The present disclosure pertains to an image-processing device and method that make it possible to suppress block noise. A βLUT_input calculator and a clip processor determine βLUT_input, which is a value inputted to an existing-β generator and an expanded-β generator. When the value of βLUT_input qp from the clip processor is 51 or less, the existing-β generator determines β using a LUT conforming to the HVEC standard, and supplies same to a filter process determination unit. When the value of βLUT_input qp from the clip processor is larger than 51, the expanded-β generator determines the expanded β and supplies same to the filter process determination part. This disclosure, for example, can be applied to an image processing device.

Image processing device and method

Mosaic-shaped block noise occurs when a compressed video signal is reproduced This block noise is removed, but removing block noise from every block using a deblocking filter imposes a significant load on the deblocking filter This load is therefore reduced by determining whether coding distortion removal (deblocking) is necessary, and applying a deblocking filter only when needed

Coding distortion removal method, video encoding method, video decoding method, and apparatus and program for the same

Techniques and tools for encoding and decoding motion vector information for video images are described. For example, a video encoder yields an extended motion vector code by jointly coding, for a set of pixels, a switch code, motion vector information, and a terminal symbol indicating whether subsequent data is encoded for the set of pixels. In another aspect, an encoder/decoder selects motion vector predictors for macroblocks. In another aspect, a video encoder/decoder uses hybrid motion vector prediction. In another aspect, a video encoder/decoder signals a motion vector mode for a predicted image. In another aspect, a video decoder decodes a set of pixels by receiving an extended motion vector code, which reflects joint encoding of motion information together with intra/inter-coding information and a terminal symbol. The decoder determines whether subsequent data exists for the set of pixels based on e.g., the terminal symbol.

Coding of motion vector information

An improved loss recovery method for coding streaming media classifies each data unit in the media stream as an independent data unit (I unit), a remotely predicted unit (R unit) or a predicted data unit (P unit). Each of these units is organized into independent segments having an I unit, multiple P units and R units interspersed among the P units. The beginning of each segment is the start of a random access point, while each R unit provides a loss recovery point that can be placed independently of the I unit. This approach separates the random access point from the loss recovery points provided by the R units, and makes the stream more impervious to data losses without substantially impacting coding efficiency. The most important data units are transmitted with the most reliability to ensure that the majority of the data received by the client is usable. The I units are the least sensitive to transmission losses because they are coded using only their own data. While they provide the best coding efficiency, the P units are the most sensitive to data loss because the loss of one P unit renders useless all of the P units that depend on it. The remotely predicted units are dependent on the I unit, or in an alternative implementation, on another R unit.

Media coding for loss recovery with remotely predicted data units

Techniques and tools for coding/decoding of video images, and in particular, B-frames, are described. In one aspect, a video encoder/decoder determines a fraction for a current image in a sequence. The fraction represents an estimated temporal distance position for the current image relative to an interval between a reference images for the current image. The video encoder/decoder processes the fraction along with a motion vector for a first reference image, resulting in a representation of motion (e.g., constant or variable velocity motion) in the current image. Other aspects are also described, including intra B-frames, forward and backward buffers for motion vector prediction, bitplane encoding of direct mode prediction information, multiple motion vector resolutions/interpolation filters for B-frames, proactive dropping of B-frames, and signaling of dropped predicted frames.

Advanced bi-directional predictive coding of video frames

A moving image coder has a forward predicting motion vector/prediction error amount detecting section for detecting an optimum motion vector from a past frame, making a predicted image and calculating a prediction error amount from the present frame. The coder also has a backward predicting motion vector/prediction error amount detecting section for detecting an optimum motion vector from a future frame, making a predicted image and calculating a prediction error amount from the present frame. The coder further has a comparator/mode selecting section for inputting the prediction error amounts from the forward predicting motion vector/prediction error amount detecting section and the backward prediction motion vector/prediction error amount detecting section, making a comparative calculation of the input prediction error amounts, and selecting one of a forward prediction mode, a backward prediction mode and a bidirectional prediction mode.

Prediction mode selecting device in moving image coder

A motion image coding apparatus providing enhanced image quality as compared with the prior art includes a coding unit for coding first, second and third frames, a prediction efficiency calculating circuit for calculating prediction efficiency in inter-frame prediction, in coding by the coding unit using said first or second frame as a reference frame, and a reference frame interval determining circuit for determining a reference frame interval which is a time interval between the first and second frames, time interval between the second frames and time interval between the first frames.

Motion image coding apparatus adaptively controlling reference frame interval

In a motion-vector detecting device for detecting motion-vectors of images processed through a two-dimensional filter by a subsampling method, a filter circuit must process pixel values at a block boundary by delaying the pixel value in both horizontal and vertical directions, which complicates reading pixel data from memory and increases the size of the filter circuit. The present invention provides a motion-vector detecting device for detecting motion-vectors by searching a match of a coding block of a coding image with a prediction candidate-block in a searching area of a reference image. The invention further applies a one-dimensional filter for a coding block and a prediction candidate-block in a horizontal direction to restrict frequency bands of the blocks, and calculates a matching error-value between a part of the pixels in the band-limited coding block and a part of the pixels in the band-limited prediction block to detect a motion-vector, in calculating error-values for a group of pixels by the motion-vector detecting circuit, block-end pixels are considered to exist inside the block boundary by the number of pixels rounded off after a decimal point corresponding to one half of the number of taps of the spatial filters.

Motion vector detecting device

A moving image coder has an arithmetic unit (22) for calculating an average value of a coding object block; an arithmetic unit (23) for obtaining an alternating current component by subtracting the average value from each of pixel values of the coding object block; an arithmetic unit (24) for obtaining a intra frame activity amount by making a calculation of the same kind as an error calculation in a motion prediction with respect to the obtained alternating current component; and a comparator (25) for comparing the intra frame activity amount with a predicting error amount calculated when the motion prediction is made. The inter frame coding mode or the intra frame coding mode is judged by large and small relations of the predicting error amount and the intra frame activity amount. In this moving image coder, codings of a intra frame block and a inter frame differential block are adaptively switched.

Moving image coder

The prediction error value calculated by a motion estimating portion is used for selecting the frame or field orthogonal transform coding mode. The frame prediction error value EFr and the field prediction error value EFi are calculated by the motion estimating portion and entered into a comparator of an orthogonal transform mode selecting portion which in turn compares them with each other and generates an orthogonal transform mode selecting signal TC. The use of the prediction error values for selecting the orthogonal transform mode makes it possible to reduce the size of the necessary hardware and saves much time of data processing necessary for judgment of the orthogonal transform mode selection.

Yoichi Fujiwara

Papers

Prediction mode selecting device in moving image coder

Motion image coding apparatus adaptively controlling reference frame interval

Motion vector detecting device

Moving image coder

Video coding device