摘要:
A method and apparatus for extracting a higher quality video stream for a given bit-rate by replacing a specific frame by a base layer frame at a predecoder are provided. A predecoding method performed by the predecoder includes selecting a mode by determining frames to be skipped according to a predetermined criterion among frames located at positions where the base layer exists, and extracting a portion of the bitstream according to the selected mode and extraction conditions.
摘要:
A method and apparatus for supporting scalability for motion vectors in scalable video coding are provided. The motion estimation apparatus includes a motion estimation module searching for a variable block size and a motion vector that minimize a cost function for each layer according to predetermined pixel accuracy, a sampling module upsampling an original frame when the pixel accuracy is less than a pixel size, and before searching for a motion vector in a layer having a lower resolution than the original frame downsampling the original frame into the low resolution, a motion residual module calculating a residual between motion vectors found in the respective layers, and a rearrangement module rearranging the residuals between the found motion vectors and the found variable block size information using significance obtained from a searched lower layer. Accordingly, true motion scalability can be achieved to improve adaptability to changing network circumstances.
摘要:
A method and apparatus for scalable encoding providing scalability in an encoder. The scalable video encoding apparatus includes a mode selector that determines a temporal filtering order of a frame and a predetermined time limit as a condition for determining to which frame temporal filtering is to be performed, and a temporal filter which performs motion compensation and temporal filtering, according to the temporal filtering order determined in the mode selector, on frames that satisfy the above-described condition. According to the method and apparatus, since scalability is provided in the encoder, stability in the operation of real-time, bidirectional video streaming applications, such as video conferencing, can be ensured.
摘要:
A scalable video codec includes an encoder that encodes an original moving picture; a rate control unit that allocates an optimal amount of bits for each coding unit based on a bit-rate desired by a user; a pre-decoder that receives a bit-stream and extracts a bit-stream having an appropriate amount of bits; and a decoder that decodes image sequences of the moving picture from the extracted bit-stream, so as to reconstruct the original moving picture. In particular, the present invention focuses on the operation performed in the rate control unit 340. The rate control unit operates a definition step of a bit-rate function available for use in the predecoder, a pre-summation step to thereby obtain the uniform visual quality, an approximation to determine the distortion function, and a normalization step to allow the total allocated bit-rates to be equal to a target bit-rate.
摘要:
A video encoding method is provided. The method includes: encoding a current region of a video by performing a transformation on the current region by using transformation units in a variable tree-structure which are determined from among transformation units that are hierarchically split from a base transformation unit with respect to the current region and which are generated based on a maximum split level of a transformation unit. The method further includes outputting encoded data of the current region, information about an encoding mode, and transformation-unit hierarchical-structure information including maximum size information and minimum size information of the transformation unit with respect to the video.
摘要:
A method and apparatus for encoding and decoding a video are provided. The method of encoding the video includes: determining whether a unidirectional motion estimation mode and a bidirectional motion estimation mode are to be used based on a size of a current prediction unit to be encoded, performing the motion estimation and the motion compensation on the current prediction unit according to the determining of whether the unidirectional motion estimation mode and the bidirectional motion estimation mode are to be used, determining an optimum motion estimation mode of the current prediction unit based on an encoding cost of the current prediction unit obtained through the performing of the motion estimation and the motion compensation, and encoding information indicating the determined optimum motion estimation mode based on the size of the current prediction unit.
摘要:
Provided are a method and apparatus for encoding a video and a method and apparatus for decoding a video. The encoding method includes: splitting a picture of the video into one or more maximum coding units; encoding the picture based on coding units according to depths which are obtained based on a partition type determined according to the depths of the coding units according to depths, determining coding units according to coded depths with respect to each of the coding units according to depths, and thus determining coding units having a tree structure; and outputting data that is encoded based on the partition type and the coding units having the tree structure, information about the coded depths and an encoding mode, and coding unit structure information indicating a size and a variable depth of a coding unit.
摘要:
Disclosed are an image encoding method and apparatus for encoding an image by grouping a plurality of adjacent prediction units into a transformation unit and transforming the plurality of adjacent prediction into a frequency domain, and an image decoding method and apparatus for decoding an image encoded by using the image encoding method and apparatus.
摘要:
Provided are a method and apparatus for interpolating an image. The method includes: selecting a first filter, from among a plurality of different filters, for interpolating between pixel values of integer pixel units, according to an interpolation location; and generating at least one pixel value of at least one fractional pixel unit by interpolating between the pixel values of the integer pixel units by using the selected first filter.
摘要:
An image transformation method substitutes element based on a trigonometric function included in a discrete cosine transform (DCT) matrix with a rational number, performs upscaling and transformation process on an input signal using the substituted DCT matrix based on a maximum value of a denominator of an intermediate value generated in the transformation process, and performs downscaling on the transformed signal.