Line doubler

Abstract: Television signal processing apparatus act on a received standard-bandwidth television signal to produce a high-definition-like video image relatively free of artifacts. A motion-adaptive line doubler operates in combination with a non-linear enhancer. In a practical implementation, the combination further includes a digital decoder. When the output of the decoder is applied to the line doubler, an interface provides a transition from the time base of the decoder to the time base of the line doubler. The non-linear enhancer includes bandwidth expanding enhancement for horizontal and/or vertical picture transitions.

Abstract: For large screen video displays using line-doubling to reduce scan line visibility, where a video source signal in standard interlaced format such as NTSC is converted to line-doubled non-interlaced format for progressively scanned display, visible motion degradations such as edge shimmer and strobe effects due to film-sourced video material are minimized by improved motion-detection video processing taught by this invention. In advance of actual display, successive fields are monitored for motion value in a first motion-detector and microprocessor comparator/analyzer where fields having high field-motion-value are detected as H-fields. Then, for display, each H-field is modified by pixel-averaging with a selected non-H-field. The regular and averaged fields are correctly sequenced to achieve vertical pixel alignment and smooth motion transitions thus minimizing film-source edge motion degradation. Film-mode entry and exit are accomplished automatically in a second motion-detector-analyzer that accomplishes fast film/video recognition and mode-switching. Film-mode entry and exit are each accomplished within a time period of one field, several times faster than in known art; such fast entry and exit are particularly important in avoiding visible motion defects under worst case conditions where regular video material is fragmented by frequent and/or non-synchronous spliced insertions of film-sourced or computer-generated portions.

Abstract: A television signal processing system includes a source of video images for providing luminance and chrominance components of the video images by generating and putting out scan lines. The source includes a low level horizontal domain detail processor connected for boosting low level horizontal transitions of the luminance component put out by the source below a predetermined threshold level. The system typically includes a signal-degrading path such as one characteristic of transmission or recording. The signal is passed through the degrading path to a display unit. A line doubler is preferably, although not necessarily, included in the display unit for doubling the number of decoded scan lines of the signal and for putting out scan line doubled luminance and chrominance components. A display image processor is connected to the line doubler and provides horizontal domain transition high level enhancement for enhancing horizontal domain transitions having amplitudes above the predetermined threshold level. The display image processor further preferably includes vertical enhancement for enhancing vertical domain transitions in accordance with predetermined vertical domain enhancement criteria, such as low level vertical detail boost and vertical contouring.

Abstract: A scan line doubler includes an input for receiving a video signal at a first scan rate, an output for providing a video signal at a second scan rate twice the first scan rate, a main path leading between the input and the output. The main path includes a scan line interpolation circuit for averaging pixels over two adjacent lines, a two-to-one scan line compression circuit for compressing original and interpolation scan lines into a scan line doubled format, and an optional additive path insertion location between the line interpolation circuit and the two-to-one line compression circuit. An openable connection path bridging the optional additive path insertion location is replaceable with an additive signal processing path including a field delayed pixel extraction circuit, a control circuit for generating a control in relation to detection of motion within the main path video signal, and a combining circuit responsive to the control for adding to the main path the one field delayed pixels and subtracting the line interpolated pixels, whereby when the optional path is connected, the scan line doubler operates in the horizontal, vertical and temporal domain, and when the optional path is not connected, the scan line doubler operates in the horizontal and vertical domains. An improved and simplified three-dimensional scan line doubler is an aspect of the present invention.