JPH031761A - Picture input device - Google Patents
Picture input deviceInfo
- Publication number
- JPH031761A JPH031761A JP1136503A JP13650389A JPH031761A JP H031761 A JPH031761 A JP H031761A JP 1136503 A JP1136503 A JP 1136503A JP 13650389 A JP13650389 A JP 13650389A JP H031761 A JPH031761 A JP H031761A
- Authority
- JP
- Japan
- Prior art keywords
- video signal
- low frequency
- outputs
- frequency component
- image
- 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
Links
- 238000003384 imaging method Methods 0.000 claims description 8
- 230000000694 effects Effects 0.000 abstract description 3
- 238000005286 illumination Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 230000002123 temporal effect Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 238000001739 density measurement Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
Landscapes
- Picture Signal Circuits (AREA)
- Facsimile Scanning Arrangements (AREA)
Abstract
Description
【発明の詳細な説明】
［概要］
画像認識装置や印刷濃度測定装置等に用いられ、対象物
を撮像し、その撮影画像に含まれる明るさむらを補正し
た映像信号を出力する画像入力装置に関し、
照明むらや外乱光強度の時間的変化に応じて、適正かつ
自動的に明るさむらを補正できるようにすることを目的
とし、
対象物を撮像しその映像信号を出力する撮像装置と、該
映像信号が人力され該映像信号に含まれる低周波成分を
出力するローパスフィルタと、該映像信号及び該低周波
成分が入力され該映像信号を該低周波成分で除した信号
を補正された映像信号として出力する除算器と、を備え
て構成する。[Detailed Description of the Invention] [Summary] This invention relates to an image input device used in an image recognition device, a print density measurement device, etc., which captures an image of a target object and outputs a video signal in which unevenness in brightness contained in the captured image is corrected. The purpose of the present invention is to appropriately and automatically correct uneven brightness according to temporal changes in uneven illumination and disturbance light intensity. A low-pass filter that inputs a video signal and outputs a low frequency component included in the video signal; and a video signal that receives the video signal and the low frequency component and corrects a signal obtained by dividing the video signal by the low frequency component. and a divider that outputs .
［産業上の利用分野］
本発明は画像認識装置や印刷濃度測定装置等に用いられ
、対象物を撮像し、その撮影画像に含まれる明るさむら
を補正した映像信号を出力する画像人力装置に関する。[Industrial Field of Application] The present invention relates to an image-powered device that is used in image recognition devices, print density measuring devices, etc., and that captures an image of an object and outputs a video signal that corrects uneven brightness contained in the captured image. .
［従来の技術］
例えばプリンタの印刷濃度測定装置では、印刷物を撮像
し、その画像の輝度信号から印刷濃度を求める。しかし
、印刷物に対する照明のむらや結像レンズのシェーディ
ング等により、画像に明るさむらが生じて、印刷濃度を
正確に測定することができない。そこで、従来では、無
地の印刷用紙を最初に撮像し、その画像（参照画像）の
第４図に示すような輝度分布をメモリに記憶させておき
、次に印刷物を撮像し、この画像の各画素輝度を参照画
像の対応する画素輝度で除することにより、画像の明る
さむらを補正していた（例えば特願昭６２−２７１９
、特願昭６２−４１４５）。[Prior Art] For example, a print density measuring device for a printer captures an image of a printed matter and calculates the print density from a luminance signal of the image. However, due to uneven illumination of the printed matter, shading of the imaging lens, etc., uneven brightness occurs in the image, making it impossible to accurately measure print density. Therefore, in the past, the plain printing paper was first imaged, the brightness distribution of that image (reference image) as shown in Figure 4 was stored in memory, and then the printed matter was imaged, and each of the images Image brightness unevenness was corrected by dividing the pixel brightness by the corresponding pixel brightness of the reference image (for example, Japanese Patent Application No. 62-2719
, patent application No. 62-4145).
［課題を解決するための手段］ 第１図は本発明の原理構成を示す。[Means to solve the problem] FIG. 1 shows the basic configuration of the present invention.
図中、１は撮像装置であり、対象物２を撮像しその映像
信号を出力する。In the figure, reference numeral 1 denotes an imaging device, which images an object 2 and outputs a video signal thereof.
３はローパスフィルタであり、この映像信号が人力され
、映像信号に含まれる低周波成分を出力する。3 is a low-pass filter, which inputs this video signal manually and outputs low frequency components contained in the video signal.
４は除算器であり、これら映像信号及び低周波成分が人
力され、映像信号を低周波成分で除した信号を補正され
た映像信号として出力する。4 is a divider which manually inputs the video signal and the low frequency component and outputs a signal obtained by dividing the video signal by the low frequency component as a corrected video signal.
［発明が解決しようとする課題］
しかし、照明灯の明るさや外乱光の強度は一定ではなく
、その変動により、測定誤差が生ずる。[Problems to be Solved by the Invention] However, the brightness of the illumination lamp and the intensity of the disturbance light are not constant, and their fluctuations cause measurement errors.
この誤差を除去するためには、参照輝度データを頻繁に
更新しなければならず、煩雑である。In order to remove this error, the reference luminance data must be updated frequently, which is cumbersome.
本発明の目的は、このような問題点に鑑み、照明むらや
外乱光強度の時間的変化に応じて、適正かつ自動的に明
るさむらを補正することができる画像入力装置を提供す
ることにある。In view of these problems, an object of the present invention is to provide an image input device that can appropriately and automatically correct brightness unevenness in accordance with temporal changes in illumination unevenness and ambient light intensity. be.
［作用］
本発明はリアルタイムで明るさむら補正を行なうので、
照明むらや外乱光強度の時間的変化が生じてもこれらに
影響されない。[Operation] Since the present invention corrects brightness unevenness in real time,
It is not affected by uneven illumination or temporal changes in the intensity of disturbance light.
［実施例］ 以下、図面に基づいて本発明の一実施例を説明する。[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.
第２図は画像人力装置の構成を示す。FIG. 2 shows the configuration of the image human power device.
白紙に文字が印刷された印刷物１０は、不図示の照明灯
で照明され、印刷物１０の上方に配置された撮像装置１
２により撮像される。撮像装置！２から取り出された複
合映像信号は、同期信号分離回路１４へ供給されて同期
信号が分離され、映像信号１（ｘ）がアナログ除算器１
６及びローパスフィルタ１８へ供給される。ローパスフ
ィルタ１８のカットオフ周波数は、設定器２０に設定さ
れている。A printed matter 10 on which characters are printed on a blank sheet of paper is illuminated by an illumination light (not shown), and an imaging device 1 is placed above the printed matter 10.
2. Imaging device! The composite video signal taken out from 2 is supplied to the synchronization signal separation circuit 14 to separate the synchronization signal, and the video signal 1(x) is sent to the analog divider 1.
6 and a low-pass filter 18. The cutoff frequency of the low-pass filter 18 is set in the setting device 20.
ある水平走査線の映像信号Ｊ （Ｘ）が例えば第３図（
Ａ）に示すような場合には、ローパスフィルタ１８の出
力ｍ（Ｘ）は同図（Ｂ）に示す如くなる。For example, if the video signal J (X) of a certain horizontal scanning line is
In the case shown in A), the output m(X) of the low-pass filter 18 becomes as shown in FIG. 3B.
このｍ（Ｘ）は、印刷物１０に対する照明のむらや撮像
装置１２の結像レンズ１２ａのシェーディングによるも
のであり、これらがもしなければ平坦になる。This m(X) is due to uneven illumination of the printed matter 10 and shading of the imaging lens 12a of the imaging device 12, and would be flat if these were not present.
アナログ除算器１６は１（ｘ）をｍ（Ｘ）で除した映像
信号ｎ（Ｘ）を出力する。このｎ（Ｘ）は、第３図（Ｃ
）に示す如く、印刷物１０の生地に対応した部分が平坦
となる。すなわち、撮影画像に含まれていた明るさむら
が補正される。補正された映像信号ｎ（Ｘ）は、同期信
号合成回路２２へ供給され、同期信号分離回路１４で分
離された同期信号がこれに合成されて複合映像信号が出
力される。The analog divider 16 outputs a video signal n(X) obtained by dividing 1(x) by m(X). This n(X) is shown in Figure 3 (C
), the portion of the printed matter 10 corresponding to the fabric becomes flat. That is, the brightness unevenness included in the photographed image is corrected. The corrected video signal n(X) is supplied to the synchronization signal synthesis circuit 22, and the synchronization signal separated by the synchronization signal separation circuit 14 is combined therewith to output a composite video signal.
本画像入力装置は、明るさむらの補正をリアルタイムで
行っているので、照明むらや外乱光強度が時間的に変動
してもこれらに影響されない。Since this image input device corrects uneven brightness in real time, it is not affected by uneven illumination or disturbance light intensity even if they change over time.
なお、同期信号は明るさむら信号に比し高周波数である
ので、ローパスフィルタ１８の遮断特性が充分であれば
特に回路１４及び１６を設けなくてもよい。Note that since the synchronization signal has a higher frequency than the uneven brightness signal, it is not necessary to provide the circuits 14 and 16 if the low-pass filter 18 has sufficient cutoff characteristics.
［発明の効果］
以上説明した如く、本発明に係る画像入力装置では、映
像信号に含まれる低周波成分でこの映像信号を除するの
で、簡単な構成で、照明むらや外乱光強度の時間的変化
に応じて、適正かつ自動的に明るさむらを補正すること
ができるという優れた効果を奏する。[Effects of the Invention] As explained above, in the image input device according to the present invention, since the video signal is divided by the low frequency component contained in the video signal, it is possible to eliminate uneven illumination and disturbance light intensity over time with a simple configuration. This provides an excellent effect in that brightness unevenness can be appropriately and automatically corrected in accordance with changes.
第１図は本発明の原理構成を示すブロック図である。
第２図及び第３図は本発明の一実施例に係り、第２図は
画像人力装置のブロック図、
第３図（Ａ）〜（Ｃ）は第２図に示す回路に於ける信号
の波形図である。
第４図は人力画像の明るさむらを示すグラフである。
図中、
１０は印刷物
１２は撮像装置
１４は同期信号分離回路
１６はアナログ除算器
は同期信号合成回路
々、二
、ピ嬌
（Ａ）補正前の輝度信号
（Ｂ）ローパスフィルタの出力
（Ｃ）補正後の輝度信号FIG. 1 is a block diagram showing the basic configuration of the present invention. 2 and 3 relate to an embodiment of the present invention, FIG. 2 is a block diagram of a human-powered image device, and FIGS. 3(A) to 3(C) are diagrams of signals in the circuit shown in FIG. 2. FIG. FIG. 4 is a graph showing unevenness in brightness of a human image. In the figure, 10 is a printed matter 12 is an imaging device 14 is a synchronization signal separation circuit 16 is an analog divider is a synchronization signal synthesis circuit, 2. A luminance signal before correction (A) Luminance signal before correction (B) Output of a low-pass filter (C) Luminance signal after correction
Claims (1)
（１）と、 該映像信号が入力され、該映像信号に含まれる低周波成
分を出力するローパスフィルタ（３）と、該映像信号及
び該低周波成分が入力され、該映像信号を該低周波成分
で除した信号を補正された映像信号として出力する除算
器（４）と、 を有することを特徴とする画像入力装置。[Claims] An imaging device (1) that images an object (2) and outputs a video signal thereof; and a low-pass filter (3) that receives the video signal and outputs low frequency components included in the video signal. ), and a divider (4) into which the video signal and the low frequency component are input and outputs a signal obtained by dividing the video signal by the low frequency component as a corrected video signal. Image input device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1136503A JPH031761A (en) | 1989-05-30 | 1989-05-30 | Picture input device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1136503A JPH031761A (en) | 1989-05-30 | 1989-05-30 | Picture input device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH031761A true JPH031761A (en) | 1991-01-08 |
Family
ID=15176688
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1136503A Pending JPH031761A (en) | 1989-05-30 | 1989-05-30 | Picture input device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH031761A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002227504A (en) * | 2001-01-31 | 2002-08-14 | Kaken Hanbai Kk | Rail height adjusting unit |
| JP2007296601A (en) * | 2006-04-28 | 2007-11-15 | Disco Abrasive Syst Ltd | Grinding wheel |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55162669A (en) * | 1979-06-07 | 1980-12-18 | Kowa Co | Shading of video signal and gain correction circuit |
| JPS5726155B2 (en) * | 1978-04-14 | 1982-06-02 |
-
1989
- 1989-05-30 JP JP1136503A patent/JPH031761A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5726155B2 (en) * | 1978-04-14 | 1982-06-02 | ||
| JPS55162669A (en) * | 1979-06-07 | 1980-12-18 | Kowa Co | Shading of video signal and gain correction circuit |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002227504A (en) * | 2001-01-31 | 2002-08-14 | Kaken Hanbai Kk | Rail height adjusting unit |
| JP2007296601A (en) * | 2006-04-28 | 2007-11-15 | Disco Abrasive Syst Ltd | Grinding wheel |
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