Abstract: For improving the grey scale portrayal, several dithering methods are used: Cell-based dithering, multi-mask dithering or error diffusion. Each of them has specific disadvantages. A simple combination of them does not bring expected advantages. However, an improvement is obtained if the result of the multi-mask dithering is used for controlling the error diffusion by a switch, for example.

Abstract: A system and method for adjusting modulation transfer function includes a color correction module configured to adjust source picture content based upon a reference display to output color corrected picture content. A modulation frequency function (MTF) simulation module is configured to receive the color corrected picture content and simulate the reference display using the color corrected picture content for a display with MTF characteristics different than the reference display.

Abstract: The invention relates to a method for processing video data to be displayed on a display device having a plurality of luminous elements corresponding to the pixels of a video picture, wherein an error diffusion step is applied to at least a part of said video data to refine the grey scale portrayal of said video picture, said error diffusion step comprising, for each current pixel of said part of video picture, a step of truncating the value of the corresponding video data and a step of diffusing the truncation error to at least one neighboring pixel. According to the invention, a noise is inserted on the error before and/or after its diffusion to the neighbouring cells. Owing to this principle no static pattern should be visible, improving the overall picture quality.

Abstract: A system and method for compensating for average brightness dependency (ABD) differences between displays with and without average brightness dependency (ABD) includes color correcting source picture content on a reference display to output color corrected picture content. In addition, an ABD simulation process uses the color corrected picture content to simulate the display of content on the reference display. Subsequently, a compensation process receives the color corrected picture content and information from the simulation process and applies an ABD compensation characteristic to the color corrected picture content for correctly displaying the source picture content on a display with different ABD characteristics than the reference display.

Abstract: CMOS image sensors are usually suffering from fixed pattern noise and random defect pixels. However, for economical reasons and in order to increase the manufacturing yield, some random defective pixels are usually accepted even for professional devices. In this case, the defect pixels are usually corrected by signal processing.

Abstract: The invention relates to a method and a device for coding video levels of pixels of a colour component of a picture to be displayed on a display device into code words. The invention is more particularly applicable to Plasma Display Panels (PDP) to improve the picture quality (grayscale enhancement, dynamic false contour reduction). The main idea of the invention is to automatically change the floor and ceiling levels used classically for dithering each pixel value depending on the neighboring pixels of the same color component. The size of the window determining the neighboring pixels is dependent on the definition of the wanted flat field size.

Abstract: The present invention relates to an apparatus for displaying an input picture of a sequence of input pictures during a video frame made up of N consecutive sub-frames, with N?2, comprising an active matrix comprising a plurality of light emitting cells, encoding means for encoding the video data of each pixel of the input picture to be displayed and delivering N sub-frame data, each sub-frame data being displayed during a sub-frame, a driving unit for selecting row by row the cells of said active matrix and converting, sub-frame by sub-frame, the sub-frame data delivered by said encoding means into signals to be applied to the selected cells of the matrix. According to the invention, at least one of the N sub-frame data generated for a pixel is different from the video data of said pixel.

Abstract: In the field of video displaying the low video levels do not generate large area flicker. For displaying video sources with higher frame rate, it is therefore the idea of the invention, to extract from two corresponding pixels of two successive video frames a common portion (Vx) that will be displayed at a sub-frequency fv/2 while the individual portions (V1?, V2?) of the corresponding pixels video are displayed at the correct high frequency fv. The time period for displaying two frames is divided into three sub-groups. Two groups of sub-fields with similar sizes, for displaying the individual portions (V1?, V2?) and one group of sub-fields, called extra-codes, for displaying the common portion (Vx). This enables to eliminate large area flicker artifacts from PDPs, when displaying 50 Hz based video norms by using upconverted 100 Hz video sequences and to display real high frequency video on the PDP (ca. up to 120 Hz) without frame dropping.

Abstract: The invention relates to a method for processing video pictures data for display on a display device having a plurality of luminous elements corresponding to the pixels of a video picture. The invention is related to every kind of display devices based on the principle of duty cycle modulation (pulse width modulation) of light emission and comprising a data driver. The aim of this method is to reduce the data driver overheating by optimizing the dithering of the pixel values of the video pictures. According to the invention, the pixel values used for dithering are chosen for reducing the state changes between successive bits of subfield code words of adjacent luminous elements.

Abstract: The invention relates to a method for correcting chromatic aberration in an image capture device like a camera. It comprises the steps of determining, in the image, an analyzing area around the current pixel, comparing, for the current pixel, a first color component data of a first block of pixels comprising the current pixel to a second color component data of pixels of second blocks of pixels having the same size as the first block within the analyzing area, selecting the second block of pixels having the highest correlation with the first block of pixels, determining the shift vector to be applied to the selected second block in order that said selected second block coincides spatially with said first block of pixels, and shifting the second color component data of the pixel of the selected second block corresponding to the current pixel in accordance with the shift vector so as to correct chromatic aberration.

Abstract: In many cases it is not possible to reproduce enough video levels on a PDP due to timing issues or a specific solution against the false contour effect. In such cases dithering is used to render all required levels. In order to reduce the visibility of the dithering noise there is performed a common change of the sub-field organization together with a modification of the input video data through an appropriate transformation curve based on the human visual system luminance sensitivity (Weber-Fechner law).

Abstract: The driving of an active matrix organic light emitting display (AMOLED) shall be improved. A pulsing grayscale rendition shall be combined with an improved motion rendition when driving the AMOLED with analog signals. Therefore, there is provided a data signal which is applied to each cell of the AMOLED for displaying a first grayscale level of a pixel of the image during a first group of sub-frames for displaying at least a second grayscale level of a pixel of the image during at least a second group of sub-frames. The first group of sub-frames and the at least second group of sub-frames are constituting a video frame N. Each group of sub-frames is divided into a plurality of sub-frames. Each, the first group of sub-frames and the second group of sub-frames is belonging to a separate complete image of the display (AMOLED).

Abstract: The picture quality on a plasma display panel shall be improved when the contrast and/or the brightness are reduced. This is achieved by estimating the reduction of the dynamic occurring in the front-end of the data processing of the plasma display device and by compensating it in the back-end. Specifically, the gain and/or offset of the video input data are adjusted and the power level of the adjusted video data is measured. The resulting power level information is updated on the basis of an attenuation information. The updated power level is used for the power management and the level of the video data being reduced in the front-end is increased on the basis of the attenuation information. Thus, the dynamic of the video and, as a result, the picture quality are improved.

Abstract: The invention relates to a method and a device for encoding the video level of a pixel of a picture into a subfield code word in a display device. It can be applied to every display device using a PWM (Pulse Width Modulation) technology and subfields for displaying video picture. The bits of the subfield code word are computed recursively one after the other from the bit having the most significant weight to the bit having the least significant weight. According to the invention, for determining the state of a bit of the subfield code word, a first threshold and a second threshold is associated with said bit, said second threshold being greater than said first threshold, and the video level to be encoded by this bit and its following bits in the subfield code word are compared to the first and second thresholds. If the video level is lower than the first threshold, a state “OFF” is allocated to the bit.

Abstract: The present invention relates to a grayscale rendition method in an active matrix OLED (Organic Light Emitting Display) where each cell of the display is controlled via an association of several Thin-Film Transistors (TFTs). In order to improve the grayscale rendition in an AM-OLED when displaying low grayscale levels and/or when displaying moving pictures, it is proposed to split each frame into a plurality of subframes wherein the amplitude of the data signal applied to a cell of the AM-OLED can be adapted to conform to the visual response of a CRT display. According to the invention, the video frame used for displaying an image is divided into N consecutive subframes, with N?2, and the data signal applied to the cell comprises N independent elementary data signals, each of said elementary data signals being applied to the cell during a subframe. The grayscale level displayed by the cell during the video frame is depending on the amplitude of the elementary data signals and the duration of the subframes.

Abstract: The present invention relates to a method and an apparatus for processing video pictures for dynamic false contour effect compensation.

Abstract: The sharpness impression when displaying a movement on an AMOLED (Active Matrix Organic Light Emitting Display) shall be improved. For this purpose, an apparatus for driving a cell of an AMOLED is provided including driving means for applying a driving voltage to the cell and for applying a luminance control signal to the cell during a pregiven time frame. The apparatus further includes controlling means for varying the driving voltage within the time frame according to a predefined function of time. For example, the driving voltage may be varied in the form of a triangle so that the lighting time over the frame is reduced while a CRT like behavior is emulated.

Abstract: The present invention concerns a method for transcoding a N bits word into a M bits word with M<N. The invention is applicable in various fields and more particularly in the display field. The method comprises the following steps:-breaking down the N bits word into an exponent part and a mantissa part having each a size which varies according to the value of said N bits word, the size of the mantissa part increasing with the value of said N bits word, and -encoding the exponent part of the N bits word into a variable number of bits A and removing, if need be, least significant bits of the mantissa part in order to obtain a mantissa with a variable number of bits B, with A+B=M.

Abstract: For reducing the false contour effect the gravity centre coding is utilized. However, a GCC with a few number of levels introduces noise in a picture. Therefore, each picture is divided into segments and such GCC is performed only in regions, where the false contour effect is critical. This is the case for skin areas of a picture. Such areas are detected by the colour analysis and texture analysis. If this analysis leads to a skin area, a specific false contour mode for data processing is used. Otherwise, a standard mode is employed.

Abstract: An imager achieves a desired image resolution by successively reproducing partial images which complement each other. The imager assigns pixels from an input image to the respective partial images according to complementing patterns that correspond to the pixel pattern of the imager. The imager reproduces the complementing pattern at different spatial positions, such that the complementing patterns merge. In order to avoid perceived double imaging of moving object s the image signal provided to the imager is assembled from an original image and a motion compensated interpolated image, which is derived from at least two consecutive images. Accordingly, every other partial image that is reproduced is derived from an interpolated image and takes into account movement of objects in the image that takes place between two consecutive images. In one embodiment the partial images are re-combined into one full image in a sequence that anticipates the distribution of the pixels used in the imaging device.