JP5880184B2 - Color measurement program and color measurement method - Google Patents

Description

  The present invention relates to a color target, a color measurement program, and a color measurement method.

  Techniques for measuring colors are known for the purpose of skin diagnosis and design. When performing such color measurement, a dedicated colorimeter such as a photoelectric colorimeter or a spectrophotometer can be used. However, since the dedicated colorimeter is an expensive device, it is easy for the end user. It is difficult to use.

  For this reason, a camera or a digital camera mounted on a portable terminal may be used instead of a dedicated colorimeter. In this way, when taking a picture using a camera, the measurement part of the object to be measured for color is affected by the light source such as sunlight or illumination. There is a light / dark difference between the color of the measurement site.

  For this reason, there has been proposed a method for correcting the color of a measurement site in an image photographed by a camera using a color chart in which a plurality of color signs are two-dimensionally arranged. Such a technique utilizes the fact that the color chart affected by the light source is reflected in the image in the same manner as the measurement part by performing imaging while the color chart is attached in the vicinity of the measurement part. That is, in the above method, based on the amount of change between the color chart color stored in advance and the color chart color shown in the image, the color of the measurement part shown in the image is changed to the original color of the measurement part. A correction amount for correction is calculated.

JP 2002-370500 A

  However, the above-described conventional technology has a problem in that there is a limit to the color measurement accuracy as described below.

  That is, the above color chart has a restriction that even if it is arranged close to the measurement site, the colors arranged in the color chart can be adjacent to only a part of the measurement site. For this reason, there is a difference also in the influence received from the light source with respect to the color chart except for the portion where the color chart is adjacent in the measurement region. Thus, when there is a difference in the influence of the light source between the color chart and the measurement part, even if the measurement part color reflected in the image is corrected using the amount of color change arranged in the color chart, The original color of the measurement site cannot be reproduced.

  The disclosed technology has been made in view of the above, and an object thereof is to provide a color target, a color measurement program, and a color measurement method capable of improving color measurement accuracy.

  The color target disclosed in the present application is a color target that is imaged together with an object whose color is to be measured. The color mark includes a display surface on which a color marking area is formed and a through-hole penetrating the back surface of the display surface in contact with the object, and the marking area of the same color sandwiches the through-hole. It is formed on both sides of the display surface.

  According to one aspect of the color target disclosed in the present application, there is an effect that the color measurement accuracy can be improved.

FIG. 1 is a top view of the color chart according to the first embodiment. FIG. 2 is a block diagram illustrating a functional configuration of the color measuring apparatus according to the first embodiment. FIG. 3 is a diagram illustrating an example in which the reference color defined in the reference color master is expressed as a vector quantity in the RGB space. FIG. 4 is a diagram showing an example in which the reference color appearing in the image is expressed as a vector quantity in the RGB space. FIG. 5 is a flowchart illustrating the procedure of the color measurement process according to the first embodiment. FIG. 6 is a diagram illustrating an application example 1 of the color chart. FIG. 7 is a diagram illustrating an application example 2 of the color chart. FIG. 8 is a diagram for explaining an example of a computer that executes a color measurement program according to the first and second embodiments.

  Hereinafter, embodiments of a color target, a color measurement program, and a color measurement method disclosed in the present application will be described in detail with reference to the drawings. Note that this embodiment does not limit the disclosed technology. Each embodiment can be appropriately combined within a range in which processing contents are not contradictory.

[Color target structure]
First, the structure of the color chart according to the present embodiment will be described. FIG. 1 is a top view of the color chart 1 according to the first embodiment. In the example of FIG. 1, a top view when the display surface of the color chart 1 is viewed from above, with the display surface on which the color marking area is formed as the top and the back surface of the display surface in contact with the object whose color is to be measured as the bottom. Indicates. In the following, it is assumed that a person's skin color is measured using the color chart 1 in order to provide a skin diagnosis service.

  As shown in FIG. 1, the color chart 1 is attached to or placed on a subject whose color is to be measured, and is imaged together with the measurement region, whereby the image of the image is captured in the same manner as the measurement region. This is for reflecting the affected color chart 1.

  Here, in the color chart 1 according to the present embodiment, the through holes 3 penetrating the display surface and the back surface of the color chart 1 are formed, and the marking areas C11 to C14, C21 to C24, C31 to C34, and C41 of the same color are formed. To C44 are formed on both sides of the display surface with the through hole 3 interposed therebetween.

  In this way, the through-hole 3 is formed in the central portion of the color chart 1 when the color chart 1 is affixed to the subject whose color is to be measured, and the skin of the subject who is the measurement site is removed from the through-hole 3. This is for exposing as a measurement range. Thus, when the subject's skin is exposed from the through-hole 3, the marking regions C11 to C14, C21 to C24, C31 to C34, and C41 to C44 formed on the display surface of the color chart 1 It will be arranged to surround.

  For this reason, in the color chart 1 which concerns on a present Example, it becomes possible to make each marking area | region arrange | positioned circularly centering around the through-hole 3 mutually adjacent to a measurement site | part without omission. Therefore, the color chart 1 according to the present embodiment can make the portion adjacent to the measurement site larger than the conventional color chart in which the color indications are two-dimensionally arranged in a matrix.

  The marking areas C11 to C14, the marking areas C21 to C24, the marking areas C31 to C34, and the marking areas C41 to C44 shown in FIG. 1 are areas on the display surface on which the same color markings are made. Among these, the marking area C11 and the marking area C13 are arranged in pairs facing each other. Further, the marking area C12 and the marking area C14 are also arranged in pairs facing each other. Also, the labeling areas C21 to C24, the marking areas C31 to C34, and the marking areas C41 to C44 are different in color type from the marking areas C11 to C14, but their positional relationship is the same as that of the marking areas C11 to C14. It is.

  Here, in the following description, the label areas C11 to C14 of the same color are collectively referred to as “label areas C1”, and the label areas C21 to C24 of the same color are collectively referred to as “label. May be described as “region C2”. In the following description, the label areas C31 to C34 of the same color are collectively referred to as “label areas C3”, and the label areas C41 to C44 of the same color are collectively referred to as “label areas C4”. May be described. Furthermore, in the following, the color of the color marking indicated by the marking areas C1 to C4 may be described as “reference color” from the viewpoint of the reference when correcting the color of the measurement part in the image.

  In this way, the marking regions of the same color are arranged so as to face each other because the amount of change between the color that the reference color of the color chart 1 originally has and the reference color of the color chart 1 that appears in the image together with the measurement site is changed. This is because when the color measuring device 10 described later corrects the skin color of the subject appearing in the image, an accurate amount of change is calculated.

  That is, it may be insufficient to reproduce the color of the subject's skin simply by observing the amount of change in one marking area. This is because the influence of the subject's skin on the light source is not necessarily uniform over the entire measurement range. Therefore, in the color chart 1 according to the present embodiment, in order to reflect the non-uniform change in the change amount, the same color is used at the position of the pair adjacent to both ends of the contour representing the measurement range or the position of the pair equivalent thereto. The marking areas were arranged in pairs. As a result, the paired labeling areas of the marking areas C1 to C4 of the same color are affected by the light source at positions adjacent to or opposite to both ends of the contour that represents the measurement range. Therefore, it is possible to accurately calculate the color change amount of the portion sandwiched between the paired marking areas among the marking areas C1 to C4 of the same color. Furthermore, in the color chart 1 according to the present embodiment, four types of reference colors C1 to C4 and two pairs of marking areas for the same color can be reflected in the image. Therefore, it is possible to cause the color measurement device 10 described later to calculate the amount of change reflecting the influence of the light source over the entire measurement range.

  Furthermore, when arranging the marking area | region of the same color as a pair, it is preferable to arrange | position symmetrically about the center of the through-hole 3 as a reference | standard. For example, as shown in FIG. 1, a pair of a marking area C11 and a marking area C13, or a pair of a marking area C12 and a marking area 14 are arranged to face each other with the same size and the same shape. To do. Further, as for the marking area C2, the marking area C3, and the marking area C4, two pairs are arranged symmetrically in the same manner as the marking area C1. As a result, the amount of change in the sign area adjacent to the measurement range is calculated on the diagonal line of the measurement range, and the amount of change that equally reflects the influence of the sign area of the same size and shape by the light source is calculated. It becomes possible.

  As described above, in the color chart 1 according to the present embodiment, it is possible to make the respective marking areas arranged in an annular shape around the through hole 3 to be adjacent to the measurement site without omission. Furthermore, when the color chart 1 according to the present embodiment is photographed together with the measurement site, the color of the portion sandwiched between the pair of labeling areas among the labeling areas C1 to C4 of the same color from the photographed image. Can be calculated accurately. Therefore, when correcting the color of the measurement part reflected in the image by using the change amount of the reference color arranged in the color chart 1, the probability of reproducing the color that the measurement part originally has or a color close thereto is increased. it can. Therefore, according to the color chart 1 according to the present embodiment, the color measurement accuracy can be improved.

  Further, in the color chart 1 according to the present embodiment, white marking areas Wh1 to Wh4 are arranged at a predetermined interval, for example, an interval of 90 degrees. For this reason, it is possible to correct the white balance using the pixel values when the four white marking areas Wh1 to Wh4 adjacent to the measurement range appear in the image.

  Furthermore, in the color chart 1 according to the present embodiment, the outer shape of the color chart 1 is formed in an annular shape by forming the shape of the through holes 3 forming the outer periphery of the display surface and the inner periphery of the display surface in a circular shape. As a result, the measurement range photographed together with the measurement site by the camera 11 described later can be circular, and the outer shape of the color chart 1 can be circular. For this reason, even if the display surface of the color chart 1 is not photographed from the front but photographed from various directions other than the front, the photographed image shows the measurement range on the subject's skin and the display of the color chart 1. Surface deformation can be suppressed to an elliptical shape. Therefore, it is possible to easily detect the measurement range and the display surface from the captured image.

  In addition, in the color chart 1 according to the present embodiment, the display areas C1 to C2 are arranged by dividing the display surface into two layers of an outer ring and an inner ring. For this reason, it is possible to efficiently arrange a larger number of marking areas as compared with the case where the marking areas are arranged without being divided into an outer ring and an inner ring.

  In addition, although arbitrary colors can be employ | adopted for the reference color of marking area | region C1, C2, C3, and C4, it is preferable that it is a color similar to skin color. For example, when four types of marking areas are arranged, a color distributed in a position surrounding an extension of an area where human skin color is generally distributed in RGB (Red-Green-Blue color model) space, for example, skin color A reddish or yellowish color can be used. The reference colors of the marking areas C1 to C4 displayed on the display surface of the color chart 1 may be colored by printing or may be colored by other methods.

[Configuration of color measuring device]
Subsequently, the functional configuration of the color measuring apparatus according to the present embodiment will be described. FIG. 2 is a block diagram illustrating a functional configuration of the color measuring apparatus according to the first embodiment. A color measuring apparatus 10 shown in FIG. 2 executes a color measuring process for measuring the color in the measuring range surrounded by the through hole 3 of the color chart 1 included in the image photographed by the camera 11 or the like.

  As one aspect of the color measurement apparatus 10, it can be implemented by installing or preinstalling a color measurement program that provides a color measurement service on a personal computer connected to a digital camera or a mobile terminal such as a smartphone equipped with a camera function. . As another aspect, it may be implemented as a Web server that executes the above color measurement program, or may be implemented as a cloud that provides a color measurement service by outsourcing.

  As illustrated in FIG. 2, the color measurement device 10 includes a camera 11, an output unit 12, a storage unit 13, and a control unit 15. The color measuring apparatus 10 includes various functional units included in known computers in addition to the functional units illustrated in FIG. 2, such as various input devices, audio output devices, and communication interfaces for communicating with external devices. It does not matter as having the functional part.

  Among these, the camera 11 is an imaging device using a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), or the like. As an implementation example of the camera 11, a digital camera may be connected, or the camera can be used when the camera is mounted in advance, such as a mobile terminal. Here, the case where the color measuring apparatus 10 has the camera 11 is illustrated, but the image does not necessarily need to have the camera 11 when an image can be acquired via a network or a storage device.

  The output unit 12 is a display device that displays various kinds of information, such as skin color images and skin RGB values. As an example, a monitor, a display, a touch panel, or the like is applied. it can.

  The storage unit 13 is a storage device that stores various programs such as an OS (Operating System) executed by the control unit 15 and a color measurement program that provides a color measurement service. As one aspect of the storage unit 13, a storage device such as a semiconductor memory element such as a flash memory, a hard disk, or an optical disk is given. The storage unit 13 is not limited to the type of storage device described above, and may be a RAM (Random Access Memory) or a ROM (Read Only Memory).

  The storage unit 13 stores a reference color master 13a as an example of data used in a program executed by the control unit 15. In addition to the reference color master 13a, the storage unit 13 determines the positional relationship between the template image of the color chart 1 and the white and reference color marking areas in order to specify the position and orientation in which the color chart 1 is reflected. It can also be memorized.

  The reference color master 13a is master data in which RGB values of the reference color marking areas C1 to C4 are defined. As an example, the reference color master 13a can register RGB values measured in advance from the reference color marking regions C1 to C4 using a dedicated colorimeter, or a reference color acquired via a network. RGB values can also be registered. As another example, the reference color master 13a calculates the amount of change in RGB value due to imaging with the RGB value of the reference area of the reference color of the color chart 1 that appears in the image captured together with the measurement site. It is referred to by the calculation unit 15d.

  The control unit 15 has an internal memory for storing programs defining various processing procedures and control data, and executes various processes using these. As shown in FIG. 2, the control unit 15 includes an acquisition unit 15a, a measurement unit 15b, a first correction unit 15c, a calculation unit 15d, and a second correction unit 15e.

  The acquisition unit 15a is a processing unit that acquires an image. As one aspect, the acquisition unit 15a acquires an image photographed by the camera 11. As another uniformity, the acquisition unit 15a can also acquire an image via a network such as the Internet or a LAN (Local Area Network). As a further aspect, the acquisition unit 15a can also acquire an image from a storage device such as a memory card or a USB (Universal Serial Bus) memory.

  The measurement unit 15b is a processing unit that measures RGB values from the image acquired by the acquisition unit 15a. As an aspect, the measurement unit 15b detects a position where the white marking regions Wh1 to Wh4 of the color chart 1 included in the image acquired by the acquisition unit 15a are reflected. For example, the measurement unit 15b uses the characteristics of the white marking areas Wh1 to Wh4 arranged at a certain rotation angle, for example, every 90 degrees on the display surface of the color chart 1, to display a white marking area from the image. The positions of Wh1 to Wh4 are detected. Further, when a specific marker is marked on the color chart 1 so that the white marking areas Wh1 to Wh4 can be identified, the measurement unit 15b detects the markers in the white marking areas Wh1 to Wh4. Then, the measurement unit 15b measures the RGB values of the white marking areas Wh1 to Wh4 that appear in the image. At this time, the measurement unit 15b performs a statistical process such as an arithmetic average or a weighted average on the RGB values measured in the pixels corresponding to the white marking areas Wh1 to Wh4 to thereby display the white marking area Wh1 in the image. An RGB value representing ~ Wh4 is calculated.

  Further, the measurement unit 15b measures the RGB values of the reference color marking areas C1 to C4 in the image for each reference color. For example, the measurement unit 15b can estimate the presence of the reference color marking areas C11 to C14 based on the positions of the white marking areas Wh1 to Wh4 detected from the image, for example, all the white marking areas Wh1. Narrows the area of a circle containing ~ Wh4. Then, the measuring unit 15b has an RGB value similar to the RGB value of the reference color marking area C1 defined in the reference color master 13a from the estimated range narrowed down from the entire image, that is, the reference color. The marking areas C11 to C14 are extracted. In addition, the measurement unit 15b performs statistical processing such as arithmetic average or weighted average on the RGB values measured in the pixels corresponding to the reference areas C11 to C14, thereby determining the reference color in the image. An RGB value representative of the marking area C1 is calculated. The same processing is executed for the reference color marking regions C2 to C4. As a result, an RGB value representing the marking area C1, an RGB value representing the marking area C2, an RGB value representing the marking area C3, and an RGB value representing the marking area C4 are obtained for each reference color.

  Furthermore, the measurement unit 15b measures the RGB value of the measurement range that appears in the image. For example, the measurement unit 15b detects the measurement range surrounded by the through hole 3 by edge detection or the like from the previous estimation range. In addition, the measurement unit 15b performs a statistical process such as an arithmetic average or a weighted average on the RGB values measured at each pixel corresponding to the measurement range shown in the image, thereby representing the measurement range in the image. Calculate the value.

The first correction unit 15c is a processing unit that corrects the white balance of the image acquired by the acquisition unit 15a. As one aspect, the first correction unit 15c has a predetermined value, for example, an R component, of RGB values (R _x , G _x , B _x ) representing the white marking regions Wh1 to Wh4 measured by the measurement unit 15b. The white balance correction amount (255 / R _x , 255 / G _x , 255 / B _x ) at which both the G component and the B component are 255 is calculated. The first correction unit 15c multiplies the RGB values representing the reference areas C1 to C4 of the respective reference colors by the white balance correction amount, and sets the white balance correction amount to the RGB value representing the measurement range. Multiply. Such white balance correction can reduce variations in color temperature during shooting.

  The calculation unit 15d is a processing unit that calculates the amount of change in the marking areas C1 to C4 of each reference color. As an aspect, the calculation unit 15d uses the RGB values representing the reference areas C1 to C4 of the reference colors whose white balance has been corrected, to indicate the reference areas C1 to C4 of the reference colors defined in the reference color master 13a. The RGB value of is subtracted. As a result, a change amount indicating how much the original color of the reference color marking regions C1 to C4 has changed due to photographing is obtained.

  The second correction unit 15e is a processing unit that corrects the RGB values of the measurement range appearing in the image using the amount of change in the marking areas C1 to C4 of each reference color. As one aspect, the second correction unit 15e includes a reference color indicating region having an RGB value that is close to the RGB value of the measurement range reflected in the image and out of the amount of change in the indicating regions C1 to C4 of each reference color. The RGB value of the measurement range that appears in the image is corrected by performing weighting that increases the weight as the amount of change.

  Here, with reference to FIGS. 3 and 4, weighting of the change amounts of the reference color marking regions C <b> 1 to C <b> 4 will be described. In general, colors can be expressed as vector quantities in the RGB space. FIG. 3 is a diagram illustrating an example in which the reference color defined in the reference color master 13a is expressed as a vector quantity. FIG. 4 is a diagram illustrating an example in which a reference color appearing in a photographed image is expressed as a vector quantity.

Reference numerals C ₀₁ , C ₀₂ , C _03, and C ₀₄ shown in FIGS. 3 and 4 indicate the reference color of the marking area C1, the reference color of the marking area C2, and the marking area C3 defined in the reference color master 13a. This represents a vector in the RGB space of the reference color and the reference color of the marking area C4. Symbol S ₀ shown in FIG. 3 and FIG. 4 represents a color vector that the subject's skin in the measurement range originally has, that is, a color vector to be obtained. The code C _P1 , the code C _P2 , the code C _P3, and the code C _P4 shown in FIG. 4 are the reference color of the marking area C1 that appears in the image, the reference color of the marking area C2, the reference color of the marking area C3, and the reference of the marking area C4. Represents a color vector. Code S _P shown in FIG. 4 represents the color vector of the measurement captured area in the image. Code D ₁ shown in FIG. 4, reference numeral D _2, reference numeral D ₃ and reference numeral D ₄ represents the distance between the reference color caught on color and image measurement captured area in the image. In the example of FIGS. 3 and 4, for convenience of explanation, the vector is represented in two dimensions. However, in reality, the vector has an R component, a G component, and a B component in a three-dimensional RGB space. To do.

As shown in FIG. 3, the reference color master 13a includes an area including the color vector S ₀ inherent to the skin of the subject in the measurement range, that is, an area in which the skin color of a general person is assumed to be distributed in the RGB space. Four reference color vectors C ₀₁ , C ₀₂ , C ₀₃ and C ₀₄ surrounding the extension are defined. When the color chart 1 in which the marking areas C1 to C4 having these four reference color vectors C ₀₁ , C ₀₂ , C ₀₃ and C ₀₄ are photographed together with the measurement part of the subject, the influence of the light source is exerted. receive. For this reason, as shown in FIG. 4, the reference colors of the color chart 1 are not shown in the image as vectors C ₀₁ , C ₀₂ , C ₀₃ and C ₀₄ , but the vectors C _P1 , C _P2 , C _P3 and C _P4. To change.

Here, be corrected by a way to push added to RGB values of the measuring range appear in the image ratably the amount of change in sign area of each reference color, the reference color similar to the color of the vector S _P output measurement captured area in the image It is considered that the influence of the light source from the light source is closer to the skin color of the subject.

Therefore, in the second correction unit 15e, the distance D between the color vector S _P of the measurement range appearing in the image and the vectors C _P1 , C _P2 , C _P3, and C _P4 of the reference colors appearing in the image. The reciprocal of the squares of ₁ , D ₂ , D _3, and D ₄ is used for weighting the amount of change in the marking area of each reference color.

Here, the distance D _1, D _2, D ₃ and D _{4 ^{is, | S P -C P1 | 2}} , | S P -C P2 | 2, | S P -C P3 | 2, | S P -C P4 | ² can be expressed. For this reason, the weighting coefficients to be given to the change amounts of the marking areas C1 to C4 of the respective reference colors are (1 / | S _P −C _P1 | ² ) / A and (1 / | S _P −C _P2 | ² ), respectively. / A, (1 / | S _P -C _P3 | ² ) / A, (1 / | S _P -C _P4 | ² ) / A. Note that “A” included in the weighting coefficient is represented by the following equation (1). The change amount of the reference color marking area C1 is calculated as “C _P1 −C ₀₁ ” by the calculation unit 15d. Similarly, the change amount “C _P2 -C ₀₂ ” of the reference color marking area C2, the change amount “C _P3 -C ₀₃ ” of the reference color marking area C3, and the change amount “C _P4 − of the reference color marking area C4”. C ₀₄ ”is calculated by the calculation unit 15d.

Therefore, the calculation formula of the color vector S ₀ inherent to the skin of the subject in the measurement range uses the color vector S _P of the measurement range that appears in the image, the amount of change in the marking area of each reference color, and the weighting factor. Can be represented by the following formula (2).

The second correction unit 15e uses the RGB value of the measurement range in which the white balance is corrected and the amount of change “C _P1 -C ₀₁ ”, “ “C _P2 −C ₀₂ ”, “C _P3 −C ₀₃ ” and “C _P4 −C ₀₄ ” and the distances D _{1 to} D ₄ are substituted. As a result, the RGB value of the measurement range shown in the image is corrected to the RGB value of the color originally possessed by the subject's skin in the measurement range.

  The skin color of the subject calculated in this way can be output to the output unit 12 as an RGB value or a color image expressed by RGB values, or can be output to an application for diagnosing skin. .

[Process flow]
FIG. 5 is a flowchart illustrating the procedure of the color measurement process according to the first embodiment. This color measurement process is activated when an image is acquired by the acquisition unit 15a. As shown in FIG. 5, when the image is acquired (step S101), the measurement unit 15b measures the RGB values of the white marking areas Wh1 to Wh4 that appear in the image (step S102).

  Subsequently, the measuring unit 15b measures the RGB values of the marking areas C1 to C4 of the reference colors that appear in the image (step S103). Further, the measurement unit 15b measures the RGB value of the measurement range that appears in the image (step S104).

  Then, the first correction unit 15c multiplies the RGB values of the reference areas C1 to C4 by the white balance correction amount, and performs correction by multiplying the RGB values of the measurement range by the white balance correction amount. (Step S105).

  Subsequently, the calculation unit 15d subtracts the RGB values of the reference areas C1 to C4 defined in the reference color master 13a from the RGB values of the reference areas C1 to C4. The amount of change in the marking areas C1 to C4 is calculated (step S106).

  After that, the second correction unit 15e increases the amount of change in the reference area of the reference color having the RGB value that is close to the RGB value of the measurement range shown in the image and the Euclidean distance among the changes in the reference areas C1 to C4 of the reference colors. The RGB values in the measurement range appearing in the image are corrected by performing weighting that increases the weight (step S107).

  Finally, the second correction unit 15e outputs the RGB value of the measurement range corrected in step S107 or a color image expressed by the RGB value to the output unit 12 (step S108), and ends the process.

[Effect of Example 1]
As described above, the color measurement apparatus 10 according to the present embodiment corrects the RGB values of the measurement range appearing in the image using the change amounts of the reference areas C1 to C4 of the reference colors. For this reason, the color measuring apparatus 10 according to the present embodiment can accurately calculate the amount of change in color of the portion sandwiched between the pair of marking areas C1 to C4 of the same color from the image. . Therefore, the color measuring apparatus 10 according to the present embodiment can increase the probability of reproducing the original color of the measurement site or a color close thereto by correction. Therefore, according to the color measuring apparatus 10 according to the present embodiment, the color measurement accuracy can be improved.

  Although the embodiments related to the disclosed apparatus have been described above, the present invention may be implemented in various different forms other than the above-described embodiments. Therefore, another embodiment included in the present invention will be described below.

[Application example 1 of color chart]
In the above-described first embodiment, the color chart 1 in which the marking area is arranged in two layers of the outer ring and the inner ring is illustrated, but the marking area needs to be arranged in two layers. There is no. FIG. 6 is a diagram illustrating an application example of a color chart. As shown in FIG. 6, the color chart 5 is formed with through-holes 3 penetrating the display surface and the back surface of the color chart 1 in the same manner as the color chart 1 shown in FIG. 1. Further, in the color chart 5, as in the color chart 1 shown in FIG. 1, the same color marking area is formed on the display surface with the through-hole 3 interposed therebetween. That is, as shown in FIG. 6, reference color marking regions C <b> 11 and C <b> 12 are respectively formed on both sides of the display surface with the through hole 3 interposed therebetween. The reference color marking areas C21 and C22, the reference color marking areas C31 and C32, and the reference color marking areas C41 and C42 are also formed on both sides of the display surface with the through-hole 3 interposed therebetween. Therefore, the color chart 5 shown in FIG. 6 can obtain the same effect as the color chart 1 of the first embodiment.

[Application 2 of color chart]
In the first embodiment, the color chart 1 in which the marking area is arranged in two layers of the outer ring and the inner ring is illustrated, but contrary to the application example 1, Three or more layers can be used. In this case, it is also possible to provide a white marking region in an intermediate ring located between the outer ring and the inner ring.

  FIG. 7 is a diagram illustrating an application example 2 of the color chart. As shown in FIG. 7, in the color chart 7, a white marking region Wh <b> 5 is formed in an intermediate ring located between the outer ring and the inner ring. The reason why the white marking area Wh5 is arranged in the intermediate ring in this way is that the white balance can be corrected without necessarily placing the white marking area adjacent to the measurement site. For this reason, in the color chart 7 shown in FIG. 7, compared with the color chart 1 shown in FIG. 1, it is possible to further enlarge the portion where the reference region of the reference color is adjacent to the measurement site.

[Modification of color chart]
In the first embodiment, the case where the marking areas of the same color are arranged point-symmetrically has been illustrated, but it is not always necessary to arrange them point-symmetrically or to face each other. In the first embodiment, the case where the shape of the through hole 3 is circular is illustrated. However, even if the shape is other than a circle, for example, a polygon, the color chart of the first embodiment is used. The same effect as 1 can be obtained. Furthermore, in the first embodiment, the case where a plurality of reference colors are provided on the display surface of the color chart 1 is exemplified. However, it is not always necessary to arrange a plurality of reference colors, and there is only one type of reference color. However, the same effect as the color chart 1 of the first embodiment can be obtained at a certain ratio.

[Distribution and integration]
In addition, each component of each illustrated apparatus does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. Can be integrated and configured. For example, the measurement unit 15b, the first correction unit 15c, the calculation unit 15d, or the second correction unit 15e may be connected as an external device of the color measurement device 10 via a network. In addition, the functions of the color measurement device 10 described above can be obtained by having the measurement unit 15b, the first correction unit 15c, the calculation unit 15d, or the second correction unit 15e, which are connected to each other through a network. May be realized.

[Color measurement program]
The various processes described in the above embodiments can be realized by executing a prepared program on a computer such as a personal computer or a workstation. In the following, an example of a computer that executes a color measurement program having the same function as that of the above-described embodiment will be described with reference to FIG.

  FIG. 8 is a diagram for explaining an example of a computer that executes a color measurement program according to the first and second embodiments. As illustrated in FIG. 8, the computer 100 includes an operation unit 110a, a speaker 110b, a camera 110c, a display 120, and a communication unit 130. Further, the computer 100 includes a CPU 150, a ROM 160, an HDD 170, and a RAM 180. These units 110 to 180 are connected via a bus 140.

  As shown in FIG. 8, the HDD 170 has a color measurement program that exhibits the same functions as those of the measurement unit 15b, the first correction unit 15c, the calculation unit 15d, and the second correction unit 15e described in the first embodiment. 170a is stored in advance. The color measurement program 170a is appropriately integrated or similar to each component of the acquisition unit 15a, the measurement unit 15b, the first correction unit 15c, the calculation unit 15d, and the second correction unit 15e illustrated in FIG. May be separated. In other words, all data stored in the HDD 170 need not always be stored in the HDD 170, and only data necessary for processing may be stored in the HDD 170.

  Then, the CPU 150 reads the color measurement program 170 a from the HDD 170 and develops it in the RAM 180. Thereby, as shown in FIG. 8, the color measurement program 170a functions as a color measurement process 180a. The color measurement process 180a expands various data read from the HDD 170 in an area allocated to itself on the RAM 180 as appropriate, and executes various processes based on the expanded data. The color measurement process 180a includes processing executed by the measurement unit 15b, the first correction unit 15c, the calculation unit 15d, and the second correction unit 15e illustrated in FIG. 2, for example, the processing illustrated in FIG. In addition, each processing unit virtually realized on the CPU 150 does not always require that all processing units operate on the CPU 150, and only a processing unit necessary for the processing needs to be virtually realized.

  Note that the color measurement program 170a is not necessarily stored in the HDD 170 or the ROM 160 from the beginning. For example, each program is stored in a “portable physical medium” such as a flexible disk inserted into the computer 100, so-called FD, CD-ROM, DVD disk, magneto-optical disk, or IC card. Then, the computer 100 may acquire and execute each program from these portable physical media. In addition, each program is stored in another computer or server device connected to the computer 100 via a public line, the Internet, a LAN, a WAN, etc., and the computer 100 acquires and executes each program from these. It may be.

1 Color chart 3 Through hole C11, C12, C13, C14, C21, C22, C23, C24, C31, C32, C33, C34, C41, C42, C43, C44 Marking area Wh1, Wh2, Wh3, Wh4 White marking area DESCRIPTION OF SYMBOLS 10 Color measuring device 11 Camera 12 Output part 13 Memory | storage part 15 Control part 15a Acquisition part 15b Measurement part 15c 1st correction | amendment part 15d Calculation part 15e 2nd correction | amendment part

Claims (2)

On the computer,
Get an image,
A through hole penetrating the back surface of the display surface that is in contact with a display surface on which a color marking area is formed and an object whose color is to be measured is formed in the through hole. The color located at the outer edge of the range in which the color of the object to be exposed is distributed in the color space is used as the marking area, and the marking areas of the same color are arranged on both sides of the display surface with the through hole interposed therebetween. Measure the representative value of the pixel value of the marking area from the image for each marking area of the same color of the color mark,
Measure the representative value of the pixel value of the measurement range surrounded by the through hole of the color target from the image,
Calculating the difference between the representative value of the pixel value measured for each marking area of the same color and the pixel value stored in the storage unit storing the pixel value of the marking area for each marking area of the same color;
A color measurement program that executes processing for correcting a representative value of pixel values in the measurement range using the difference. Computer
Get an image,
A through hole penetrating the back surface of the display surface that is in contact with a display surface on which a color marking area is formed and an object whose color is to be measured is formed in the through hole. The color located at the outer edge of the range in which the color of the object to be exposed is distributed in the color space is used as the marking area, and the marking areas of the same color are arranged on both sides of the display surface with the through hole interposed therebetween. Measure the representative value of the pixel value of the marking area from the image for each marking area of the same color of the color mark,
Measure the representative value of the pixel value of the measurement range surrounded by the through hole of the color target from the image,
Calculating the difference between the representative value of the pixel value measured for each marking area of the same color and the pixel value stored in the storage unit storing the pixel value of the marking area for each marking area of the same color;
Using the difference, a process of correcting a representative value of pixel values in the measurement range is executed.

Images