Patent EP0444918A2 successfully refreshed from Google Patents.
EP0444918A2
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EP
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Data compression apparatus
Assignee: Victor Company of Japan Ltd
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Filing: 1991-02-28
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Granted: —
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Expires: 2011-02-28
Abstract
Abstract In a data compression apparatus, input data are subjected to a predetermined filtering process. A predetermined calculation is executed on data which result from the filtering process. The predetermined calculation includes at least an addition. The result of the predetermined calculation is converted into a corresponding predicted code amount. A target code amount is set. A difference between the predicted code amount and the target code amount is derived, and a quantization step size is generated in correspondence with the difference. The input data are subjected to a predetermined orthogonal transform. Data which result from the orthogonal transform are quantized with the generated quantization step size.
Inventors
- 👤 Takayuki Sugahara
- 👤 Ichiro Ando
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 13:12
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/24; H04N7/52; H04N7/54; H04N19/00; H04N19/10; H04N19/102; H04N19/117; H04N19/124; H04N19/126; H04N19/134; H04N19/136; H04N19/137; H04N19/14; H04N19/146; H04N19/149; H04N19/169; H04N19/17; H04N19/172; H04N19/42; H04N19/423; H04N19/50; H04N19/503; H04N19/51; H04N19/527; H04N19/60; H04N19/61; H04N19/80; H04N19/82; H04N19/90; H04N19/152
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
81 words
A data compression apparatus comprising:- means for processing input data to produce quantitised compressed output data in a manner which, for a given bandwidth of the input data and given quantitisation steps would produce a variable amount of said output data for a given amount of the input data, and means for varying the bandwidth of data being processed and/or quantitisation levels used to quantitise it, in a manner tending to reduce the variation in the amount of said output data.
Claim 2
Dependent Claim
120 words
A data compression apparatus comprising: processing means for subjecting input data to a predetermined filtering process; calculating means for executing a predetermined calculation on output data from the processing means, the predetermined calculation including at least an addition; means for converting output data from the calculating means into a corresponding predicted code amount; means for setting a target code amount; step-size generating means for deriving a difference between the predicted code amount and the target code amount, and outputting a quantization step size corresponding to the difference; transform means for subjecting the input data to a predetermined orthogonal transform; and means for quantizing output data from the transform means with the quantization step size outputted from the step-size generating means.
Claim 3
Dependent Claim
108 words
A data compression apparatus comprising: processing means for subjecting input data to a predetermined filtering process; calculating means for executing a predetermined calculation on output data from the processing means, the predetermined calculation including at least an addition; means for converting output data from the calculating means into a corresponding predicted code amount; means for setting a target code amount; limit-value generating means for deriving a difference between the predicted code amount and the target code amount, and outputting a band limiting value corresponding to the difference; and means for limiting a band of the input data with the band limiting value outputted from the limit-value generating means.
Claim 4
Dependent Claim
174 words
A data compression apparatus comprising: processing means for subjecting input data to a predetermined filtering process; calculating means for executing a predetermined calculation on output data from the processing means, and deriving an activity value from the output data from the processing means, the predetermined calculation including at least an addition; predicted-amount generating means for converting the activity value outputted from the calculating means into a corresponding predicted code amount; means for setting a target code amount; step-size generating means for deriving a difference between the predicted code amount and the target code amount, and outputting a quantization step size corresponding to the difference; transform means for subjecting the input data to a predetermined orthogonal transform; and means for quantizing output data from the transform means with the quantization step size outputted from the step-size generating means; wherein the predicted-amount generating means includes means for varying a current predicted code amount as a function of at least one of a previous predicted code amount, a previous activity value, and a previous actual code amount.
Claim 5
Dependent Claim
162 words
A data compression apparatus comprising: processing means for subjecting input data to a predetermined filtering process; calculating means for executing a predetermined calculation on output data from the processing means, and deriving an activity value from the output data from the processing means, the predetermined calculation including at least an addition; predicted-amount generating means for converting the activity value outputted from the calculating means into a corresponding predicted code amount; means for setting a target code amount; limit-value generating means for deriving a difference between the predicted code amount and the target code amount, and outputting a band limiting value corresponding to the difference; and means for limiting a band of the input data with the band limiting value outputted from the limit-value generating means; wherein the predicted-amount generating means includes means for varying a current predicted code amount as a function of at least one of a previous predicted code amount, a previous activity value, and a previous actual code amount.
Claim 6
Dependent Claim
107 words
A data compression apparatus comprising: block separating means for separating input image data into blocks each having a predetermined number of successive pixels; transform means for subjecting output data from the block separating means to a predetermined orthogonal transform; predicting means for predicting a code amount of the input image data; quantizing means for quantizing output data from the transform means in correspondence with output data from the predicting means; encoding means for encoding output data from the quantizing means; and means for controlling the predicting means so that a code amount of each segment can be approximately constant, each segment including a predetermined number of blocks.
Claim 7
Dependent Claim
117 words
A data compression apparatus comprising: block separating means for separating input image data into blocks each having a predetermined number of successive pixels; predicting means for predicting a code amount of the input image data; limiting means for limiting a band of the input image data in correspondence with output data from the predicting means; transform means for subjecting output data from the limiting means to a predetermined orthogonal transform; quantizing means for quantizing output data from the transform means; encoding means for encoding output data from the quantizing means; and means for controlling the predicting means so that a code amount of each segment can be approximately constant, each segment including a predetermined number of blocks.
Claim 8
Dependent Claim
164 words
A data compression apparatus comprising: first processing means for subjecting input image data to a predetermined horizontal-direction filtering process; second processing means for subjecting the input image data to a predetermined vertical-direction filtering process; calculating means for executing a predetermined calculation on output data from the first and second processing means, the predetermined calculation including at least an addition; predicted-amount generating means for converting output data from the calculating means into a corresponding predicted code amount; means for setting a target code amount; limit-value generating means for deriving a difference between the predicted code amount and the target code amount, and outputting a horizontal-direction band limiting value and a vertical-direction band limiting value corresponding to the difference; means for limiting a horizontal-direction band of the input image data with the horizontal-direction band limiting value outputted from the limit-value generating means; and means for limiting a vertical-direction band of the input image data with the vertical-direction band limiting value outputted from the limit-value generating means.
Claim 9
Dependent Claim
206 words
A data compression apparatus comprising: first processing means for subjecting input image data to a predetermined horizontal-direction filtering process having at least two different filtering characteristics; second processing means for subjecting the input image data to a predetermined vertical-direction filtering process having at least two different filtering characteristics; first calculating means for calculating a horizontal-direction activity value from output data from the first processing means; second calculating means for calculating a vertical-direction activity value from output data from the second processing means; adding means for adding the horizontal-direction activity value and the vertical-direction activity value calculated by the first and second calculating means; means for converting output data from the adding means into a corresponding predicted code amount; means for setting a target code amount; limit-value generating means for deriving a difference between the predicted code amount and the target code amount, and outputting a horizontal-direction band limiting value and a vertical-direction band limiting value corresponding to the difference; means for limiting a horizontal-direction band of the input image data with the horizontal-direction band limiting value outputted from the limit-value generating means; and means for limiting a vertical-direction band of the input image data with the vertical-direction band limiting value outputted from the limit-value generating means.
References Cited (Backward Citations)
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