Image analysis – Image compression or coding – Adaptive coding
Reexamination Certificate
1995-04-04
2001-07-03
Chang, Jon (Department: 2623)
Image analysis
Image compression or coding
Adaptive coding
C382S251000, C375S240050, C348S419100
Reexamination Certificate
active
06256420
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a data transmission system, and more particularly to an improvement of transmitting picture data after compression thereof through a communication line or the like.
DESCRIPTION OF THE PRIOR ART
Conventionally, a data transmission system for transmitting picture data and audio data to remote places or recording these data in a digital system recording media, the picture data and the audio data are compressed by utilizing correlation between data thereof in order to obtain efficient transmission of picture data having large data quantities.
In the conventional data transmission apparatus, when the compressed picture data or audio data is quantized, the quantization size is controlled on the basis of the quantity of generated data of the transmission data in order to make the quantity of generated data substantially constant.
Thus, even when there is an allowance for the data transfer capacity, the picture data, such as a motion picture having a large quantity of generated data, is controlled such that the quantity of generated data thereof decreases, i.e., such that the quantization size thereof is rough. Consequently, the quantity of the transmission picture deteriorates, and the data transfer capability cannot thus be utilized effectively.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of this invention is to provide a data transmission system which is capable of reliably transmitting data while maintaining the picture quality or audio quality substantially at a constant level regardless of a data source.
The foregoing object and other objects of the invention have been achieved by the provision of the present data transmission system. In the first aspect of the present invention, there is provided a data transmission system
1
for quantizing data signal S
1
into quantized data S
8
by means of a quantization means
13
and for transmitting the quantized data S
8
. A system control includes a constant distortion control means
32
for controlling the quantization means
13
so that the quantity of distortion is a constant value. The system control
17
also includes a variable distortion control means
33
for transmitting the quantized data S
2
while controlling the quantization means so that the quantity of data generated is maintained at a constant value. The data transmission system
1
also includes first and second memory means
7
and
8
for alternately storing the quantized data S
2
, the quantized data S
8
being written in one of the first and second memory means
7
and
8
while the coded quantized data S
3
is being read out from the other memory means and transmitted. The system control
17
also includes change-over means
34
for changing control between control by the constant distortion control means
32
and control by the variable distortion control
33
means on the basis of the storage data S
13
of the coded quantized data S
2
which is written in the first and second memory means
7
and
8
.
In the second aspect of the present invention, there is provided a data transmission system
1
for quantizing data signal S
1
into quantized data S
8
by means of a quantization means
13
and for transmitting the quantized data S
8
, which includes a system control
17
having a first control means for controlling quantization characteristics that are held to a constant value, and a second control means controlling the quantizing means
13
so that the quantization characteristics are varied. The data transmission system
1
also includes first and second memory means
7
and
8
for alternately storing the quantized data S
8
, the quantized data S
2
being written in one of the first and second memory means
7
and
8
while the quantized data S
3
being read out from the other memory means and transmitted. The system control
17
also includes change-over means
34
for changing over control between control by the first control means and control by the second control means on the basis of the storage data S
13
of the quantized data S
2
which is written in the first and second memory means
7
and
8
.
Since transmission of data is changed over on the basis of the storage data of quantized data S
2
which is written in first and second memory means
7
and
8
between transmission of the quantized data S
2
by constant distortion transmission means
17
and transmission of the quantized data S
2
by variable distortion transmission means
17
, i.e., between transmission of the quantized data S
2
obtained by controlling the quantization characteristics to constant characteristics and transmission of the quantized data S
2
obtained by variably controlling the quantizing data S
2
, the transmission data can be transmitted with the quality thereof maintained to a constant quality regardless of the type of transmission data or transmission path.
In the data transmission system according to the present invention, digital data is obtained by the convention in which the transmission data is compressed and transmitted. Control of the quantizing means is changed over on the basis of the amount of stored data in the memory means so that the quantizing means quantizes the quantized data at constant distortion or variable distortion transmission of data, i.e., between quantization with constant quantization characteristics or quantization with variable quantization characteristics. It is possible therefore to transmit data while maintaining the quantity of the quantized data to be transmitted at a constant level regardless of the type of transmitted data or transmitted path.
The nature, principle and utility of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings in which like parts are designated by like reference numerals or characters.
REFERENCES:
patent: 4093962 (1978-06-01), Ishiguro et al.
patent: 4179710 (1979-12-01), Ishiguro et al.
patent: 4751736 (1988-06-01), Gupta et al.
patent: 5025482 (1991-06-01), Murakami et al.
patent: 5029019 (1991-07-01), Yoshihara et al.
patent: 5029112 (1991-07-01), Sakamoto et al.
patent: 5038209 (1991-08-01), Haug
patent: 5136283 (1992-08-01), Nobs
patent: 5138144 (1992-08-01), Sakamoto
patent: 5144426 (1992-09-01), Tanaka et al.
patent: 5151941 (1992-09-01), Nishiguchi et al.
patent: 5159447 (1992-10-01), Haskell et al.
patent: 5164828 (1992-11-01), Tahara et al.
patent: 5301242 (1994-04-01), Gonzales et al.
patent: 5349383 (1994-09-01), Parke et al.
patent: 5410351 (1995-04-01), Kojima
patent: 5412431 (1995-05-01), Vogel
patent: 5450132 (1995-09-01), Harris et al.
patent: 5606539 (1997-02-01), De Haan et al.
patent: 399-487 (1990-11-01), None
patent: 57-125517 (1982-08-01), None
patent: 63-110821 (1988-05-01), None
patent: 2-202285 (1990-08-01), None
patent: 3-129980 (1991-06-01), None
patent: 3-255792 (1991-11-01), None
patent: 5-41859 (1993-02-01), None
Kojima Yuichi
Sako Yoichiro
Chang Jon
Limbach & Limbach L.L.P.
Sony Corporation
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