Provided are methods and apparatuses for encoding and decoding a motion vector. The method of encoding the motion vector includes: selecting, as a mode of encoding information about a motion vector predictor of the current block, a first mode in which information indicating the motion vector predictor from among at least one motion vector predictor is encoded or a second mode in which information indicating generation of the motion vector predictor based on blocks or pixels included in a previously encoded area adjacent to the current block is encoded; determining the motion vector predictor of the current block according to the selected mode and encoding the information about the motion vector predictor of the current block; and encoding a difference vector between the motion vector of the current block and the motion vector predictor of the current block.

Method and apparatus for encoding/decoding motion vector

A video compression framework based on parametric object and background compression is proposed. At the encoder, an object is detected and frames are segmented into regions corresponding to the foreground object and the background. The encoder generates object motion and appearance parameters. The motion or warping parameters may include at least two parameters for object translation; two parameters for object scaling in two primary axes and one object orientation parameter indicating a rotation of the object. Particle filtering may be employed to generate the object motion parameters. The proposed methodology is the formalization of the concept and usability for perceptual quality scalability layer for Region(s) of Interest. A coded video sequence format is proposed which aims at “network friendly” video representation supporting appearance and generalized motion of object(s).

Advance video coding with perceptual quality scalability for regions of interest

This disclosure describes techniques for improving functionalities of a back-end device, e.g., a video encoder, using parameters detected and estimated by a front-end device, e.g., a video camera. The techniques may involve estimating a blurriness level associated with frames captured during a refocusing process. Based on the estimated blurriness level, the quantization parameter (QP) used to encode blurry frames is adjusted either in the video camera or in the video encoder. The video encoder uses the adjusted QP to encode the blurry frames. The video encoder also uses the blurriness level estimate to adjust encoding algorithms by simplifying motion estimation and compensation in the blurry frames.

Control of video encoding based on image capture parameters

In one example, a video decoder is configured to determine, from data associated with an open decoding refresh (ODR) picture of video data, an identifier for a previous picture of the video data, determine whether the previous picture is currently stored in a reference picture memory, and decode only data for pictures of the video data having display order values that are greater than a display order value of the ODR picture, when the previous picture is not stored in the reference picture memory. In another example, a video encoder is configured to encode an open decoding refresh (ODR) picture, determine a previously coded picture having a display order value less than a display order value of the ODR picture and having a temporal identifier value equal to zero, and signal syntax data for the ODR picture representative of an identifier of the determined previously coded picture.

Buffer management in video codecs

A graphics processing system includes a graphics processor 1 that renders output frames that are written to a frame buffer in a memory 2 for display on a display 7. Comparison and control hardware 5 of the graphics processing system operates to compare successive output frames that are being generated for display, and then controls one or more aspects of the way in which the display of the output frames generated by the graphics processor 1 is carried out. In one preferred embodiment, the rate at which the display device 7 is updated (refreshed) from the frame buffer is controlled on the basis of the output frame comparisons. In another preferred embodiment, the format used when storing the output frames in the frame buffer is selected on the basis of the output frame comparisons.

Method and apparatus for controlling display operations

A method of and apparatus for encoding and/or decoding an image are provided, in which motion estimation and compensation are performed by using a reference background image and a reference object image extracted from an input image frame. In the method and apparatus, a background image of each of input image frames is used, and a background area which any one image frame lacks is updated by using a background image of another image frame. In this way, a reference background image is generated and stored, and an object image in each image frame is stored as a reference object image. Then, by using the stored reference background images and reference object images, motion estimation and compensation are performed, thereby increasing encoding efficiency.

Method and apparatus for encoding and decoding video images

Provided is a method for encoding and decoding a motion picture frame, which achieve natural picture conversion of frames near an Instantaneous Decoding Refresh-I (IDR-I) frame. The decoding method includes: decoding a first frame which is a P frame that is to be displayed last among a plurality of P frames that are to be displayed before an IDR-I frame is displayed; decoding the IDR-I frame; decoding a second frame which is a P frame that is to be displayed first among a plurality of P frames that are to be displayed after the IDR-I frame is displayed; and maintaining a reference frame stored in a buffer, for decoding the first frame until the second frame is decoded. Therefore, by allowing frames near an IDR-I frame to access reference frames stored in a buffer, natural picture conversion is possible, and accordingly smooth picture conversion without flickering is possible.

Method of encoding and decoding motion picture frames

A method and an apparatus for encoding and decoding a image are provided to update and store a reference background image and a reference object image continuously by using previous image frames and perform motion prediction and correction by using the reference background image and the reference object image, thereby improving the efficiency of encoding by generating a prediction image by using the updated reference background image without storing plural reference images. A method for encoding a image comprises the following steps of: dividing a current image frame into a background area and an object area(710); comparing the current image frame with a previous image frame to determine whether an area is changed between a background and an object from the current image frame and the previous image frame(720); updating a reference background image generated from the background area of previous image frames according to the determination result by using the background image of the current image frame and storing the updated reference background image(730); and performing motion prediction for a image frame after the current image frame by using the updated reference background image(740).

Method and apparatus for encoding video, method and apparatus for decoding video

A method for decoding and encoding video frames is provided to change screen images smoothly and naturally by allowing frames near an IDR(Instantaneous Decoding Refresh)-I frame to approach a buffer storing a reference frame. The first frame is encoded(S100). An IDR-I frame is encoded(S110). Access to a buffer is possible when encoding the IDR-I frame. The second frame is encoded(S120). The buffer is maintained without deletion before the second frame is encoded. After the second frame is encoded, a buffer in which a reference frame is stored is emptied(S130).

Method of decoding motion picture frame and method of encoding the same

A motion estimation method and an apparatus thereof are provided to select a search center value and to improve the flexibility of the motion estimation algorithm due to changing various search algorithms. One or more search central values for the motion estimation toward the predetermined block of the current frame are inputted(310). A reference block corresponding to a search area within a reference frame based on the inputted search central value is searched(340).

Ahn Tae Gyoung

Papers

Method and apparatus for encoding and decoding video images

Method of encoding and decoding motion picture frames

Method and apparatus for encoding video, method and apparatus for decoding video

Method of decoding motion picture frame and method of encoding the same

Method for motion estimation based on image block and apparatus thereof