Abstract: With the new plasma display panel technology new kinds of artefacts can occur in video pictures. These artefacts are commonly described as “dynamic false contour effect”, since they correspond to disturbances of grey levels and colors in the form of an apparition of colored edges in the picture, when the observation point on the PDP screen moves.

Abstract: The difference between the time responses of phosphor elements of a plasma display panel (17) shall be reduced by signal processing means without a need of a motion estimator.

Abstract: The invention is related two a new kind of plasma display panel control. A known principle for PDP control is based on a combination of sub-field addressing and priming. Within the priming period all the plasma cells of the panel are pre-excited by a strong voltage pulse. This treatment of the cells produces a slight background luminance which is a drawback for picture quality aspects because the achievable contrast is reduced. According to the invention it is proposed to use self-priming sub-fields (SPSF) and refreshing sub-fields (RSF) instead of this hard priming period. With these concept it is assured that the cells which ought to be black remain black. Self-priming sub-fields (SPSF) reduce or eliminate the need for priming, thus making dark areas darker, while refreshing sub-fields (RSF), can be addressed faster. In practice, the number of refreshing sub-fields (RSF) in a frame period is higher than the number of the self-priming sub-fields (SPSF).

Abstract: When the observation point on a PDP screen moves, artifacts will be introduced which are commonly described as “dynamic false contour”. A simple way to reduce this effect requires the use of more sub-fields at the expense of panel brightness. A first idea called Bit-Line-Repeat (BLR) makes it possible to exchange vertical resolution with addressing time in order to dispose of more sub-fields for the same brightness. Nevertheless, such a solution introduces some vertical artifacts mostly during movement. Therefore, before the step of sub-field encoding a vertically filtering of the picture divided into pixel blocks is performed, wherein each block includes at least one pixel in horizontal direction and a number of pixels corresponding to the number of common lines in vertical direction. The effect of the pre-filtering step is that the difference of brightness values within each pixel block is limited to a predetermined value.

Abstract: For stereoscopic displaying the new plasma display panels are providing promising results. When using shutter glasses that are controlled by the PDP, it is possible to display left and right image in short succession for stereoscopic displaying. However, there is the phosphor lag effect that is really disturbing and can totally impede the stereovision.

Abstract: The invention is related to a new kind of dithering method for plasma display panels. In a former Europena Patent Application a dithering method for the plasma display technology has been presented that utilizes a 3-dimensional dither pattern for the repeated use in a video sequence. A first dimension corresponds to a number of video frames, a second dimension corresponds to a number of video lines, and a third dimension corresponds to a number of cells or pixels in a video line. It has been found that this dither pattern has for some video levels the drawback of a generating a noticeable pattern in homogenous surfaces on the screen that reduces the picture quality.

Abstract: With the new plasma display panel technology new kinds of artefacts can occur in video pictures. These artefacts are commonly described as “dynamic false contour effect”, since they correspond to disturbances of gray levels and colors in the form of an apparition of colored edges in the picture when the observation point on the PDP screen moves. According to the invention, such an artefact is compensated by analyzing the pictures, and determining the pixels which need to be corrected. The digital sub-field code words of these pixels are replaced by corrected sub-field code words. Thereby, the correction sub-fields (C1, C2, C3) which are inserted in or omitted from the digital code word are selected under consideration of its position within the frame period for optimal results.

Abstract: With the new plasma display panel technology new kinds of artefacts can occur in video pictures. These artefacts are commonly described as “dynamic false contour effect”, since they correspond to disturbances of gray levels and colors in the form of an apparition of colored edges in the picture when the observation point on the PDP screen moves. According to the invention, such an artefact is compensated by analyzing the motion in the pictures, assigning to each block of a picture a corresponding motion vector and performing a re-coding step in which the different sub-fields of a pixel are shifted to distribute the sub-fields of a pixel more closely on the eye trajectory.

Abstract: Analyzing steps are used for automatic aspect format detection in digital video pictures. A black bars analyzing step is performed wherein for each possible aspect format (14:9, 16:9, 2:1) a top and/or bottom area is defined and checked for whether a black bar is present. A center analysis also is performed to check whether an active picture area is present. A horizontal transition analysis determines whether a horizontal border between a dark area and the active part of the picture is present, and then a format choice is made and the picture aspect format is selected. The method can control zoom operation in a TV receiver with a 16:9 picture tube or can control the recording function of a video recording device, in combination with the appropriate apparatus.

Abstract: With the new plasma display panel technology new kinds of artifacts can occur in video pictures. These artifacts are commonly described as dynamic false contour effect, since they correspond to disturbances of grey levels and colors in the form of an apparition of colored edges in the picture when the observation point on the PDP screen moves. According to the invention such an artifact is compensated by analyzing the motion in the pictures assigning to each block of a picture a corresponding motion vector and performing a re-coding step in which a sub-field code word entry of a current pixel are calculated. For this purpose the motion vector is defined to point from a pixel in a previous picture to a pixel in the current picture. The sub-field code word entries for a current pixel (P8) are determined by dragging sub-field entries of the pixels lying on the motion vector trajectory.

Abstract: The invention is related two an improved addressing scheme for plasma display panel control. In the conventional addressing scheme called ADS (Adressing and Displaying Separated), the whole panel is treated as one section and the addressing period within the sub-fields is broad because all lines of the whole panel are addressed one after the other in this single addressing period. This has the drawback that a long time distance is between writing a cell during addressing phase and light generation during the sustaining period. An improved addressing scheme has been proposed in literature, where the panel is partitioned in a number of sections and correspondingly the addressing period is split up in corresponding small addressing periods for each section. Inbetween the small addressing periods there is some light generation, so that the time distance between addressing and light emission is substantially reduced.

Abstract: With the new plasma display panel technology new kinds of artefacts can occur in video pictures. These artefacts are commonly described as “dynamic false contour effect”, since they correspond to disturbances of gray levels and colors in the form of an apparition of colored edges in the picture when the observation point on the PDP screen moves.