JPH10215454A - Encoding device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the deterioration of picture quality and also to control the quantity of generated data despite the occurrence of a rate-over state by dividing the input image data into plural bands to successively array them to the frames corresponding to the high frequency components from the frames corresponding to the low frequency components and controlling the quantization step width to generate the frame data of fixed length. SOLUTION: A wavelet conversion part 11 converts the input image data DG, of an encoder 5 into the sub-band image data DSB which are divided into plural frequency bands. A quantization part 12 outputs plural quantization sub-band data DQSB in the step width set based on the step width control data DCSW. A variable length encoding part 13 turns the data DQSB into the image data DVLG through the two-dimensional Huffman encoding. A formatter part 14 successively arrays plural data DVLG from the partial frames corresponding to the low frequency components to collect them into a format of the prescribed fixed length and outputs it as the frame data FL.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encoding apparatus and an encoding method, and more particularly to an encoding apparatus and an encoding method for compressing image data and recording or transmitting the compressed data to an image recording medium.

[0002]

2. Description of the Related Art Conventionally, JPEG (Joint Photographic Experts Group) has been used as a high efficiency coding technique for image signals.
And MPEG (Moving Picture Experts Group) are known.

[0003] These high-efficiency coding techniques for image signals include:
Redundancy is reduced using the high correlation of the image signal. More specifically, the screen corresponding to the image signal is divided into small blocks (generally, 8 pixels in the vertical direction × 8 pixels in the horizontal direction), and the DCT (Discrete Cosine) is reduced so that the correlation between the pixels in each block is reduced. Transform) and quantizing the transform result to reduce redundancy.

By the way, the amount of data after the redundancy is reduced, that is, the generated code amount differs for each image depending on the properties of the input image signal (resolution, motion components, etc.). On the other hand, the amount of data recorded on a recording medium (recording tape, recording disk, etc.) for recording the generated data (code) and the amount of data transmitted on the transmission path are limited.

As described above, in the high-efficiency coding technology such as JPEG or MPEG, since the redundancy of an image is reduced in units of blocks, the amount of generated code is limited to the recording capacity of a recording medium or the transmission data of a transmission path. If the amount exceeds the limit (hereinafter, referred to as rate over), image data will be lost in units of blocks, causing a problem that serious deterioration will occur on the display screen.

Therefore, conventionally, in order to prevent this deterioration, control of the generated code amount (hereinafter, referred to as rate control) is performed so as not to cause rate over.

[0007]

However, since the control is performed in real time, it is not only difficult to completely control the rate, but also complicated circuits are required to perform the rate control with high accuracy. In general, there is a problem in that the code amount generated in advance must be set to a small value so that the rate over does not occur.

Accordingly, an object of the present invention is to provide an image quality on a screen even when data (code) is generated exceeding the recording capacity of a recording medium or the transmission rate of a transmission path and data (code) is lost. It is an object of the present invention to provide an encoding device and an encoding method that can reduce the degree of deterioration and can easily control the amount of generated data (code).

[0009]

According to the first aspect of the present invention,
Band dividing means for dividing the input image data into a plurality of bands and outputting the divided band data, and a quantization step width controlling means for determining a quantization step width for each of the band divided data and outputting quantization step width control data Quantization means for quantizing the band-divided data at a step width corresponding to the quantization step width control data and outputting the quantized data as quantized data, and variable-length-encoding the quantized data to output as encoded data Encoding means, and generates partial frame data based on each of the encoded data, and in the order of the partial frame data corresponding to the higher frequency component from the partial frame data corresponding to the lowest frequency component, a predetermined A fixed-length frame data is generated by sequentially arranging the partial frame data until the code amount is reached. And formatting means, configured with a.

According to a second aspect of the present invention, in the first aspect of the present invention, the formatting means sequentially converts the encoded data from a side corresponding to the lowest frequency component to a side corresponding to a higher frequency component. Is configured to generate partial frame data based on.

According to a third aspect of the present invention, in the first or second aspect of the invention, when the formatting means generates the partial frame data, the formatting means starts from a central portion of a screen corresponding to the input image data. The partial frame data is sequentially generated toward the periphery of the screen.

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, when the formatting means generates the partial frame data, each of the pixels constituting a screen corresponding to the input image data is generated. A rearranged screen in which the screens are rearranged in units is assumed, and the partial frame data is generated based on the rearranged screen.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the frame data is a higher frequency component from the partial frame data side corresponding to the lowest frequency component. To the encoded data side including the partial frame data corresponding to the luminance signal Y, the luminance signal encoded data corresponding to the luminance signal Y,
The first color difference signal encoded data corresponding to the color difference signal (RY signal) and the second color difference signal encoded data corresponding to the second color difference signal (BY signal) are arranged in this order. .

According to a sixth aspect of the present invention, there is provided a band dividing means for dividing input image data into a plurality of bands and outputting as band divided data, a quantization step width for each band divided data, and a quantization step width. Quantization step width control means for outputting control data, quantization means for quantizing the band-divided data at a step width corresponding to the quantization step width control data, and outputting the result as quantized data, An encoding unit that performs variable-length encoding and outputs the encoded data, and forms a frame data group by a plurality of the input image data, and each of the plurality of input image data corresponding to any one of the input image data configuring the frame data group Generating first partial frame data based on the encoded data, and corresponding to the other input image data constituting the frame data group; Second based on a difference between each said encoded data corresponding to any one of the input image data with each said encoded data constituting the frame data group that
Generating first and second partial frame data corresponding to the lowest frequency component;
The first partial frame data and the second partial frame data are sequentially transferred from the partial frame data toward the first partial frame data and the second partial frame data corresponding to higher frequency components until a predetermined code amount is reached. And formatting means for generating fixed-length frame data by arranging them.

According to a seventh aspect of the present invention, in the invention of the sixth aspect, the formatting means sequentially performs the encoding from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. The apparatus is configured to generate the first partial frame data or the second partial frame data based on data.

According to an eighth aspect of the present invention, in the sixth or seventh aspect of the invention, when the formatting means generates the partial frame data, the formatting means starts from a central portion of a screen corresponding to the input image data. The first partial frame data or the second partial frame data is sequentially generated toward the periphery of the screen.

According to a ninth aspect of the present invention, in the sixth or seventh aspect, the formatting means generates the first partial frame data and the second partial frame data by using the input image data. Is configured to assume a rearranged screen in which the screen is rearranged in units of pixels constituting a screen corresponding to the above, and to generate the first partial frame data and the second partial frame data based on the rearranged screen. I do.

[0018] According to a tenth aspect of the present invention, in the first aspect of the present invention, the frame data includes the first frequency component corresponding to the lowest frequency component.
From the side of the partial frame data and the second partial frame data to the side of the encoded data including the first partial frame data and the second partial frame data corresponding to higher frequency components, the first partial frame data , The first luminance signal encoded data corresponding to the luminance signal Y, the second luminance signal encoded data corresponding to the luminance signal Y for the second partial frame data, and the first color difference signal ( RY signal)
, The first chrominance signal encoded data corresponding to the first chrominance signal (RY signal) for the second partial frame data, and the second chrominance signal encoded data for the first partial frame data. The second color difference signal encoded data corresponding to the color difference signal (BY signal), and the second color difference signal encoded data corresponding to the second color difference signal (BY signal) for the second partial frame data. Configure as arranged.

According to an eleventh aspect of the present invention, a frame data group is constituted by a plurality of input image data, and any one of the input image data constituting the frame data group is divided into a plurality of bands to form a first band. Along with outputting as divided data, difference input image data that is a difference between any one of the input image data forming the frame data group and the other input image data forming the frame data group is output to a plurality of bands. Band dividing means for dividing and outputting as second band divided data, and a quantization step for determining a quantization step width for each of the first band divided data or the second band divided data and outputting quantization step width control data Width control means, and a step width corresponding to the first band division data and the second band division with a step width corresponding to the quantization step width control data. Quantizing means for outputting the data as the first quantized data and the second quantized data by quantizing,
Encoding means for performing variable-length encoding on the first quantized data and outputting it as first encoded data, and encoding the second quantized data as variable-length encoded data and outputting it as second encoded data;
Generating first partial frame data based on the first encoded data, generating second partial frame data based on the second encoded data, and generating the first partial frame data corresponding to the lowest frequency component; And the first and second partial frame data toward the first and second partial frame data corresponding to higher frequency components until a predetermined code amount is reached. And formatting means for generating fixed-length frame data by sequentially arranging the data.

According to a twelfth aspect of the present invention, in the invention of the eleventh aspect, the formatting means sequentially converts the first code from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. The first partial frame data is generated based on encoded data, or the second partial frame data is generated based on the second encoded data.

According to a thirteenth aspect of the present invention, in the first or the twelfth aspect of the present invention, when the formatting means generates the first partial frame data or the second partial frame data, , The first partial frame data or the second partial frame data is sequentially generated from the center of the screen to the outside of the screen.

According to a fourteenth aspect of the present invention, in the eleventh or twelfth aspect of the present invention, the formatting means includes the first partial frame data and the second partial frame data.
Upon generating the partial frame data, assuming a rearranged screen in which the screen is rearranged in units of pixels constituting a screen corresponding to the input image data, the first partial frame data and It is configured to generate the second partial frame data.

According to a fifteenth aspect of the present invention, in the first aspect of the present invention, the frame data includes the first partial frame data and the second partial frame data corresponding to the lowest frequency component. From the partial frame data side toward the coded data side including the first partial frame data and the second partial frame data corresponding to higher frequency components, it corresponds to the luminance signal Y for the first partial frame data. First luminance signal encoded data, second luminance signal encoded data corresponding to the luminance signal Y for the second partial frame data,
First chrominance signal encoded data corresponding to the first chrominance signal (RY signal) for the partial frame data, and first chrominance corresponding to the first chrominance signal (RY signal) for the second partial frame data Signal encoded data, second color difference signal encoded data corresponding to a second color difference signal (BY signal) for the first partial frame data, and second color difference signal (BY) for the second partial frame data. ) Are arranged in the order of the second chrominance signal encoded data corresponding to the signals.

[0024] According to a sixteenth aspect of the present invention, there is provided a band dividing step of dividing input image data into a plurality of bands and outputting the divided band data as a band divided data, and determining a quantization step width for each of the band divided data. A quantization step width control step of outputting control data, and a quantization step of quantizing the band division data with a step width corresponding to the quantization step width control data and outputting the quantized data as quantized data,
An encoding step of performing variable-length encoding on the quantized data and outputting the encoded data as encoded data, and generating partial frame data based on each of the encoded data, and further reducing the partial frame data corresponding to the lowest frequency component. A formatting step of generating fixed-length frame data by sequentially arranging the partial frame data in the order of the partial frame data corresponding to a high frequency component until a predetermined code amount is obtained.

According to a seventeenth aspect of the present invention, in the invention according to the sixteenth aspect, in the formatting step, the encoded data is sequentially arranged from a side corresponding to the lowest frequency component to a side corresponding to a higher frequency component. Is configured to generate partial frame data based on.

According to an eighteenth aspect of the present invention, in the invention according to the sixteenth aspect or the seventeenth aspect, in the formatting step, when generating the partial frame data, the formatting step starts from a central portion of a screen corresponding to the input image data. The partial frame data is sequentially generated toward the periphery of the screen.

[0027] According to a nineteenth aspect of the present invention, in the invention according to the sixteenth or seventeenth aspect, in the formatting step, when the partial frame data is generated, each pixel constituting a screen corresponding to the input image data is generated. A rearranged screen in which the screens are rearranged in units is assumed, and the partial frame data is generated based on the rearranged screen.

According to a twentieth aspect of the present invention, in the invention according to any one of the sixteenth to nineteenth aspects, the formatting step includes the step of setting the partial frame data corresponding to the lowest frequency component in the frame data. From the side toward the encoded data side including the partial frame data corresponding to the higher frequency component, the luminance signal encoded data corresponding to the luminance signal Y, the first color difference signal (R
-Y signal), the first chrominance signal encoded data corresponding to
The second chrominance signal encoded data corresponding to the chrominance signal (BY signal) is arranged in the order of encoded data.

According to a twenty-first aspect of the present invention, there is provided a band dividing step for dividing input image data into a plurality of bands and outputting the divided band data as a band divided data, and a quantization step width is determined for each of the band divided data. A quantization step width control step of outputting control data, and a quantization step of quantizing the band division data with a step width corresponding to the quantization step width control data and outputting the quantized data as quantized data,
An encoding step of performing variable-length encoding on the quantized data and outputting the encoded data as encoded data, and forming a frame data group by a plurality of the input image data, and any one of the input image data constituting the frame data group Generating the first partial frame data based on each of the encoded data corresponding to each of the encoded data and the frame data group corresponding to each of the other input image data constituting the frame data group. Generating second partial frame data based on a difference from each of the encoded data corresponding to the one input image data, and generating the first partial frame data and the second partial frame data corresponding to the lowest frequency component From the first partial frame data and the second partial frame data corresponding to higher frequency components. The until the predetermined code amount first
And a formatting step of generating fixed-length frame data by sequentially arranging the partial frame data and the second partial frame data.

According to a twenty-second aspect of the present invention, in the invention of the twenty-first aspect, in the formatting step, the encoding is sequentially performed from a side corresponding to the lowest frequency component to a side corresponding to a higher frequency component. The apparatus is configured to generate the first partial frame data or the second partial frame data based on data.

According to a twenty-third aspect of the present invention, in the invention of the twenty-first or twenty-second aspect, the formatting step includes, when generating the partial frame data, starting from a central portion of a screen corresponding to the input image data. The first partial frame data or the second partial frame data is sequentially generated toward the periphery of the screen.

[0032] According to a twenty-fourth aspect of the present invention, in the invention of the twenty-first or twenty-second aspect, the formatting step comprises the steps of:
Upon generating the partial frame data, assuming a rearranged screen in which the screen is rearranged in units of pixels constituting a screen corresponding to the input image data, the first partial frame data and The second partial frame data is generated. According to a twenty-fifth aspect of the present invention, in the invention according to any one of the twenty-first to twenty-fourth aspects, the formatting step includes, in the frame data, the first partial frame data corresponding to the lowest frequency component and From the second partial frame data side to the encoded data side including the first partial frame data and the second partial frame data corresponding to higher frequency components, a luminance signal Y for the first partial frame data And the luminance signal Y for the second partial frame data.
, The first chrominance signal coded data corresponding to the first chrominance signal (RY signal) for the first partial frame data, and the first chrominance signal data for the second partial frame data. First color difference signal encoded data corresponding to a color difference signal (RY signal), second color difference signal encoded data corresponding to a second color difference signal (BY signal) for the first partial frame data, The second chrominance signal encoded data corresponding to the second chrominance signal (BY signal) for the two partial frame data is arranged in order.

According to a twenty-sixth aspect of the present invention, a frame data group is constituted by a plurality of input image data, and any one of the input image data constituting the frame data group is divided into a plurality of bands to form a first band. Along with outputting as divided data, difference input image data that is a difference between any one of the input image data forming the frame data group and the other input image data forming the frame data group is output to a plurality of bands. A band division step of dividing and outputting as second band division data, and a quantization step of determining a quantization step width for each of the first band division data or the second band division data and outputting quantization step width control data A width control step, and a step width corresponding to the quantization step width control data for the first band division data and the second band division. A quantization step of outputting the data as the first quantized data and the second quantized data by quantizing,
An encoding step in which the first quantized data is variable-length encoded and output as first encoded data, and the second quantized data is variable-length encoded and output as second encoded data;
Generating first partial frame data based on the first encoded data, generating second partial frame data based on the second encoded data, and generating the first partial frame data corresponding to the lowest frequency component; And the first and second partial frame data toward the first and second partial frame data corresponding to higher frequency components until a predetermined code amount is reached. And a formatting step of generating fixed-length frame data by sequentially arranging the data.

According to a twenty-seventh aspect of the present invention, in the twenty-sixth aspect of the present invention, in the formatting step, the first code is sequentially formed from a side corresponding to the lowest frequency component to a side corresponding to a higher frequency component. The first partial frame data is generated based on encoded data, or the second partial frame data is generated based on the second encoded data.

According to a twenty-eighth aspect of the present invention, in the twenty-sixth aspect or the twenty-seventh aspect, the formatting step includes the step of generating the first partial frame data or the second partial frame data by using the input image data. , The first partial frame data or the second partial frame data is sequentially generated from the center of the screen to the outside of the screen.

According to a twenty-ninth aspect of the present invention, in the twenty-sixth aspect or the twenty-seventh aspect, the formatting step comprises the steps of:
Upon generating the partial frame data, assuming a rearranged screen in which the screen is rearranged in units of pixels constituting a screen corresponding to the input image data, the first partial frame data and The second partial frame data is generated.

According to a thirty-fourth aspect of the present invention, in the invention according to any one of the twenty-sixth to twenty-seventh aspects, the formatting step comprises the step of: From the frame data and the second partial frame data side toward the coded data side including the first partial frame data and the second partial frame data corresponding to higher frequency components, the first partial frame data First luminance signal encoded data corresponding to the luminance signal Y;
The second luminance signal coded data corresponding to the luminance signal Y for the partial frame data, and the first chrominance signal (RY signal) corresponding to the first color difference signal (RY signal) for the first partial frame data.
Color difference signal encoded data, first color difference signal encoded data corresponding to a first color difference signal (RY signal) for the second partial frame data, and second color difference signal (B- The second chrominance signal coded data corresponding to the Y signal) and the second chrominance signal coded data corresponding to the second chrominance signal (BY signal) for the second partial frame data are arranged in this order. I do.

According to the first aspect of the present invention, the band dividing means divides the input image data into a plurality of bands and outputs the divided data to the quantization step width control means and the quantization means. The quantization step width control means determines a quantization step width for each band division data, and outputs the quantization step width control data to the quantization means.

The quantization means quantizes the band-divided data with a step width corresponding to the quantization step width control data, and outputs the quantized data to the coding means. The encoding unit performs variable length encoding on the quantized data and outputs the encoded data to the formatting unit as encoded data.

The formatting means generates partial frame data based on each encoded data,
The fixed-length frame data is generated by arranging the partial frame data in order from the partial frame data corresponding to the lowest frequency component to the partial frame data corresponding to the higher frequency component until a predetermined code amount is reached.

According to the second aspect of the present invention, in addition to the operation of the first aspect, the formatting means further comprises:
Partial frame data is generated based on the encoded data sequentially from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component.

According to the third aspect of the present invention, in addition to the operation of the first or second aspect of the present invention, when the formatting means generates the partial frame data,
Partial frame data is sequentially generated from the center portion of the screen corresponding to the input image data toward the periphery of the screen.

According to the fourth aspect of the present invention, in addition to the operation of the first or second aspect of the present invention, when the formatting means generates the partial frame data,
Assuming a rearranged screen in which the screen is rearranged for each pixel constituting the screen corresponding to the input image data, partial frame data is generated based on the rearranged screen.

According to the fifth aspect of the invention, in addition to the operation of the first aspect of the present invention, the frame data is transmitted from the side of the partial frame data corresponding to the lowest frequency component. Toward the encoded data side including the partial frame data corresponding to the high frequency component, encoded luminance signal data corresponding to the luminance signal Y, and encoded first color difference signal corresponding to the first color difference signal (RY signal) data,
The second chrominance signal is arranged in the order of the second chrominance signal encoded data corresponding to the second chrominance signal (BY signal). Therefore, data that has a greater effect on the image quality is arranged first.

According to the sixth aspect of the invention, the band dividing means divides the input image data into a plurality of bands and outputs the divided image data to the quantization step width controlling means and the quantizing means. The quantization step width control means determines a quantization step width for each band division data, and outputs the quantization step width control data to the quantization means.

The quantization means quantizes the band division data with a step width corresponding to the quantization step width control data, and outputs the quantized data to the coding means. The encoding means performs variable length encoding on the quantized data and outputs the encoded data as encoded data.

The formatting means forms a frame data group by a plurality of input image data, and generates the first partial frame data based on each encoded data corresponding to any one of the input image data forming the frame data group. And a second part based on a difference between each encoded data corresponding to another input image data forming the frame data group and each encoded data corresponding to any one of the input image data forming the frame data group. While generating frame data, predetermined first and second partial frame data corresponding to higher frequency components are shifted from the first partial frame data and second partial frame data corresponding to the lowest frequency component to predetermined partial frame data. The first partial frame data and the second partial frame data are sequentially arranged until the code amount is reached. And by generating a frame data of a fixed length.

According to the seventh aspect of the present invention, in addition to the operation of the sixth aspect, the formatting means further comprises:
From the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component, the first partial frame data or the second partial frame data is sequentially generated based on the encoded data.

According to the eighth aspect of the present invention, in addition to the operation of the sixth or seventh aspect of the present invention, when the formatting means generates the partial frame data,
The first partial frame data or the second partial frame data is sequentially generated from the center portion of the screen corresponding to the input image data toward the periphery of the screen.

According to the ninth aspect of the present invention, in addition to the operation of the sixth or seventh aspect of the present invention, the formatting means is capable of inputting the first partial frame data and the second partial frame data when generating the first partial frame data and the second partial frame data. Assuming a rearranged screen in which the screen is rearranged for each pixel constituting the screen corresponding to the image data, first partial frame data and second partial frame data are generated based on the rearranged screen.

According to the tenth aspect, the sixth aspect is provided.
In addition to the effects of the invention described in any one of claims 9 to 9,
The frame data is the first data corresponding to the lowest frequency component.
From the partial frame data and the second partial frame data to the encoded data including the first partial frame data and the second partial frame data corresponding to the higher frequency components, the luminance signal Y for the first partial frame data is obtained.
, The second luminance signal encoded data corresponding to the luminance signal Y for the second partial frame data, and the first luminance signal encoded data corresponding to the first partial frame data.
First color difference signal encoded data corresponding to the color difference signal (RY signal), first color difference signal encoded data corresponding to the first color difference signal (RY signal) for the second partial frame data, first portion Second chrominance signal encoded data corresponding to a second chrominance signal (BY signal) for the frame data;
The second color difference signal (B-
(Y signal) corresponding to the second chrominance signal encoded data. Therefore, data that has a greater effect on the image quality is arranged first.

According to the eleventh aspect, the band dividing means forms a frame data group by a plurality of input image data, and divides one of the input image data constituting the frame data group into a plurality of bands. And outputs the divided data as first band division data, and converts the difference input image data, which is the difference between any one of the input image data constituting the frame data group and the other input image data constituting the frame data group, into a plurality of bands. And outputs it to the quantization step width control means and the quantization means as second band division data.

The quantization step width control means determines a quantization step width for each of the first band division data and the second band division data, and outputs the quantization step width control data to the quantization means. The quantization means quantizes the first band-divided data and the second band-divided data with a step width corresponding to the quantization step width control data, and outputs the quantized data as first and second quantized data to the encoding means. .

The encoding means performs variable-length encoding on the first quantized data and outputs it as first encoded data, and variable-length encodes the second quantized data and outputs it as second encoded data to the formatting means. . The formatting means generates first partial frame data based on the first encoded data, generates second partial frame data based on the second encoded data, and generates the first partial frame data corresponding to the lowest frequency component. From the data and the second partial frame data toward the first partial frame data and the second partial frame data corresponding to higher frequency components,
Fixed-length frame data is generated by sequentially arranging the first partial frame data and the second partial frame data until a predetermined code amount is reached.

According to the twelfth aspect, according to the first aspect,
In addition to the function of the invention described in 1, the formatting means generates the first partial frame data based on the first encoded data sequentially from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. Alternatively, the second partial frame data is generated based on the second encoded data.

According to the invention of claim 13, claim 1 is
In addition to the operation of the first or twelfth aspect of the invention, the formatting means, when generating the first partial frame data or the second partial frame data, moves from the center of the screen corresponding to the input image data to the outside of the screen. To generate first partial frame data or second partial frame data in sequence.

According to the fourteenth aspect of the present invention, a first aspect is provided.
In addition to the function of the first or twelfth aspect of the invention, the formatting means includes a first partial frame data and a second partial frame data.
When generating the partial frame data, it is assumed that a rearranged screen is obtained by rearranging the screen in units of pixels constituting the screen corresponding to the input image data, and the first partial frame data and the second partial frame are based on the rearranged screen. Generate data.

According to the fifteenth aspect, the first aspect is provided.
In addition to the operation of the invention according to any one of the first to fourteenth aspects, the frame data includes a first partial frame data corresponding to the lowest frequency component and a second partial frame data corresponding to a higher frequency component from the second partial frame data side. Toward the encoded data including the one partial frame data and the second partial frame data, the first luminance signal encoded data corresponding to the luminance signal Y for the first partial frame data, and the luminance signal for the second partial frame data The first chrominance signal coded data corresponding to the second chrominance signal coded data corresponding to Y, the first chrominance signal (RY signal) for the first partial frame data, and the first chrominance for the second partial frame data The first color difference signal encoded data corresponding to the signal (RY signal) and the second color difference signal (BY signal) for the first partial frame data Second color difference signal coded data response,
The second color difference signal (B-
(Y signal) corresponding to the second chrominance signal encoded data. Therefore, data that has a greater effect on the image quality is arranged first.

According to the sixteenth aspect of the invention, in the band dividing step, the input image data is divided into a plurality of bands and output as band divided data. In the quantization step width control step, a quantization step width is determined for each band division data, and the quantization step width control data is output.

In the quantization step, the band division data is quantized with a step width control step and a step width corresponding to the quantization step width control data, and is output as quantized data. In the encoding step, the quantized data is variable-length encoded and output as encoded data.

In the formatting step, partial frame data is generated based on each encoded data.
The fixed-length frame data is generated by arranging the partial frame data in order from the partial frame data corresponding to the lowest frequency component to the partial frame data corresponding to the higher frequency component until a predetermined code amount is reached.

According to the seventeenth aspect of the present invention, the first aspect
In addition to the effect of the invention described in the sixth aspect, the formatting step generates partial frame data based on the encoded data sequentially from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component.

According to the eighteenth aspect, according to the first aspect,
In addition to the function of the invention described in claim 6 or claim 17, in the formatting step, when generating the partial frame data, the partial frame data is sequentially generated from the central portion of the screen corresponding to the input image data toward the periphery of the screen. Generate.

According to the invention of claim 19, claim 1
In addition to the effect of the sixth or 17th aspect of the invention, in the formatting step, when generating the partial frame data, a rearranged screen in which the screen is rearranged in units of pixels constituting the screen corresponding to the input image data is assumed. Then, partial frame data is generated based on the rearranged screen.

According to the twentieth aspect, according to the first aspect,
In addition to the effect of the invention according to any one of claims 6 to 19, the formatting step includes the steps of:
From the partial frame data corresponding to the lowest frequency component to the encoded data including the partial frame data corresponding to the higher frequency component, the luminance signal encoded data corresponding to the luminance signal Y and the first color difference signal (R -Y signal), the first chrominance signal encoded data and the second chrominance signal (B
−Y signal) in the order of the second color difference signal encoded data. Therefore, data that has a greater effect on the image quality is arranged first.

According to the twenty-first aspect of the present invention, in the band dividing step, the input image data is divided into a plurality of bands and output as band divided data. In the quantization step width control step, a quantization step width is determined for each band division data, and the quantization step width control data is output.

In the quantization step, the band division data is quantized with a step width corresponding to the quantization step width control data, and is output as quantized data. In the encoding step, the quantized data is variable-length encoded and output as encoded data.

In the formatting step, a frame data group is constituted by a plurality of input image data, and first partial frame data is generated based on each encoded data corresponding to any one of the input image data constituting the frame data group. And a second part based on a difference between each encoded data corresponding to another input image data forming the frame data group and each encoded data corresponding to any one of the input image data forming the frame data group. While generating frame data, predetermined first and second partial frame data corresponding to higher frequency components are shifted from the first partial frame data and second partial frame data corresponding to the lowest frequency component to predetermined partial frame data. The first partial frame data and the second partial frame data are sequentially arranged until the code amount is reached. And by generating a frame data of a fixed length.

According to the twenty-second aspect, the second aspect is provided.
In addition to the operation of the invention according to the first aspect, the formatting step includes the step of sequentially performing the first partial frame data or the second partial frame data based on the encoded data in order from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. Generate partial frame data.

According to the twenty-third aspect of the present invention, the second aspect is provided.
23. In addition to the operation of the first or second aspect of the invention, in the formatting step, when the partial frame data is generated, the first partial frame is sequentially formed from the center portion of the screen corresponding to the input image data toward the periphery of the screen. Generate data or second partial frame data.

According to the invention of claim 24, claim 2
In addition to the operation of the first or second aspect of the present invention, the formatting step includes the step of:
When generating the partial frame data, it is assumed that a rearranged screen is obtained by rearranging the screen in units of pixels constituting the screen corresponding to the input image data, and the first partial frame data and the second partial frame are based on the rearranged screen. Generate data.

According to the invention set forth in claim 25, claim 2 is provided.
In addition to the effect of the invention according to any one of claims 1 to 24, the formatting step includes the steps of:
From the first partial frame data and the second partial frame data corresponding to the lowest frequency component to the coded data including the first partial frame data and the second partial frame data corresponding to the higher frequency component, the first First encoded luminance signal corresponding to luminance signal Y for partial frame data, second encoded luminance signal corresponding to luminance signal Y for second partial frame data, first
The first chrominance signal encoded data corresponding to the first chrominance signal (RY signal) for the partial frame data, and the first chrominance signal corresponding to the first chrominance signal (RY signal) for the second partial frame data Encoded data, second color difference signal encoded data corresponding to the second color difference signal (BY signal) for the first partial frame data, and second color difference signal (BY signal) for the second partial frame data Corresponding second
They are arranged in the order of the color difference signal encoded data. Therefore, data that has a greater effect on the image quality is arranged first.

According to the twenty-sixth aspect, in the band dividing step, a frame data group is constituted by a plurality of input image data, and any one of the input image data constituting the frame data group is divided into a plurality of bands. And outputs the divided data as first band division data, and converts the difference input image data, which is the difference between any one of the input image data constituting the frame data group and the other input image data constituting the frame data group, into a plurality of bands. And output as second band division data.

In the quantization step width control step, a quantization step width is determined for each of the first band division data and the second band division data, and quantization step width control data is output. The quantization step quantizes the first band-divided data and the second band-divided data with a step width corresponding to the quantization step-width control data, and outputs the result as first quantized data and second quantized data.

In the encoding step, the first quantized data is variable-length encoded and output as first encoded data, and the second quantized data is variable-length encoded and output as second encoded data. The formatting step generates first partial frame data based on the first encoded data, generates second partial frame data based on the second encoded data, and generates the first partial frame data corresponding to the lowest frequency component. From the data and the second partial frame data, the first partial frame data and the second partial frame data are sequentially transmitted toward the first partial frame data and the second partial frame data corresponding to higher frequency components until a predetermined code amount is reached. By arranging them, fixed-length frame data is generated.

According to the twenty-seventh aspect, the second aspect is provided.
In addition to the operation of the invention described in 6, the formatting step generates the first partial frame data based on the first encoded data sequentially from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. Alternatively, the second partial frame data is generated based on the second encoded data.

According to the twenty-eighth aspect of the present invention, the second aspect is provided.
In addition to the effect of the invention described in Item 6 or Claim 27, in the formatting step, in generating the first partial frame data or the second partial frame data, the formatting step is performed from the center portion of the screen corresponding to the input image data to the outside of the screen. To generate first partial frame data or second partial frame data in sequence.

According to the invention set forth in claim 29, claim 2
In addition to the effect of the sixth or 27th aspect of the invention, the formatting step includes the step of:
When generating the partial frame data, it is assumed that a rearranged screen is obtained by rearranging the screen in units of pixels constituting the screen corresponding to the input image data, and the first partial frame data and the second partial frame are based on the rearranged screen. Generate data.

According to the thirtieth aspect, the second aspect is provided.
In addition to the effect of the invention according to any one of claims 6 to 27, the formatting step includes the steps of:
From the first partial frame data and the second partial frame data corresponding to the lowest frequency component to the coded data including the first partial frame data and the second partial frame data corresponding to the higher frequency component, the first First encoded luminance signal corresponding to luminance signal Y for partial frame data, second encoded luminance signal corresponding to luminance signal Y for second partial frame data, first
The first chrominance signal encoded data corresponding to the first chrominance signal (RY signal) for the partial frame data, and the first chrominance signal corresponding to the first chrominance signal (RY signal) for the second partial frame data Encoded data, second color difference signal encoded data corresponding to the second color difference signal (BY signal) for the first partial frame data, and second color difference signal (BY signal) for the second partial frame data Corresponding second
They are arranged in the order of the color difference signal encoded data. Therefore, data that has a greater effect on the image quality is arranged first.

[0080]

Preferred embodiments of the present invention will now be described with reference to the drawings. Prior to the description of the first embodiment for the sub-band coding, briefly described subband coding.

The sub-band coding is a method in which an image signal is divided into a plurality of frequency bands (sub-bands) using a digital filter, and each frequency band is independently quantized and coded. Therefore, according to the sub-band coding, J
There is no need to perform processing by dividing into blocks as in PEG or MPEG, and processing can be continuously performed on the entire image.

Further, according to the sub-band coding,
Frequency band, the high correlation of the image signal
Generally, the higher the frequency band containing low frequency components, the higher the power.
Power is smaller in the frequency band containing higher frequency components.
The lower the frequency band containing low frequency components, the more
This has a great effect on the image quality of the image after the signal. First embodiment 1) Configuration of Video Recording / Reproducing Apparatus FIG. 1 shows a wavelet transform as a subband encoding method.
Of video recording / reproducing apparatus as first embodiment using replacement
FIG.

The video recording / reproducing apparatus 1 can be roughly classified into a video camera 2 which captures an object to be captured and outputs it as an image signal SG, a display 3 which performs various displays based on the decoded image signal SDG, and a video camera 2 The image signal SG input from the ITU-R Rec. 601 is converted to image data DG having a 4: 2: 2 format and output to an encoder 5 described later, and decoded image data DDG output from a decoder 8 described later is converted to a decoded image signal SDG and displayed. A video interface 4 for outputting the frame data FL to a video interface 4; an encoder 5 for outputting the frame data FL by performing a wavelet transform on the image data input via the video interface; and a recording medium 6 such as a semiconductor memory or an optical disk for storing the frame data FL. , The frame data FL output by the encoder 4
Is written into the recording medium 6, and the frame data FL read from the recording medium 6 is output to a decoder 8 described below. The interface unit 7 decodes the frame data FL read from the recording medium 6 via the interface unit 7. 8 that outputs decoded image data DDG
And a playback control unit 9 for performing various playback controls based on external instructions.

The encoder 5 receives the input image data D
Wavelet transform G to sub-band image data DSB
A quantization unit 12 that quantizes the sub-band image data DSB with a quantization step width based on the step width control data DCSW described later and outputs a plurality of quantized sub-band data DQSB; Variable-length encoding unit 13 that performs two-dimensional Huffman encoding of encoded subband data DQSB and outputs the encoded image data DVLG, and frame data that has a predetermined format (see FIG. 5) by combining a plurality of encoded image data DVLGs. It comprises a formatter unit 14 for outputting as FL, and a rate control unit 19 for outputting step width control data DCSW for controlling a quantization step width based on the sub-band image data DSB and the quantized sub-band data DCSB. It is configured.

The decoder 8 performs the inverse formatting of the input frame data FL and outputs it as a plurality of variable-length decoded image data DVLG '.
5, a variable-length decoding unit 16 that performs two-dimensional Huffman decoding on each of the plurality of variable-length decoded image data DVLG ′ and outputs a plurality of quantized decoded image data DQSB ′. An inverse quantization unit 17 for quantizing and outputting as inversely quantized image data DSB ', and an inverse wavelet transform unit 18 for performing inverse wavelet transform on the inversely quantized image data DSB' and outputting decoded image data DDG. It is configured.

2) Operation of Encoder Here, a more specific operation of the encoder 5 will be described. First, the general operation of the wavelet transform unit 11 (3
2 and 3 for hierarchical two-dimensional wavelet transform)
This will be described with reference to FIG.

The three-layer two-dimensional wavelet transform is shown in FIG.
As shown in FIG. 3, a process of performing one-dimensional subband division in a first direction (horizontal direction in FIG. 2) and further performing one-dimensional subband division in a second direction (vertical direction in FIG. 2) is performed. Can be realized by recursively applying to the lowest sub-band data LL1 (LL2).

In FIG. 2, reference numerals “L” and “H”
Is a quadrature mirror filter (QMF) designed based on the wavelet theory, where the symbol “L” represents a low-pass filter and the symbol “H” represents a high-pass filter. In this case, the low-pass filter L
And the impulse response of the high-pass filter H
Assuming that (n) and h (n), h (n) = (-1) ^(1-n) l (1-n).

The symbol “↓ 2” represents サ ブ sub-sampling. Furthermore, a pair of “L ↓ 2” and “H ↓”
"2" constitutes a split filter pair. Next, a detailed operation of the wavelet transform unit 11 will be described. a) First Hierarchy The input image data DG is divided into sub-bands in the horizontal direction, and is divided into a low-frequency signal and a high-frequency signal on a first frame memory as shown in FIG.

Next, subband division is performed in the vertical direction based on the data in the first frame memory, and as shown in FIG. 3B, the subband data LL1, DSB7, DSB8, It is divided into four subband data of DSB9. b) Second layer Subsequently, the sub-band data LL1, DSB7, DSB8, DSB9
The subband data LL1 in the lowest band is divided into subbands in the horizontal direction, and is divided into a lowband signal and a highband signal on the first frame as shown in FIG.

Next, subband division is performed in the vertical direction based on the subband data LL1 on the first frame memory, and as shown in FIG. 3D, an area corresponding to the subband data LL1 on the second frame is obtained. To the subband data L
The data is divided into four subband data L2, DSB4, DSB5, and DSB6.

C) Third layer Similarly, the sub-band data LL2, DSB4, DSB5, DSB6
Of the low band sub-band data LL2 is divided into sub-bands in the horizontal direction and, as shown in FIG. 3 (e), divided into a low band signal and a high band signal on the first frame.

Next, subband division is performed in the vertical direction based on the data in the area corresponding to the subband data LL2 on the first frame memory, and as shown in FIG.
In the area corresponding to the sub-band data LL2 on the second frame, four of the sub-band data DSB0, DSB1, DSB2, and DSB3 are stored.
Is divided into two sub-band data.

The image data DG input by performing the two-dimensional wavelet transform of the first to third layers is divided into ten sub-band data DSB0 to DSB9. These sub-band data DSB0 to DSB9 constitute sub-band image data DSB.

The sub-band image data DSB (= sub-band data DSB0 to DSB9) obtained by performing the wavelet transform on the image data DG is output to the quantization unit 12 and the rate control unit 19. In this case, among the obtained sub-band data DSB0 to DSB9, the sub-band data DSB0 is the sub-band data including the lowest frequency component, and the remaining sub-band data DSB1 to
For DSB9, the sub-band data DSB1, DSB2 → sub-band data DSB3 → sub-band data DSB4, DSB5
→ Subband data DSB6 → Subband data DSB7, D
High frequency components increase in the order of SB8 → subband data DSB9.

In general, the power containing a large amount of low frequency components is large because of the high correlation of the image signal.
Since the power that includes more high frequency components has lower power, the sub-band data DSB0 has the highest power and the sub-band data DSB9 has the lowest power.

The power amount and the importance as image information match, and the sub-band data with a large power, that is,
It can be said that the importance is higher as the subband data contains more low frequency components. Therefore, in order to reduce the image quality degradation while keeping the data amount constant, it is only necessary to adopt sub-band data including lower frequency components as data and not to employ sub-band data including higher frequency components. Becomes The technique for this will be described later in detail.

The subband image data DSB is quantized by the quantization unit 12 based on the step width control data DSCW output from the rate control unit 19, and corresponds to each of the subband data DSB0, DSB1,..., DSB8, DSB9. The data is output to the rate control unit 19 and the variable-length coding unit 13 as a plurality of quantized sub-band data DQSB.

In parallel with this quantization, the rate control unit 19
Calculates the optimum quantization step width based on the input sub-band image data DSB and the quantized sub-band data DQSB, and outputs the corresponding step width control data DCSW to the quantization unit 12. The variable length coding unit 13 performs two-dimensional Huffman coding on the plurality of quantized sub-band data DQSB, and outputs the result to the formatter unit 14 as a plurality of variable length coded image data DVLG.

The formatter unit 14 collectively outputs the input plurality of variable-length coded image data DVLG to the recording medium 6 via the interface unit 7 as frame data FL having a predetermined format. 3) Configuration of Frame Data FIG. 4 shows fixed-length (= constant data amount) frame data FL.
FIG.

The frame data FL is roughly composed of an index information section 30 and an image data section 31. The index information section 30 stores SOF (Start Of Frame) data 3 representing the head of frame data.
2, frame number data 33 representing a frame number (Frame No.), and frame byte count data 34 representing the total number of bytes of the frame.

The image data section 31 is composed of sub-band data corresponding to the partial frame data. The sub-band data is based on its importance, and is composed of sub-band data DSB0 including the lowest frequency component → sub-band data DSB1.
→ Subband data DSB2 → Subband data DSB3 →
Subband data DSB4 → subband data DSB5 → subband data DSB6 → subband data DSB7 → subband data DSB8 → subband data DSB9.

In this case, each sub-band data includes luminance signal (Y) component data, RY chrominance signal component data, and BY chrominance signal component data. For example, sub-band data DSB0 Are luminance signal component data SB0Y, RY color difference signal component data SB0R
And BY-color difference signal component data SB0B.

Similarly, the image data section 31 stores the luminance signal (Y) component data SB1Y,... Corresponding to the sub-band data DSB1, the luminance signal (Y) component data SB9Y corresponding to the sub-band data DSB9, Band data DS
It is provided with RY color difference signal component data SB9R corresponding to B9 and BY color difference signal component data SB9B corresponding to the sub-band data DSB9.

By the way, each sub-band data is composed of luminance signal (Y) component data → RY color difference signal component data → BY
The reason that the color difference signal component data is recorded in the order is that the luminance signal has a greater effect on the image quality (visual) of the luminance signal and the color difference signal, and the RY color difference signal and the BY color difference signal This is because the RY color difference signal has a greater effect on the image quality (visual).

Here, as the luminance signal (Y) component data, the luminance signal (Y) corresponding to the sub-band data DSB8
A description will be given by taking the component data SB8Y as an example. The luminance signal (Y) component data SB8Y is the sub-band data DS
SOS (Start Of Subband) indicating the start of B8
Data 40, Q-value data 41 representing the quantization step width (Q Value) of the sub-band data DSB8, sub-band byte count data 42 representing the number of bytes of the sub-band data DSB8, and two-dimensional Huffman coding And Huffman coded data 43, which is the actual data of the sub-band thus obtained.

In FIG. 4, image data section 31 stores all sub-band data DSB0 to DSB9 in frame data FSB.
In the case where the frame data FL reaches a predetermined number of bits in the middle of any of the sub-band data DSBX (X: 0 to 9) (at the time of rate over), An end code indicating the end of data is added, and the generation processing of the frame data FL ends.

As described above, even when a part of the sub-band data is not included in the frame data FL due to the rate over, the frame data FL contains
The sub-band data on the low frequency component side is preferentially included in comparison with the sub-band data on the high frequency component side, that is, the sub-band data that has a significant effect on the degradation of the reproduction image quality is preferentially framed. Since only the sub-band data included in the data FL and not significantly affecting the deterioration of the reproduction image quality is not included, the deterioration of the reproduction image can be reduced while the data amount is kept constant. Further, the sub-band data not included in the frame data FL (or a part of the sub-band data)
By performing wavelet inverse transformation by complementing 0 data at the time of reproduction, the entire screen can be reproduced without causing significant image quality deterioration.

As described above, since the sub-band data having higher importance is employed as a part of the frame data FL in order to secure the image quality, if the sub-band data is partially Alternatively, even when a part of the sub-band data is not included in the frame data FL, the effect can be reduced.

The above encoding is generally performed in the order of raster scan, which is the display order of image signals, as shown in FIG. 5 (a). For example, FIG. 5 (b) As shown in the figure, if encoding is performed so as to draw a spiral from the center of the screen toward the periphery, even if a rate over occurs, the frame data FL is fixed length. The missing data corresponds to the periphery of the screen and contains many high-frequency components, and the deterioration of the screen occurs at the periphery of the screen. Deterioration is less likely to occur, making it difficult to recognize screen deterioration.

In addition, when encoding is performed so that the pixels constituting one screen are arranged in a seemingly random order, if each pixel constituting the screen corresponding to the input image data is encoded, Assuming a rearranged screen in which the screen is rearranged, this is equivalent to a case where encoding is performed based on this rearranged screen.Even if a rate over occurs, image quality degradation is almost uniformly distributed over the entire screen. Will be
It is possible to make it difficult to recognize screen deterioration.

[0112] Here, "seemingly random order" means a pseudo-random order so that decoding can be performed in the same order at the time of decoding. 5) Operation of Decoder Here, a specific operation of the decoder 8 will be described.

First, when a reproduction command is input to the reproduction control unit 9, the interface unit 7 reads out the frame data FL corresponding to the reproduction command from the recording medium 6, and
The data is sequentially output to the inverse formatter unit 15 of the decoder 8. The inverse formatter 15 generates a plurality of encoded image data DVLG ′ corresponding to each subband from the frame data FL and outputs the plurality of encoded image data DVLG ′ to the variable-length decoder 16.

The variable length decoding unit 16 performs two-dimensional Huffman decoding of the coded image data DVLG ', and generates a plurality of quantized subband data DQSB corresponding to each of the subband data DSB0, DSB1,..., DSB8, and DSB9. 'To the inverse quantization unit 1
7 is output. In this case, the variable length decoding unit 16
When a part of the input dequantized image data DSB ′, that is, a part of the sub-band data DSBX is missing, the missing part is complemented by 0 data to obtain the quantized sub-band data DQSB. 'Will be generated.

The inverse quantization unit 17 inversely quantizes the quantized sub-band data DQSB 'and outputs the inverse-quantized image data DS
B ′ is output to the inverse wavelet transform unit 18. The inverse wavelet transform unit 18 performs inverse wavelet transform on the input inverse quantized image data DSB 'and outputs the result to the video interface unit 4 as decoded image data DDG.

6) Operation of Wavelet Inverse Transformation Unit Next, the schematic operation of the wavelet inverse transformation unit 18 (three layers 2
The two-dimensional wavelet inverse transform will be described with reference to FIGS. In the three-layer two-dimensional inverse wavelet transform, as shown in FIG. 6, one-dimensional subband synthesis is performed in a first direction (vertical direction in FIG. 6) and further in a second direction (horizontal direction in FIG. 6). This can be realized by performing a process of performing one-dimensional subband synthesis, and sequentially resynthesizing the two synthesis results.

In FIG. 6, reference numerals “L” and “H”
Is a quadrature mirror filter (QMF) designed based on the wavelet theory, where the symbol “L” represents a low-pass filter and the symbol “H” represents a high-pass filter. Also in this case, the low-pass filter L
And the impulse response of the high-pass filter H
Assuming that (n) and h (n), h (n) = (-1) ^(1-n) l (1-n).

The symbol “$ 2” indicates double upsampling. Further, a pair of “$ 2L” and “$ 2
"H" constitutes a synthesis filter pair. Next, the detailed operation of the inverse wavelet transform unit 18 will be described. a) The third-layer sub-band data DSB0 'and the sub-band data DSB1' are converted to the second layer by the third-layer first vertical synthesis filter pair.
The low frequency signal is synthesized on the frame memory FM2.

On the other hand, the sub-band data DSB2 'and the sub-band data DSB3' are synthesized into a high-frequency signal on the second frame memory FM2 by the third hierarchical second vertical synthesizing filter pair. A low-frequency signal as a result of the vertical synthesis of the sub-band data DSB0 'and the sub-band data DSB1', and the sub-band data DSB2 'and the sub-band data DSB
The high-frequency signal, which is the result of vertical synthesis of 3 ', is synthesized as sub-band data LL2' by a third layer horizontal synthesis filter pair in a corresponding area on the first frame memory FM1.

B) The second-layer sub-band data LL2 'and sub-band data DSB4' are converted to the second-layer first vertical synthesis filter pair by the second-layer first vertical synthesis filter pair.
The low frequency signal is synthesized on the frame memory FM2.

On the other hand, the sub-band data DSB 5 ′ and the sub-band data DSB 6 ′ are synthesized into a high-frequency signal on the second frame memory FM 2 by the second hierarchy second vertical synthesis filter pair. A low-frequency signal as a result of vertical synthesis of the sub-band data LL2 and the sub-band data DSB4 ', and the sub-band data DSB5' and the sub-band data DS
The high-frequency signal, which is the result of the vertical synthesis of B6 ', is synthesized as sub-band data LL1' by a second layer horizontal synthesis filter pair in a corresponding area on the first frame memory FM1.

C) First-layer sub-band data LL1 'and sub-band data DSB7' are converted to second-layer data by the first-layer first vertical-direction synthesis filter pair.
The low frequency signal is synthesized on the frame memory FM2.

On the other hand, the sub-band data DSB 8 ′ and the sub-band data DSB 9 ′ are synthesized into a high-frequency signal on the second frame memory FM 2 by the first hierarchical second vertical synthesis filter pair. The low band signal which is the vertical synthesis result of the subband data LL1 'and the subband data DSB7' and the high band signal which is the vertical synthesis result of the subband data DSB8 'and the subband data DSB9' are the first layer horizontal synthesis filter The pair is combined as decoded image data DDG on the first frame memory FM1.

The decoded image data DDG is D / A-converted via the video interface unit 4 to obtain the image signal SDG.
Is output to the display 3. As a result, an image is displayed on the screen of the display 3. Second Embodiment In the first embodiment described above, intra-frame coding which is image information compression based on spatial screen correlation has been described. However, in the second embodiment, temporal screen correlation is used in addition to intra-frame coding. This is an embodiment in the case of using inter-frame predictive coding, which is image information compression based on an image.

In the inter-frame predictive coding, data of one pixel constituting a frame is represented by using difference data which is a difference from the data of the pixel at another time. In the following, as shown in FIG. 8, a case will be described where one frame group is composed of two frames (first frame and second frame) separated by 1/30 second that constitute an image of the NTSC system.

In this case, as a method of the inter-frame predictive coding, assuming that the image data constituting the first frame is the first image data and the image data constituting the second frame is the second image data, 1) A method of performing a wavelet transform after obtaining a difference between the first image data and the second image data 2) A method of performing a wavelet transform on the first image data and the second image data and obtaining a difference between the obtained subband data It is also possible to employ.

More specifically, when the above-described first method is adopted, first, the first image data is subjected to wavelet transform, and a first sub-band data group (= sub-band data DSB01 to DSB91). Next, a difference between the pixel data forming the first image data and the pixel data forming the second image data corresponding to the pixel data is calculated, difference image data is generated, and a wavelet transform is performed on the difference image data. A second subband data group (= subband data DSB02 to DSB92) corresponding to the difference image data is generated.

By formatting the sub-band data DSB01 to DSB91 constituting the first sub-band data group and the sub-band data DSB02 to DSB92 constituting the second sub-band data group, the frame data F
Generate L2. As in the first embodiment, the frame data FL2 is roughly divided into an index information section and an image data section. The index information section includes an SOF (Start Of Of) representing the head of the frame data.
Frame) data, frame number data indicating a frame number (Frame No.), and frame byte count data indicating the total number of bytes of the frame.

Here, the configuration of the image data portion of the frame data FL2 will be described with reference to FIG. As shown in FIG. 9, the image data unit 51 is configured in a state where sub-band data forming the first sub-band data group and sub-band data forming the second sub-band data group are mixed. From the importance of the data, the subband data DSB01 + subband data DSB02 → subband data DSB11 + subband data DSB12 → subband data DSB21 + subband data DSB22 → subband data DSB31 + subband data DSB32 → subband data DSB41 + subband data DSB42 → subband data DSB51 + subband data DSB52 → subband data DSB61 + subband data DSB62 → subband data D
SB71 + subband data DSB72 → subband data DSB
81 + subband data DSB82 → subband data DSB91
+ Subband data DSB92 are recorded in this order.

In this case, each sub-band data includes luminance signal (Y) component data, RY chrominance signal component data, and BY chrominance signal component data, and within the frame data FL2, The sub-band data forming the first sub-band data group and the luminance signal (Y) component data of the sub-band data forming the second sub-band data group corresponding to the sub-band data, RY
The color difference signal component data and the BY color difference signal component data are arranged in a mixed state.

For example, as for the sub-band data DSB01 and the sub-band data DSB02, the frame data FL
2, the luminance signal component data SB0Y1 corresponding to the sub-band data DSB01 → the luminance signal component data SB0Y2 corresponding to the sub-band data DSB02 → the sub-band data DSB01
RY color difference signal component data SB0R1 corresponding to the sub-band data DSB02 RY color difference signal component data SB0R2 corresponding to the sub-band data DSB01 BY color difference signal component data SB0B1 corresponding to the sub-band data DSB01 corresponding to the sub-band data DSB02 Are arranged in the order of the BY color difference signal component data SB0B2.

Similarly, the luminance signal (Y) component data SB1Y1 corresponding to the sub-band data DSB11 → the luminance signal (Y) component data S corresponding to the sub-band data DSB12
B1Y2 → RY color difference signal component data SB1R1 corresponding to subband data DSB11 → RY color difference signal component data SB1R2 corresponding to subband data DSB12 → BY color difference signal component data SB corresponding to subband data DSB11
1B1 → BY color difference signal component data SB1B2 corresponding to subband data DSB12 →... → subband data DSB91
Luminance signal (Y) component data SB9Y1 corresponding to sub-band data DSB92 luminance signal (Y) component data SB9Y2 corresponding to sub-band data DSB91 RY color difference signal component data SB9R1 corresponding to sub-band data DSB92 corresponding to sub-band data DSB92 RY color difference signal component data SB9R2 → BY color difference signal component data S corresponding to the subband data DSB91
B9B1 → BY color difference signal component data SB9B2 corresponding to the sub-band data DSB92 are arranged in this order.

Each sub-band data is recorded in the order of luminance signal (Y) component data → RY color difference signal component data → BY color difference signal component data. This has a greater effect on the image quality (visual), and the RY color difference signal has a greater effect on the image quality (visual) between the RY color difference signal and the BY color difference signal.

In FIG. 9, all sub-band data DSB01, DSB02,...
Although the case where SB92 is recorded in the frame data FL is shown, any of the subband data DSBXZ (X: 0 to 0)
When the frame data FL reaches a predetermined number of bits in the middle of (9, Z: 1, 2) (at the time of rate over), an end code indicating the end of data is added, and the generation processing of the frame data FL ends. I do.

As described above, even when a part of the subband data is not included in the frame data FL due to the rate over, the subband data on the low frequency component side is replaced with the subband data on the high frequency component side. Therefore, sub-band data that has a significant effect on the degradation of the playback image quality is recorded with priority, and sub-band data that does not significantly affect the degradation of the playback image quality is recorded. Since only the data is not recorded, it is possible to reduce the deterioration of the reproduced image while keeping the data amount constant.

Further, the sub-band data (or a part of the sub-band data), which could not be recorded, is complemented with 0 data at the time of reproduction and the inverse wavelet transform is performed to reproduce the entire screen without causing significant image quality deterioration. Can be. As described above, also in the second embodiment, the sub-band data is adopted as a part of the frame data FL first from the sub-band data having high importance in order to secure the image quality. Even if the subband data of the part or a part of the subband data is not included in the frame data FL2 (recording is not possible), the effect can be reduced.

[0137]

According to the first aspect of the present invention, the formatting means generates partial frame data based on each encoded data, and converts the partial frame data corresponding to the lowest frequency component into higher frequency components. Since the fixed-length frame data is generated by sequentially arranging the partial frame data in the order of the corresponding partial frame data until a predetermined code amount is reached, even if the rate over occurs, the image quality is serious when decoding the image. It is possible to maintain the image quality while keeping the generated code amount constant without any data on the low-frequency component side affecting the data being lost.

Further, since the control of the code amount is performed by the formatting means, the control of the quantization step width can be simplified and the configuration of the apparatus can be simplified. According to the second aspect of the invention, in addition to the operation of the first aspect, the formatting means sequentially encodes the encoded data from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. , The partial frame data that further affects the image quality of the decoded image is included in the frame data, and the deterioration of the image quality can be reduced.

According to the third aspect of the present invention, in addition to the operation of the first or second aspect of the present invention, when the formatting means generates the partial frame data,
Since partial frame data is sequentially generated from the center of the screen corresponding to the input image data toward the periphery of the screen, the image quality of the center of the screen where the user's vision tends to concentrate is less likely to occur, and the image quality deteriorates. Even if it does, the deterioration can be hardly recognized.

According to the fourth aspect of the present invention, in addition to the operation of the first or second aspect of the present invention, when the formatting means generates the partial frame data,
Assuming a rearranged screen in which the screen is rearranged for each pixel constituting the screen corresponding to the input image data, and generating partial frame data based on the rearranged screen, image quality degradation is evenly distributed over the entire decoded screen Thus, even if the image quality deteriorates, it is difficult to recognize the deterioration.

According to the fifth aspect of the invention, in addition to the operation of the first aspect, the frame data is transmitted from the side of the partial frame data corresponding to the lowest frequency component. Toward the encoded data side including the partial frame data corresponding to the high frequency component, encoded luminance signal data corresponding to the luminance signal Y, and encoded first color difference signal corresponding to the first color difference signal (RY signal) data,
The second chrominance signal is arranged in the order of the second chrominance signal encoded data corresponding to the second chrominance signal (BY signal). Therefore, data having a greater effect on the image quality is arranged first, and even if a rate over occurs, the effect of image quality degradation can be reduced.

According to the invention of claim 6, the band dividing means divides the input image data into a plurality of bands and outputs the divided image data as band divided data to the quantization step width control means and the quantization means. The width control means determines a quantization step width for each band division data, outputs the quantization step width control data to the quantization means, and the quantization means performs band division with a step width corresponding to the quantization step width control data. The data is quantized and output to the encoding unit as quantized data, the encoding unit performs variable length encoding of the quantized data and outputs the encoded data, and the formatting unit outputs a frame data group based on a plurality of input image data. And generates the first partial frame data based on each encoded data corresponding to any one of the input image data constituting the frame data group. And a second part based on a difference between each encoded data corresponding to another input image data forming the frame data group and each encoded data corresponding to any one of the input image data forming the frame data group. While generating frame data, predetermined first and second partial frame data corresponding to higher frequency components are shifted from the first partial frame data and second partial frame data corresponding to the lowest frequency component to predetermined partial frame data. The first partial frame data and the second
Since the fixed-length frame data is generated by sequentially arranging the partial frame data, when the information compression efficiency is improved by combining the intra-frame encoding and the inter-frame prediction encoding, even if the rate is over, the image It is possible to maintain the image quality while keeping the generated code amount constant without missing data on the low frequency component side that has a significant effect on the image quality during decoding.

Further, since the control of the code amount is performed by the formatting means, the control of the quantization step width can be simplified, and the configuration of the apparatus can be simplified. According to the invention described in claim 7, in addition to the effect of the invention described in claim 6, the formatting means performs the encoding in order from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. Since the first partial frame data or the second partial frame data is generated based on the data, the partial frame data that further affects the image quality of the decoded image is included in the frame data.
Image quality degradation can be reduced.

According to the invention described in claim 8, in addition to the effect of the invention described in claim 6 or 7, the formatting means, when generating the partial frame data,
Since the first partial frame data or the second partial frame data is sequentially generated from the central portion of the screen corresponding to the input image data toward the peripheral portion of the screen, the image quality of the central portion of the screen where the user's vision tends to concentrate is reduced. Less likely to occur,
Even if the image quality deteriorates, it is possible to make it difficult to recognize the deterioration.

According to the ninth aspect of the present invention, in addition to the operation of the sixth or seventh aspect, the formatting means is capable of inputting the first partial frame data and the second partial frame data when generating the first partial frame data and the second partial frame data. Assuming a rearranged screen in which the screen is rearranged for each pixel constituting the screen corresponding to the image data and generating the first partial frame data and the second partial frame data based on the rearranged screen,
The image quality deterioration can be evenly distributed over the entire decoded screen, and even if the image quality deteriorates, the deterioration can be hardly recognized.

According to the tenth aspect, the sixth aspect is provided.
In addition to the effects of the invention described in any one of claims 9 to 9,
The frame data is the first data corresponding to the lowest frequency component.
From the partial frame data and the second partial frame data to the encoded data including the first partial frame data and the second partial frame data corresponding to the higher frequency components, the luminance signal Y for the first partial frame data is obtained.
, The second luminance signal encoded data corresponding to the luminance signal Y for the second partial frame data, and the first luminance signal encoded data corresponding to the first partial frame data.
First color difference signal encoded data corresponding to the color difference signal (RY signal), first color difference signal encoded data corresponding to the first color difference signal (RY signal) for the second partial frame data, first portion Second chrominance signal encoded data corresponding to a second chrominance signal (BY signal) for the frame data;
The second color difference signal (B-
(Y signal) corresponding to the second chrominance signal encoded data. Therefore, data having a greater effect on the image quality is arranged first, and even if a rate over occurs, the effect of image quality degradation can be reduced.

According to the eleventh aspect, the band dividing means forms a frame data group by a plurality of input image data, and divides one of the input image data constituting the frame data group into a plurality of bands. And outputs the divided data as first band division data, and converts the difference input image data, which is the difference between any one of the input image data constituting the frame data group and the other input image data constituting the frame data group, into a plurality of bands. And outputs the data to the quantization step width control means and the quantization means as second band division data,
The quantization step width control means determines a quantization step width for each of the first band division data or the second band division data, outputs the quantization step width control data to the quantization means, and the quantization means The first band-divided data and the second band-divided data are quantized at a step width corresponding to the width control data and output to the encoding unit as first quantized data and second quantized data. The quantized data is variable-length coded and output as first coded data, the second quantized data is variable-length coded and output as second coded data to formatting means, and the formatting means outputs the first coded data And generates second partial frame data based on the second encoded data, and generates the first partial frame data based on the second encoded data. From the first partial frame data and the second partial frame data to the first partial frame data and the second partial frame data corresponding to higher frequency components until the predetermined code amount is reached. Since the fixed-length frame data is generated by sequentially arranging the partial frame data, when the information compression efficiency is improved by combining the intra-frame encoding and the inter-frame prediction encoding, even if the rate is over, the image It is possible to maintain the image quality while keeping the generated code amount constant without missing data on the low frequency component side that has a significant effect on the image quality during decoding.

Further, since the control of the code amount is performed by the formatting means, the control of the quantization step width can be simplified and the configuration of the apparatus can be simplified. According to the twelfth aspect of the present invention, in addition to the operation of the eleventh aspect, the formatting means sequentially converts the first code from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. Since the first partial frame data is generated based on the encoded data or the second partial frame data is generated based on the second encoded data, the partial frame data that further affects the image quality of the decoded image is included in the frame data. As a result, the deterioration of the image quality can be reduced.

According to the thirteenth aspect, the first aspect
In addition to the operation of the first or twelfth aspect of the invention, the formatting means, when generating the first partial frame data or the second partial frame data, moves from the center of the screen corresponding to the input image data to the outside of the screen. , The first partial frame data or the second partial frame data is sequentially generated, so that the image quality of the central portion of the screen where the user's vision tends to concentrate is hardly deteriorated, and even if the image quality is deteriorated, it is difficult to recognize the deterioration. be able to.

According to the fourteenth aspect of the present invention, the first aspect is provided.
In addition to the function of the first or twelfth aspect of the invention, the formatting means includes a first partial frame data and a second partial frame data.
When generating the partial frame data, it is assumed that a rearranged screen is obtained by rearranging the screen in units of pixels constituting the screen corresponding to the input image data, and the first partial frame data and the second partial frame are based on the rearranged screen. Since the data is generated, the image quality degradation can be evenly distributed over the entire decoded screen, and even if the image quality is degraded, it is difficult to recognize the degradation.

According to the fifteenth aspect, according to the first aspect,
In addition to the operation of the invention according to any one of the first to fourteenth aspects, the frame data includes a first partial frame data corresponding to the lowest frequency component and a second partial frame data corresponding to a higher frequency component from the second partial frame data side. Toward the encoded data including the one partial frame data and the second partial frame data, the first luminance signal encoded data corresponding to the luminance signal Y for the first partial frame data, and the luminance signal for the second partial frame data The first chrominance signal coded data corresponding to the second chrominance signal coded data corresponding to Y, the first chrominance signal (RY signal) for the first partial frame data, and the first chrominance for the second partial frame data The first color difference signal encoded data corresponding to the signal (RY signal) and the second color difference signal (BY signal) for the first partial frame data Second color difference signal coded data response,
The second color difference signal (B-
(Y signal) corresponding to the second chrominance signal encoded data. Therefore, data having a greater effect on the image quality is arranged first, and even if a rate over occurs, the effect of image quality degradation can be reduced.

According to the sixteenth aspect of the invention, in the formatting step, the partial frame data is generated based on each of the encoded data, and the partial frame data corresponding to the lowest frequency component corresponds to the higher frequency component. Since the fixed-length frame data is generated by sequentially arranging the partial frame data in the order of the partial frame data until a predetermined code amount is obtained, even if a rate over occurs, the image quality is seriously affected at the time of image decoding. It is possible to maintain the image quality while keeping the generated code amount constant without losing the data on the low frequency component side to be given.

Further, since the control of the code amount is performed by the formatting means, the control of the quantization step width can be simplified and the configuration of the apparatus can be simplified. According to the seventeenth aspect of the present invention, in addition to the operation of the sixteenth aspect, in the formatting step, the encoded data is sequentially encoded from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. , The partial frame data that further affects the image quality of the decoded image is included in the frame data, and the deterioration of the image quality can be reduced.

According to the eighteenth aspect of the present invention, the first aspect is provided.
In addition to the function of the invention described in claim 6 or claim 17, in the formatting step, when generating the partial frame data, the partial frame data is sequentially generated from the central portion of the screen corresponding to the input image data toward the periphery of the screen. Since the image quality is generated, the image quality is hardly degraded in the central portion of the screen where the user's vision is likely to be concentrated, and even if the image quality is degraded, the degradation can be hardly recognized.

According to the nineteenth aspect of the present invention, the first aspect
In addition to the effect of the sixth or 17th aspect of the invention, in the formatting step, when generating the partial frame data, a rearranged screen in which the screen is rearranged in units of pixels constituting the screen corresponding to the input image data is assumed. However, since the partial frame data is generated based on the rearranged screen, the deterioration of the image quality can be uniformly distributed over the entire decoded screen, and even if the image quality deteriorates, it is difficult to recognize the deterioration.

According to the twentieth aspect, according to the first aspect,
In addition to the effect of the invention according to any one of claims 6 to 19, the formatting step includes the steps of:
From the partial frame data corresponding to the lowest frequency component to the encoded data including the partial frame data corresponding to the higher frequency component, the luminance signal encoded data corresponding to the luminance signal Y and the first color difference signal (R -Y signal), the first chrominance signal encoded data and the second chrominance signal (B
−Y signal) in the order of the second color difference signal encoded data. Therefore, data having a greater effect on the image quality is arranged first, and even if a rate over occurs, the effect of image quality degradation can be reduced.

According to the twenty-first aspect, in the band dividing step, the input image data is divided into a plurality of bands and output as band divided data, and the quantization step width controlling step includes:
The quantization step width is determined for each band division data, the quantization step width control data is output, and the quantization step quantizes the band division data with the step width corresponding to the quantization step width control data to obtain quantization data. Output, the encoding step performs variable length encoding of the quantized data and outputs the encoded data, and the formatting step configures a frame data group by a plurality of input image data, and forms one of the frame data groups. The first partial frame data is generated based on each of the encoded data corresponding to the input image data, and any one of the encoded data and the frame data group corresponding to the other input image data constituting the frame data group is generated. While generating the second partial frame data based on the difference from each encoded data corresponding to one input image data, From the first partial frame data and the second partial frame data corresponding to the lower frequency component toward the first partial frame data and the second partial frame data corresponding to the higher frequency component until the predetermined code amount is reached. Since the fixed-length frame data is generated by sequentially arranging the partial frame data and the second partial frame data, when the information compression efficiency is improved by combining the intra-frame encoding and the inter-frame prediction encoding, a rate over occurs. Even in the case of occurrence, it is possible to maintain the image quality while keeping the generated code amount constant without losing data on the low frequency component side that has a significant effect on the image quality when decoding the image.

Further, since the control of the code amount is performed by the formatting means, the control of the quantization step width can be simplified and the configuration of the apparatus can be simplified. According to the invention described in claim 22, in addition to the effect of the invention described in claim 21, the formatting step includes the step of sequentially encoding from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. Since the first partial frame data or the second partial frame data is generated based on the data, the partial frame data that further affects the image quality of the decoded image is included in the frame data, and the deterioration of the image quality can be reduced. .

According to the twenty-third aspect, the second aspect is provided.
23. In addition to the operation of the first or second aspect of the invention, in the formatting step, when the partial frame data is generated, the first partial frame is sequentially formed from the center portion of the screen corresponding to the input image data toward the periphery of the screen. Since the data or the second partial frame data is generated, the image quality is hardly degraded in the central portion of the screen where the user's vision tends to concentrate, and even if the image quality is degraded, the degradation can be hardly recognized.

According to the invention set forth in claim 24, claim 2 is provided.
In addition to the operation of the first or second aspect of the present invention, the formatting step includes the step of:
When generating the partial frame data, it is assumed that a rearranged screen is obtained by rearranging the screen in units of pixels constituting the screen corresponding to the input image data, and the first partial frame data and the second partial frame are based on the rearranged screen. Since the data is generated, the image quality degradation can be evenly distributed over the entire decoded screen, and even if the image quality is degraded, it is difficult to recognize the degradation.

According to the twenty-fifth aspect, the second aspect is provided.
In addition to the effect of the invention according to any one of claims 1 to 24, the formatting step includes the steps of:
From the first partial frame data and the second partial frame data corresponding to the lowest frequency component to the coded data including the first partial frame data and the second partial frame data corresponding to the higher frequency component, the first First encoded luminance signal corresponding to luminance signal Y for partial frame data, second encoded luminance signal corresponding to luminance signal Y for second partial frame data, first
The first chrominance signal encoded data corresponding to the first chrominance signal (RY signal) for the partial frame data, and the first chrominance signal corresponding to the first chrominance signal (RY signal) for the second partial frame data Encoded data, second color difference signal encoded data corresponding to the second color difference signal (BY signal) for the first partial frame data, and second color difference signal (BY signal) for the second partial frame data Corresponding second
They are arranged in the order of the color difference signal encoded data. Therefore, data having a greater effect on the image quality is arranged first, and even if a rate over occurs, the effect of image quality degradation can be reduced.

According to the twenty-sixth aspect, in the band dividing step, a frame data group is constituted by a plurality of input image data, and any one of the input image data constituting the frame data group is divided into a plurality of bands. And outputs the divided data as first band division data, and converts the difference input image data, which is the difference between any one of the input image data constituting the frame data group and the other input image data constituting the frame data group, into a plurality of bands. And outputs it as second band division data. The quantization step width control step determines a quantization step width for each of the first band division data or the second band division data, and outputs quantization step width control data. , The quantization step quantizes the first band division data and the second band division data with a step width corresponding to the quantization step width control data, and The first quantized data is output as first encoded data by performing variable length encoding on the first quantized data, and the second quantized data is subjected to variable length encoding by outputting the second quantized data as second encoded data. 2 as encoded data, and the formatting step includes: generating first partial frame data based on the first encoded data; generating second partial frame data based on the second encoded data; From the first partial frame data and the second partial frame data corresponding to the component to the first partial frame data and the second partial frame data corresponding to the higher frequency component, the first partial frame data and the second partial frame data are used until the predetermined code amount is reached.
Since the fixed-length frame data is generated by sequentially arranging the partial frame data and the second partial frame data, when the information compression efficiency is improved by combining the intra-frame encoding and the inter-frame prediction encoding, a rate over occurs. Even in the case of occurrence, it is possible to maintain the image quality while keeping the generated code amount constant without losing data on the low frequency component side that has a significant effect on the image quality when decoding the image.

Further, since the control of the code amount is performed by the formatting means, the control of the quantization step width can be simplified, and the configuration of the apparatus can be simplified. According to the twenty-seventh aspect, in addition to the effect of the twenty-sixth aspect, in the formatting step, the first code is sequentially formed from the side corresponding to the lowest frequency component to the side corresponding to the higher frequency component. Since the first partial frame data is generated based on the encoded data or the second partial frame data is generated based on the second encoded data, the partial frame data that further affects the image quality of the decoded image is included in the frame data. As a result, the deterioration of the image quality can be reduced.

According to the twenty-eighth aspect of the present invention, the second aspect is provided.
In addition to the effect of the invention described in Item 6 or Claim 27, in the formatting step, in generating the first partial frame data or the second partial frame data, the formatting step is performed from the center portion of the screen corresponding to the input image data to the outside of the screen. , The first partial frame data or the second partial frame data is sequentially generated, so that the image quality of the central portion of the screen where the user's vision tends to concentrate is hardly deteriorated, and even if the image quality is deteriorated, it is difficult to recognize the deterioration. be able to.

According to the twenty-ninth aspect, the second aspect is provided.
In addition to the effect of the sixth or 27th aspect of the invention, the formatting step includes the step of:
When generating the partial frame data, it is assumed that a rearranged screen is obtained by rearranging the screen in units of pixels constituting the screen corresponding to the input image data, and the first partial frame data and the second partial frame are based on the rearranged screen. Since the data is generated, the image quality degradation can be evenly distributed over the entire decoded screen, and even if the image quality is degraded, it is difficult to recognize the degradation. According to the thirty-fourth aspect, in addition to the effect of the twenty-sixth aspect, the formatting step further includes a first partial frame corresponding to the lowest frequency component in the frame data. From the data and the second partial frame data to the encoded data including the first partial frame data and the second partial frame data corresponding to the higher frequency components, the luminance signal Y corresponding to the first partial frame data corresponds to the luminance signal Y. The first luminance signal encoded data, the second luminance signal encoded data corresponding to the luminance signal Y for the second partial frame data, and the second luminance signal encoded data corresponding to the first color difference signal (RY signal) for the first partial frame data. The first chrominance signal coded data corresponding to the first chrominance signal (RY signal) for the one chrominance signal coded data and the second partial frame data Data,
The second color difference signal (B-
The second chrominance signal coded data corresponding to the Y signal) and the second chrominance signal coded data corresponding to the second chrominance signal (BY signal) for the second partial frame data are arranged in this order. Therefore, data having a greater effect on the image quality is arranged first, and even if a rate over occurs, the effect of image quality degradation can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a video recording / reproducing apparatus according to an embodiment.

FIG. 2 is an explanatory diagram (1) of a wavelet transform operation.

FIG. 3 is an explanatory diagram (2) of a wavelet transform operation.

FIG. 4 is a diagram illustrating a data configuration of frame data.

FIG. 5 is an explanatory diagram of an encoding order.

FIG. 6 is an explanatory diagram (1) of an inverse wavelet transform operation;

FIG. 7 is an explanatory diagram (2) of the inverse wavelet transform operation.

FIG. 8 is an explanatory diagram of the second embodiment.

FIG. 9 is a diagram illustrating a data configuration of an image data portion of frame data according to the second embodiment.

[Description of Signs] 1 Video recording / reproducing device 2 Video camera 3 Display 4 Video interface unit 5 Encoder 6 Recording medium 7 Interface unit 8 Decoder 9 Reproduction control unit 11 Wavelet transform unit 12 Quantization unit 13 Variable length encoding unit 14 Formatter unit 15 inverse formatter section 16 variable length decoding section 17 inverse quantization section 18 wavelet inverse transform section 30 index information section 31 image data section 51 image data section SG image signal DG image data DDG decoded image data FL frame data DSB subband image data DQSB Quantized sub-band data DVLG Encoded image data DVLG 'Variable-length decoded image data DQSB' Quantized decoded image data DSB 'Dequantized image data SDG Decoded image signal

Claims (30)

[Claims] 1. A band dividing unit that divides input image data into a plurality of bands and outputs the divided band data, and a quantization step width that determines a quantization step width for each of the band division data and outputs quantization step width control data. Quantization step width control means, quantization means for quantizing the band-divided data at a step width corresponding to the quantization step width control data and outputting it as quantized data, and performing variable-length encoding on the quantized data to code Encoding means for outputting as partial data, generating partial frame data based on each of the encoded data, and converting the partial frame data corresponding to the higher frequency component from the partial frame data corresponding to the lowest frequency component. By sequentially arranging the partial frame data until the predetermined code amount is reached, a fixed-length frame Encoding apparatus is characterized in that and a formatting means for generating data. 2. The encoding apparatus according to claim 1, wherein the formatting means sequentially performs a partial operation on the basis of the encoded data from a side corresponding to the lowest frequency component to a side corresponding to a higher frequency component. An encoding device characterized by generating frame data. 3. The encoding device according to claim 1, wherein the formatting unit generates the partial frame data from a central portion of a screen corresponding to the input image data to a peripheral portion of the screen. An encoding device for sequentially generating the partial frame data toward a side. 4. The encoding device according to claim 1, wherein the formatting unit generates the partial frame data by using the screen unit for each pixel constituting a screen corresponding to the input image data. A rearrangement screen in which the partial frame data is rearranged, and the partial frame data is generated based on the rearrangement screen. 5. The encoding apparatus according to claim 1, wherein the frame data corresponds to a higher frequency component from a side of the partial frame data corresponding to the lowest frequency component. Toward the coded data including the partial frame data, the coded luminance signal corresponding to the luminance signal Y and the first chrominance signal (RY signal) corresponding to the first chrominance signal (RY signal).
An encoding apparatus characterized by being arranged in the order of chrominance signal encoded data and second chrominance signal encoded data corresponding to a second chrominance signal (BY signal). 6. A band dividing unit that divides input image data into a plurality of bands and outputs the divided band data, and a quantization step width that determines a quantization step width for each of the band division data and outputs quantization step width control data. Quantization step width control means, quantization means for quantizing the band-divided data at a step width corresponding to the quantization step width control data and outputting it as quantized data, and performing variable-length encoding on the quantized data to code Encoding means for outputting as encoded data, a frame data group is constituted by a plurality of the input image data, and based on each of the encoded data corresponding to any one of the input image data constituting the frame data group Generating first partial frame data, and generating each of the encoded data corresponding to the other input image data constituting the frame data group; And the second partial frame data is generated based on a difference between each of the encoded data corresponding to any one of the input image data constituting the frame data group and the second partial frame data, and the second partial frame data corresponding to the lowest frequency component is generated. The first partial frame data and the second partial frame data correspond to the first frequency component corresponding to the higher frequency component.
Formatting means for generating fixed-length frame data by sequentially arranging the first partial frame data and the second partial frame data toward the partial frame data and the second partial frame data until a predetermined code amount is reached. An encoding device comprising: 7. The encoding device according to claim 6, wherein the formatting means sequentially performs the formatting based on the encoded data from a side corresponding to the lowest frequency component to a side corresponding to a higher frequency component. An encoding device characterized in that the encoding device is configured to generate the first partial frame data or the second partial frame data. 8. The encoding device according to claim 6, wherein the formatting unit generates the partial frame data from a central portion of a screen corresponding to the input image data to a peripheral portion of the screen. An encoding device for sequentially generating the first partial frame data or the second partial frame data toward a side. 9. The encoding device according to claim 6, wherein the formatting unit generates the first partial frame data and the second partial frame data, and generates a screen corresponding to the input image data. A rearranged screen in which the screen is rearranged in units of pixels constituting the pixel data, and the first partial frame data and the second partial frame data are generated based on the rearranged screen. apparatus. 10. The encoding device according to claim 6, wherein the frame data is the first partial frame data and the second partial frame data corresponding to the lowest frequency component. From a first luminance signal corresponding to a luminance signal Y for the first partial frame data toward the encoded data side including the first partial frame data and the second partial frame data corresponding to a higher frequency component. Encoded data, second luminance signal encoded data corresponding to the luminance signal Y for the second partial frame data,
First chrominance signal encoded data corresponding to a first chrominance signal (R-Y signal) for the first partial frame data;
First chrominance signal coded data corresponding to a first chrominance signal (RY signal) for the second partial frame data;
Second chrominance signal encoded data corresponding to a second chrominance signal (BY signal) for the first partial frame data;
An encoding device, wherein the encoded data is arranged in the order of second color difference signal encoded data corresponding to a second color difference signal (BY signal) for the second partial frame data. 11. A frame data group is configured by a plurality of input image data, and any one of the input image data configuring the frame data group is divided into a plurality of bands and output as first band division data. Dividing the difference input image data, which is a difference between any one of the input image data constituting the frame data group and the other input image data constituting the frame data group, into a plurality of bands, Band division means for outputting as divided data, quantization step width control means for determining a quantization step width for each of the first band division data or the second band division data, and outputting quantization step width control data, Quantizing the first band division data and the second band division data with a step width corresponding to the quantization step width control data Quantizing means for outputting the first quantized data and the second quantized data; variable-length encoding of the first quantized data to output as first encoded data; and variable-length encoding of the second quantized data. Encoding means for outputting the second encoded data as
Generating first partial frame data based on the first encoded data, generating second partial frame data based on the second encoded data, and generating the first partial frame data corresponding to the lowest frequency component; And the first and second partial frame data toward the first and second partial frame data corresponding to higher frequency components until a predetermined code amount is reached. And a formatting means for generating fixed-length frame data by sequentially arranging the data. 12. The encoding device according to claim 11, wherein the formatting means sequentially determines the first encoded data from a side corresponding to the lowest frequency component to a side corresponding to a higher frequency component. The first
An encoding device configured to generate partial frame data or to generate the second partial frame data based on the second encoded data. 13. The encoding device according to claim 11, wherein said formatting means generates a first partial frame data or a second partial frame data, and generates a screen corresponding to the input image data. An encoding device for sequentially generating the first partial frame data or the second partial frame data from a central portion of the image data toward the outside of the screen. 14. The encoding device according to claim 11, wherein the formatting unit generates the first partial frame data and the second partial frame data, and generates a screen corresponding to the input image data. A rearranged screen in which the screen is rearranged in units of pixels constituting the pixel data, and the first partial frame data and the second partial frame data are generated based on the rearranged screen. apparatus. 15. The encoding device according to claim 11, wherein the frame data is the first partial frame data and the second partial frame data corresponding to the lowest frequency component. From a first luminance signal corresponding to a luminance signal Y for the first partial frame data toward the encoded data side including the first partial frame data and the second partial frame data corresponding to a higher frequency component. Encoded data, second luminance signal encoded data corresponding to the luminance signal Y for the second partial frame data,
First chrominance signal encoded data corresponding to a first chrominance signal (R-Y signal) for the first partial frame data;
First chrominance signal coded data corresponding to a first chrominance signal (RY signal) for the second partial frame data;
Second chrominance signal encoded data corresponding to a second chrominance signal (BY signal) for the first partial frame data;
An encoding device, wherein the encoded data is arranged in the order of second color difference signal encoded data corresponding to a second color difference signal (BY signal) for the second partial frame data. 16. A band dividing step of dividing input image data into a plurality of bands and outputting the divided band data as band dividing data, and a step of determining a quantization step width for each of the band divided data and outputting quantization step width control data. A quantization step width control step, a quantization step of quantizing the band-divided data with a step width corresponding to the quantization step width control data and outputting the quantized data as quantized data, and a variable length encoding of the quantized data to code An encoding step of outputting as partial data, generating partial frame data based on each of the encoded data, and converting the partial frame data corresponding to the higher frequency component from the partial frame data corresponding to the lowest frequency component. By sequentially arranging the partial frame data until a predetermined code amount is reached, a fixed-length frame Coding method characterized by comprising: a formatting step of generating Mudeta, the. 17. The encoding method according to claim 16, wherein the formatting step is performed based on the encoded data sequentially from a side corresponding to the lowest frequency component to a side corresponding to a higher frequency component. An encoding method characterized by generating frame data. 18. The encoding method according to claim 16, wherein the formatting step includes, when generating the partial frame data, starting from a central portion of a screen corresponding to the input image data to a peripheral portion of the screen. Encoding means for sequentially generating the partial frame data toward the side. 19. The encoding method according to claim 16, wherein the formatting step includes the steps of: generating the partial frame data in units of pixels constituting a screen corresponding to the input image data; A rearranged screen obtained by rearranging the partial frame data, and generating the partial frame data based on the rearranged screen. 20. The encoding method according to any one of claims 16 to 19, wherein the formatting step includes, in the frame data, a higher level from the side of the partial frame data corresponding to the lowest frequency component. Toward the encoded data side including the partial frame data corresponding to the frequency component,
The luminance signal encoded data corresponding to the luminance signal Y, the first color difference signal encoded data corresponding to the first color difference signal (RY signal), and the second color difference signal corresponding to the second color difference signal (BY signal) An encoding method characterized by arranging in the order of encoded data. 21. A band division step of dividing input image data into a plurality of bands and outputting the divided band data as band division data, a quantization step width for each band division data, and a quantization step width for outputting quantization step width control data. A quantization step width control step, a quantization step of quantizing the band-divided data with a step width corresponding to the quantization step width control data and outputting the quantized data as quantized data, and a variable length encoding of the quantized data to code An encoding step of outputting as encoded data, a frame data group is constituted by a plurality of the input image data, and based on each of the encoded data corresponding to any one of the input image data constituting the frame data group Generating first partial frame data, each of the encodings corresponding to the other input image data constituting the frame data group; And the second partial frame data is generated based on the difference between the encoded data corresponding to the input image data and any one of the input image data constituting the frame data group, and the second partial frame data corresponding to the lowest frequency component is generated. The first subframe data corresponding to a higher frequency component from the first subframe data and the second subframe data.
Formatting step of generating fixed-length frame data by sequentially arranging the first partial frame data and the second partial frame data toward the partial frame data and the second partial frame data until a predetermined code amount is reached. And a coding method comprising: 22. The encoding method according to claim 21, wherein the formatting step is based on the encoded data sequentially from a side corresponding to the lowest frequency component to a side corresponding to a higher frequency component. An encoding method, wherein the first partial frame data or the second partial frame data is generated. 23. The encoding method according to claim 21, wherein the formatting step includes, when generating the partial frame data, from a center portion of a screen corresponding to the input image data to a peripheral portion of the screen. An encoding method, wherein the first partial frame data or the second partial frame data is sequentially generated toward a side. 24. The encoding method according to claim 21 or 22, wherein the formatting step includes the steps of: generating a first partial frame data and a second partial frame data; a screen corresponding to the input image data; A rearranged screen in which the screen is rearranged in units of pixels constituting the pixel data, and the first partial frame data and the second partial frame data are generated based on the rearranged screen. Method. 25. The encoding method according to any one of claims 21 to 24, wherein, in the formatting step, the first partial frame data and the first partial frame data corresponding to the lowest frequency component are included in the frame data. From the second partial frame data side toward the encoded data side including the first partial frame data and the second partial frame data corresponding to higher frequency components, the luminance signal Y for the first partial frame data is Corresponding first luminance signal encoded data,
Second luminance signal encoded data corresponding to the luminance signal Y for the second partial frame data, and first color difference signal encoded data corresponding to the first color difference signal (RY signal) for the first partial frame data , First chrominance signal encoded data corresponding to a first chrominance signal (RY signal) for the second partial frame data, and second chrominance signal (BY signal) for the first partial frame data The second chrominance signal coded data to be arranged, and the second chrominance signal coded data corresponding to the second chrominance signal (BY signal) for the second partial frame data. . 26. A frame data group is configured by a plurality of input image data, and any one of the input image data configuring the frame data group is divided into a plurality of bands and output as first band division data. Dividing the difference input image data, which is a difference between any one of the input image data constituting the frame data group and the other input image data constituting the frame data group, into a plurality of bands, A band division step of outputting as divided data; a quantization step width control step of determining a quantization step width for each of the first band division data or the second band division data and outputting quantization step width control data; Quantizing the first band division data and the second band division data with a step width corresponding to the quantization step width control data A quantization step of outputting the first quantized data and the second quantized data, and a variable length encoding of the first quantized data to output as first encoded data, and a variable length encoding of the second quantized data. An encoding step of outputting the encoded data as second encoded data,
Generating first partial frame data based on the first encoded data, generating second partial frame data based on the second encoded data, and generating the first partial frame data corresponding to the lowest frequency component; And the first and second partial frame data toward the first and second partial frame data corresponding to higher frequency components until a predetermined code amount is reached. A formatting step of generating fixed-length frame data by sequentially arranging the data. 27. The encoding method according to claim 26, wherein the formatting step is based on the first encoded data sequentially from a side corresponding to the lowest frequency component to a side corresponding to a higher frequency component. The first
An encoding method comprising: generating partial frame data; or generating the second partial frame data based on the second encoded data. 28. The encoding method according to claim 26 or claim 27, wherein the formatting step includes a step of generating the first partial frame data or the second partial frame data by using a screen corresponding to the input image data. An encoding method, wherein the first partial frame data or the second partial frame data is sequentially generated from a central portion of the image data toward the outside of the screen. 29. The encoding method according to claim 26, wherein the formatting step includes generating a first partial frame data and a second partial frame data, the screen corresponding to the input image data. A rearranged screen in which the screen is rearranged in units of pixels constituting the pixel data, and the first partial frame data and the second partial frame data are generated based on the rearranged screen. Method. 30. The encoding method according to claim 26, wherein, in the formatting step, the first partial frame data and the second partial frame corresponding to the lowest frequency component are included in the frame data. From the data side toward the encoded data side including the first partial frame data and the second partial frame data corresponding to higher frequency components, a first signal corresponding to the luminance signal Y for the first partial frame data Luminance signal encoded data,
Second luminance signal encoded data corresponding to the luminance signal Y for the second partial frame data, and first color difference signal encoded data corresponding to the first color difference signal (RY signal) for the first partial frame data , First chrominance signal encoded data corresponding to a first chrominance signal (RY signal) for the second partial frame data, and second chrominance signal (BY signal) for the first partial frame data The second chrominance signal coded data to be arranged, and the second chrominance signal coded data corresponding to the second chrominance signal (BY signal) for the second partial frame data. .