JPH0446419A - Vector quantizer - Google Patents

Vector quantizer

Info

Publication number
JPH0446419A
JPH0446419A JP2155871A JP15587190A JPH0446419A JP H0446419 A JPH0446419 A JP H0446419A JP 2155871 A JP2155871 A JP 2155871A JP 15587190 A JP15587190 A JP 15587190A JP H0446419 A JPH0446419 A JP H0446419A
Authority
JP
Japan
Prior art keywords
circuit
codebook
input signal
code book
signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2155871A
Other languages
Japanese (ja)
Inventor
Naohisa Kamimura
上村 尚久
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Priority to JP2155871A priority Critical patent/JPH0446419A/en
Publication of JPH0446419A publication Critical patent/JPH0446419A/en
Pending legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T9/00Image coding
    • G06T9/008Vector quantisation

Abstract

PURPOSE:To suppress disturbance of a code book due to noise included in an input signal and to attain normal quantization output in the normal state by providing a delay circuit, a distance calculation circuit and a code book correction stop circuit or the like to the quantizer. CONSTITUTION:A distance calculation circuit 5 makes distance calculation between a current input signal and the result of vector quantization output delayed by one unit at a delay circuit 4 and outputs a detection signal when the calculation result exceeds a prescribed threshold level. After the receipt of the detection signal outputted from the circuit 5, a code book correction stop circuit 6 sends a control signal to a code book generating circuit 1 to stop the generation of a code book. Then the input signal is quantized and outputted by using a code book when the threshold level of the distance calculation is within a prescribed range. Thus, the disturbance in the code book due to noise included in the input signal is suppressed and quantization output is attained in the normal state.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は画像信号などを符号化し、その識別符号を出力
するベクトル量子化器に関する。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vector quantizer that encodes an image signal or the like and outputs an identification code thereof.

〔従来の技術〕[Conventional technology]

従来のベクトル量子化器では、画像信号などの入力信号
に対して、常時、コードブックの修正を行い、このコー
ドブックを参照し、識別符号を出力する構成になってい
る。
A conventional vector quantizer is configured to constantly correct a codebook for an input signal such as an image signal, refer to this codebook, and output an identification code.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

上述したように従来のベクトル量子化器では、常時、コ
ードブックの修正を行っているので、入力信号に雑音が
重畳された場合、コードブックが乱れ、量子化結果に雑
音が増加するということになり、従って、相手側で信号
が正常に再生されないという問題点がある。
As mentioned above, in conventional vector quantizers, the codebook is constantly corrected, so if noise is superimposed on the input signal, the codebook will be disturbed and noise will increase in the quantization result. Therefore, there is a problem that the signal cannot be reproduced normally on the other party's side.

本発明の目的は、入力信号に含まれてくる雑音によるコ
ードブックの乱れを抑制し、正常な状態で量子化出力す
ることができるベクトル量子化器を提供することにある
SUMMARY OF THE INVENTION An object of the present invention is to provide a vector quantizer that can suppress codebook disturbances caused by noise contained in an input signal and output quantized signals in a normal state.

〔課題を解決するための手段〕[Means to solve the problem]

本発明のベクトル量子化器は、入力信号に対して最適な
代表ベクトルを生成するコードブック生成回路と、前記
コードブックによって生成された代表値を記憶するコー
ドブック記憶回路と、前記入力信号を符号化し前記コー
ドブック記憶回路を参照し出力する符号化器と、前記符
号化器の出力を1単位遅延させた信号を出力する遅延回
路と、前記入力信号と前記遅延回路によって出力された
信号との距離計算を行い所定のしきい値を越えているこ
とを検出したときには検出信号を出力する距離計算回路
と、前記検出信号を受信し前記コードブック生成回路へ
コードブックの生成を停止させるための制御信号を送出
するコードブック修正停止回路とを備える構成である。
The vector quantizer of the present invention includes a codebook generation circuit that generates an optimal representative vector for an input signal, a codebook storage circuit that stores representative values generated by the codebook, and a codebook storage circuit that encodes the input signal. an encoder that refers to and outputs the codebook storage circuit; a delay circuit that outputs a signal obtained by delaying the output of the encoder by one unit; and a signal that outputs the input signal and the signal output by the delay circuit. a distance calculation circuit that calculates a distance and outputs a detection signal when it detects that the distance exceeds a predetermined threshold; and a control that receives the detection signal and causes the codebook generation circuit to stop generating a codebook. This configuration includes a codebook correction stop circuit that sends out a signal.

〔実施例〕〔Example〕

次に、本発明の実施例について図面を参照して説明する
Next, embodiments of the present invention will be described with reference to the drawings.

本発明の一実施例を示す第1図を参照すると、ベクトル
量子化器は、入力信号に対して最適な代表ベクトルを生
成するコードブック生成回路1と、このコードブックに
よって生成された代表値を記憶するコードブック記憶回
路2と、入力信号を符号化しコードブック記憶回路2を
参照し出力する符号化器3と、符号化器3の出力を1単
位遅延させた信号を出力する遅延回路4と、入力信号と
遅延回路4によって出力された信号との距離計算を行い
検出信号を出力する距離計算回路5と、この検出信号を
受信しコードブックの生成を停止させるための制御信号
を送出するコードブック修正停止口!I@6とを備える
Referring to FIG. 1 showing an embodiment of the present invention, a vector quantizer includes a codebook generation circuit 1 that generates an optimal representative vector for an input signal, and a codebook generation circuit 1 that generates a representative value generated by this codebook. A codebook storage circuit 2 for storing, an encoder 3 that encodes an input signal and outputs it by referring to the codebook storage circuit 2, and a delay circuit 4 that outputs a signal obtained by delaying the output of the encoder 3 by one unit. , a distance calculation circuit 5 that calculates the distance between the input signal and the signal output by the delay circuit 4 and outputs a detection signal, and a code that receives this detection signal and sends a control signal to stop the generation of the codebook. Book correction stop mouth! I@6.

以下に、動作を説明する。入力信号はコードブック生成
回路1へ入力され、コードブック生成回路1は符号化器
3の出力のちとになる代表値であるコードブック3’ 
i + y2 、・・・ylを生成し、コードブック記
憶部2に記憶させる。このコードブック生成回路1は常
時入力信号に対して最適なコードブックを生成している
。符号化器3は入力信号である入力ベクトルX、に対し
てコードブック記憶回路2を参照し、距1id(Xty
k)が最小となるFつ」を出力する。距離計算回路5は
、遅延回路4で1単位遅らせたベクトル量子化結果を現
在の入力信号との間の距離計算を行い、所定のしきい値
を越えていることを検出したときには検出信号を出力す
る。コードブック修正停止回路6は、距離計算回路5か
ら出力された検出信号を受信後、コードブック生成回路
1に対して制御信号を送出し、コードブックの生成を停
止させる。そして、距離計算のしきい値が所定の範囲の
ときのコードブックによって、入力信号を量子化出力す
る。以後、距離計算のしきい値が所定の範囲内にあるこ
とが距離計算回路5によって確認されたとき、コードブ
ック修正停止回路6からコートブックの生成を再開する
ための制御信号をコードブック生成回路1に対して送出
する。
The operation will be explained below. The input signal is input to a codebook generation circuit 1, and the codebook generation circuit 1 generates a codebook 3' which is a representative value after the output of the encoder 3.
i + y2, . . . yl are generated and stored in the codebook storage unit 2. This codebook generation circuit 1 constantly generates an optimal codebook for input signals. The encoder 3 refers to the codebook storage circuit 2 for the input vector X, which is the input signal, and calculates the distance 1id(Xty
k) is the minimum. The distance calculation circuit 5 calculates the distance between the vector quantization result delayed by one unit by the delay circuit 4 and the current input signal, and outputs a detection signal when it detects that it exceeds a predetermined threshold. do. After receiving the detection signal output from the distance calculation circuit 5, the codebook modification stop circuit 6 sends a control signal to the codebook generation circuit 1 to stop the generation of the codebook. Then, the input signal is quantized and output using the codebook when the distance calculation threshold is within a predetermined range. Thereafter, when the distance calculation circuit 5 confirms that the distance calculation threshold is within a predetermined range, the codebook correction stop circuit 6 sends a control signal to restart the generation of the coatbook to the codebook generation circuit. Send for 1.

〔発明の効果〕〔Effect of the invention〕

本発明は以上説明したように、入力信号である入力ベク
トルと1単位前の出力ベクトルとの距離を計算し、この
計算結果が予め設定したある一定値以上になった場合、
コードブックの修正を停止することにより、入力信号に
含まれてくる雑音によるコードブックの乱れを抑制し、
正常な状態で量子化出力することができるという効果を
有する。
As explained above, the present invention calculates the distance between the input vector, which is the input signal, and the output vector one unit before, and when the calculation result exceeds a certain preset value,
By stopping modification of the codebook, disturbances in the codebook due to noise contained in the input signal are suppressed.
This has the effect that quantized output can be performed in a normal state.

【図面の簡単な説明】[Brief explanation of drawings]

第1図は本発明の一実施例を示す構成図である6 1・・−・・・コードブック生成回路、2・・・・・・
コードブック記憶回路、3・・・・・符号化器、4・・
・・・・遅延回路、5・・・・・・距離計算回路、6−
・・・・コードブック修正停止回路。
FIG. 1 is a block diagram showing an embodiment of the present invention. 6 1... Codebook generation circuit, 2...
Codebook storage circuit, 3... Encoder, 4...
... Delay circuit, 5 ... Distance calculation circuit, 6-
...Codebook correction stop circuit.

Claims (1)

【特許請求の範囲】[Claims] 入力信号に対して最適な代表ベクトルを生成するコード
ブック生成回路と、前記コードブックによって生成され
た代表値を記憶するコードブック記憶回路と、前記入力
信号を符号化し前記コードブック記憶回路を参照し出力
する符号化器と、前記符号化器の出力を1単位遅延させ
た信号を出力する遅延回路と、前記入力信号と前記遅延
回路によって出力された信号との距離計算を行い所定の
しきい値を越えていることを検出したときには検出信号
を出力する距離計算回路と、前記検出信号を受信し前記
コードブック生成回路へコードブックの生成を停止させ
るための制御信号を送出するコードブック修正停止回路
とを備えたことを特徴とするベクトル量子化器。
a codebook generation circuit that generates an optimal representative vector for an input signal; a codebook storage circuit that stores representative values generated by the codebook; and a codebook storage circuit that encodes the input signal and refers to the codebook storage circuit. An encoder that outputs an output, a delay circuit that outputs a signal obtained by delaying the output of the encoder by one unit, and a distance between the input signal and the signal output by the delay circuit is calculated and a predetermined threshold value is set. a distance calculation circuit that outputs a detection signal when it detects that the distance exceeds the threshold, and a codebook correction stop circuit that receives the detection signal and sends a control signal to the codebook generation circuit to stop generation of the codebook. A vector quantizer characterized by comprising:
JP2155871A 1990-06-14 1990-06-14 Vector quantizer Pending JPH0446419A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2155871A JPH0446419A (en) 1990-06-14 1990-06-14 Vector quantizer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2155871A JPH0446419A (en) 1990-06-14 1990-06-14 Vector quantizer

Publications (1)

Publication Number Publication Date
JPH0446419A true JPH0446419A (en) 1992-02-17

Family

ID=15615328

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2155871A Pending JPH0446419A (en) 1990-06-14 1990-06-14 Vector quantizer

Country Status (1)

Country Link
JP (1) JPH0446419A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0679033A2 (en) * 1994-04-20 1995-10-25 Matsushita Electric Industrial Co., Ltd. Vector quantization coding apparatus and decoding apparatus

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60159899A (en) * 1984-01-31 1985-08-21 松下電器産業株式会社 Voice recognition equipment with learning function
JPS62166655A (en) * 1986-01-20 1987-07-23 Nippon Telegr & Teleph Corp <Ntt> Vector quantizing system having self training function

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60159899A (en) * 1984-01-31 1985-08-21 松下電器産業株式会社 Voice recognition equipment with learning function
JPS62166655A (en) * 1986-01-20 1987-07-23 Nippon Telegr & Teleph Corp <Ntt> Vector quantizing system having self training function

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0679033A2 (en) * 1994-04-20 1995-10-25 Matsushita Electric Industrial Co., Ltd. Vector quantization coding apparatus and decoding apparatus
EP0679033A3 (en) * 1994-04-20 2000-02-16 Matsushita Electric Industrial Co., Ltd. Vector quantization coding apparatus and decoding apparatus

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