WO2007110965A1 - Color pattern extracting device and color pattern extracting program - Google Patents
Color pattern extracting device and color pattern extracting program Download PDFInfo
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- WO2007110965A1 WO2007110965A1 PCT/JP2006/306585 JP2006306585W WO2007110965A1 WO 2007110965 A1 WO2007110965 A1 WO 2007110965A1 JP 2006306585 W JP2006306585 W JP 2006306585W WO 2007110965 A1 WO2007110965 A1 WO 2007110965A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/46—Colour picture communication systems
- H04N1/56—Processing of colour picture signals
- H04N1/60—Colour correction or control
- H04N1/62—Retouching, i.e. modification of isolated colours only or in isolated picture areas only
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/90—Determination of colour characteristics
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/46—Colour picture communication systems
- H04N1/56—Processing of colour picture signals
Definitions
- the present invention relates to a color pattern extraction apparatus for extracting a pattern of a specific color with a color image power, and a color pattern extraction program for causing a computer to function as such an apparatus, and in particular, a stamp post-printed on color paper. It relates to a method suitable for extracting patterns such as.
- Patent Document 1 discloses a method of comparing a pattern color in an image with a registered color on the basis of a background in the image in order to remove the influence of color mixing with the background color. ing .
- This method calculates the angle ⁇ c between the target pattern color vector in the image and the background color vector, and the angle ⁇ t between the registered color vector and the background color vector in the image. When the difference between these angles is smaller than the predetermined threshold, it is determined that the color of the target pattern matches the registered color.
- the angle ⁇ t for a plurality of registered colors the color of the target pattern can be assigned to the registered color with the smallest angle difference, and the pattern corresponding to the specified color can be extracted.
- Patent Document 1 Japanese Patent Laid-Open No. 10-104075
- the present invention has been made in view of the above-described problems, and the problem is that the pattern is accurately determined based on the registered color even when the color of the target pattern changes greatly due to color mixing with the background.
- Another object of the present invention is to provide a color pattern extraction device that can be extracted in a simple manner and a color pattern extraction program that causes a computer to function as such a device.
- a color pattern extraction apparatus is an apparatus for extracting a pattern of a specific color with a color image power, and a basic background of a specific color pattern to be extracted.
- the combination of the basic pattern color and basic background color, which is the color on the color, and the reference pattern color and reference background color, which is a color on the reference background color different from the basic background color of the pattern of the specific color Based on at least two sets of color information, it is estimated that a pattern color obtained when a pattern of a specific color is displayed on an arbitrary background color is displayed on the basic background color.
- Correction parameters Extraction means for converting the pattern color into a color estimated to be obtained when displayed on the basic background color, and extracting a pattern that matches the basic pattern color from the converted target pattern color.
- the learning means includes a learning pattern registration unit for registering a basic image in which a specific color pattern is represented on a basic background color and a reference image in which a specific color pattern is represented on a reference background color; For each of the image and the reference image, a separation unit that separates the pattern and the background, a color calculation unit that obtains a representative color of the separated pattern and the background, and a correction parameter is obtained based on the obtained representative color And a correction parameter setting unit.
- the extraction unit includes a separation unit that separates an input image into a target pattern and a background, a color calculation unit that obtains a representative color of the separated target pattern and the background, and the obtained representative color
- a color mixing correction unit that converts the representative color of the target pattern based on the correction parameter
- a determination unit that determines whether the color of the target pattern after color conversion matches the basic pattern color. Is desirable.
- a particle density model is applied, and at least for the pattern color, a parameter is introduced into the density coefficient of the particle density model to determine the color for each pattern portion. It is desirable to reflect this difference in color conversion.
- the color pattern extraction program allows a computer to set a combination of a basic pattern color and a basic background color, which is a color on a basic background color of a specific color pattern to be extracted, Based on at least two sets of color information of a reference pattern color and a reference background color, which is a color on the reference background color different from the basic background color of the color pattern, the pattern of the specific color is arbitrarily set A learning function for obtaining correction parameters for converting the pattern color obtained when displayed on the background color into a color estimated to be obtained when displayed on the basic background color, and the input image
- the target pattern color and background color are obtained separately from the target pattern and background, and the target pattern color is displayed on the basic background color using these values and the correction parameters obtained by the learning means Presumed to be obtained It is converted to the color being characterized in that to execute an extracting function of extracting a pattern matching the basic pattern color from converted by target pattern.
- the background color is added. Even if the color of the post-printed pattern changes significantly due to a color mixture with the background color, the pattern color can be corrected to the color displayed on the basic background color, and the matching with the specified color can be determined. Can be accurately performed to extract a color pattern.
- the system 1 of the embodiment includes a color pattern extraction apparatus 10 and a display 30, a printer 31, and a scanner 32 connected to the color pattern extraction apparatus 10.
- the color pattern extraction apparatus 10 is configured by a general-purpose computer such as a personal computer, and includes a CPU 11, a hard disk (HD) 20, a memory (RAM) 12, and an interface 13 connected to the CPU 11.
- An operating system (not shown) is installed in the HD 20 and a color pattern extraction program 21 is installed.
- the display 30, printer 31, and scanner 32 are connected to the CPU 11 via the interface 13.
- the CPU 11 expands and executes the color pattern extraction program 21 on the RAMI 2 as necessary.
- the target color image is read by the scanner 32 or provided as an image file.
- the extraction process and results are displayed on the display 30 as needed and printed out by the printer 31.
- the color pattern extraction program 21 includes a learning module 22 that registers a pattern or background color as a pre-processing for extraction and obtains a correction parameter, and an extraction module 23 that extracts a pattern of actual image power.
- the learning module (learning means) 22 is a combination of a basic pattern color and a basic background color, which is a color on a basic background color of a pattern of a specific color to be extracted, and a basic pattern of the specific color.
- a pattern of a specific color is displayed on any background color based on at least two sets of color information of a reference pattern color and a reference background color, which is a color on the reference background color different from the background color It has a function to obtain correction parameters for converting the obtained pattern color into a color estimated to be obtained when displayed on the basic background color.
- And learning module 22 includes a learning pattern registration unit 22a for registering a basic image in which a specific color pattern is represented on a basic background color and a reference image in which a specific color pattern is represented on a reference background color, and a basic image For each of the reference image and the reference image, a separation unit 22b that separates the pattern and the background, a color calculation unit 22c that calculates a representative color of the separated pattern and the background, and a correction parameter based on the obtained representative color And a correction parameter setting unit 22d.
- a representative color is a color assigned to each pattern by, for example, averaging the colors of pixels constituting the pattern. Each color is calculated by taking an average value after extracting a pattern.
- the extraction module (extraction means) 23 obtains the target pattern color and the background color by separating the input image into the target pattern and the background, and these values and the correction obtained by the learning module 22 Using the parameters, the target pattern color is converted to the color estimated to be obtained when displayed on the basic background color, and the converted target pattern force has a function to extract a pattern that matches the basic pattern color .
- the extraction module 23 includes a separation unit 23a that separates the input image into a target pattern and a background, a connected component calculation unit 23b that separates the target pattern for each connected component, and representatives of the background color and each connected component.
- the determination unit 23e determines a match between the corrected target pattern and the designated basic pattern color using a known method. For example, the case where the angle between the color vector of the target pattern after correction and the color vector of the basic pattern color is equal to or smaller than the threshold value is matched, and the case where the angle exceeds the threshold value is determined to be mismatched.
- an image obtained by reading a paper on which a handwritten pattern with ink is post-printed by the scanner 32 is a processing target
- a paper color is a background color
- a post-printed handwritten pattern is an extraction target.
- the basic background color is white.
- C be the representative color of the pattern (handwritten A).
- C corresponds to the basic pattern color.
- C represents the representative color of the target pattern (handwritten ABCD) post-printed with a specific color ink
- the pattern “item name” of the representative color D is printed.
- the learning module 22 obtains correction parameters based on the two sets of color information (SO, CA) and (SI, CA,).
- SO, CA color information
- SI, CA color information
- a known particle density moire (Terai et al., Base Recognition by etragonal Regression for Ovena pped Watercolors ", Proc. Of lWFHR-9, 2004) is used as a color mixture model for defining color overlap.
- the colors C and C 'of the target pattern post-printed on the background colors S and S are respectively
- C and S are mixed colors.
- T is the ink color (specific color) of the target pattern and is the ink density of the target pattern.
- A is generally determined by the color distribution (not the representative color of the pattern) of each pixel composing the pattern.
- the pattern colors C,, and D are used as the basis.
- FIG. Fig. 3 (A) is a vector indicating the background color and pattern color of the image of Fig. 2 (B), and Fig. 3 (B) is the background color and pattern of the image of Fig. 2 (C) after color mixture correction. This is a vector indicating the representative color.
- FIG. 3 (A) shows the non-target pattern “item” for the basic pattern color C color vector.
- the angle ⁇ + formed by the color vector of the color D + after correcting the non-target pattern with respect to the vector is
- the target pattern is a line drawing such as a character
- the color distribution of each pixel constituting the line pattern has extremely high dispersion in one axial direction, and becomes a distribution form on the line.
- the assumption that, is a constant is difficult to hold.
- the background is almost the same as the surface figure.
- FIG. Figure 5 shows the color distribution E of each pixel that makes up the pattern printed on the basic background color, and each pixel that makes up the pattern printed with the same ink on a predetermined background color different from the basic color.
- Color correction means conversion from F to G.
- Equation (4) a parameter t representing the fluctuation of is introduced and replaced as shown in Equation (4).
- ⁇ can be obtained by obtaining the intersection coordinates.
- Equation (14) is derived from the above equation and equation (8). Using this equation, this is displayed on the basic background color based on the pattern color C, (t) of the input image. Color C (t)
- the color distribution of the line drawing pattern that has been post-printed on a background color different from the basic background color is correctly converted to the color distribution that is expected to be obtained when displayed on the basic background color. Can do. Therefore, when extracting line drawing patterns such as characters, the extraction accuracy can be improved by using the extended particle density model of the present application.
- FIG. 9 shows an example of an image to be registered.
- each of the two registered images is binarized by an existing method and separated into a no-turn and a background (S02).
- Figure 10 (B) shows a binary binary image with a separated background force.
- the color calculation unit 22c then displays the representative color of the basic background color and the color of each pixel, the representative color of the reference background color and the color of each pixel, the representative color of the target pattern post-printed on each background color, and each pixel. Calculate the color (S03).
- FIG. 10 (C) shows an example in which the background and the pattern are displayed in respective representative colors for each image.
- the correction parameter setting unit 22d calculates parameters in the color mixture correction formula of the target pattern in accordance with the above extended particle density model (S04).
- the representative color of the target pattern on the basic background color registered in the learning pattern registration unit 22a is registered as a color that can be selected when the user specifies it during pattern extraction.
- the basic background color and the correction parameters are Are registered in the parameter file as coefficients used in
- the user selects and designates a pattern color (extracted ink color) from which the color power registered by the process of the learning module 22 is to be extracted (Sll). Subsequently, an extraction target image in which a pattern is post-printed with the same ink on an arbitrary background color is input (S12).
- An example of the input image is shown in Fig. 12 (A).
- the separation unit 23a separates the image input by the binary key into a pattern and a background (S13).
- the binary image of the separated pattern is shown in Fig. 12 (B).
- the connected component calculation unit 23b performs labeling or the like on the binary image, and extracts a noturn force connected component (S14).
- Fig. 12 (C) shows the calculation result of the connected component, and the part enclosed by the dotted circumscribed rectangle is one connected component.
- the color calculation unit 23c calculates a representative color of the background color and a representative color of each connected component of the pattern (S15).
- Figure 12 (D) shows the representative colors for each connected component.
- the color mixing correction unit 23d uses the correction formula obtained by the learning module 22 to perform color mixing correction using the background color and the representative color of the connected component for each connected component, and displays it on the basic background color.
- the case color is estimated (S16).
- FIG. 12 (E) shows the corrected pattern.
- the judgment unit 23e compares the representative color after the color mixture correction of each connected component with the specified color (representative color of the pattern for which extraction is specified) (S17), and determines whether the corrected pattern color matches the specified color. As shown in FIG. 13, it is determined for each connected component by threshold processing (S18). When it is determined that they match, the target connected component is extracted as a target pattern (S19), and when it is determined that they do not match, the target connected component is deleted (S20). If you want to make a determination in units smaller than the connected components, for example, in units of pixels, you can perform color mixture correction and determine the match with the specified color in units of pixels without calculating the connected components in S14.
- the extraction result is displayed on the display 30 or printed out by the printer 31 according to the user's request. At that time, as shown in Fig. (Shown on a single scale), or as a binary image as shown in FIG. 14 (B).
- FIG. 1 is a block diagram showing a system including a color pattern extraction apparatus according to an embodiment of the present invention.
- FIG. 2 (A) is an image of a basic background color post-printed with a specific color ink, (B) is an image of a reference background color with a specific color ink post-printed, (C) is an image FIG. 5B is an explanatory diagram showing an image obtained by correcting color mixture with the apparatus of the embodiment (B).
- FIG. 3A is an explanatory diagram showing a color vector of the image of FIG. 2B
- FIG. 3B is an explanatory diagram showing a color vector of the image of FIG. 2C.
- FIG. 4 (A) and (B) are explanatory diagrams showing extraction results by a conventional extraction method, and (C) are explanatory diagrams showing extraction results by the apparatus of the embodiment.
- FIG. 5 is a graph showing an example of color distribution for each pixel when the pattern is a line drawing.
- FIG. 6 is an explanatory diagram conceptually showing color mixture correction by a particle density model of Terai et al.
- FIG. 7 is an explanatory diagram conceptually showing color mixture correction by an extended particle density model of the embodiment.
- FIG. 8 is an explanatory diagram conceptually showing the result of color mixture correction of the color distribution of a line drawing pattern using a particle density model of Terai et al.
- FIG. 9 is a flowchart showing the processing contents of a learning module of the color pattern extraction apparatus of the embodiment.
- FIG. 10 Examples of images processed in Fig. 9.
- A) is a registered image
- B) is a binary image separated from the background
- C is a representative of the background and pattern. It is explanatory drawing which shows the image displayed with the color.
- FIG. 11 is a flowchart showing the processing contents of the extraction module of the color pattern extraction apparatus of the embodiment.
- FIG. 12 is an example of the image processed in FIG. 11, where (A) is the input image, (B) is the binary image of the separated pattern, (C) is the calculation result of the connected component, and (D) is Representative colors for each connected component, (E) is an explanatory diagram showing a pattern after color mixture correction.
- FIG. 13 is an explanatory diagram showing a state of threshold processing for each connected component in the processing of FIG. 11.
- FIG. 14 (A) is an image showing a color image of the extraction result in gray scale, and (B) is an explanatory diagram showing a binary image of the extraction result.
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Abstract
[PROBLEMS] An object pattern can be correctly extracted with reference to a registered color even if the color of the object pattern is varied due to mix with the background color. [MEANS FOR SOLVING PROBLEMS] Installed in an HD (20) of a color pattern extracting device (10) is a color pattern extracting program (21) including a learning module (22) having a function of determining a correction parameter used to convert the pattern color acquired when a specific color pattern is displayed on an arbitrary background color into a color acquired when the specific color pattern is displayed on a basic background color by using two images showing the specific color pattern displayed on different background colors and an extracting module (23) for separating the inputted image into the pattern and the background, acquiring the colors of the pattern and the background, converting the object pattern color into a color estimated when the object pattern color is displayed on the basic background color by using these values and the correction parameter acquiring by the learning module (22), and extracting a pattern matching the basic pattern color from the converted object patterns.
Description
明 細 書 Specification
カラーパターン抽出装置及びカラーパターン抽出プログラム 技術分野 Color pattern extraction apparatus and color pattern extraction program
[0001] 本発明は、カラー画像力 特定色のパターンを抽出するカラーパターン抽出装置、 及び、このような装置としてコンピュータを機能させるカラーパターン抽出プログラム に関し、特に、カラー用紙上にポストプリントされたスタンプ等のパターンを抽出する のに適した手法に関する。 TECHNICAL FIELD [0001] The present invention relates to a color pattern extraction apparatus for extracting a pattern of a specific color with a color image power, and a color pattern extraction program for causing a computer to function as such an apparatus, and in particular, a stamp post-printed on color paper. It relates to a method suitable for extracting patterns such as.
背景技術 Background art
[0002] カラー画像力 特定色のパターンを抽出する技術は、例えばスタンプや印鑑等の パターンがポストプリントされたカラー帳票からスタンプ等のパターンを抽出する等の 用途に従来から利用されている。例えば、ポストプリントされるパターンの色を登録し ておき、帳票等を光学的に読み取って得られた画像力も登録された色に近似する色 のパターンを抽出する方法が知られている。ただし、スタンプ等のインクにより形成さ れるパターンの色は、インクの色が同一であっても、用紙の色である背景色が異なる と、背景色との混色を生じて異なる色になる場合がある。このように読み取られた画像 内のパターンの色が混色により変化すると、登録されたパターンの色との近似性が失 われ、パターンを抽出できなくなる可能性がある。 [0002] Technology for extracting a pattern of a specific color has been conventionally used for applications such as extracting a pattern such as a stamp from a color form on which a pattern such as a stamp or a seal is post-printed. For example, a method is known in which the color of a post-printed pattern is registered, and the image pattern obtained by optically reading a form or the like is used to extract a color pattern that approximates the registered color. However, even if the color of the pattern formed by ink such as stamps is the same, if the background color, which is the color of the paper, is different, it may be mixed with the background color and become a different color. is there. If the color of the pattern in the image read in this way changes due to color mixing, the similarity with the color of the registered pattern is lost, and the pattern may not be extracted.
[0003] これに対して特許文献 1には、背景色との混色の影響を除去するため、画像中の背 景色を基準にして画像中のパターン色と登録色とを比較する手法が開示されている 。この手法では、画像中の対象パターンの色ベクトルと背景色の色ベクトルのなす角 度 Θ cと、登録色の色ベクトルと画像中の背景色の色ベクトルとのなす角度 Θ tとを算 出し、これらの角度の差が所定の閾値より小さいときに、対象パターンの色が当該登 録色に一致すると判断する。複数の登録色について角度 Θ tを計算しておくことによ り、対象パターンの色を角度差が最も小さくなる登録色に割り当て、指定された色に 対応するパターンを抽出することができる。 [0003] On the other hand, Patent Document 1 discloses a method of comparing a pattern color in an image with a registered color on the basis of a background in the image in order to remove the influence of color mixing with the background color. ing . This method calculates the angle Θc between the target pattern color vector in the image and the background color vector, and the angle Θt between the registered color vector and the background color vector in the image. When the difference between these angles is smaller than the predetermined threshold, it is determined that the color of the target pattern matches the registered color. By calculating the angle Θt for a plurality of registered colors, the color of the target pattern can be assigned to the registered color with the smallest angle difference, and the pattern corresponding to the specified color can be extracted.
[0004] 特許文献 1 :特開平 10— 104075号公報 Patent Document 1: Japanese Patent Laid-Open No. 10-104075
発明の開示
発明が解決しょうとする課題 Disclosure of the invention Problems to be solved by the invention
[0005] し力しながら、特許文献 1の方法では、画像中のパターンと背景との混色の度合が 大きぐ画像中のパターン色と登録色との色ずれが大きくなると、上記の角度差が大 きくなり、色の判定を誤り、パターンの抽出に失敗する可能性が高くなる。 However, in the method of Patent Document 1, the degree of color mixture between the pattern in the image and the background is large, and the color difference between the pattern color in the image and the registered color becomes large, the above angle difference is It becomes larger, and there is a higher possibility that the color judgment will be wrong and pattern extraction will fail.
[0006] また、特許文献 1の方法では、画像に同色系で RGB値が異なる色のパターンが混 在する場合、登録色で指定したものとは異なる色のパターンが抽出される可能性が ある。例えば、登録時の基本背景色と異なる彩色領域上に RGB値は異なるが同色系 のスタンプと文字とが存在し、ポストプリントされたスタンプのパターンのみを抽出しよ うとする場合、インクにより表されるスタンプの色は背景色との混色により登録された 基本背景色上のスタンプの色とは離れる。このとき、印刷された文字の色が、登録さ れた基本背景色上のスタンプの色に近 、場合には、文字のパターンが誤って抽出さ れる。 [0006] In addition, in the method of Patent Document 1, when a pattern of a color having the same color system and different RGB values is mixed in the image, there is a possibility that a pattern of a color different from that specified by the registered color may be extracted. . For example, if there are stamps and characters of the same color but different RGB values on a chromatic area different from the basic background color at the time of registration, and you want to extract only the pattern of the post-printed stamp, it will be represented by ink. The stamp color is different from the stamp color on the basic background color registered by mixing with the background color. At this time, if the color of the printed character is close to the stamp color on the registered basic background color, the character pattern is erroneously extracted.
[0007] 本発明は、上記の問題点に鑑みてなされたものであり、その課題は、対象パターン の色が背景との混色により大きく変化した場合にも、登録色に基づいてパターンを正 確に抽出することができるカラーパターン抽出装置、及び、コンピュータをこのような 装置として機能させるカラーパターン抽出プログラムを提供することにある。 [0007] The present invention has been made in view of the above-described problems, and the problem is that the pattern is accurately determined based on the registered color even when the color of the target pattern changes greatly due to color mixing with the background. Another object of the present invention is to provide a color pattern extraction device that can be extracted in a simple manner and a color pattern extraction program that causes a computer to function as such a device.
課題を解決するための手段 Means for solving the problem
[0008] 本発明に力かるカラーパターン抽出装置は、上記の課題を解決するため、カラー画 像力 特定色のパターンを抽出する装置であって、抽出対象となる特定色のパター ンの基本背景色上での色である基本パターン色と基本背景色との組、及び、特定色 のパターンの基本背景色とは異なる参照背景色上での色である参照パターン色と参 照背景色との組の少なくとも 2組の色情報に基づ 、て、特定色のパターンを任意の 背景色上に表示した場合に得られるパターン色を、基本背景色上に表示させた際に 得られると推定される色に変換するための補正パラメータを求める学習手段と、入力 された画像を対象パターンと背景とに分離して対象パターン色と背景色とを求め、こ れらの値と学習手段により得られた補正パラメータとを用いて、対象パターン色を基 本背景色上に表示した際に得られると推定される色に変換し、変換された対象バタ ーンカゝら基本パターン色に一致するパターンを抽出する抽出手段と、を備えることを
特徴とする。 [0008] In order to solve the above-described problems, a color pattern extraction apparatus according to the present invention is an apparatus for extracting a pattern of a specific color with a color image power, and a basic background of a specific color pattern to be extracted. The combination of the basic pattern color and basic background color, which is the color on the color, and the reference pattern color and reference background color, which is a color on the reference background color different from the basic background color of the pattern of the specific color Based on at least two sets of color information, it is estimated that a pattern color obtained when a pattern of a specific color is displayed on an arbitrary background color is displayed on the basic background color. Learning means for obtaining a correction parameter for conversion to a target color, and separating the input image into a target pattern and a background to obtain a target pattern color and a background color, and obtaining these values and the learning means. Correction parameters Extraction means for converting the pattern color into a color estimated to be obtained when displayed on the basic background color, and extracting a pattern that matches the basic pattern color from the converted target pattern color. Features.
[0009] 学習手段は、基本背景色上に特定色のパターンが表された基本画像と、参照背景 色上に特定色のパターンが表された参照画像とを登録する学習パターン登録部と、 基本画像及び参照画像のそれぞれについて、パターンと背景とに分離する分離部と 、分離されたパターンと背景との代表色を求める色計算部と、求められた代表色に基 づ 、て補正パラメータを求める補正パラメータ設定部と、を備えることが望ま 、。 [0009] The learning means includes a learning pattern registration unit for registering a basic image in which a specific color pattern is represented on a basic background color and a reference image in which a specific color pattern is represented on a reference background color; For each of the image and the reference image, a separation unit that separates the pattern and the background, a color calculation unit that obtains a representative color of the separated pattern and the background, and a correction parameter is obtained based on the obtained representative color And a correction parameter setting unit.
[0010] また、抽出手段は、入力された画像を対象パターンと背景とに分離する分離部と、 分離された対象パターンと背景との代表色を求める色計算部と、求められた代表色と 補正パラメータとに基づ 、て対象パターンの代表色を変換する混色補正部と、色変 換された対象パターンの色が基本パターン色に一致する力否かを判定する判定部と 、を備えることが望ましい。 [0010] In addition, the extraction unit includes a separation unit that separates an input image into a target pattern and a background, a color calculation unit that obtains a representative color of the separated target pattern and the background, and the obtained representative color A color mixing correction unit that converts the representative color of the target pattern based on the correction parameter; and a determination unit that determines whether the color of the target pattern after color conversion matches the basic pattern color. Is desirable.
[0011] 学習手段及び抽出手段における色の重なりモデルとしては、粒子密度モデルを適 用すると共に、少なくともパターンの色に関しては粒子密度モデルの密度係数にパラ メータを導入してパターンの部分毎の色の相違を色変換に反映させるようにすること が望ましい。 [0011] As a color overlap model in the learning means and the extraction means, a particle density model is applied, and at least for the pattern color, a parameter is introduced into the density coefficient of the particle density model to determine the color for each pattern portion. It is desirable to reflect this difference in color conversion.
[0012] 一方、本発明にかかるカラーパターン抽出プログラムは、コンピュータに、抽出対象 となる特定色のパターンの基本背景色上での色である基本パターン色と基本背景色 との組、及び、特定色のパターンの基本背景色とは異なる参照背景色上での色であ る参照パターン色と参照背景色との組の少なくとも 2組の色情報に基づ 、て、特定色 のパターンを任意の背景色上に表示した場合に得られるパターン色を、基本背景色 上に表示させた際に得られると推定される色に変換するための補正パラメータを求め る学習機能と、入力された画像を対象パターンと背景とに分離して対象パターン色と 背景色とを求め、これらの値と学習手段により得られた補正パラメータとを用いて、対 象パターン色を基本背景色上に表示した際に得られると推定される色に変換し、変 換された対象パターンから基本パターン色に一致するパターンを抽出する抽出機能 と、を実行させることを特徴とする。 On the other hand, the color pattern extraction program according to the present invention allows a computer to set a combination of a basic pattern color and a basic background color, which is a color on a basic background color of a specific color pattern to be extracted, Based on at least two sets of color information of a reference pattern color and a reference background color, which is a color on the reference background color different from the basic background color of the color pattern, the pattern of the specific color is arbitrarily set A learning function for obtaining correction parameters for converting the pattern color obtained when displayed on the background color into a color estimated to be obtained when displayed on the basic background color, and the input image When the target pattern color and background color are obtained separately from the target pattern and background, and the target pattern color is displayed on the basic background color using these values and the correction parameters obtained by the learning means Presumed to be obtained It is converted to the color being characterized in that to execute an extracting function of extracting a pattern matching the basic pattern color from converted by target pattern.
発明の効果 The invention's effect
[0013] 以上のように構成された本発明のカラーパターン抽出装置によれば、背景色上に
ポストプリントされたパターンの色が背景色と混色を生じて大きく変化した場合にも、 パターンの色を基本背景色上に表示された際の色に補正することができ、指定色と の一致判定を正確に実行し、カラーパターンを抽出することができる。 [0013] According to the color pattern extraction apparatus of the present invention configured as described above, the background color is added. Even if the color of the post-printed pattern changes significantly due to a color mixture with the background color, the pattern color can be corrected to the color displayed on the basic background color, and the matching with the specified color can be determined. Can be accurately performed to extract a color pattern.
発明を実施するための最良の形態 BEST MODE FOR CARRYING OUT THE INVENTION
[0014] 以下、本発明にかかるカラーパターン抽出装置及びカラーパターン抽出プログラム の実施形態を図面に基づいて説明する。最初に、図 1に基づいて本実施形態のカラ 一パターン抽出装置を含むシステム全体の概要を説明する。図 1に示されるように、 実施形態のシステム 1は、カラーパターン抽出装置 10と、これに接続されたディスプ レイ 30、プリンタ 31、スキャナ 32とを備えている。 Hereinafter, embodiments of a color pattern extraction apparatus and a color pattern extraction program according to the present invention will be described with reference to the drawings. First, the outline of the entire system including the color pattern extraction apparatus of this embodiment will be described based on FIG. As shown in FIG. 1, the system 1 of the embodiment includes a color pattern extraction apparatus 10 and a display 30, a printer 31, and a scanner 32 connected to the color pattern extraction apparatus 10.
[0015] カラーパターン抽出装置 10は、パーソナルコンピュータ等の汎用コンピュータにより 構成され、 CPU11、並びにこの CPU11に接続されたハードディスク (HD)20、メモリ (RAM) 12及びインターフェイス 13を備えている。 HD20には、図示せぬオペレーテ イングシステムがインストールされると共に、カラーパターン抽出プログラム 21がインス トールされている。ディスプレイ 30、プリンタ 31、スキャナ 32は、インターフェイス 13を 介して CPU 11に接続されている。 CPU11は、カラーパターン抽出プログラム 21を 必要に応じて RAMI 2上に展開して実行する。対象となるカラー画像は、スキャナ 32 により読み取られ、あるいは、画像ファイルとして提供される。また、抽出の過程、結 果は、必要に応じてディスプレイ 30に表示され、プリンタ 31によりプリントアウトされる The color pattern extraction apparatus 10 is configured by a general-purpose computer such as a personal computer, and includes a CPU 11, a hard disk (HD) 20, a memory (RAM) 12, and an interface 13 connected to the CPU 11. An operating system (not shown) is installed in the HD 20 and a color pattern extraction program 21 is installed. The display 30, printer 31, and scanner 32 are connected to the CPU 11 via the interface 13. The CPU 11 expands and executes the color pattern extraction program 21 on the RAMI 2 as necessary. The target color image is read by the scanner 32 or provided as an image file. The extraction process and results are displayed on the display 30 as needed and printed out by the printer 31.
[0016] カラーパターン抽出プログラム 21は、抽出の前処理としてパターンや背景色を登録 して補正パラメータを求める学習モジュール 22と、実際の画像力もパターンを抽出す る抽出モジュール 23とを備えている。 [0016] The color pattern extraction program 21 includes a learning module 22 that registers a pattern or background color as a pre-processing for extraction and obtains a correction parameter, and an extraction module 23 that extracts a pattern of actual image power.
[0017] 学習モジュール (学習手段) 22は、抽出対象となる特定色のパターンの基本背景色 上での色である基本パターン色と基本背景色との組、及び、特定色のパターンの基 本背景色とは異なる参照背景色上での色である参照パターン色と参照背景色との組 の少なくとも 2組の色情報に基づいて、特定色のパターンを任意の背景色上に表示 した場合に得られるパターン色を、基本背景色上に表示させた際に得られると推定さ れる色に変換するための補正パラメータを求める機能を持つ。そして、学習モジユー
ル 22には、基本背景色上に特定色のパターンが表された基本画像と、参照背景色 上に特定色のパターンが表された参照画像とを登録する学習パターン登録部 22aと 、基本画像及び参照画像のそれぞれについて、パターンと背景とに分離する分離部 22bと、分離されたパターンと背景との代表色を計算する色計算部 22cと、求められ た代表色に基づいて補正パラメータを求める補正パラメータ設定部 22dとが含まれる 。代表色とは、パターンを構成する画素の色の平均をとるなどして、各パターンに一 色を割り当てたものである。各色は、正確にはパターンを抽出した後に平均値をとる などして求められる。 [0017] The learning module (learning means) 22 is a combination of a basic pattern color and a basic background color, which is a color on a basic background color of a pattern of a specific color to be extracted, and a basic pattern of the specific color. When a pattern of a specific color is displayed on any background color based on at least two sets of color information of a reference pattern color and a reference background color, which is a color on the reference background color different from the background color It has a function to obtain correction parameters for converting the obtained pattern color into a color estimated to be obtained when displayed on the basic background color. And learning module 22 includes a learning pattern registration unit 22a for registering a basic image in which a specific color pattern is represented on a basic background color and a reference image in which a specific color pattern is represented on a reference background color, and a basic image For each of the reference image and the reference image, a separation unit 22b that separates the pattern and the background, a color calculation unit 22c that calculates a representative color of the separated pattern and the background, and a correction parameter based on the obtained representative color And a correction parameter setting unit 22d. A representative color is a color assigned to each pattern by, for example, averaging the colors of pixels constituting the pattern. Each color is calculated by taking an average value after extracting a pattern.
[0018] 一方、抽出モジュール (抽出手段) 23は、入力された画像を対象パターンと背景とに 分離して対象パターン色と背景色とを求め、これらの値と学習モジュール 22により得 られた補正パラメータとを用いて、対象パターン色を基本背景色上に表示した際に 得られると推定される色に変換し、変換された対象パターン力 基本パターン色に一 致するパターンを抽出する機能を持つ。そして、抽出モジュール 23には、入力された 画像を対象パターンと背景とに分離する分離部 23aと、対象パターンを連結成分毎 に分ける連結成分計算部 23bと、背景色と各連結成分との代表色を求める色計算部 23cと、求められた代表色と補正パラメータとに基づいて対象パターンの代表色を変 換する混色補正部 23dと、色変換された対象パターンの色が基本パターン色に一致 する力否かを判定する判定部 23eとが含まれる。判定部 23eは、公知の手法を用い て補正後の対象パターンと指定された基本パターン色との一致を判断する。例えば 、補正後の対象パターンの色ベクトルと基本パターン色の色ベクトルとの間の角度が 閾値以下である場合を一致、閾値を超える場合を不一致と判定する。 On the other hand, the extraction module (extraction means) 23 obtains the target pattern color and the background color by separating the input image into the target pattern and the background, and these values and the correction obtained by the learning module 22 Using the parameters, the target pattern color is converted to the color estimated to be obtained when displayed on the basic background color, and the converted target pattern force has a function to extract a pattern that matches the basic pattern color . The extraction module 23 includes a separation unit 23a that separates the input image into a target pattern and a background, a connected component calculation unit 23b that separates the target pattern for each connected component, and representatives of the background color and each connected component. The color calculation unit 23c for obtaining the color, the color mixing correction unit 23d for converting the representative color of the target pattern based on the obtained representative color and the correction parameter, and the color of the target pattern after the color conversion match the basic pattern color And a determination unit 23e for determining whether or not the force to perform is included. The determination unit 23e determines a match between the corrected target pattern and the designated basic pattern color using a known method. For example, the case where the angle between the color vector of the target pattern after correction and the color vector of the basic pattern color is equal to or smaller than the threshold value is matched, and the case where the angle exceeds the threshold value is determined to be mismatched.
[0019] 続いて、本発明のカラーパターン抽出装置の抽出原理を具体例に基づいて説明 する。なお、以下の説明では、インクによる手書きパターンがポストプリントされた用紙 をスキャナ 32で読み取った画像を処理対象とし、用紙の色を背景色、ポストプリントさ れた手書きのパターンを抽出対象とする。また、基本背景色は白色とする。 Subsequently, the extraction principle of the color pattern extraction apparatus of the present invention will be described based on a specific example. In the following description, an image obtained by reading a paper on which a handwritten pattern with ink is post-printed by the scanner 32 is a processing target, a paper color is a background color, and a post-printed handwritten pattern is an extraction target. The basic background color is white.
[0020] 図 2(A)に示すように、基本背景色 S上に特定色のインクでポストプリントされた対象 [0020] As shown in FIG. 2 (A), an object that is post-printed with a specific color ink on the basic background color S
0 0
パターン (手書きの A)の代表色を Cとする。 Cは基本パターン色に対応する。また、 Let C be the representative color of the pattern (handwritten A). C corresponds to the basic pattern color. Also,
A A A A
図 2(B)に示すように、基本背景色とは異なる参照背景色 Sのカラー帳票に、上記と同
じ特定色のインクでポストプリントされた対象パターン (手書きの ABCD)の代表色を C As shown in Fig. 2 (B), the same color as above with the reference background color S that is different from the basic background color. C represents the representative color of the target pattern (handwritten ABCD) post-printed with a specific color ink
A A
'とする。 C 'は参照パターン色に対応する。なお、図 2(B)には、同一画像内に抽出 'And. C ′ corresponds to the reference pattern color. In Fig. 2 (B), it is extracted in the same image.
A A
対象ではな 、代表色 Dのパターン「項目名」がプリントされて 、る。 The pattern “item name” of the representative color D is printed.
[0021] 学習モジュール 22は、上記の 2組の色情報 (SO, CA)、 (SI, CA,)に基づいて補正パ ラメータを求める。この例では、色の重なりを定義する混色モデルとして、公知の粒子 密度モアノレ (Terai他, Baseし olor Recognition by etragonal Regression for Ovena pped Watercolors", Proc. of lWFHR- 9, 2004)をベースとしている。このモデルを用 いると、背景色 S、 S上にポストプリントされた対象パターンの色 C、 C 'は、それぞれ The learning module 22 obtains correction parameters based on the two sets of color information (SO, CA) and (SI, CA,). In this example, a known particle density moire (Terai et al., Base Recognition by etragonal Regression for Ovena pped Watercolors ", Proc. Of lWFHR-9, 2004) is used as a color mixture model for defining color overlap. Using this model, the colors C and C 'of the target pattern post-printed on the background colors S and S are respectively
0 1 A A 0 1 A A
式 (1), (2)のように表される。 Sは基本背景色 (白色)であるため、 C 'は式 (3)に示すよう It is expressed as equations (1) and (2). Since S is the basic background color (white), C 'is as shown in equation (3)
0 A 0 A
に、 Cと Sとの混色となる。 In addition, C and S are mixed colors.
A 1 A 1
[0022] [数 1] ^ニ /^ +ひ一^ 。 (1) [0022] [Equation 1] ^ ni / ^ + hiichi ^. (1)
C, = ,T, + (1- ^)8, (2) C, =, T, + (1- ^) 8, (2)
C^ C. - -^X^ -S,,) (3) [0023] 上式中、 Tは対象パターンのインク色 (特定色)、 は対象パターンのインク密度に C ^ C.--^ X ^ -S ,,) (3) [0023] where T is the ink color (specific color) of the target pattern and is the ink density of the target pattern.
A A A A
対応する係数であり、対象とする色の面に対し色が一様である場合には 0.0≤ p ≤1 Corresponding coefficient, 0.0≤ p ≤1 if the color is uniform for the target color surface
A A
.0の値をとる定数と考えることができる。上記のように、二組の背景色とパターン色と がわかれば、 p を求めることができる。そして、 p が定まれば、任意の背景色上に It can be thought of as a constant with a value of .0. As described above, if two sets of background color and pattern color are known, p can be obtained. And if p is determined, on any background color
A A A A
特定色のインクでポストプリントして混色を生じたパターンの色を補正して基本背景色 上に表示させた際に得られると推定される色に変換 (混色補正)することができる。 A は一般的に、ノターンを構成する各画素の色分布 (パターンの代表色ではない)によ つて決定される。 It is possible to correct the color of the pattern that has been mixed by post-printing with a specific color of ink and convert it to a color estimated to be obtained when displayed on the basic background color (mixed color correction). A is generally determined by the color distribution (not the representative color of the pattern) of each pixel composing the pattern.
[0024] 例えば、図 2(B)の画像を対象画像として混色補正すると、パターンの色 C, , Dが基 For example, when color mixture correction is performed using the image in FIG. 2 (B) as the target image, the pattern colors C,, and D are used as the basis.
A A
本背景色 S上に表示させた際に得られると推定される色 C '+, D+に変換され、図 2(C) The background color S is converted to the color C '+, D +, which is presumed to be obtained when displayed on S. Figure 2 (C)
0 A 0 A
に示すような画像が得られる。図 3(A)は、図 2(B)の画像の背景色、パターン色の代表 色を示すベクトル、図 3(B)は、混色補正後の図 2(C)の画像の背景色、パターン色の 代表色を示すベクトルである。 An image as shown in FIG. Fig. 3 (A) is a vector indicating the background color and pattern color of the image of Fig. 2 (B), and Fig. 3 (B) is the background color and pattern of the image of Fig. 2 (C) after color mixture correction. This is a vector indicating the representative color.
[0025] ここで、図 3(A)は、基本パターン色 Cの色ベクトルに対して非対象パターン「項目
名」の色 Dの色ベクトルがなす角度 0 力 基本パターン色 Cの色ベクトルに対して対 Here, FIG. 3 (A) shows the non-target pattern “item” for the basic pattern color C color vector. Name “Color” Angle formed by D color vector 0 Force Basic pattern color
1 A 1 A
象パターン (手書きの ABCD)の色ベクトルがなす角度 Θ より小さい場合を想定してい It is assumed that the color vector of the elephant pattern (handwritten ABCD) is smaller than the angle Θ.
2 2
る。この場合、従来のように図 3(A)に示す状態で混色補正をしないでパターンを抽出 しょうとすると、同一色とみなす判定の閾値を 0 にすると、図 4(A)に示すように非対 The In this case, if the pattern is to be extracted without correcting the color mixture in the state shown in Fig. 3 (A) as in the conventional case, if the threshold value for judging that the color is the same is set to 0, the pattern is not shown as shown in Fig. 4 (A). versus
1 1
象パターンのみが抽出され、本来抽出すべきパターンが抜け落ち、閾値を Θ にする Only the elephant pattern is extracted, the pattern that should be extracted is dropped, and the threshold is set to Θ
2 と、図 4(B)に示すように対象パターンのみでなぐ非対象のパターンも抽出される。 2 and non-target patterns that are not only target patterns as shown in Fig. 4 (B) are also extracted.
[0026] 一方、混色補正を実行すると、図 3(B)に示すように、対象パターンの色は C 'から C On the other hand, when color mixture correction is performed, the color of the target pattern changes from C ′ to C as shown in FIG. 3 (B).
A A
'+に変換されて特定色の基本パターン色 Cに近づき、非対象パターンの色は Dから It is converted to '+ and approaches the basic pattern color C of the specific color, and the color of the non-target pattern is changed from D
A A A A
D+に変換されて基本パターン色 Cカゝら遠ざかる。この結果、基本パターン色 Cの色 Converted to D + and moved away from basic pattern color C. As a result, the basic pattern color C
A A A A
ベクトルに対して非対象パターンの補正後の色 D+の色ベクトルがなす角度 Θ +が、基 The angle Θ + formed by the color vector of the color D + after correcting the non-target pattern with respect to the vector is
1 本パターン色 Cの色ベクトルに対して対象パターンの色ベクトルがなす角度 Θ +より From angle Θ + formed by the color vector of the target pattern with respect to the color vector of one pattern color C
A 2 大きい。このため、同一色とみなす判定の閾値を 0 +にすると、図 4(C)に示すように A 2 Large. For this reason, if the threshold value for judging the same color is 0+, as shown in Fig. 4 (C)
2 2
対象パターンのみが抽出される。 Only the target pattern is extracted.
[0027] なお、対象パターンが文字等の線画である場合には、線パターンを構成する各画 素の色分布はひとつの軸方向の分散が極端に高くなり、線上にのった分布形となり、 が定数であるという仮定は成立しにくい。ただし、背景部は面図形と同様に、ほぼ[0027] When the target pattern is a line drawing such as a character, the color distribution of each pixel constituting the line pattern has extremely high dispersion in one axial direction, and becomes a distribution form on the line. The assumption that, is a constant is difficult to hold. However, the background is almost the same as the surface figure.
A A
一様と仮定できる。パターンが線画である場合の画素毎の色分布の例を図 5に基づ いて説明する。図 5は、基本背景色上にポストプリントされたパターンを構成する各画 素の色分布 Eと、基本色とは異なる所定の背景色上に同じインクでポストプリントされ たパターンを構成する各画素の色分布 F、基本背景色の背景の各画素の色分布 G、 上記の所定の背景色の背景の各画素の色分布 Hを表す。混色補正とは、 Fから Gへ の変換を意味する。 It can be assumed to be uniform. An example of the color distribution for each pixel when the pattern is a line drawing will be described with reference to FIG. Figure 5 shows the color distribution E of each pixel that makes up the pattern printed on the basic background color, and each pixel that makes up the pattern printed with the same ink on a predetermined background color different from the basic color. Color distribution F, color distribution G of each background pixel of the basic background color, and color distribution H of each background pixel of the predetermined background color. Color correction means conversion from F to G.
[0028] そこで、実施形態では、 の変動を表すパラメータ tを導入し、式 (4)のように置き換 [0028] Therefore, in the embodiment, a parameter t representing the fluctuation of is introduced and replaced as shown in Equation (4).
A A
える。 tの範囲は式 (5)に示す通りである。 Yeah. The range of t is as shown in Equation (5).
0 < ί < 1 (5)
[0030] また、 (0)=0, P (1)=1とする。よって、式 (1)〜(3)は以下の式 (6)〜(8)ように書き換0 <ί <1 (5) [0030] Further, it is assumed that (0) = 0 and P (1) = 1. Therefore, equations (1) to (3) can be rewritten as the following equations (6) to (8).
A A
えられる。 available.
[0031] [数 3] [0031] [Equation 3]
CA{t) = pA{tyiA+ \-pA{t))S,C A (t) = p A (tyi A + \ -p A (t)) S,
C り = (り- (1- )( - s0) Cri = (ri- (1-) (-s 0 )
[0032] (6)、(7)式より t = 1、 t=0でそれぞれ、式 (10)ズ11)が成立する。 [0032] From Equations (6) and (7), Equation (10) 11) holds true at t = 1 and t = 0, respectively.
[0033] [数 4] [0033] [Equation 4]
C,(1) = C,(1) = T, (10) C, (1) = C, (1) = T, (10)
C,(0) = S C^(0) = S0 (11) C, (0) = SC ^ (0) = S 0 (11)
[0034] よって、 C (t)-S、 C '(t)-Sの 2直線の近似直線をそれぞれ分布から求め、 2直線の [0034] Therefore, two approximate straight lines of C (t) -S and C '(t) -S are obtained from the distribution, and the two straight lines
A O A 1 A O A 1
交点座標を求めることで τを求めることができる。ある画素に対し c Τ can be obtained by obtaining the intersection coordinates. C for a pixel
A A 'ωを観測し、こ のとき t=tであるとする。式 (7)より以下の式 (12)が導かれる。一方、背景色はそれぞ A A 'ω is observed, and t = t at this time. The following equation (12) is derived from equation (7). On the other hand, the background color
P P
れ分布平均値を用いることで式 (13)のように近似する。 Approximation as shown in Eq. (13) using the mean value of the distribution.
[0035] [数 5] c ( - [0035] [Equation 5] c (-
(12) (12)
I -s' l— I -s' l—
(13) (13)
TA-SX T A -S X
ただし、 Sい s。は分布平均値である。 However, S s. Is the distribution average.
[0036] 上式と式 (8)より式 (14)が導かれ、この式を利用して、入力された画像のパターン色 C ,(t)に基づいて、これを基本背景色上に表示した場合の色 C (t)を推定することがで[0036] Equation (14) is derived from the above equation and equation (8). Using this equation, this is displayed on the basic background color based on the pattern color C, (t) of the input image. Color C (t)
A A A A
きる。 wear.
[0037] [数 6] [0037] [Equation 6]
C tX(t) + り^11) (^"^) (14) 以上の導出により、背景色とその背景色上のパターン色との組み合わせを 2組用意 することにより、任意の背景色上でのパターン色が復元可能となることがわかる。学習
モジュール 22は、 2組の色の組から上記の Tを学習する。 C tX (t) + ri ^ 11 ) (^ "^) (14) Based on the above derivation, two combinations of the background color and the pattern color on the background color are prepared. It can be seen that the pattern color of can be restored. Module 22 learns the above T from two sets of colors.
A A
[0039] なお、ここで前述した論文に掲載された Terai他の粒子密度モデルと、 にパラメ [0039] It should be noted that the particle density model of Terai et al.
A A
ータを導入した本願の拡張粒子密度モデルとの違 ヽを図 6及び図 7を用いて概念的 に説明する。背景画素の色分布は、いずれのモデルでもほぼ一様と仮定し、 S , Sで Differences from the extended particle density model of the present application, in which data is introduced, will be explained conceptually with reference to Figs. Assuming that the color distribution of the background pixels is almost uniform in all models,
0 1 示している。一方、背景色上にポストプリントされたパターンの各画素の色分布につ いては、 Terai他の粒子密度モデルではほぼ一様と仮定し、 C , C ,で示しているの 0 1 shows. On the other hand, the color distribution of each pixel of the pattern post-printed on the background color is assumed to be almost uniform by Terai et al.
A A A A
に対し、本願の拡張粒子密度モデルでは、 にパラメータを導入することにより、実 In contrast, the extended particle density model of the present application introduces a parameter to
A A
際の分布を考慮して直線にのった分布と仮定して 、る。 It is assumed that the distribution is on a straight line in consideration of the distribution.
[0040] Terai他のモデルで基本背景色とは異なる背景色上にポストプリントされた線画パタ 一ンの色分布を、基本背景色上での色に変換しょうとすると、図 8に示すように、正し い分布には変換されない。したがって、線画パターンを正しく抽出できない可能性が ある。これに対して、本願のモデルによれば、 C (t)-S、 C ,(t)-Sの 2直線の近似直 [0040] When trying to convert the color distribution of a line drawing pattern that was post-printed on a background color different from the basic background color in Terai's model to a color on the basic background color, as shown in Figure 8 It is not converted to a correct distribution. Therefore, the line drawing pattern may not be extracted correctly. On the other hand, according to the model of the present application, C (t) -S, C and (t) -S
A O A 1 A O A 1
線を求めることにより、基本背景色とは異なる背景色上にポストプリントされた線画パ ターンの色分布を、基本背景色上に表示した場合に得られると推定される色分布に 正しく変換することができる。したがって、文字などの線画パターンを抽出する場合に は、本願の拡張粒子密度モデルを用いる方が抽出精度を高めることができる。 By calculating the line, the color distribution of the line drawing pattern that has been post-printed on a background color different from the basic background color is correctly converted to the color distribution that is expected to be obtained when displayed on the basic background color. Can do. Therefore, when extracting line drawing patterns such as characters, the extraction accuracy can be improved by using the extended particle density model of the present application.
[0041] 続いて、実施形態のカラーパターン抽出プログラム 21の処理の流れをフローチヤ ートに基づいて説明する。学習モジュール 22の処理がスタートすると、図 9に示すよう に、学習パターン登録部 22aの作用により、学習画像パターンが登録される (S01)。こ こでは、抽出したい基本背景色上にポストプリントされた対象パターンの画像と、この 基本背景色とは異なる参照背景色上に同じインクでポストプリントされた対象パター ンの画像とが登録される。図 10(A)は、登録される画像の例を示す。 [0041] Next, the processing flow of the color pattern extraction program 21 of the embodiment will be described based on a flow chart. When the processing of the learning module 22 is started, a learning image pattern is registered by the action of the learning pattern registration unit 22a as shown in FIG. 9 (S01). Here, the image of the target pattern post-printed on the basic background color to be extracted and the image of the target pattern post-printed with the same ink on a reference background color different from this basic background color are registered. . FIG. 10 (A) shows an example of an image to be registered.
[0042] 次に、分離部 22bの作用により、登録された 2組の画像のそれぞれを、既存の手法 で 2値ィ匕し、ノターンと背景とに分離する (S02)。図 10(B)は、背景力も分離されたバタ 一ンのニ値画像を示す。そして、色計算部 22cは、基本背景色の代表色と各画素の 色、参照背景色の代表色と各画素の色、それぞれの背景色上におけるポストプリント された対象パターンの代表色と各画素の色を計算する (S03)。図 10(C)は、各画像に っ 、て、背景とパターンとをそれぞれの代表色で表示した例を示す。
[0043] 補正パラメータ設定部 22dは、上記の拡張粒子密度モデルにしたがって、対象パタ ーンの混色補正式におけるパラメータを計算する (S04)。学習パターン登録部 22aで 登録した基本背景色上の対象パターンの代表色は、ユーザがパターン抽出時に指 定する際に選択可能な色として登録され、基本背景色と補正パラメータとは、補正計 算に用いられる係数としてパラメータファイルに登録される。 [0042] Next, by the operation of the separation unit 22b, each of the two registered images is binarized by an existing method and separated into a no-turn and a background (S02). Figure 10 (B) shows a binary binary image with a separated background force. The color calculation unit 22c then displays the representative color of the basic background color and the color of each pixel, the representative color of the reference background color and the color of each pixel, the representative color of the target pattern post-printed on each background color, and each pixel. Calculate the color (S03). FIG. 10 (C) shows an example in which the background and the pattern are displayed in respective representative colors for each image. [0043] The correction parameter setting unit 22d calculates parameters in the color mixture correction formula of the target pattern in accordance with the above extended particle density model (S04). The representative color of the target pattern on the basic background color registered in the learning pattern registration unit 22a is registered as a color that can be selected when the user specifies it during pattern extraction. The basic background color and the correction parameters are Are registered in the parameter file as coefficients used in
[0044] 抽出モジュール 23の処理が開始すると、ユーザは、学習モジュール 22の処理で登 録された色力も抽出したいパターン色 (抽出インク色)を選択して指定する (Sll)。続い て、任意の背景色上に同インクでパターンがポストプリントされた抽出対象画像を入 力する (S12)。入力画像の例を図 12(A)に示す。分離部 23aは、 2値ィ匕により入力され た画像をパターンと背景とに分離する (S13)。分離されたパターンの二値画像を図 12( B)に示す。 [0044] When the process of the extraction module 23 starts, the user selects and designates a pattern color (extracted ink color) from which the color power registered by the process of the learning module 22 is to be extracted (Sll). Subsequently, an extraction target image in which a pattern is post-printed with the same ink on an arbitrary background color is input (S12). An example of the input image is shown in Fig. 12 (A). The separation unit 23a separates the image input by the binary key into a pattern and a background (S13). The binary image of the separated pattern is shown in Fig. 12 (B).
[0045] 連結成分計算部 23bは、二値画像に対してラベリングなどを行い、ノターン力 連 結成分を抽出する (S14)。図 12(C)は、連結成分の計算結果を示し、点線の外接矩形 で囲まれた部分が 1つの連結成分である。続いて、色計算部 23cは、背景色の代表 色とパターンの各連結成分の代表色とを計算する (S15)。図 12(D)は、連結成分毎の 代表色を示す。 [0045] The connected component calculation unit 23b performs labeling or the like on the binary image, and extracts a noturn force connected component (S14). Fig. 12 (C) shows the calculation result of the connected component, and the part enclosed by the dotted circumscribed rectangle is one connected component. Subsequently, the color calculation unit 23c calculates a representative color of the background color and a representative color of each connected component of the pattern (S15). Figure 12 (D) shows the representative colors for each connected component.
[0046] 混色補正部 23dは、学習モジュール 22で求めた補正式を使 、、連結成分毎に背 景色と連結成分の代表色を用いて混色補正を行!、、基本背景色上に表示した場合 の色を推定する (S16)。図 12(E)は、補正後のパターンを示す。判定部 23eは、各連結 成分の混色補正後の代表色と、指定色 (抽出を指定したパターンの代表色)とを照合 し (S17)、補正後のパターン色が指定色と一致する力否かを図 13に示すように、閾値 処理によって連結成分毎に判断する (S18)。一致すると判定された場合には、対象連 結成分を対象パターンとして抽出し (S19)、一致しないと判定された場合には、対象 連結成分を消去する (S20)。なお、連結成分より細かい単位で、例えば画素単位で判 定したい場合には、 S14の連結成分計算を行わずに、画素単位で混色補正、指定色 との一致判定を実行すればょ 、。 [0046] The color mixing correction unit 23d uses the correction formula obtained by the learning module 22 to perform color mixing correction using the background color and the representative color of the connected component for each connected component, and displays it on the basic background color. The case color is estimated (S16). FIG. 12 (E) shows the corrected pattern. The judgment unit 23e compares the representative color after the color mixture correction of each connected component with the specified color (representative color of the pattern for which extraction is specified) (S17), and determines whether the corrected pattern color matches the specified color. As shown in FIG. 13, it is determined for each connected component by threshold processing (S18). When it is determined that they match, the target connected component is extracted as a target pattern (S19), and when it is determined that they do not match, the target connected component is deleted (S20). If you want to make a determination in units smaller than the connected components, for example, in units of pixels, you can perform color mixture correction and determine the match with the specified color in units of pixels without calculating the connected components in S14.
[0047] 抽出結果は、ユーザの要求に応じて、ディスプレイ 30に表示され、あるいは、プリン タ 31によりプリントアウトされる。その際、図 14(A)に示すようにカラー画像 (図ではダレ
一スケールで示される)で出力してもよいし、図 14(B)に示すように 2値画像で出力し てもよい。 The extraction result is displayed on the display 30 or printed out by the printer 31 according to the user's request. At that time, as shown in Fig. (Shown on a single scale), or as a binary image as shown in FIG. 14 (B).
図面の簡単な説明 Brief Description of Drawings
[図 1]本発明の実施形態にカゝかるカラーパターン抽出装置を含むシステムを示すプロ ック図である。 FIG. 1 is a block diagram showing a system including a color pattern extraction apparatus according to an embodiment of the present invention.
[図 2](A)は基本背景色上に特定色のインクでパターンをポストプリントした画像、 (B) は参照背景色上に特定色のインクでパターンをポストプリントした画像、(C)は (B)を実 施形態の装置により混色補正して得られた画像を示す説明図である。 [Fig. 2] (A) is an image of a basic background color post-printed with a specific color ink, (B) is an image of a reference background color with a specific color ink post-printed, (C) is an image FIG. 5B is an explanatory diagram showing an image obtained by correcting color mixture with the apparatus of the embodiment (B).
[図 3](A)は図 2(B)の画像の色ベクトル、(B)は図 2(C)の画像の色ベクトルを示す説明 図である。 3A is an explanatory diagram showing a color vector of the image of FIG. 2B, and FIG. 3B is an explanatory diagram showing a color vector of the image of FIG. 2C.
[図 4](A)及び (B)は従来の抽出方法による抽出結果、(C)は実施形態の装置による抽 出結果を示す説明図である。 [FIG. 4] (A) and (B) are explanatory diagrams showing extraction results by a conventional extraction method, and (C) are explanatory diagrams showing extraction results by the apparatus of the embodiment.
[図 5]パターンが線画である場合の画素毎の色分布の例を示すグラフである。 FIG. 5 is a graph showing an example of color distribution for each pixel when the pattern is a line drawing.
[図 6]Terai他の粒子密度モデルによる混色補正を概念的に示す説明図である。 FIG. 6 is an explanatory diagram conceptually showing color mixture correction by a particle density model of Terai et al.
[図 7]実施形態の拡張粒子密度モデルによる混色補正を概念的に示す説明図であ る。 FIG. 7 is an explanatory diagram conceptually showing color mixture correction by an extended particle density model of the embodiment.
[図 8]Terai他の粒子密度モデルにより線画パターンの色分布を混色補正した結果を 概念的に示す説明図である。 FIG. 8 is an explanatory diagram conceptually showing the result of color mixture correction of the color distribution of a line drawing pattern using a particle density model of Terai et al.
[図 9]実施形態のカラーパターン抽出装置の学習モジュールの処理内容を示すフロ 一チャートである。 FIG. 9 is a flowchart showing the processing contents of a learning module of the color pattern extraction apparatus of the embodiment.
[図 10]図 9で処理される画像の例であり、(A)は登録画像、(B)は背景カゝら分離された 二値画像、(C)は背景とパターンとをそれぞれの代表色で表示した画像を示す説明 図である。 [Fig. 10] Examples of images processed in Fig. 9. (A) is a registered image, (B) is a binary image separated from the background, and (C) is a representative of the background and pattern. It is explanatory drawing which shows the image displayed with the color.
[図 11]実施形態のカラーパターン抽出装置の抽出モジュールの処理内容を示すフロ 一チャートである。 FIG. 11 is a flowchart showing the processing contents of the extraction module of the color pattern extraction apparatus of the embodiment.
[図 12]図 11で処理される画像の例であり、(A)は入力画像、(B)は分離されたパターン の二値画像、(C)は連結成分の計算結果、(D)は連結成分毎の代表色、(E)は混色補 正後のパターンを示す説明図である。
[図 13]図 11の処理における連結成分毎の閾値処理の様子を示す説明図である。 FIG. 12 is an example of the image processed in FIG. 11, where (A) is the input image, (B) is the binary image of the separated pattern, (C) is the calculation result of the connected component, and (D) is Representative colors for each connected component, (E) is an explanatory diagram showing a pattern after color mixture correction. FIG. 13 is an explanatory diagram showing a state of threshold processing for each connected component in the processing of FIG. 11.
[図 14](A)は抽出結果のカラー画像をグレースケールで表した画像、(B)は抽出結果 の二値画像を示す説明図である。 [FIG. 14] (A) is an image showing a color image of the extraction result in gray scale, and (B) is an explanatory diagram showing a binary image of the extraction result.
符号の説明 Explanation of symbols
10 カラーパターン抽出装置 10 Color pattern extraction device
11 CPU 11 CPU
13 RAM 13 RAM
14 インターフェイス 14 interface
20 HD 20 HD
21 カラーパターン抽出プログラム 21 Color pattern extraction program
22 学習部 22 Learning Department
23 抽出部
23 Extractor
Claims
[1] カラー画像力 特定色のパターンを抽出するカラーパターン抽出装置であって、 抽出対象となる特定色のパターンの基本背景色上での色である基本パターン色と 前記基本背景色との組、及び、前記特定色のパターンの前記基本背景色とは異なる 参照背景色上での色である参照パターン色と前記参照背景色との組の少なくとも 2 組の色情報に基づいて、前記特定色のパターンを任意の背景色上に表示した場合 に得られるパターン色を、前記基本背景色上に表示させた際に得られると推定され る色に変換するための補正パラメータを求める学習手段と、 [1] Color image power A color pattern extraction apparatus for extracting a pattern of a specific color, which is a set of a basic pattern color that is a color on a basic background color of the pattern of the specific color to be extracted and the basic background color And the specific color based on at least two sets of color information of a reference pattern color and a reference background color which are different from the basic background color of the pattern of the specific color Learning means for obtaining a correction parameter for converting a pattern color obtained when the pattern is displayed on an arbitrary background color into a color estimated to be obtained when the pattern color is displayed on the basic background color;
入力された画像を対象パターンと背景とに分離して対象パターン色と背景色とを求 め、これらの値と前記学習手段により得られた補正パラメータとを用いて、対象パター ン色を前記基本背景色上に表示した際に得られると推定される色に変換し、変換さ れた対象パターン力も前記基本パターン色に一致するパターンを抽出する抽出手段 と、 The input image is separated into the target pattern and the background to obtain the target pattern color and the background color, and using these values and the correction parameter obtained by the learning means, the target pattern color is determined as the basic pattern color. An extraction means for converting to a color estimated to be obtained when displayed on a background color, and extracting a pattern whose converted target pattern force also matches the basic pattern color;
を備えることを特徴とするカラーパターン抽出装置。 A color pattern extraction apparatus comprising:
[2] 前記学習手段は、 [2] The learning means includes
前記基本背景色上に前記特定色のパターンが表された基本画像と、前記参照背 景色上に前記特定色のパターンが表された参照画像とを登録する学習パターン登 録部と、 A learning pattern registration unit for registering a basic image in which the pattern of the specific color is represented on the basic background color and a reference image in which the pattern of the specific color is represented on the reference background.
前記基本画像及び前記参照画像のそれぞれについて、パターンと背景とに分離す る分離部と、 A separation unit for separating the basic image and the reference image into a pattern and a background;
分離されたパターンと背景との代表色を求める色計算部と、 A color calculation unit for obtaining a representative color of the separated pattern and the background;
求められた代表色に基づいて前記補正パラメータを求める補正パラメータ設定部と を備えることを特徴とする請求項 1に記載のカラーパターン抽出装置。 The color pattern extraction apparatus according to claim 1, further comprising: a correction parameter setting unit that obtains the correction parameter based on the obtained representative color.
[3] 前記抽出手段は、 [3] The extraction means includes
入力された画像を対象パターンと背景とに分離する分離部と、 A separation unit that separates an input image into a target pattern and a background;
分離された対象パターンと背景との代表色を求める色計算部と、 A color calculator for obtaining representative colors of the separated target pattern and the background;
求められた代表色と前記補正パラメータとに基づいて前記対象パターンの代表色
を変換する混色補正部と、 Based on the obtained representative color and the correction parameter, the representative color of the target pattern A color mixing correction unit for converting
色変換された対象パターンの色が前記基本パターン色に一致するか否かを判定す る判定部と、 A determination unit for determining whether or not the color of the target pattern subjected to color conversion matches the basic pattern color;
を備えることを特徴とする請求項 1または 2に記載のカラーパターン抽出装置。 The color pattern extraction apparatus according to claim 1, further comprising:
[4] 前記学習手段及び前記抽出手段における色の重なりモデルとして、粒子密度モデ ルを適用すると共に、少なくともパターンの色に関しては前記粒子密度モデルの密 度係数にパラメータを導入して前記パターンの部分毎の色の相違を色変換に反映さ せるようにしたことを特徴とする請求項 1〜3のいずれかに記載のカラーパターン抽出 装置。 [4] A particle density model is applied as a color overlap model in the learning unit and the extraction unit, and at least for the pattern color, a parameter is introduced into the density coefficient of the particle density model to obtain a portion of the pattern. 4. The color pattern extraction apparatus according to claim 1, wherein a difference in color for each color is reflected in color conversion.
[5] コンピュータを、カラー画像力も特定色のパターンを抽出するカラーパターン抽出 装置として昨日させるカラーパターン抽出プログラムであって、 [5] A color pattern extraction program that makes a computer yesterday as a color pattern extraction device that extracts a pattern of a specific color with color image power,
コンピュータに、 On the computer,
抽出対象となる特定色のパターンの基本背景色上での色である基本パターン色と 前記基本背景色との組、及び、前記特定色のパターンの前記基本背景色とは異なる 参照背景色上での色である参照パターン色と前記参照背景色との組の少なくとも 2 組の色情報に基づいて、前記特定色のパターンを任意の背景色上に表示した場合 に得られるパターン色を、前記基本背景色上に表示させた際に得られると推定され る色に変換するための補正パラメータを求める学習機能と、 A set of a basic pattern color that is a color on the basic background color of the pattern of the specific color to be extracted and the basic background color, and a reference background color that is different from the basic background color of the specific color pattern A pattern color obtained when a pattern of the specific color is displayed on an arbitrary background color based on at least two sets of color information of a reference pattern color that is a color of the reference color and the reference background color. A learning function for obtaining a correction parameter for conversion to a color estimated to be obtained when displayed on the background color;
入力された画像を対象パターンと背景とに分離して対象パターン色と背景色とを求 め、これらの値と前記学習手段により得られた補正パラメータとを用いて、対象パター ン色を前記基本背景色上に表示した際に得られると推定される色に変換し、変換さ れた対象パターン力も前記基本パターン色に一致するパターンを抽出する抽出機能 と、 The input image is separated into the target pattern and the background to obtain the target pattern color and the background color, and using these values and the correction parameter obtained by the learning means, the target pattern color is determined as the basic pattern color. An extraction function for converting to a color estimated to be obtained when displayed on the background color, and extracting a pattern whose converted target pattern power also matches the basic pattern color;
を実行させることを特徴とするカラーパターン抽出プログラム。
A color pattern extraction program characterized in that
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Citations (3)
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JPH05216989A (en) * | 1992-01-13 | 1993-08-27 | Nec Corp | Method and device for extracting area of color picture |
JPH06203157A (en) * | 1992-10-14 | 1994-07-22 | Fujitsu Ltd | Method for processing color image and device thereof |
JPH10104075A (en) * | 1996-09-27 | 1998-04-24 | Glory Ltd | Color discriminating device |
-
2006
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Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH05216989A (en) * | 1992-01-13 | 1993-08-27 | Nec Corp | Method and device for extracting area of color picture |
JPH06203157A (en) * | 1992-10-14 | 1994-07-22 | Fujitsu Ltd | Method for processing color image and device thereof |
JPH10104075A (en) * | 1996-09-27 | 1998-04-24 | Glory Ltd | Color discriminating device |
Non-Patent Citations (1)
Title |
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TERAI T. ET AL.: "A Study of Gradation Printing Using Particle Density Model in Virtual Woodblock Printing", VISUAL COMPUTING, 2003, pages 87 - 92, XP003002441 * |
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