Canon Kabushiki Kaisha

Susumu Igarashi

Katsumi Otsuka

Tetsuya Tateno

Yukio Chiba

Makoto Satoh

Makoto Sato

Koji Okawa

Koji Aoki

Satoshi Naito

Tsutomu Ando

Keiji Ishizuka

An obtaining unit obtains a plurality of first pixel values and a plurality of second pixel values generated by an image sensor and corresponding to a plurality of pixels. A first gain is applied to each of the plurality of first pixel values and a second gain greater than the first gain is applied to each of the plurality of second pixel values. An encoding unit encodes each of a plurality of target pixel values on the basis of a correlation with a reference pixel value corresponding to a same pixel among a plurality of reference pixel values. The plurality of target pixel is one of the plurality of first pixel values and the plurality of second pixel values, and the plurality of reference pixel values is the other of the plurality of first pixel values and the plurality of second pixel values.

Encoding apparatus, encoding method, and storage medium

An image coding apparatus which codes an image using intra prediction determines a size of a prediction block to be a unit of processing for performing intra prediction. The image coding apparatus derives a prediction error by performing intra prediction on the prediction block, derives a coding cost of a prediction mode when performing the intra prediction using a reference according to the determined size, and determines the coding cost of the prediction mode based on the coding cost of the prediction mode and the prediction error. The image coding apparatus determines a prediction mode of the prediction block from among a plurality of prediction modes based on the coding cost.

Image coding apparatus, image coding method, and program

To use both intraframe prediction coding and interframe prediction coding, and at the same time restrict a transfer volume of reference data used in motion detection in interframe prediction coding. In a coding apparatus that compression-codes moving images, both intraframe prediction coding and interframe prediction coding are applied and prediction coding is carried out using a prediction image produced by the coding system deemed to have the higher coding efficiency.

Image coding apparatus and image coding method

An area where a specific object is captured is extracted as a specific area from the image of a frame of interest, and the evaluation value of the specific area is obtained using a predetermined evaluation formula. It is determined whether the evaluation value of the specific area in a frame preceding the frame of interest has exceeded a predetermined threshold. When it is determined that the evaluation value of the specific area has exceeded the predetermined threshold, the frame of interest is encoded to set the code amount of the specific area in the image of the frame of interest to be smaller than that of the specific area in the image of the frame preceding the frame of interest.

Image processing apparatus and image processing method

In this invention, scan conversion processing of changing the scan order for each block is used. Parallel scan conversion processing is executed if possible, thereby making the number of scan conversion target blocks per unit time larger than before. To do this, a scan status holding unit holds statistical information based on the appearance frequency values of coefficients in a block. A scan order holding unit holds coefficient position information in which the coefficient positions in a block are arranged based on the scan order. A parallel number determination unit determines the number of blocks processable in parallel based on the statistical information held in the scan status holding unit and supplies the result to a scan conversion unit as a control signal. If the control signal from the parallel number determination unit indicates parallel processing, the scan conversion unit executes scan conversion of two input blocks in parallel.

Scan conversion apparatus, image encoding apparatus, and methods of controlling the same

In image data coding and decoding processing, in order to improve efficiency by processing a plurality of factors in one cycle as long as possible, the factors are rearranged, in coding or decoding processing, in a predetermined scan sequence such that significant factors and 0s are paired. In addition, an appropriate scan sequence is selected in accordance with the distribution state of frequencies to further improve the efficiency.

Image coder/decoder, image coding/decoding method, and storage medium

An apparatus has a one-dimensional DCT transformer for applying the one-dimensional orthogonal transforms to n inputs and outputting n coefficients, a transposition converter for transposing n&#xd7;n coefficients output from the one-dimensional DCT transformer and outputting every n outputs, and a multiplexer for selecting one output of the n outputs from the transposition converter or one output of the n outputs from the one-dimensional DCT transformer. The apparatus further includes a selector for selecting data as a combination of one output selected by the multiplexer and remaining (n&#x2212;1) outputs, which are not input to the multiplexer, of the n outputs from the transposition converter, or the input image data, and supplying the selected data as n data to the one-dimensional DCT transformer.

Image processing apparatus and method, program, and storage medium

A decoding apparatus has: M tables for storing, in correspondence with M types of variable-length code tables, minimum code words or maximum code words of classes of variable-length code words constructing a variable-length code table; a table selector which selects one table from the M tables; N comparators which compare input coded data with the minimum code words or maximum code words outputted from the table selected by the table selector; a switch circuit and a priority encoder which obtain a class number corresponding to an initial code word of the input coded data based on results of comparison by the N comparators; a code length converter which converts the class number into a code length; and an address generator which generates an address to access a memory holding decoded data from the class number and the code length outputted said code length converter. The data outputted from the memory based on the address becomes decoded data of the input coded data.

Decoding apparatus, method, and storage medium for inputting and decoding variable-length coded data

Whether a header information processor quickly enters a program inactive state at the timing when it issues an operation start command of an encoding process for a predetermined processing unit to a variable-length code encoder, or the header information processor enters the program inactive state upon completion of execution steps to be processed is adaptively selected in accordance with the number of execution steps. One memory is shared by the header information processor and variable-length code encoder, and address input permission means for controlling to grant permission of an address input to the memory to one of the header information processor and the variable-length code encoder is provided. The memory is used as a work area of the header information processor, and as a storage area of a variable-length code table which is looked up by the variable-length code encoder.

Image processing method, apparatus, and storage medium

This invention implements a variable-length code pipeline decoding process as hardware by providing additional bit processing means, reducing the load on external control, and clarifying encoded data shift means. For this purpose, in order to determine a code length and additional bit length, two different decode processes are executed, the overall process is separated into three stages, i.e., a stage for shifting out a code word of encoded data, a decode processing stage, and a symbol determination & additional bit processing stage, and these stages are executed in a pipeline manner.

Variable-length decoding apparatus and method

Address information generated and output by an address converter for each pixel of input image data in accordance with the phase based on the position of the pixel to be coded is stored in an address storage divided into address groups which are periodically referred to. Information indicative of the occurrence probability of the pixel to be coded and phase information of the pixel are selectively output from the address storage, and an arithmetic coding is performed for the output. During the processing, update data is written in to one group while a read-out is being performed for the other group. A template is constituted by excluding a pixel which predeses one pixel, and a prediction state in each phase is divided into two parts. The template output is applied to both of the divided storage devices, and read actions are independently performed.

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Kawasaki, Japan

Susumu Igarashi