A moving picture coding apparatus for performing inter-picture predictive coding for pictures constituting a moving picture is provided with a coding unit for performing predictive error coding for image data; a decoding unit for performing predictive error decoding for an output from the coding unit; a reference picture memory for holding output data from the decoding unit; and a motion vector detection unit for detecting motion vectors on the basis of the decoded image data stored in the memory. When coding a B picture as a target picture, information indicating whether or not the target picture should be used as a reference picture when coding another picture is added as header information. Therefore, in a decoding apparatus for decoding a bit stream Bs outputted from the moving picture coding apparatus, management of a memory for holding the reference picture can be facilitated on the basis of the header information.

Moving picture coding method and moving picture decoding method

A picture encoding method of the present invention is a picture encoding method of predictively encoding an input picture with reference to pictures stored in a picture buffer, decoding the encoded input picture, judging whether or not the decoded picture is a picture for reference and whether or not the decoded picture is a picture for output which needs to be stored until its display time, and storing, in the picture buffer, the picture for reference and the picture for output based on the determination result.

Picture coding method and picture decoding method

A TV GUI is provided to display a program guide that contains information on TV programming for a time period of predetermined duration. The program guide has a time scroll bar that enables a user to scroll a TV program schedule back and forward in time within the selected time period. When the user clicks on a MORE icon on the time scroll bar, the GUI switches into a "more times" mode to offer a menu of time options that represent various preselected time periods of TV programming. A time preset button may be provided on the program guide to enable users to review TV program information covering any preselected time period. A single click on the time preset button causes the GUI to switch to a program guide for the preselected time period.

TV graphical user interface for providing user access to preset time periods of TV program information

When a block (MB22) of which motion vector is referred to in the direct mode contains a plurality of motion vectors, 2 motion vectors MV23 and MV24, which are used for inter picture prediction of a current picture (P23) to be coded, are determined by scaling a value obtained from averaging the plurality of motion vectors or selecting one of the plurality of the motion vectors.

Motion vector calculating method

A TV graphical user interface (GUI) is provided to produce a multi-layered graphical presentation. The TV GUI operates in a channel changer mode to enable a user to tune to a required TV channel, and in a program guide mode to show TV program information. A memory for storing graphics data is capable of storing two graphics planes that represent upper and lower layers of graphics displayable on a TV screen. A graphics accelerator combines the graphics planes to produce various graphical effects on the screen. In the channel changer mode, the right hand side of the upper layer is made transparent to expose graphical buttons produced in the lower layer of graphics. In the program guide mode, the graphical buttons are partially covered by a program guide produced in the upper layer. When the user moves a cursor to the right hand side of the screen, the right hand portion of the program guide is made transparent to fully expose the graphical buttons in the lower layer.

Multi-layered television graphical user interface

An interframe motion predicting method for prediction of the motion in a bidirectionally predictive-coded frame from an intra-coded frame and a predictive-coded frame, predicts the motion in another bidirectionally predictive-coded frame from the preceding bidirectionally predictive-coded frame and the predictive-coded frame. A picture signal coding apparatus executes orthogonal transformation of a picture signal, then quantizes the transformed data, and codes the data thus quantized. The apparatus includes a local decoder for the quantized data; first and second memories for storing the decoded picture data of an intra-coded or bidirectionally predictive-coded frame, and a predictive-coded frame respectively; a predictive picture generator for generating a predictive picture of a second bidirectionally predictive-coded frame; and a difference calculator for calculating the difference between the predictive picture and the original picture signal corresponding thereto. A picture signal decoding apparatus includes inverse multiplexer for separating the coded data into interframe predictive error data and vector coded data; a decoder for generating decoded picture data on the basis of such error data; first and second memories for storing the decoded picture data of the intra-coded frame and the predictive-coded frame respectively; a predictive picture generator for generating a predicted picture of a second bidirectionally predictive-coded frame; and a frame switching selector for selectively rearranging the decoded picture data in the order of reproduction.

Interframe motion predicting method and picture signal coding/decoding apparatus

PURPOSE:To improve the prediction accuracy of dynamic image data by executing a motion prediction of the other both direction prediction encoding frame, from one both direction prediction encoding frame and a forward prediction frame, etc. CONSTITUTION:A both direction prediction encoding frame B0 is predicted from an intra-encoding frame I0 and a forward prediction encoding frame P0 as heretofore, but a both direction prediction encoding frame B1 is predicted from the B0 and the P0 of one frame before. Also, the case when a both direction prediction frame B exists more than three frames (B0, B1, B2) between the frames I0 and P0 is also the same, and the frame B1, B2... except the frame B0 are always predicted from the B0, the B1... and the frame P0 of one frame before. In such a way, since the prediction from the both direction prediction encoding frame of one frame before can be executed, the prediction accuracy is raised, compared with the prediction from the frame I0 separated timewise, and the compression efficiency of image data is improved.

Iwamura Ryuichi

Papers

Interframe motion predicting method and picture signal coding/decoding apparatus

Inter-frame motion predicting method