Nokia Corporation

Nokia Technologies Oy

Justin Ridge

Xianglin Wang

Marta Karczewicz

Yiliang L Bao

Ye-Kui Wang

Miska Matias Hannuksela

Igor Danilo Diego Curcio

Stephane Coulombe

A method, apparatus and computer program products are provided for capturing omnidirectional video with one or more cameras, streaming the video over a network, and rendering the video on a Head Mounted Display (HMD) and more specifically to a method, apparatus, and computer program product for improving the visual quality of viewport-based omnidirectional video streaming. One example method includes selecting a primary viewport, encoding a first representation that covers the primary viewport, and encoding a second representation that provides a gradual picture quality change from a background viewport to the primary viewport.

Method and apparatus for improving the visual quality of viewport-based omnidirectional video streaming

A video coding method comprises dividing a coefficient vector into two or more sub-vectors, each sub-vector having a length less than or equal to a length of the coefficient vector, indicating a size of each sub-vector and a position of each sub-vector within the coefficient vector, and forming a block corresponding to each sub-vector.

System and method for video encoding and decoding

An improved system and method for providing improved inter-layer prediction for extended spatial scalability in video coding, as well as improving inter-layer prediction for motion vectors in the case of extended spatial scalability. In various embodiments, for the prediction of macroblock mode, the actual reference frame index and motion vectors from the base layer are used in determining if two blocks should be merged. Additionally, multiple representative pixels in a 4&#xd7;4 block can be used to represent each 4&#xd7;4 block in a virtual base layer macroblock. The partition and motion vector information for the relevant block in the virtual base layer macroblock can be derived from all of the partition information and motion vectors of those 4&#xd7;4 blocks.

Inter-layer prediction for extended spatial scalability in video coding

A system and method for predicting an enhancement layer macroblock. A base layer frame is divided into intra-coded and inter-coded regions. If any portion of the enhancement layer macroblock is covered by both an intra-coded base layer macroblock and an inter-coded base layer macroblock, predictions utilizing the intra-coded and inter-coded macroblocks are established independently to generate at least two prediction values. The at least two prediction values are then combined to give a prediction from which the enhancement layer block is coded. Various embodiments serve to smooth the boundary effect between intra-coded regions and inter-coded regions inside the inter-layer prediction for extended spatial scalability.

Scalable video coding

A system and method for providing improved FGS identification in scalable video coding. According to the present invention, each FGS enhancement layer is assigned a unique dependency identifier and contains only FGS enhancement information. For subsequent enhancement layers, the base dependency identifier for the subsequent enhancement layers will point to either a base-quality layer or an FGS enhancement layer.

FGS identification in scalable video coding

A method, program product and apparatus for decoding from a scalable bit stream the binarization results of a video sequence by selectively decoding syntax elements and avoiding redundancy in coding. The result is a decrease in the size of the compressed bit stream of an enhancement layer bit stream. It has been demonstrated that the compression efficiency equals that of a single, non-scalable video stream for some video sequences. These features may be achieved by determining whether a skipping flag in the base layer macro block of the video data is set, and decoding a skipping flag from an enhancement layer macro block of the video data, corresponding to the base layer macro block, only if the base layer macro block skipping flag is set.

Method and system for entropy decoding for scalable video bit stream

A method for coding spatial and quality enhancement information in scalable video coding using variable length codes. Conventional systems have been capable of using variable length codes only with nonscalable video coding, In the present invention, the coded block pattern for each block of information, significance passes, and refinement passes can all be coded with different types of variable length codes. The present invention also provides for a variable length encoder/decoder that dynamically adapts to the actual symbol probability. The encoder/decoder of the present invention counts the number of times each symbol is coded. Based upon these counts, the encoder/decoder selects how many symbols to group when forming a code word. The encoder also uses these counts to select the specific codeword that should be used.

Scalable video coding and decoding

Methods, computer code products and devices for encoding and/or decoding video data in multiple passes, the video data having a multiple components each component including multiple coefficients. The method can starting the next pass of the encoding or decoding process immediately after the end of the current encoding or decoding pass for a given component without regard to whether other components have finished the current encoding or decoding pass. In addition, stagger delays and dampers can be used to more closely regulate the encoding or decoding process to ensure that one component is not encoded or decoded too quickly with respect to other components.

Method and system for coding/decoding of a video bit stream for fine granularity scalability

An apparatus and corresponding method () for reencoding an input image already encoded in some format in order to provide a possibly more suitable encoding, based on whether the input image is determined by the system to be a graphic image (i.e. an artificial image) or a natural image (i.e. for example photographs of real world objects). The invention uses a decision function (f) having some predetermined parameters (&#x3b1;,&#x3b2;,&#x3bb;) that are constant or are changed only occasionally so as to refine their values, and also uses some inputs (c,r,d) that correlate in some way with the naturalness of an image and are determined by analyzing the input image using several analyzer modules (). The value of the decision function (f) is compared to a threshold, or two various thresholds in a table () of thresholds versus predetermined formats, to decide on what format to use to reencode the image.

Method and apparatus for selecting a format in which to re-encode a quantized image

A method and device for reducing an input image by modifying the palette used in image compression. The reduction process involves mapping one or more colors of the original palette to a single color in a new palette. The image size of the reduced image is estimated from the entropy of the input image and that of the modified palette. A scaling factor, which can be computed from the image statistics inherent to the input image, is also used for adjusting the estimated image size of the reduced image.

Method and device for reducing image by palette modification

A method and device for reducing a compressed image to a target size by reducing the quality of the image by a quality scaling factor. Image statistics inherent to the image are used to compute the size reduction as a function of the quality scaling factor. Using the relationship between the quality and the size of the image, an estimated quality scaling factor is obtained based on the target size in an iterative process until the size reduction corresponding to the estimated quality scaling factor is substantially equal to the target reduction.

Size reduction method and device for compressed images

A method and corresponding equipment () for encoding different types of objects of a multimedia data stream so as to provide improved overall quality (Q), according to relationships () between quality (Q) and encoding size/transmission rate (R) for each object, and according to penalties () for removing objects from the multimedia data stream. A multimedia data stream is provided in which the quality of the different objects tends to be similar according to rules provided by the invention for assigning a value of quality to each of the different kinds of objects of the multimedia stream.

Method and apparatus for providing a multimedia data stream

A method and system for coding an image using context-based adaptive VLC where transform coefficients are partitioned into blocks having a block dimension of 4n&times;4m (with n, m being positive integer equal to or greater than 1). Each block is scanned in a zigzag manner to produce an ordered vector of coefficients having a length of 16n&times;m. The ordered vector is sub-sampled in an interleaved manner to produce n&times;m sub-sampled sequences of transform coefficients prior to encoding the transform coefficients using an entropy encoder.

Context-based adaptive variable length coding for adaptive block transforms

Apparatus, and an associated method, for reducing the resolution of a digital image, such as a JPEG image. The digital image is pre-scaled by a pre-scaling factor that is selected such that a matrix multiplication is performed upon the digital image once pre-scaled, to reduce the resolution of the image. The matrix multiplication utilizes a multiplier that exhibits symmetry, thereby to reduce the number of calculations required to reduce the resolution of the image. Resolution reduction is performed, for instance, prior to communicating the digital image to a mobile station operable in a mobile communication system.

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Sachse, TX, United States of America

Justin Ridge