulting from random brightness variations which is superimposed on the picture elements. — Although a video signal from a TV camera always contains noise, the signal-to-noise ratio prevailing in modern equipment is of such value that impairment of picture quality is minimal. At present, a major portion of television programing is the replay of video tape recorded from a TV camera output. The level of noise generated in the video-tape recorder and its video transmission characteristics which influence the original noise structure of a TV camera output are important elements in maintaining the high standard of TV picture quality. — Origin of noise in TV camera equipment, fundamental characteristics of an FM system used in a contemporary video recorder, and the potential sources of video noise associated with the video recording/replay process are discussed.

Factors Affecting the Correlation of TV Picture Quality Between Field and Laboratory Signals

Factors Affecting the Correlation of TV Picture Quality Between Field and Laboratory Signals