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AssigneeFujitsu Limited
InventorsSatoshi Shimada, Akira Nakagawa, Akihiro Yamori, Chikara Imajo
Estimating the term…
A video encoder that encodes each of a plurality of blocks obtained by dividing an input image, includes: a definition unit configured to define a valid area which is allowed to be used as reference in a reference image in interframe coding; a detection unit configured to detect a reference area in the reference image for a target block; a predicted image generation unit configured to generate a predicted image by outputting an image of the reference area for the reference area belonging to the valid area and outputting a complementary image for the reference area not belonging to the valid area; and a coding unit configured to encode the input image using the predicted image, wherein valid area information indicating the valid area is transmitted to a video decoder, for each group of a plurality of blocks.
A video encoder that encodes each of a plurality of blocks obtained by dividing an input image, the video encoder comprising:
A video encoding method for encoding each of a plurality of blocks obtained by dividing an input image, the video encoding method comprising:
A video decoder that decodes encoded data obtained by a video encoder that encodes each of a plurality of blocks obtained by dividing an input image, the video decoder comprising:
A video decoding method for decoding encoded data obtained by a video encoder that encodes each of a plurality of blocks obtained by dividing an input image, the video decoding method comprising:
Dependencies are inferred from the claim text.
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Selection of coding mode or of prediction mode: between spatial and temporal predictive coding, e.g. picture refresh
The unit being an image region, e.g. an object: the region being a slice, e.g. a line of blocks or a group of blocks
Involving temporal prediction: motion estimation or motion compensation
Methods or arrangements for coding, decoding, compressing or decompressing digital video signals: details of filtering operations specially…
About 1 year 7 months of term left · ends 22 May 2028 (estimated)
The present invention relates to a video encoder and a video decoder having a motion compensation function.
Motion-compensated interframe prediction coding has been known as a coding system for moving image data. In the motion-compensated interframe prediction coding, motion vector representing the “motion” of a picture element between frames is detected in an encoder. Using the detected motion vector, the image of a current frame is predicted from a past frame (or, from both of a past frame and a future frame), and the difference (that is, error) between the current image and the predicted image is detected. Then, the motion vector information and the prediction error information are transmitted. A decoder reproduces a moving image using the motion vector information and the prediction error information.
Once an error which corrupts the transmitted date occurs in the motion-compensated interframe prediction coding, the error is propagated to subsequent frames. For this reason, in the motion-compensated interframe prediction coding, usually, an intraframe-coded picture is periodically inserted. The intraframe-coded picture is encoded independently from other frames. Therefore, even if an error occurs, the error is not propagated to the subsequent frames of the intraframe-coded picture.
FIG. 1 is a diagram describing the sequential refresh.
FIG. 2 is a diagram describing the restriction of the reference area.
FIG. 3 is a diagram describing the cue play of a moving image.
FIG. 6 illustrates the configuration of a video encoder according to an embodiment. A video encoder 100 encodes video data using motion-compensated prediction, for each of a plurality of blocks obtained by dividing an image. The sequential refresh descried with reference to FIG. 1 is adopted for the interframe coding. Either forward prediction or bidirectional prediction may be performed for the interframe coding.
A prediction error signal generation unit 1 calculates the difference (that is, error) between an original image and a predicted image for each frame (or, for each block), and outputs a prediction error signal representing the calculated error. The predicted image is to be described later. An orthogonal conversion unit 2 performs orthogonal conversion of the prediction error signal. The orthogonal conversion in this example is, for example, DCT (Discrete Cosine Transform). In the DCT conversion, each pixel value is converted into a frequency component, and coefficient data representing each frequency component is generated. A quantization unit 3 quantizes an output signal (in this example, the coefficient data) of the orthogonal conversion unit 3. A coefficient coding unit 4 performs entropy coding of the quantized coefficient data. A multiplexer 5 multiplexes and transmits the coded coefficient data, coded motion vector data and coded control data. The control data is to be described later.
The data output from the multiplexer 5 is transmitted to a video decoder, for example, via a network. Alternatively, the data output from the multiplexer 5 is written into a storage apparatus. The multiplex method is TDM, for example and without being a limitation.