Abstract: A method and apparatus are provided for improving the compression efficiency of motion vectors of an unsynchronized picture by efficiently predicting the motion vectors using motion vectors of a lower layer. The method compresses motion vectors of an unsynchronized picture belonging to a current layer in a video encoder based on a multilayer having at least the current layer and a lower layer of the current layer. The method includes selecting a base picture for the unsynchronized picture, generating a predicted motion vector of the current layer from a motion vector of the base picture, subtracting the predicted motion vector from a motion vector of the unsynchronized picture, and encoding the result of subtraction.

Abstract: A video encoding/decoding method and apparatus is disclosed that can efficiently compress/decompress motion vectors in a video codec including a hierarchical temporal level decomposition process. The video encoding method including a hierarchical temporal level decomposition process involves obtaining a predicted motion vector of a second frame, which exists at a present temporal level, from a first motion vector of a first frame that exists at a lower temporal level; obtaining a second motion vector of the second frame by performing a motion estimation in a predetermined motion search area using the predicted motion vector as a start point; and encoding the second frame using the obtained second motion vector.

Abstract: A color space scalable video coding and decoding method and an apparatus for the same are disclosed that can adjust color components or color depth according to the performance of a decoder side. The color space scalable video coding method includes generating transform coefficients by removing the temporal redundancy and spatial redundancy of input video frames, quantizing the transform coefficients, generating a bit stream by entropy coding the quantized transform coefficients, and generating a color space scalable bit stream that includes the bit stream and position information of luminance data in the bit stream.

Abstract: A method and an apparatus for encoding/decoding and referencing a virtual area image are disclosed. A method for encoding and referencing the virtual area image includes generating a base layer frame from an input video signal, restoring a virtual area image in an outside area of the base layer frame through a corresponding image of a reference frame of the base layer frame, adding the restored virtual area image to the base layer frame to generate a virtual area base layer frame, and differentiating the virtual area base layer frame from the video signal to generate an enhanced layer frame.

Abstract: A method of compressing a motion vector (MV) of a first macroblock when the region of a first lower layer corresponding to the first macroblock of a current layer frame does not have an MV is provided. The method includes interpolating the MV of a second macroblock to which the region belongs, based on the MV of at least one neighboring macroblock, and predicting the MV of the first macroblock using the interpolated MV.

Abstract: A multi-layered video encoding method is provided wherein motion estimation is performed by using one of two frames of a lower layer temporally closest to an unsynchronized frame of a current layer as a reference frame. A virtual base layer frame at the same temporal location as that of the unsynchronized frame is generated using a motion vector obtained as a result of the motion estimation and the reference frame. The generated virtual base layer frame is subtracted from the unsynchronized frame to generate a difference, and the difference is encoded.

Abstract: A multilayer encoding/decoding method using residual re-estimation and an apparatus using the same are disclosed. The multilayer video encoding method includes (a) encoding a first residual image obtained by subtracting a predicted frame from an original frame, (b) decoding the encoded first residual image and generating a first restored frame by adding the decoded residual image to the predicted frame, (c) deblocking the first restored frame, and (d) encoding a second residual image obtained by subtracting the predicted frame from the first deblocked restored frame.

Abstract: A method and apparatus are provided for effectively predicting a video frame that use all of the advantages of an intra mode and an intra BL mode in multi-layer structure based-video coding. The method includes reconstructing the intra block of a lower layer using the previously reconstructed first neighboring blocks of the intra block; subtracting the first neighboring blocks from previously stored the second neighboring blocks of an upper layer corresponding to the first neighboring blocks; creating a differential predicted block based on a predetermined intra prediction mode by performing intra prediction using virtual differential neighboring blocks that are created as a result of the subtraction; adding the differential predicted block and the reconstructed intra block; and subtracting a predicted block, which is created as a result of the addition, from a block of the upper layer corresponding to the intra block.

Abstract: A method of efficiently predicting a frame having no corresponding lower layer frame in video frames having a multi-layered structure, and a video coding apparatus using the prediction method is provided. In the video encoding method, motion estimation is performed by using a first frame of two frames of a lower layer temporally closest to an unsynchronized frame of a current layer as a reference frame. A residual frame between the reference frame and a second frame of the lower layer frames is obtained. A virtual base layer frame at the same temporal location as that of the unsynchronized frame is generated using a motion vector obtained as a result of the motion estimation, the reference frame, and the residual frame. The generated virtual base layer frame is subtracted from the unsynchronized frame to generate a difference, and the difference is encoded.

Abstract: A method of multi-layer based scalable video encoding and decoding and an apparatus for the same are disclosed. The encoding method includes the steps of estimating motion between a base layer frame that is placed at a temporal location closest to a current frame of an enhancement layer, and a frame that is backwardly adjacent to the base layer frame to acquire a motion vector, generating a residual image by subtracting the backwardly adjacent frame from the base layer frame, generating a virtual forward reference frame using the motion vector, the residual image and the base layer frame, and generating a predicted frame with respect to the current frame using the virtual forward reference frame, and encoding the difference between the current frame and the predicted frame.

Abstract: A deblocking filter used in a video encoder/decoder based on a multilayer is disclosed. The deblocking filtering method includes choosing a present block and its neighboring block on which a deblocking filtering will be performed, judging whether the present block and the neighboring block have been coded by the intra BL mode, choosing a deblocking filter strength according to the result of the judgment, and performing the deblocking filtering with respect to a boundary between the present block and the neighboring block and according to the deblocking filter strength.

Abstract: A video compression method, and more particularly, a prediction method for efficiently eliminating redundancy within a video frame, and a video compression method and an apparatus using the prediction method are provided. There is provided a method for encoding video based on a multi-layer structure, including performing intra-prediction on a current intra-block using images of neighboring intra-blocks of the current intra-block to obtain a prediction residual, performing prediction on the current intra-block using an image of a lower layer region corresponding to the current intra-block to obtain a prediction residual, selecting one of the two prediction residuals that offers higher coding efficiency, and encoding the selected prediction residual.

Abstract: A method and apparatus for more efficiently upsampling a base layer to perform interlayer prediction during multi-layer video coding are provided. The method includes encoding and reconstructing a base layer frame, performing discrete cosine transform (DCT) upsampling on a second block of a predetermined size in the reconstructed frame corresponding to a first block in an enhancement layer frame, calculating a difference between the first block and a third block generated by the DCT upsampling, and encoding the difference.

Abstract: Multi-layer video coding and decoding methods, multi-layer video encoder and multi-layer video decoder are provided. The multi-layer video coding method includes encoding a video frame having a predetermined resolution using a first video coding scheme, using a frame encoded by the first video coding scheme as a reference to encode the video frame with the same resolution as the predetermined resolution using a second video coding scheme, and generating a bitstream containing the frames encoded by the first and second video coding schemes.

Abstract: A video coding method using a multi-layer structure, and more particularly, a method and apparatus for facilitating a search for an intra-prediction mode in an upper layer using an intra-prediction mode in a lower layer while efficiently and compressively encoding the searched intra-prediction mode are provided. The intra-prediction method includes searching for an optimum prediction mode of a current block among a predetermined number of intra-prediction modes, and obtaining a directional difference between the searched optimum prediction mode and an optimum prediction mode of a lower layer block corresponding to the current block.

Abstract: An apparatus and method for improving the compression efficiency of a motion vector by efficiently predicting a motion vector in an enhanced layer from a motion vector in a base layer in a video coding method using a multi-layer structure are provided. The method includes obtaining a motion vector in a mother frame of a base layer that is temporally closest to an unsynchronized frame of a current layer, obtaining a predicted motion vector from the motion vector in the mother frame considering the referencing direction in the mother frame and in the unsynchronized frame and distances between the mother frame and a reference frame and between the unsynchronized frame and a reference frame, generating a residual between the motion vector in the unsynchronized frame and the predicted motion vector, and encoding the motion vector in the mother frame and the residual.

Abstract: A method and apparatus of improving the compression efficiency of a motion vector by efficiently predicting a motion vector in an enhancement layer from a motion vector in a base layer in a video coding method using a multi-layer are provided.

Abstract: A method and apparatus are provided for improving compression efficiency or picture quality by selecting a wavelet transform technique suitable to input video/image scene characteristics in video/image compression. The video encoder includes a temporal transform module that removes temporal redundancy of an input frame and generates a residual frame, a selection module that selects an appropriate wavelet filter among a plurality of wavelet filters having different taps according to a spatial correlation of the residual frame, a wavelet transform module that generates wavelet coefficients by performing wavelet transform on the residual frame using the selected wavelet filter, and a quantization module that quantizes the wavelet coefficients.

Abstract: A method and apparatus for improving video coding efficiency by combining Motion-Compensated Temporal Filtering (MCTF) with closed-loop coding are provided. The video encoding method includes performing MCTF on input frames up to a first temporal level, performing hierarchical closed-loop coding on frames up to a second temporal level higher than the first temporal level, the frames being generated by the MCTF, performing spatial transform on frames generated using the hierarchical closed-loop coding to create transform coefficients, and quantizing the transform coefficients.

Abstract: Video coding and decoding methods using interlayer filtering and a video encoder and decoder using the same are provided. Multi-layer video coding employing a plurality of video coding algorithms can improve video coding efficiency by using interlayer filtering. The video coding method includes encoding video frames using a first video coding scheme, performing interlayer filtering on the frames encoded by the first video coding scheme, encoding the video frames using a second video coding scheme by referring to the frames subjected to the interlayer filtering, and generating a bitstream containing the frames encoded by the first and second video coding schemes.