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Showing papers on "Inter frame published in 2005"


Patent
Shijun Sun1
18 Feb 2005
TL;DR: In this article, a method of coding a quality scalable video sequence is provided, where an N-bit input frame is converted to an M-bit output frame, where M is an integer between 1 and N. To be backwards compatible with existing 8-bit video systems, M would be selected to be 8.
Abstract: A method of coding a quality scalable video sequence is provided. An N-bit input frame is converted to an M-bit input frame, where M is an integer between 1 and N. To be backwards compatible with existing 8-bit video systems, M would be selected to be 8. The M-bit input frame would be encoded to produce a base-layer output bitstream. An M-bit output frame would be reconstructed from the base-layer output bitstream and converted to a N-bit output frame. The N-bit output frame would be compared to the N-bit input frame to derive an N-bit image residual that could be encoded to produce an enhancement layer bitstream.

150 citations


Proceedings ArticleDOI
16 Sep 2005
TL;DR: This paper proposes a novel approach to improve the performance of pixel domain Wyner-Ziv video coding by using a motion compensated refinement of the decoded frame and use it as improved side information.
Abstract: Distributed video coding (DVC) is a new coding paradigm that enables to exploit video statistics, partially or totally at the decoder. A particular case of DVC, Wyner-Ziv coding, deals with lossy source coding with side information at the decoder and allows a shift of complexity from the encoder to the decoder, theoretically without any penalty in the coding efficiency. The Wyner-Ziv solution here described encodes each video frame independently (intraframe coding), but decodes the same frame conditionally (interframe decoding). At the decoder, and compensation tools are responsible to obtain an accurate interpolation of the original frame using previously decoded (temporally adjacent) frames. This paper proposes a novel approach to improve the performance of pixel domain Wyner-Ziv video coding by using a motion compensated refinement of the decoded frame and use it as improved side information. More precisely, upon partial decoding of each frame, the decoder refines its motion trajectories in order to achieve a better reconstruction of the decoded frame.

122 citations


Patent
Sang-Chang Cha1, Woo-jin Han1
06 Jul 2005
TL;DR: In this article, the video encoding method includes determining one of inter predictive coding and intra predictive coding mode as a coding mode for each block in an input video frame, generating a predicted frame for the input video frames based on predicted blocks obtained according to the determined coding mode, and encoding the video frame based on the predicted frame.
Abstract: Video coding and decoding methods and video encoder and decoder are provided. The video encoding method includes determining one of inter predictive coding and intra predictive coding mode as a coding mode for each block in an input video frame, generating a predicted frame for the input video frame based on predicted blocks obtained according to the determined coding mode, and encoding the input video frame based on the predicted frame. When the intra predictive coding mode is determined as the coding mode, an intra basis block composed of representative values of a block is generated for a block and the intra basis block is interpolated to generate an intra predicted block for the block.

119 citations


Patent
20 Jul 2005
TL;DR: In this paper, an Encoder Assisted Frame Rate Up Conversion (EA-FRUC) system that utilizes video coding and pre-processing operations at the video encoder to exploit the FRUC processing that will occur in the decoder in order to improve compression efficiency and reconstructed video quality is disclosed.
Abstract: An Encoder Assisted Frame Rate Up Conversion (EA-FRUC) system that utilizes video coding and pre-processing operations at the video encoder to exploit the FRUC processing that will occur in the decoder in order to improve compression efficiency and reconstructed video quality is disclosed. One operation of the EA-FRUC system involves determining whether to encode a frame in a sequence of frames of a video content by determining a spatial activity in a frame of the sequence of frames; determining a temporal activity in the frame; determining a spatio-temporal activity in the frame based on the determined spatial activity and the determined temporal activity; determining a level of a redundancy in the source frame based on at least one of the determined spatial activity, the determined temporal activity, and the determined spatio-temporal activity; and, encoding the non-redundant information in the frame if the determined redundancy is within predetermined thresholds.

94 citations


Patent
20 Jul 2005
TL;DR: In this paper, a method for creating an interpolated video frame using a current video frame, and a plurality of previous video frames is presented, which includes creating a set of extrapolated motion vectors from at least one reference video frame in the plurality of preceding video frames.
Abstract: A method for creating an interpolated video frame using a current video frame, and a plurality of previous video frames. The method includes creating a set of extrapolated motion vectors from at least one reference video frame in the plurality of previous video frames ; performing an adaptive motion estimation using the extrapolated motion vectors and a content type of each extrapolated motion vector ; deciding on a motion compensated interpolation mode ; and, creating a set of motion compensated motion vectors based on the motion compensated interpolation mode decision. An apparatus for performing the method is also disclosed.

63 citations


Patent
Woo-Jin Han1, Kyo-Hyuk Lee1, Jae-Young Lee1, Sang-Chang Cha1, Bae-Keun Lee1, Ho-Jin Ha1 
20 Oct 2005
TL;DR: In this paper, a method and apparatus of improving the compression efficiency of a motion vector by efficiently predicting the motion vector in an enhancement layer from the motion vectors in a base layer in a video coding method using a multi-layer are provided.
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 The method includes obtaining a motion vector in a base layer frame having a first frame rate from an input frame, obtaining a motion vector in a first enhancement layer frame having a second frame rate from the input frame, the second frame rate being greater than the first frame rate, generating a predicted motion vector by referring to a motion vector for at least one frame among base layer frames present immediately before and after the same temporal position as the first enhancement layer frame if there is no base layer frame at the same temporal position as the first enhancement layer frame, and coding a difference between the motion vector in the first enhancement layer frame and the generated predicted motion vector, and the obtained motion vector in the base layer

57 citations


Proceedings ArticleDOI
22 Apr 2005
TL;DR: Experimental results show that the proposed algorithm outperforms decoder-only frame rate up conversion methods and gives better performance in terms of PSNR and visual quality over encoding at full frame rate without frame skipping.
Abstract: In low bandwidth video coding applications, frame rate is reduced to increase the spatial quality of the frames. However, video sequences that are encoded at low frame rates demonstrate motion jerkiness artifacts when displayed. Therefore, a mechanism is required at the decoder to increase the frame rate while keeping an acceptable level of spatial quality. In this paper, we present a new method to perform video frame interpolation by sending effective side information for frame rate up conversion applications. The proposed scheme encodes the skipped frames lightly by sending motion vectors and an important information map which indicates to the decoder the type of interpolation method to perform. We also propose a novel overhead reduction method to keep the side information cost low. Experimental results show that the proposed algorithm outperforms decoder-only frame rate up conversion methods and gives better performance in terms of PSNR and visual quality over encoding at full frame rate without frame skipping.

49 citations


Patent
Keiichi Chono1, Yuzo Senda1
27 Dec 2005
TL;DR: In this paper, a reference frame displayed at the reproduction side immediately before a current image frame to be encoded is an inter encoding image frame, and a quantization control device appropriately corrects the level (quantization value) of an intra encoding so as to visually reduce I-frame flicker caused by a difference between the inter encoding noise characteristic of the inter-encoding image frame and the noise characteristics of the current intra encoding.
Abstract: If a reference frame displayed at the reproduction side immediately before a current image frame to be encoded is an inter encoding image frame, a quantization control device (999) appropriately corrects the level (quantization value) of an intra encoding so as to visually reduce I-frame flicker caused by a difference between the inter encoding noise characteristic of the inter encoding image frame and the noise characteristic of the current intra encoding.

49 citations


Patent
21 Jul 2005
TL;DR: In this paper, a method for processing a plurality of motion vectors for a video frame to be interpolated using a first reference frame and a second reference frame, each reference frame having a content map, is presented.
Abstract: A method for processing a plurality of motion vectors for a video frame to be interpolated using a first reference frame and a second reference frame, each reference frame having a content map, the method including partitioning the video frame to be interpreted into a plurality of areas; determining a number of motion vectors passing through one area of the plurality of areas based on the content maps of the first reference frame and the second reference frame; and generating a motion vector to assign to the one area based on the number of motion vectors passing through the one area. An apparatus for performing the method is also described.

45 citations


Patent
04 May 2005
TL;DR: In this article, a method and apparatus for video frame interpolation using a current video frame, at least one previous video frame and a set of transmitted motion vectors is described, and a video frame is generated using the second set of motion vectors.
Abstract: A method and apparatus for video frame interpolation using a current video frame, at least one previous video frame, and a set of transmitted motion vectors is described. A first set of motion vectors is created as a function of the set of transmitted motion vectors. An intermediated video frame is identified, where the intermediate video frame having a plurality of non-overlapping blocks. Each non-overlapping block is assigned with at least one motion vector chosen from the first set of motion vectors to create a set of assigned motion vectors. Then, a second set of motion vectors is created as a function of the assigned set of motion vectors. A video frame is generated using the second set of motion vectors.

45 citations


Patent
Woo-Jin Han1, Ho-Jin Ha1
04 Jul 2005
TL;DR: In this paper, a method of more efficient conducting temporal filtering in a scalable video codec by use of a base layer is provided, which includes generating a base-layer frame from an input original video sequence, having the same temporal position as a first higher layer frame, and upsampling the base layer frame to have the resolution of a higher layer.
Abstract: A method of more efficiently conducting temporal filtering in a scalable video codec by use of a base-layer is provided. The method of efficiently compressing frames at higher layers by use of a base-layer in a multilayer-based video coding method includes (a) generating a base-layer frame from an input original video sequence, having the same temporal position as a first higher layer frame, (b) upsampling the base-layer frame to have the resolution of a higher layer frame, and (c) removing redundancy of the first higher layer frame on a block basis by referencing a second higher layer frame having a different temporal position from the first higher layer frame and the upsampled base-layer frame.

Patent
22 Sep 2005
TL;DR: In this paper, a method for encoding video signals by inverse motion compensated temporal filtering where video frames of a base layer are used to encode video frames from an enhanced layer into predicted images was proposed.
Abstract: A method for encoding video signals by inverse motion compensated temporal filtering where video frames of a base layer are used to encode video frames of an enhanced layer into predicted images. For each image block in an arbitrary frame in an enhanced layer frame sequence, an area including a block, which is present in a base layer frame temporally coincident with the arbitrary frame and is at the same position as the image block, is enlarged according to the ratio between screen sizes of the two layers. A reference block most highly correlated with the image block is searched for in the enlarged area in the temporally coincident base layer frame through motion estimation and is used to obtain pixel difference values and a motion vector of the image block for encoding the image block into a predicted image, thereby improving coding efficiency.

Patent
02 May 2005
TL;DR: In this article, a method, apparatus and system for decoding a bi-directional picture predicted from two reference frames with a motion compensation codec that is capable of locating reference frame portions from only one reference frame at a time.
Abstract: A method, apparatus and system for decoding a bi-directional picture predicted from two reference frames with a motion compensation codec that is capable of locating reference frame portions from only one reference frame at a time. Including locating a first reference frame portion from a first frame in a first pass, storing the first reference frame portion in memory; locating a second reference frame portion from a second frame in a second pass, and combining the first reference frame portion and the second reference frame portion to form a bi-directionally predicted portion. Also, a method and apparatus for restricting the encoding of a bi-directional picture predicted from two reference frames to be decoded by a motion compensation codec that is capable of locating reference frame portions from only one reference frame at a time and is capable of decoding a limited number of partitions for each macroblock.

Proceedings ArticleDOI
Yamada Toru1, M. Ikekawa1, I. Kuroda1
18 Mar 2005
TL;DR: In the encoding of an SDTV size video, the addition of range adjustment results in a reduction in the computational complexity of motion estimation of roughly 65%, while maintaining the same video quality.
Abstract: The paper presents a fast and accurate motion estimation algorithm. To obtain accurate motion vectors while minimizing computational complexity, we adjust the search range for each frame and each block to suit the motion level of the video. An appropriate search range for each frame is determined on the basis of motion vectors and prediction errors obtained for the previous frame. At each block, the search range is determined on the basis of the search range of its frame and of the motion vector values of all adjacent blocks for which those values have already been obtained. With our algorithm, since narrow search ranges are chosen for areas in which little motion occurs, computational complexity can be reduced without degrading estimation accuracy. Since wide search ranges are chosen for areas of significant motion, good video-quality encoding can be maintained. In the encoding of an SDTV size video, the addition of range adjustment results in a reduction in the computational complexity of motion estimation of roughly 65%, while maintaining the same video quality.

Journal ArticleDOI
TL;DR: The proposed framework enables the adaptation of the coding process to the video content, network and end-device characteristics, allows for enhanced scalability, content-adaptivity and reduced delay, while improving the coding efficiency as compared to state-of-the-art motion-compensated wavelet video coders.
Abstract: We introduce an efficient and flexible framework for temporal filtering in wavelet-based scalable video codecs called unconstrained motion compensated temporal filtering (UMCTF). UMCTF allows for the use of different filters and temporal decomposition structures through a set of controlling parameters that may be easily modified during the coding process, at different granularities and levels. The proposed framework enables the adaptation of the coding process to the video content, network and end-device characteristics, allows for enhanced scalability, content-adaptivity and reduced delay, while improving the coding efficiency as compared to state-of-the-art motion-compensated wavelet video coders. Additionally, a mechanism for the control of the distortion variation in video coding based on UMCTF employing only the predict step is proposed. The control mechanism is formulated by expressing the distortion in an arbitrary decoded frame, at any temporal level in the pyramid, as a function of the distortions in the reference frames at the same temporal level. All the different scenarios proposed in the paper are experimentally validated through a coding scheme that incorporates advanced features (such as rate-distortion optimized variable block-size multihypothesis prediction and overlapped block motion compensation). Experiments are carried out to determine the relative efficiency of different UMCTF instantiations, as well as to compare against the current state-of-the-art in video coding.

Patent
27 Jul 2005
TL;DR: In this paper, the authors proposed a technique relating to a frame rate conversion which enables display of an image of extended definition by smoothening the movement of the image, and fixed the direction of interpolation using information on a first frame which appeared before the insertion time of the interpolated frame.
Abstract: The present invention provides a technique relating to a frame rate conversion which enables display of an image of extended definition by smoothening the movement of the image. Therefore, the invention fixes the direction of interpolation using information on a first frame which appeared before the insertion time of the interpolated frame, a second frame appeared before the first frame, a third frame appeared after the insertion time, and a fourth frame appeared after the third frame, based on the insertion time of the interpolated frame. The interpolated pixel is generated from pixels of the second frame and the third frame located in the direction of interpolation, and generates the interpolated frame. Then, the interpolated frame is inserted into the inputted image signal to convert the frame rate.

Journal ArticleDOI
TL;DR: Analytic experiments over a range of network and application conditions indicate that adjustable FEC with temporal scaling can provide a significant performance improvement over current approaches, and can be effective as part of a streaming protocol that chooses FEC and temporal scaling patterns that meet dynamically-changing application and network conditions.
Abstract: New TCP-friendly constraints require multimedia flows to reduce their data rates under packet loss to that of a conformant TCP flow. To reduce data rates while preserving real-time playout, temporal scaling can be used to discard the encoded multimedia frames that have the least impact on perceived video quality. To limit the impact of lost packets, Forward Error Correction (FEC) can be used to repair frames damaged by packet loss. However, adding FEC requires further reduction of multimedia data, making the decision of how much FEC to use of critical importance. Current approaches use either inflexible FEC patterns or adapt to packet loss on the network without regard to TCP-friendly data rate constraints. In this article, we analytically model the playable frame rate of a TCP-friendly MPEG stream with FEC and temporal scaling, capturing the impact of distributing FEC within MPEG frame types with interframe dependencies. For a given network condition and MPEG video encoding, we use our model to exhaustively search for the optimal combination of FEC and temporal scaling that yields the highest playable frame rate within TCP-friendly constraints. Analytic experiments over a range of network and application conditions indicate that adjustable FEC with temporal scaling can provide a significant performance improvement over current approaches. Extensive simulation experiments based on Internet traces show that our model can be effective as part of a streaming protocol that chooses FEC and temporal scaling patterns that meet dynamically-changing application and network conditions.

Patent
08 Jul 2005
TL;DR: In this paper, a method and related system of generating a frame of video is disclosed, in which a request is received and a motion search between an object in a subsequent frame and the object in the current frame is performed.
Abstract: A method and related system of generating a frame of video is disclosed. In the method, a request is received. For instance, the request may initiate a video game. A motion search between an object in a subsequent frame of video and the object in a current frame of video is performed. A pre-determined motion vector for the object is selected. The object in the subsequent frame of video may correspond to a set of pre-encoded macro-blocks and the performing the motion search may include searching a corresponding set of macro-blocks associated with the current frame of video. The pre-encoded macro-blocks may be pre-encoded prior to the request. The motion vector may be pre-determined prior to the request.

Proceedings ArticleDOI
01 Jan 2005
TL;DR: A novel FRUC technique based on the motion compensated interpolation with multi-size blocks that reduces block artifacts and realizes the clear interpolation of moving objects regardless of the size of those.
Abstract: In this paper, we propose a frame rate up-conversion (FRUC) method using the motion compensation (MC) based on block matching algorithm (BMA). The property of the BMA is changed by the size of block. It is desirable for small moving object to set block size small. On the other hand, we would like to set the block size large in the global motion region. Therefore, the block size is decided depend on the property of the local region of frame image. In this paper, we present a novel FRUC technique based on the motion compensated interpolation with multi-size blocks. At first, the frame image is divided into 8/spl times/8 blocks and motion vectors are estimated for each 8/spl times/8 block. Next, the similar motion blocks are merged into one block. Thus the proposed method reduces block artifacts and realizes the clear interpolation of moving objects regardless of the size of those.

Patent
29 Jul 2005
TL;DR: In this paper, an encoder performs frame skipping in an intelligent manner that can improve video quality of the encoded sequence relative to encoding using conventional frame skipping, in order to identify certain frames that can be skipped without sacrificing significant video quality.
Abstract: The disclosure is directed to adaptive frame skipping techniques for rate controlled video encoding of a video sequence. According to the disclosed techniques, an encoder performs frame skipping in an intelligent manner that can improve video quality of the encoded sequence relative to encoding using conventional frame skipping. In particular, the disclosed frame skipping scheme is adaptive and considers motion activity of the video frames in order to identify certain frames that can be skipped without sacrificing significant video quality. The described frame skipping techniques may take into account the tradeoff between spatial and temporal quality of different video frames. In this manner, the techniques can allocate limited resources between the spatial and temporal quality in a way that can improve the visual appearance of a video sequence.

Patent
28 Mar 2005
TL;DR: In this article, an inter-frame prediction method in video coding, a video encoder using the same, a bitstream structure, and a video decoding method, and video decoder are provided.
Abstract: An inter-frame prediction method in video coding, a video encoder using the same, a bitstream structure, a video decoding method, and a video decoder are provided. The inter-frame prediction method in video encoding includes estimating a motion vector between a current block in an input frame and a reference block in a reference frame corresponding to the current block and a filtering mode defining a spatial effect to be applied to at least one of the current block and the reference block, and intercoding the input frame according to the estimated motion vector and the filtering mode.

Patent
15 Jul 2005
TL;DR: Temporal decomposition and inverse temporal decomposition methods using smoothed predicted frames for video encoding and decoding and video encoder and decoder are provided in this article, which includes estimating the motion of a current frame using at least one frame as a reference.
Abstract: Temporal decomposition and inverse temporal decomposition methods using smoothed predicted frames for video encoding and decoding and video encoder and decoder are provided. The temporal decomposition method for video encoding includes estimating the motion of a current frame using at least one frame as a reference and generating a predicted frame, smoothing the predicted frame and generating a smoothed predicted frame, and generating a residual frame by comparing the smoothed predicted frame with the current frame.

Patent
Ho-Jin Ha1, Woo-jin Han1
14 Jan 2005
TL;DR: In this article, a video encoder/decoder and method is proposed, which includes estimating a virtual frame, electing a reference frame from candidate frames including the virtual frame to remove temporal redundancy using the elected reference frame, coding a motion vector and obtaining transform coefficients from the frames free from the temporal redundancy and quantizing the obtained transform coefficients to generate a bit-stream.
Abstract: A video encoder/decoder and method. The video coding method includes estimating a virtual frame, electing a reference frame from candidate frames including the virtual frame to remove temporal redundancy using the elected reference frame, coding a motion vector and predetermined information obtained in removing the temporal redundancy, and obtaining transform coefficients from the frames free from the temporal redundancy and quantizing the obtained transform coefficients to generate a bit-stream. The video decoding method includes receiving a bit-stream and parsing the received bit-stream to extract information on coded frames, inversely quantizing the information on the coded frames to obtain the transform coefficients, and performing inverse spatial transform of the obtained transform coefficients and inverse temporal transform by use of a reference frame including a virtual frame in inverse order to an order in which redundancy of the coded frames is removed and restoring the coded frames. As a result, it is possible to code the video at a higher compression rate.

Patent
Zhi Zhou1, Yeong-Taeg Kim1
27 Sep 2005
TL;DR: In this paper, an improved temporal noise reduction method and system detects the global motion and adjusts the overall gain of the temporal filtering, which is applied to two video frames, wherein one video frame is the current input noisy frame, and the other video frame was a previous filtered frame stored in memory.
Abstract: An improved temporal noise reduction method and system detects the global motion and adjusts the overall gain of the temporal filtering. Temporal noise reduction is applied to two video frames, wherein one video frame is the current input noisy frame, and the other video frame is a previous filtered frame stored in memory. In this method, noise estimation is first performed to estimate the noise variance/standard deviation in the input video sequence. Then, motion estimation is applied to obtain the motion vectors indicating relative motion between the pixels in the current noisy frame and the corresponding pixels in the previous noise-reduced frame. From such motion vectors, global motion estimation is applied to estimate the camera motion of the video sequence. If reliable global motion is obtained, the overall gain of the temporal filtering is reduced by adjusting the estimated noise level. Motion blur is thus prevented.

Patent
30 Nov 2005
TL;DR: In this article, a motion estimation method is proposed to estimate the motion vector of a current frame block by calculating the sum of absolute differences (SAD) for candidate pattern blocks corresponding to the current frame pattern block among the reference frame pattern blocks and determining the candidate pattern block corresponding to SAD satisfying a predetermined condition.
Abstract: Provided are a motion estimation device and method adaptive to change in illumination. The motion estimation method includes the steps of: generating a current frame pattern block for a current frame block and a reference frame pattern block for a reference frame block; calculating the sum of absolute differences (SAD) for candidate pattern blocks corresponding to the current frame pattern block among the reference frame pattern blocks and determining the candidate pattern block corresponding to the SAD satisfying a predetermined condition among the calculated SADs as a motion vector; encoding the current frame block, by generating a residual signal using a difference signal between the candidate pattern block corresponding to the motion vector and the current frame pattern block then performing discrete cosine transform and quantization to the residual signal with a predetermined encoding mode; and adding flag information indicating the addition of a mean pixel value applied to the encoded current frame block and identification information on the encoding mode as header information corresponding to the encoded current frame block. By omitting insertion of a mean pixel value for some fields, it is possible to minimize the amount of bit streams transmitted to a decoder.

Journal ArticleDOI
04 Apr 2005
TL;DR: A comparative performance study demonstrates that the proposed gradient correlation method outperforms state-of-the-art methods in frequency-domain motion estimation, in the shape of phase correlation, in terms of sub-pixel accuracy for a range of test material and motion scenarios.
Abstract: The authors present a performance study of gradient correlation in the context of the estimation of interframe motion in video sequences. The method is based on the maximisation of the spatial gradient cross-correlation function, which is computed in the frequency domain and therefore can be implemented by fast transformation algorithms. Enhancements to the baseline gradient-correlation algorithm are presented which further improve performance, especially in the presence of noise. A comparative performance study is also presented, which demonstrates that the proposed method outperforms state-of-the-art methods in frequency-domain motion estimation, in the shape of phase correlation, in terms of sub-pixel accuracy for a range of test material and motion scenarios.

Patent
24 May 2005
TL;DR: In this article, a method for fast multiple reference frame motion estimation is proposed, which performs a special block matching to find a plurality of motion vectors for blocks of each frame with respective to a previous frame.
Abstract: A method for fast multiple reference frame motion estimation, which is used to perform motion estimation between a current frame and reference frames Fn−1, Fn−2, . . . , Fn−k. The method performs a special block matching to find a plurality of motion vectors for blocks of each frame with respective to a previous frame and then composes motion vector(s) of the current frame referring to the reference frame Fn−(k−1) and a motion vector of the reference frame Fn−(k−1) referring to the reference frame Fn−k into composed motion vectors of the current frame referring to the reference frame Fn−k for the block in the current frame. The method selects a composed motion vector with a minimum of cost function from the composed motion vectors produced when composing the motion vectors and then finely adjusts the composed motion vector selected, thereby obtaining an adjusted motion vector.

Journal ArticleDOI
TL;DR: A novel algorithm for extracting key frames to represent video shots that can capture the important yet salient content as the key frame is proposed and validated by experiments with various kinds of video sequences.

Patent
14 Apr 2005
TL;DR: In this paper, motion estimation between a current noisy frame and a previous noise-reduced frame is performed to generate motion vectors indicating relative motion between the pixels in the current noise frame and the corresponding pixels in a previous noisy frame.
Abstract: A method of reducing noise in a sequence of digital video frames is performed by motion estimation between a current noisy frame and a previous noise-reduced frame, to generate motion vectors indicating relative motion between the pixels in the current noisy frame and the corresponding pixels in the previous noise-reduced frame; and removing noise from the current noisy frame by computing the weighted average of pixels in the current noise frame and the corresponding pixels in the previous noise-reduced frame based on the motion vectors, to generate a noise-reduced output frame.

Proceedings ArticleDOI
01 Jul 2005
TL;DR: Simulation results show significantly improved error resiliency performance of the proposed reference picture selection methods compared to conventional methods, and a novel simple reference frame management method that enables using of flexible reference frame is proposed.
Abstract: Conventional video coding techniques make use of the most recently decoded reference frame(s) for motioncompensated inter prediction. However, it has been shown that to allow using reference frames in a flexible way such that not only the latest reference frames are used is beneficial. A typical use of flexible reference frame is feedback based reference picture selection, wherein error-free reference frames available in both the encoder and decoder sides are selected and used for inter prediction reference. This paper first overviews support of reference picture selection in different video coding standards, and then presents three specific feedback based reference picture selection methods using flexible reference frames. In addition, a novel simple reference frame management method that enables using of flexible reference frame is proposed. The reference frame management method enables much simpler video codec implementations compared to the complex reference frame management methods in H.263 Annex U and H.264/AVC. The proposed coding methods and some conventional methods are compared with each other. Simulation results show significantly improved error resiliency performance of the proposed reference picture selection methods compared to conventional methods. The effect on the performance imposed by feedback delay variation is also shown. Thanks to the merits, support of flexible reference frame and the reference frame management has been adopted to the AVS-M video coding standard.