JPH0777499A - Detecting method for white rust section area ratio of steel sheet - Google Patents
Detecting method for white rust section area ratio of steel sheetInfo
- Publication number
- JPH0777499A JPH0777499A JP24620193A JP24620193A JPH0777499A JP H0777499 A JPH0777499 A JP H0777499A JP 24620193 A JP24620193 A JP 24620193A JP 24620193 A JP24620193 A JP 24620193A JP H0777499 A JPH0777499 A JP H0777499A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- color
- white rust
- image
- separator
- 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.)
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- Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は鋼板または表面処理鋼板
の腐食評価に関わり、例えば腐食試験に供した試験片の
白錆部面積を検出するための方法を提供するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrosion evaluation of a steel plate or a surface-treated steel plate, and provides a method for detecting the white rust area of a test piece subjected to a corrosion test, for example.
【０００２】[0002]
【従来の技術】近年、自動車や家電・建材向けの鋼板に
対して、製品の耐食性という市場ニーズが高まり、これ
に呼応した新製品の開発研究が盛んに行われている。し
たがって、鋼板の耐食性評価が開発研究に占めるウエイ
トは非常に高い。2. Description of the Related Art In recent years, market demand for corrosion resistance of products has increased for steel sheets for automobiles, home appliances and building materials, and research and development of new products in response to this has been actively conducted. Therefore, the weight of the corrosion resistance evaluation of steel sheets in development research is extremely high.
【０００３】鋼板の耐食性評価は暴露試験、促進試験等
の腐食試験に供した試験片に発生した錆の面積を測定す
ることにより行われるが、それは熟練された人間の手作
業に頼っている。そこで従来から、色による自動識別方
法が検討されてきた。The corrosion resistance of a steel sheet is evaluated by measuring the area of rust generated on a test piece that has been subjected to a corrosion test such as an exposure test and an accelerated test, which depends on the manual work of a skilled person. Therefore, an automatic identification method based on color has been conventionally studied.
【０００４】色を自動的に識別する従来の装置としては
例えば、特開昭６２−２９１５２２号公報及び特開昭６
３−２０００２７号公報に開示されたものが知られてい
る。これら従来の装置では、カラーテレビカメラからＲ
（レッド）、Ｇ（グリーン）及びＢ（ブルー）に色分解
された３つの信号を取り出し、これらの信号を複雑なデ
ジタル処理回路で処理することによって撮像対象の色を
高精度で識別可能にしている。しかし、ＲＧＢ３色の各
信号に基づいて色を識別する場合には、信号レベルを比
較する回路が少なくとも３系統以上必要であるので、回
路構成が複雑になる。しかも、比較回路を３系統設ける
場合には、３組の回路のしきい値をそれぞれ調整する必
要があるので、それらのしきい値を特定の物質に合わせ
るためには、しきい値の調整操作に特別な知識や経験を
有する専門家を必要とする。As a conventional device for automatically identifying a color, for example, Japanese Patent Laid-Open No. 62-291522 and Japanese Patent Laid-Open No. 6-291522.
The thing disclosed by the 3-200027 publication is known. In these conventional devices, a color TV camera to an R
By extracting three signals separated into (red), G (green) and B (blue) and processing these signals by a complicated digital processing circuit, the color of the imaging target can be identified with high accuracy. There is. However, in the case of identifying a color based on each signal of RGB three colors, at least three circuits for comparing the signal levels are required, and the circuit configuration becomes complicated. Moreover, when three systems of comparison circuits are provided, it is necessary to adjust the threshold values of the three sets of circuits, and therefore, in order to adjust those threshold values to a specific substance, the threshold value adjustment operation is performed. Need a specialist with special knowledge and experience.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、白錆を有す
る鋼板の白錆発生面積を、照明のムラ等による明るさの
変化の影響を受けること無く、誰もが自動的に、容易
に、正確に検出することを実現するものである。SUMMARY OF THE INVENTION According to the present invention, the white rust occurrence area of a steel plate having white rust can be easily and automatically adjusted by anyone without being affected by a change in brightness due to uneven lighting. , Realizes accurate detection.
【０００６】[0006]
【課題を解決するための手段】上記課題解決のため本発
明は、表面に白錆のある鋼板表面を撮像するカラーテレ
ビカメラと、該カラーテレビカメラのカラー映像信号よ
り、Ｙ（輝度）映像信号とＣ（色変調）信号に分離する
Ｙ／Ｃ分離器と、該Ｃ信号（３．５８ＭＨｚの色変調交
流信号）を整流し、３．５８ＭＨｚの周期の直流パルス
とする整流器と、該整流器直流パルス信号を平滑化した
映像信号とするローパスフィルタとがあって、該ローパ
スフィルタの出力映像信号と前記Ｙ／Ｃ分離器のＹ映像
信号出力の内、ある一定レベル以下の映像信号を
［０］、それ以外を［１］とする２値化装置との論理積
をとるＡＮＤゲートと、該ＡＮＤゲートの［１］と
［０］の出力映像信号を一時的に記録する画像メモリ
と、該画像メモリに記録した［１］となった部分のが素
数を計数すると共に、 ｛［１］となった部分の画素数／（［１］となった画素
数＋［０］となった画素数）｝×１００ の演算を行う演算装置、を具備することを特徴とする鋼
板の白錆部面積率検出方法の発明に至った。In order to solve the above problems, the present invention provides a color television camera for picking up an image of a steel plate surface with white rust on the surface, and a Y (luminance) video signal from a color video signal of the color television camera. Y / C separator for separating into C and C (color modulation) signals, a rectifier for rectifying the C signal (3.58 MHz color modulation AC signal) into a DC pulse with a period of 3.58 MHz, and the rectifier DC There is a low-pass filter that uses a pulse signal as a smoothed video signal, and a video signal of a certain level or less among the output video signal of the low-pass filter and the Y video signal output of the Y / C separator is [0]. , An AND gate for performing a logical product with a binarizing device having the other values as [1], an image memory for temporarily recording output video signals of [1] and [0] of the AND gate, and the image Recorded in memory [ ] Is counted, and the calculation of {the number of pixels of the portion which becomes [1] / (the number of pixels which becomes [1] + the number of pixels which becomes [0])} × 100 The invention has led to the invention of a method for detecting the area ratio of white rusted portion of a steel sheet, which is characterized by including an arithmetic unit for performing.
【０００７】[0007]
【作用】発明者等は、鋼板に発生する白錆が色相を有し
ていないことに着目し、白錆の識別を自動的に行うため
に、カラーテレビカメラのようなカラー撮像手段を用い
て検出対象物を撮影し、得られる映像信号から白錆以外
の部分を抽出することで白錆のみを識別する方法を提案
した。本発明においては、表面に白錆を有する鋼板を撮
像したカラー画像の情報をＮＴＳＣ標準形式の信号とし
て出力するカラー撮像手段；該カラー撮像手段が出力す
る信号を色信号とするＹ／Ｃ分離器と、この色信号を整
流し直流パルス列信号とする整流器と、この信号を平滑
化し白錆とそれ以外の色を抽出し２値化反転するローパ
スフィルタと、白錆以外の色のないものを白錆と誤認識
しないため前記Ｙ／Ｃ分離器のＹ信号を明るさのレベル
によって２値化する２値化処理装置と該２値化信号と前
記ローパスフィルタを通った２値化信号との論理積を採
るＡＮＤゲートと、さらに該ＡＮＤゲートを通った信号
をデジタル画像信号として一時的に取り込むフレームメ
モリと、及び２値化画像のうち白錆部に相当する画素数
のみ計算し、鋼板全体に相当する画素数の比をとり、白
錆面積率を算出する面積率算出装置とを設けている。The present inventors have noticed that white rust generated on a steel sheet has no hue, and in order to automatically identify white rust, a color image pickup means such as a color television camera is used. We proposed a method to identify only white rust by photographing the object to be detected and extracting the parts other than white rust from the obtained video signal. In the present invention, a color image pickup means for outputting information of a color image obtained by picking up a steel plate having white rust on the surface as a signal of NTSC standard format; a Y / C separator having a signal outputted by the color image pickup means as a color signal. , A rectifier that rectifies this color signal into a DC pulse train signal, a low-pass filter that smoothes this signal and extracts white rust and other colors, and inverts it in binary, and a white rust filter that has no color other than white rust. A binarization processing device that binarizes the Y signal of the Y / C separator according to the brightness level so as not to be mistakenly recognized as rust, and the logic of the binarized signal and the binarized signal that has passed through the low-pass filter. The AND gate that takes the product, the frame memory that temporarily takes in the signal that has passed through the AND gate as a digital image signal, and the number of pixels corresponding to the white rust portion in the binarized image are calculated, and the entire steel plate is calculated. Taking the ratio of the equivalent to the number of pixels is provided with an area ratio calculation unit for calculating a white rust area ratio.
【０００８】日本や米国で利用される映像機器はＮＴＳ
Ｃ方式を採用することが多く、カラーテレビカメラから
標準出力されるＮＴＳＣ方式の映像信号には、同期信
号、輝度信号（Ｙ信号）およびクロマ信号が重畳されて
いる。また、クロマ信号は互いに９０度位相の異なる同
一周波数（約３．５８ＭＨｚ）の副搬送波によって振幅
変調されたＩ信号とＱ信号で構成されている。Ｉ信号は
赤−青紫の軸方向の色差信号であり、Ｑ信号はそれに直
交する黄−緑の軸方向の色差信号であり、ＩとＱの２つ
の色差信号のベクトル位相差によって映像の色相をベク
トルのスカラ値によって色の彩度として表している。The video equipment used in Japan and the United States is NTS.
The C system is often adopted, and a sync signal, a luminance signal (Y signal) and a chroma signal are superimposed on an NTSC system video signal that is standardly output from a color television camera. The chroma signal is composed of an I signal and a Q signal which are amplitude-modulated by subcarriers of the same frequency (about 3.58 MHz) whose phases are different from each other by 90 degrees. The I signal is a color difference signal in the red-blue-violet axial direction, and the Q signal is a color difference signal in the yellow-green axial direction that is orthogonal thereto, and the hue of the image is determined by the vector phase difference between the two color difference signals I and Q. The color saturation is represented by the scalar value of the vector.
【０００９】そこで本発明においては、表面に白錆を持
つ鋼板の表面をカラーテレビカメラで撮像し、白錆以外
の部分は何らかの色を有することから、ＮＴＳＣ信号か
らＹ／Ｃ分離器にて色信号（３．５８ＭＨｚ）、すなわ
ち白錆以外の部分を抽出し、この３．８５ＭＨｚを整流
し直流パルス列信号とし、これを平滑化し、２値化し、
更に反転した画像信号とすることで、何らかの色がつい
ている白錆以外の部分を認識、言い替えれば白錆部を認
識する。Therefore, in the present invention, the surface of a steel plate having white rust on the surface is imaged by a color television camera, and the portion other than white rust has some color. Therefore, the NTSC signal is colored by a Y / C separator. Signal (3.58MHz), that is, the part other than white rust is extracted, this 3.85MHz is rectified into a DC pulse train signal, which is smoothed and binarized.
Further, by inverting the image signal, a portion other than white rust with some color is recognized, in other words, a white rust portion is recognized.
【００１０】しかし、白錆以外でも例えば灰色のものや
黒色のものも色が無いため、前記ロジックのみでは白錆
と誤認識される。そこで、前記Ｙ／Ｃ分離器のＹ（輝
度）信号を、ある明るさ以下は０とする２値化処理装置
を通し、この出力と前記２値化映像信号との論理積を採
ることで、色は持っていなくてもある明るさ以下のもの
は認識しないようにすることで、白錆部分のみを認識す
ることができる。However, in addition to white rust, for example, gray ones and black ones also have no color, so that the above logic alone is erroneously recognized as white rust. Therefore, the Y (luminance) signal of the Y / C separator is passed through a binarization processing device that sets 0 for a certain brightness or less, and the logical product of this output and the binarized video signal is taken. Even if you do not have a color, you can recognize only the white rusted part by not recognizing less than a certain brightness.
【００１１】この白錆部分を認識した２値化画像信号を
アナログ／デジタル変換し、白錆以外の部分を白
［１］、白錆部分を黒［０］とし、フレームメモリに一
時的に記録する。パーソナルコンピュータは、この
［０］となった画素の数だけ計算し、鋼板全体の画素数
との比を採ることで、白錆部分の面積率を算出すること
ができる。The binarized image signal recognizing the white rusted portion is converted into an analog / digital signal, the portion other than the white rusted portion is changed to white [1] and the white rusted portion is changed to black [0], and temporarily recorded in the frame memory. To do. The personal computer can calculate the area ratio of the white rusted portion by calculating the number of pixels that have become this [0] and taking the ratio with the number of pixels of the entire steel plate.
【００１２】[0012]
【実施例】図１に鋼板の白錆部面積率検出装置の構成を
示す。照明装置１により照射された、表面に白錆を持つ
鋼板２の表面をカラーテレビカメラ３で撮像する。該カ
ラーテレビカメラの出力映像信号を前記EXAMPLE FIG. 1 shows the structure of a white rust area ratio detecting device for steel plates. An image of the surface of the steel plate 2 having white rust on the surface, which is illuminated by the lighting device 1, is captured by the color television camera 3. The output video signal of the color television camera is
【作用】の項で述べたように、ＮＴＳＣ画像信号を４の
Ｙ／Ｃ分離器にて色信号（３．８５ＭＨｚ）を抽出し、
５の整流器にて整流し直流パルス列信号とし、６のロー
パスフィルタで平滑化した後、７の２値化処理装置で２
値化信号とし、８の反転処理装置で反転信号とする。同
時に４のＹ／Ｃ分離器にて得られるＹ信号を９の２値化
処理装置で明るさによって２値化する。こうして得られ
た２値化信号と前記反転信号の論理積を１０のＡＮＤゲ
ートで採り、さらにアナログ／デジタル変換して、白錆
部分を黒［０］、それ以外の部分を白［１］としてフレ
ームメモリ１１にデジタル画像信号として一時的に記憶
するとともにモニタ１３に抽出画像を表示する。フレー
ムメモリ１０に記憶された値はパーソナルコンピュータ
１２で読み取り、［０］となった部分のみの画素数を計
算し、鋼板全体に相当する画素数との比を採ることで、
鋼板の中で白錆の占める面積率を算出する。算出した結
果はプリンタ１４で印字記録する。これらの動作を自動
的に行うためのプログラムは記憶装置１５より読み出し
実行する。As described in the section of "Function," the NTSC image signal is extracted by the Y / C separator 4 into a color signal (3.85 MHz),
It is rectified by the rectifier of 5 into a DC pulse train signal, smoothed by the low-pass filter of 6, and then 2 by the binarization processing device of 7.
The digitized signal is used as the binarized signal and is inverted by the inversion processing device 8 in FIG. At the same time, the Y signal obtained by the Y / C separator 4 is binarized by the binarization processing device 9 according to the brightness. The logical product of the binarized signal thus obtained and the inverted signal is taken by 10 AND gates, and further analog / digital converted, and the white rust portion is black [0], and the other portions are white [1]. The extracted image is displayed on the monitor 13 while being temporarily stored in the frame memory 11 as a digital image signal. The value stored in the frame memory 10 is read by the personal computer 12, the number of pixels of only the portion that becomes [0] is calculated, and the ratio to the number of pixels corresponding to the entire steel plate is taken.
Calculate the area ratio of white rust in the steel sheet. The calculated result is printed and recorded by the printer 14. A program for automatically performing these operations is read from the storage device 15 and executed.
【００１３】[0013]
【発明の効果】本法によれば、白錆がある明るさ以上を
持った無彩色として識別するため、照明のムラ等による
明るさの変化の影響を受けることがないので、正確に白
錆部分のみを識別することが可能である。以上のように
してなる本発明は、腐食試験後の鋼板の白錆発生面積を
誰もが自動的に、容易に、的確に測定しうるものであ
り、迅速な開発研究に大きな効果を発揮するものであ
る。According to this method, since white rust is identified as an achromatic color having a certain brightness or more, it is not affected by the change in brightness due to uneven lighting, etc. It is possible to identify only the parts. INDUSTRIAL APPLICABILITY The present invention configured as described above enables anyone to automatically, easily and accurately measure the white rust occurrence area of a steel sheet after a corrosion test, and exerts a great effect on rapid development research. It is a thing.
【図１】本発明の一実施例である鋼板の白錆部面積率検
出装置の概略構成を示す図である。FIG. 1 is a diagram showing a schematic configuration of a white rust portion area ratio detection device for a steel plate according to an embodiment of the present invention.
１ 照明装置 ２ 鋼板 ３ カラーテレビカメラ ４ Ｙ／Ｃ分離器 ５ 整流器 ６ ローパスフィルタ ７ ２値化処理装置 ８ 反転処理装置 ９ ２値化処理装置 １０ ＡＮＤゲート １１ フレームメモリ １２ パーソナルコンピュータ １３ モニタ １４ プリンタ １５ 記憶装置 1 Lighting Device 2 Steel Plate 3 Color TV Camera 4 Y / C Separator 5 Rectifier 6 Low Pass Filter 7 Binarization Processor 8 Inversion Processor 9 Binarization Processor 10 AND Gate 11 Frame Memory 12 Personal Computer 13 Monitor 14 Printer 15 Storage device
Claims (1)
ラーテレビカメラと、該カラーテレビカメラのカラー映
像信号より、Ｙ（輝度）映像信号とＣ（色変調）信号に
分離するＹ／Ｃ分離器と、該Ｃ信号（３．５８ＭＨｚの
色変調交流信号）を整流し、３．５８ＭＨｚの周期の直
流パルスとする整流器と、該整流器直流パルス信号を平
滑化した映像信号とするローパスフィルタとがあって、
該ローパスフィルタの出力映像信号と前記Ｙ／Ｃ分離器
のＹ映像信号出力の内、ある一定レベル以下の映像信号
を［０］、それ以外を［１］とする２値化装置との論理
積をとるＡＮＤゲートと、該ＡＮＤゲートの［１］と
［０］の出力映像信号を一時的に記録する画像メモリ
と、該画像メモリに記録した［１］となった部分の画素
数を計数すると共に、 ｛［１］となった部分の画素数／（［１］となった画素
数＋［０］となった画素数）｝×１００ の演算を行う演算装置、とを具備して鋼板の白錆部面積
率検出を行うことを特徴とする鋼板の白錆部面積率検出
方法。1. A color television camera for picking up an image of a steel plate surface having white rust on the surface, and Y / C for separating a color video signal of the color television camera into a Y (luminance) video signal and a C (color modulation) signal. A separator, a rectifier for rectifying the C signal (3.58 MHz color-modulated AC signal) into a DC pulse with a period of 3.58 MHz, and a low-pass filter for converting the rectifier DC pulse signal into a smoothed video signal There is
A logical product of the output video signal of the low-pass filter and the Y / C separator output video signal of a certain level or less is [0] and the other is [1]. AND gate, an image memory for temporarily recording the output video signals of [1] and [0] of the AND gate, and the number of pixels of the portion of [1] recorded in the image memory are counted. And a calculation device for performing calculation of {the number of pixels in the portion that becomes [1] / (the number of pixels that becomes [1] + the number of pixels that becomes [0])} × 100 A white rust area ratio detection method for a steel sheet, which comprises detecting a white rust area ratio.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24620193A JPH0777499A (en) | 1993-09-07 | 1993-09-07 | Detecting method for white rust section area ratio of steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24620193A JPH0777499A (en) | 1993-09-07 | 1993-09-07 | Detecting method for white rust section area ratio of steel sheet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0777499A true JPH0777499A (en) | 1995-03-20 |
Family
ID=17145022
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24620193A Withdrawn JPH0777499A (en) | 1993-09-07 | 1993-09-07 | Detecting method for white rust section area ratio of steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0777499A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008096429A (en) * | 2006-09-14 | 2008-04-24 | Jfe Steel Kk | Area ratio measuring instrument of corrosion part for surface-treated steel plate, and method and instrument for measuring area ratio of white rust part of galvanized sheet |
| JP2008096428A (en) * | 2006-09-14 | 2008-04-24 | Jfe Steel Kk | Observation device for corrosion part of surface-treated steel plate, and method and device for observing white rust part of galvanized sheet |
-
1993
- 1993-09-07 JP JP24620193A patent/JPH0777499A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008096429A (en) * | 2006-09-14 | 2008-04-24 | Jfe Steel Kk | Area ratio measuring instrument of corrosion part for surface-treated steel plate, and method and instrument for measuring area ratio of white rust part of galvanized sheet |
| JP2008096428A (en) * | 2006-09-14 | 2008-04-24 | Jfe Steel Kk | Observation device for corrosion part of surface-treated steel plate, and method and device for observing white rust part of galvanized sheet |
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Legal Events
| Date | Code | Title | Description |
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| A300 | Withdrawal of application because of no request for examination |
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