Patent application number | Description | Published |
20080198918 | Compression and Decompression Using Corrections of Predicted Values - A decompression process is used that forms a decompressed data value by adding a correction value to a signal value prediction. During compression the required correction value is computed. The correction value is encoded in two parts, such as an absolute value and a sign. It is tested whether more than one valid possible decompressed data value can be obtained by adding the signal value prediction to all of a plurality of different possible correction values that are consistent with a first part. A second part of the correction information is included in the compressed data, for selecting among the more than one possible decompressed data values, conditional on a result of said testing. The second part is omitted in cases where there is no more than one valid possible decompressed data value. During decompression the prediction is determined and it is tested whether the second part is needed or not to determine an unambiguous signal value. The second part is read from the compressed data when it is needed to select an unambiguous signal value. | 08-21-2008 |
20080205521 | Dpcm Coding Method of Video Signals - In a method for coding and decoding indicator data (d(x, y), S) are compared to a criterion (T). If the indicator data meet the criterion, an absolute value (Hival/Loval) is inserted instead of a predicted value based on differential coding. This amounts to a bypass of the differential coding loop, which reduces or eliminates oscillatory behavior in such loop, thereby reducing smearing of text parts of a compound image. The absolute values are preferably dynamically determined on the basis of previous predicted values. | 08-28-2008 |
20090022416 | REDUCTION OF COMPRESSION ARTEFACTS IN DISPLAYED IMAGES, ANALYSIS OF ENCODING PARAMETERS - A hither before unknown cause of image artefacts has been identified. Encoders such as MPEG encoders may use two picture structures: Field pictures and frame pictures. For a frame picture both frame and field-based DCT (and other types) of coding may be used. The decision whether to use frame or field based coding is not always made correctly. In the decoded image this leads to an image artefact visible as stripped blocks. The invention reduces, in one aspect of the invention, these artefacts by analyzing the block content on the presence of such artefacts and if the analysis proof the existence of such artefacts applying a vertical low pass filter to the data in the block. In another aspect of the invention encoding parameters are checked for combination of encoding parameters for which the artefact may occur and such blocks are indicated. The invention may be embodied in a method as well as in a device such as a receiver, encoder, decoder, display device etc. | 01-22-2009 |
20090034634 | DIFFERENTIAL CODING WITH LOSSY EMBEDDED COMPRESSION - A coding system ( | 02-05-2009 |
20100231426 | DEVICE AND METHOD FOR CODING A DATA SIGNAL AND DEVICE AND METHOD FOR DECODING A DATA SIGNAL - In a method for encoding and an encoder statistical information is generated and said statistical information (LSB=F(MSB) about the reconstruction values to be used during reconstruction (sometimes called “inverse quantization”) is added to the encoded data signal. The encoded data signal comprises data information providing information on the relation between parts of the original input data removed during quantization and the quantized data. The decoder and decoding method use the information data during reconstruction. This enables reconstruction values to be used during reconstruction that can adapt to the input data statistics thereby improving data reconstruction and reducing the quantization error. The reconstruction at the decoder is guided by information data which is gathered at the encoder, this information data being derived from determining statistical information on the removed parts of the input data in relation to the after quantization remaining quantized data. | 09-16-2010 |
20110019729 | CODING - Coding is provided in which a multi-media object is coded to obtain a bit-stream, and quality information is added to the bit-stream, which quality information indicates a quality of the object in relation to a given position in (or a given part of) the bit-stream. By adding quality information to the bit-stream, jointly storing or transmitting multiple coded objects can be optimized in that the quality of the object can be easily taken into account. | 01-27-2011 |
20120093429 | ENCODING A SIGNAL INTO A SCALABLE BITSTREAM AND DECODING SUCH BITSTREAM - The invention relates to a bit-plane coding method of signals, for example, an image or video signal in the DCT transform domain. The bit planes of the DCT blocks are transmitted bit-plane by bit-plane in order of significance. As each plane contains more signal energy than the lower significant layers together, the resulting bit-stream is scalable in the sense that it may be truncated at any position. The later the bitstream is truncated, the smaller the residual error when the image is reconstructed. For each bit plane, a zone or partition of bit plane is created that encompasses all the non-zero bits of the DCT coefficients in that bit plane. The partition is created in accordance with a strategy that is selected from a number of options in dependence of the content of the overall signal and/or the actual bit plane. A different zoning strategy may be used for natural images than for graphic content, and the strategy may vary from bitplane to bitplane. The form as well as other properties such as size of each partition can thus be optimally adapted to the content. Two-dimensional rectangular zones and one-dimensional zigzag scan zones may be mixed within an image or even within a DCT block. The selected zone creating strategy is embedded in the bitstream, along with the DCT coefficient bits in the actual partition. | 04-19-2012 |
20120155780 | Scalable Image Coding and Decoding - The invention relates to a scalable video (de)coding method for wireless transmission of high definition television signals. Scalable means that the bitstream contains successively smaller quality refinements and that the bitstream can be truncated. The video images are divided in slices, and each slice is divided in blocks of 8×8 pixels. For each block, an optimal encoding method is chosen. Depending on whether the block is found to contain natural or synthetic image content, transform coding (DCT) or graphic coding is applied. Because the different encoding modes have different properties as regards picture quality, the bitstream format has to enable the encoder to very flexibly choose which bits to send first. The bitstream format in accordance with the invention consists of a multitude of scans ( | 06-21-2012 |
20140210847 | APPARATUS AND METHOD FOR DYNAMIC RANGE TRANSFORMING OF IMAGES - An image processing apparatus comprises a receiver ( | 07-31-2014 |