JP4967490B2 - Profile creation system - Google Patents

Description

  The present invention relates to a method and apparatus for creating a monitor profile.

  In recent years, the characteristics of various devices (output devices) such as input devices such as scanners and digital cameras, display devices such as monitors, and printing devices such as printers are grasped, and the properties are described in a file. Color management technology that matches the colors of various devices has become common. This color management is generally performed according to the ICC standard advocated by the ICC (International Color Consortium). In the ICC, a characteristic file is called a profile. In order to perform color management of the monitor, the monitor calibration is performed in order to perform color conversion between the color space (RGB) depending on the characteristics of the monitor and the color space (CIEXYZ, CIELab, etc.) independent of the device. After the white adjustment for adjusting the white chromaticity and brightness and the adjustment of the gradation reproduction characteristics, the monitor profile is created.

  As a method of measuring the color of a monitor, it is roughly divided into <1> a method of visual observation. <2> A method using a contact-type colorimeter. <3> A method using a non-contact colorimeter. There is.

  <1> According to the visual method, since no special equipment is required, it is inexpensive and the influence of ambient light (the influence of illumination light in the measurement environment) can be reflected in calibration and profile creation. There is an advantage that you can. For example, Patent Document 1 discloses a technique for adjusting tone reproduction characteristics by matching a dither image and a continuous tone image.

  <2> In the method using the contact-type colorimeter, a target value of white and gradation reproduction characteristics is determined, a patch of a predetermined RGB value is displayed on a monitor screen, and the colorimetric value is measured. Adjust the monitor or the video card so as to get closer to, and create a profile. According to this method, colorimetry is performed by bringing the colorimeter body into contact with a colorimetric object (a white object serving as a reference, a monitor screen), so that it is possible to perform stable measurement with high reproducibility and environmental light. There is an advantage that it is possible to measure the inherent display characteristics of the monitor device, which eliminates the influence of (the influence of illumination light in the measurement environment).

  <3> According to the method using a non-contact colorimeter, there is an advantage that stable measurement can be performed while reflecting the influence of ambient light (the influence of illumination light in the measurement environment) in calibration and profile creation.

  Patent Document 2 discloses a technique related to a method of easily creating a monitor profile without purchasing a new measuring instrument. This technique uses a digital camera instead of a measuring instrument to create a monitor profile.

Further, according to the invention disclosed in Patent Document 3, network connection means for connecting to a network, color image display means for displaying a color image, and reproduction characteristics and observation illumination of the color image display means by a color camera or sensor. Color conversion means for acquiring conditions, performing color conversion on the color image acquired via the network, and outputting the result to the color image display means. The color conversion may be performed on a color image acquired via the network using a color conversion profile and a color conversion program downloaded via the network.
Japanese Patent Laid-Open No. 6-35430 JP 2003-6629 A Japanese Patent Laid-Open No. 2001-60082

  In the calibration and profile creation in the conventional monitor color management described above, any one of the three colorimetric methods described above is selected and used.

  However, the three colorimetric methods described above have not only advantages but also disadvantages. That is, <1> the method of visual observation causes individual differences and lacks reproducibility. Further, in the method using the <2> contact colorimeter, the influence of ambient light (the influence of illumination light in the measurement environment) cannot be reflected in calibration and profile creation. Further, in the method using the <3> non-contact colorimeter, the device main body is very expensive compared to the contact-type colorimeter, and the distance between the non-contact colorimeter and the monitor screen, This affects the colorimetric value. Further, since the influence of ambient light is reflected, the inherent display characteristics inherent to the monitor device cannot be obtained.

  Therefore, when a single color measurement method is used in the color management of the monitor, none of the color measurement methods have the above-described drawbacks and are not optimal color measurement methods.

  On the other hand, the optimum in accordance with the processing in each stage performed at the time of calibration and profile creation described above (for example, colorimetry of white color and gradation reproduction characteristics in calibration, colorimetry of RGB three primary colors in profile creation) It is also possible to select and use a colorimetric method for each process, but in that case, two colorimeters, a non-contact colorimeter and a contact colorimeter, are required. Since the non-contact type colorimeter is very expensive, the cost becomes high.

  In addition, the technique of Patent Document 2 has three problems. The first point is that an unknown digital camera cannot be used because the profile of the digital camera is assumed to be known. Second, in order to create a new digital camera profile, a separate procedure for creating a profile is required. Third, if you use a digital camera that only has an automatic exposure determination function (a mechanism that automatically controls the aperture and shutter speed), the environment between creating a digital camera profile and creating a monitor profile Since the exposure is often different, an accurate monitor profile cannot be created.

  Therefore, the present invention has been made in view of the above problems, and provides a method and apparatus for creating a monitor profile by using a digital camera instead of a measuring instrument and photographing a monitor and a chart at the same time. Aim.

In order to solve the above problem, the invention according to claim 1 is a profile creation system including a terminal device connected to a monitor and a server device connected to the terminal device, wherein the server device is a printing device. An acquisition means for acquiring image data obtained by simultaneously photographing a first chart printed on a medium and a second chart displayed on a monitor with an electronic camera, and constituting the first chart portion in the image data First color characteristic profile creating means for obtaining an RGB value of each patch to be created and creating a color characteristic profile of the electronic camera based on the RGB value and a colorimetric value of each patch constituting the first chart And a transmission means for transmitting the created color characteristic profile of the electronic camera to the terminal device, the terminal device from the server device Receiving means for receiving a color characteristic profile of the received electronic camera; and obtaining RGB values of each patch constituting the second chart portion displayed on the monitor in the image data; Second color characteristic profile creating means for creating a color characteristic profile of the monitor based on a color characteristic profile of the camera, and the electronic camera captures address information for communicating with the terminal device, It has an address transmission means which transmits to the said server apparatus , It is characterized by the above-mentioned.

  According to this, the second chart for creating the color characteristic profile of the electronic camera and the second chart for creating the color characteristic profile displayed on the monitor are photographed at the same time, so that the color of the electronic camera can be captured at one time. Since the characteristic profile and the color characteristic profile of the monitor can be created, the color characteristic profile of the monitor can be created even if the color characteristic profile of the electronic camera is unknown. In addition, even when an electronic camera having only an automatic exposure determination function is used, shooting is performed with the same exposure under the same environment, so that it is possible to create a monitor profile with high accuracy.

In order to solve the above problem, the invention according to claim 2 is the profile creation system according to claim 1, wherein the server device stores colorimetric values of each patch constituting the first chart. Storage means, and the first color characteristic profile creation means includes an RGB value of each patch constituting the first chart portion and each patch constituting the first chart acquired from the storage means. The color characteristic profile of the electronic camera is created based on the colorimetric values.

According to this, the server device stores in advance the colorimetric values of each patch constituting the first chart, and uses the colorimetric values to create the color characteristic profile of the electronic camera. A color characteristic profile of the electronic camera can be quickly created.

In order to solve the above-mentioned problems, a third aspect of the present invention is the profile creation system according to the first or second aspect, wherein the second color characteristic profile creation means is a first display displayed on the monitor. The colorimetric value corresponding to the RGB value of each patch constituting the chart part 2 is calculated by performing an interpolation operation based on the colorimetric value of the color characteristic profile of the electronic camera, and the RGB value The color characteristic profile of the monitor is created based on the measured colorimetric value.

  According to the present invention, even if the color characteristic profile of a digital camera (electronic camera) is unknown, the color characteristic profile of the monitor can be created using the digital camera. In addition, even when using a digital camera having only an automatic exposure determination function, shooting is performed with the same exposure under the same environment, so that it is possible to create a highly accurate monitor profile.

1st Embodiment Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. This embodiment shows an example in which the profile creation system of the present invention is applied to a color management system that creates a profile in monitor color management using a digital camera.

  FIG. 1 is an explanatory diagram showing a schematic configuration and a usage state of the color management system S according to the present embodiment.

  As shown in the figure, the color management system S connects a monitor 1 to be a color management target, a digital camera 2 as an example of an electronic camera, and the monitor 1 and the digital camera 2 to create a profile of the present invention. The computer 3 is an example of an apparatus, and includes an acquisition unit that acquires image data, a first and second color characteristic profile generation unit, and a computer 3 that functions as a storage unit.

  The electronic camera of the present invention is not limited to the digital camera 2, and a video camera, for example, may be applied.

  The material of the first chart printed on the print medium of the present invention may be any material such as paper or plastic. The printing according to the present invention may be performed by any printing method (offset, gravure, letterpress, ink transferred, etc.).

  The monitor 1 of the present invention reproduces color by additive color mixing of the three primary colors R (red), G (green), and B (blue), such as a color CRT, a color liquid crystal display device, and a color plasma display display device. Any display device can be used.

  Furthermore, the digital camera 2 may be of any kind, such as a high-end single-lens reflex type, a consumer type, or a portable camera, as long as it can resolve the chart.

  First, a specific method of monitor color management will be described with reference to FIGS.

  2A is a flowchart showing processing of the entire color management of the monitor 1, FIG. 2B is a flowchart showing photographing, and FIG. 2C is a flowchart showing creation of a digital camera profile. FIG. 2D is a flowchart showing the creation of the monitor profile.

  In the overall color management process of the monitor 1 shown in FIG. 2A, first, the monitor 1 and the chart are photographed by the digital camera 2 (step S11), and then the digital camera profile creation process is performed (step S12). Finally, monitor profile creation processing is performed (step S13).

  First, the process of photographing the monitor 1 and the chart with the digital camera 2 in step S11 will be specifically described with reference to the flowchart shown in FIG.

  First, chart data as an example of the second chart is displayed on the monitor 1 (step S21). The chart data displayed on the monitor 1 may be of any type as long as the profile of the monitor 1 can be created, but at least white, black, red, green, blue, red halftone, and green intermediate A patch of 8 colors of gray and blue halftone is required.

  Next, a chart of the digital camera 2 as an example of the first chart is installed beside the monitor 1 (step S22). This chart may be of any type as long as a digital camera profile can be created. For example, Digital Color Checker SG of Greatag Macbeth, Color Checker DC, etc. Further, since the amount of illumination varies depending on the angle at which the chart is installed, it is desirable to install the chart at a position horizontal to the display surface of the monitor 1. Finally, the monitor 1 and the chart are photographed simultaneously (step S23). Further, the position of the digital camera 2 is taken at a position perpendicular to the display surface of the monitor 1 and the chart surface so that the entire display surface of the monitor 1 and the chart fall within the screen. The exposure of the digital camera 2 may be performed manually with an appropriate exposure setting using an exposure meter. Moreover, you may shoot with exposure auto. The flash should not be used because the surface of the monitor 1 shines, but it may be used if measures are taken such as applying a film that does not reflect light.

  In FIG. 2B, the chart data is displayed on the monitor 1 (S21), and then the chart is placed beside the monitor 1 (S22). However, this order may be reversed.

  Next, the digital camera profile creation processing in step S12 will be specifically described with reference to the flowchart shown in FIG.

  First, a chart portion installed beside the monitor 1 is extracted from an image obtained by simultaneously capturing the monitor 1 and a chart placed beside the monitor 1 to obtain RGB values of each patch constituting the chart (step S31). Next, the colorimetric values (Lab) of the respective patches constituting the chart stored in advance (stored) in the storage means provided in the computer 3 are acquired, and the RGB values and the colorimetric values are obtained for each patch. The color characteristic profile (digital camera profile) of the association and digital camera is created (step S32). As a creation method, the digital camera 2 sends a photographed image to the computer 3 and creates a color characteristic profile of the digital camera in the computer 3. In order to send the captured image to the computer 3, the digital camera 2 and the computer 3 may be directly connected, or an image may be sent to the computer by using an external recording medium such as a USB memory. Table 1 shows an example of the created digital camera profile.

最後に、ステップＳ１３のモニタプロファイルの作成処理について、図２（Ｄ）に示すフローチャートを用いて具体的に説明する。

Finally, the monitor profile creation processing in step S13 will be specifically described with reference to the flowchart shown in FIG.

  First, a chart portion displayed on the monitor 1 is extracted from an image obtained by simultaneously photographing the monitor 1 and the chart, and RGB values of each color (each patch) of the chart are acquired based on the monitor output color component value (step S41). . Next, the colorimetric values (XYZ or Lab) of each color of the chart are interpolated from the acquired RGB values and the digital camera profile (see Table 1) showing the relationship between the created RGB values and the colorimetric values. Calculate (step S42). Finally, each RGB value acquired in step S41 and the colorimetric value (XYZ or Lab) calculated in step S42 are associated with each other to create a monitor color characteristic profile (monitor profile) ( Step S43).

  According to the above-described embodiment, the digital camera profile and the monitor profile can be captured at one time by simultaneously capturing the chart for creating the profile of the digital camera 2 and the chart of the color characteristic profile of the monitor 1 displayed on the monitor 1. Therefore, the monitor profile can be created even if the digital camera profile is unknown. In addition, even when the digital camera 2 having only the automatic exposure determination function is used, since the shooting is performed with the same exposure under the same environment, the monitor profile can be created with high accuracy.

  In addition, since the colorimetric values of the patches constituting the chart for creating the profile of the digital camera 2 are stored in advance in the storage means of the computer, the digital camera profile can be created easily and quickly.

  Further, since the colorimetric values corresponding to the RGB values of each color (each patch) of the chart are calculated by interpolating the colorimetric values of the digital camera profile, the colorimetric values of the color characteristic profile of the created electronic camera are calculated. Can be used to easily create a color characteristic profile of the monitor.

2 Second Embodiment FIG. 3 is an explanatory diagram showing a schematic configuration and a usage state of a color management system S according to a second embodiment. The color management system S according to the present embodiment is a system related to creation of a monitor profile via a network. As shown in the figure, the monitor 1, the digital camera 2, the monitor 1 and A computer 3 (an example of the terminal device of the present invention) that functions as a second color characteristic profile creating unit that connects the digital camera 2 and creates a color characteristic profile of the monitor 1, the barcode 4, and the color characteristics of the digital camera 2 The first color characteristic profile creating means for creating the profile and the server 5 as an example of the storage means (an example of the server device of the present invention) are configured.

  The digital camera 2 in the present embodiment has a function of reading the barcode 4, and any type such as a high-end single-lens reflex type, a consumer type, or a portable camera can be used as long as the chart can be resolved. . In addition, the digital camera 2 has a communication function, and can exchange information with the server 5 through a network. In FIG. 3, the digital camera 2 and the network are connected by wireless communication, but may be wired.

  The bar code 4 stores address information that enables communication with the computer 3 through the network. The barcode 4 may be of any standard such as a one-dimensional barcode and a two-dimensional barcode as long as the address information of the computer 3 can be input. Further, the position of the barcode 4 is not limited as long as it is a readable position such as in the chart, in the chart data displayed on the monitor 1 and printed and placed on the side.

  In the present embodiment, the address information is stored in the barcode 4, but the present invention is not limited to this, and a QR code or the like may be used as long as the address information can be stored. Since the configuration of other devices is the same as that of the first embodiment, description thereof is omitted.

  4A is a flowchart showing the overall color management process of the monitor 1 in this embodiment, FIG. 4B is a flowchart showing the photographing process, and FIG. 5C is executed by the server 5. FIG. 5D is a flowchart showing data transfer executed by the digital camera 2, and FIG. 5E is a monitor profile creation executed by the computer 3. It is a flowchart which shows.

  First, the process of photographing the monitor 1 and the chart with the digital camera 2 in step S51 will be specifically described with reference to the flowchart shown in FIG.

  First, the barcode 4 is installed within the range for photographing (step S61). As shown in FIG. 3, if it is installed as a tangible object, it is installed at a position where the stored information can be read. In the case of data, the information is input into the chart data displayed on the monitor 1. Next, chart data is displayed on the monitor 1 (step S62). Then, a chart is placed beside the monitor 1 (step S63). Since the processing in steps S62 and S63 is the same as that in the first embodiment, detailed description thereof is omitted.

  Finally, the monitor 1, the chart, and the barcode 4 are photographed simultaneously (step S64). In FIG. 4B, after the chart data is displayed on the monitor 1 (S62), the chart is placed beside the monitor 1 (S63), but this order may be reversed.

  Next, the digital camera 2 transmits the captured image data to the server 5 via the network (step S52). As a method of transmitting data to the server 5, there are two methods, a method of transmitting data to a known address and a method of acquiring and transmitting address information from the barcode 4.

  Then, a digital camera profile is created in the server 5 (step S53). A flowchart for creating a digital camera profile is shown in FIG.

  First, when the image data is acquired from the digital camera 2, the server 5 extracts the chart portion installed beside the monitor 1 and acquires the RGB value of each patch constituting the chart (step S71). Next, the colorimetric value (Lab) of each patch constituting the chart stored (stored) in advance in the storage means provided in the server 5 is acquired, and the RGB value and the colorimetric value for each patch are obtained. The color characteristic profile (digital camera profile) of the association and digital camera is created (step S72).

  Next, a flowchart for transmitting the digital camera profile in step S54 to the computer 3 is shown in FIG.

  First, the address information of the barcode 4 in the image data is read to acquire the address of the computer 3 (step S81), and the created digital camera profile is transmitted to the computer 3 via the network based on the address information (step S81). Step S82). At this time, image data obtained by simultaneously capturing the monitor 1 and the chart is also transmitted.

  Finally, the monitor profile creation process executed by the computer 3 in step S55 will be specifically described with reference to the flowchart shown in FIG.

  First, a chart portion displayed on the monitor 1 is extracted from an image obtained by simultaneously photographing the monitor 1 and the chart, and an RGB value of each color (each patch) of the chart is acquired based on the monitor output color component value (step S91). ). Next, a colorimetric value (XYZ or Lab) of each color of the chart is calculated by interpolation from the acquired RGB value and the digital camera profile indicating the relationship between the created RGB value and the colorimetric value (step S92). . Finally, each RGB value acquired in step S91 and the colorimetric value (XYZ or Lab) calculated in step S92 are associated with each other to create a monitor color characteristic profile (monitor profile) ( Step S93).

  In this embodiment, the server 5 functions as the server device of the present invention, and the digital camera profile is created by the server 5. However, the digital camera profile is created in the digital camera 2, and the barcode 4 is created by the digital camera 2. And the digital camera profile may be transmitted directly to the computer 3. In this case, the digital camera 4 functions as a server device in the present invention.

  According to the above-described embodiment, the server 5 obtains image data obtained by simultaneously photographing the chart printed on the print medium and the chart displayed on the monitor with the digital camera 2, and configures the chart in the image data. The RGB value of each patch is acquired, a color characteristic profile of the digital camera 2 is created based on the RGB value and the colorimetric value of each patch constituting the chart, and is transmitted to the computer 3. The computer 3 acquires the RGB values of each patch constituting the chart displayed on the monitor 1, and the RGB characteristics and the colorimetric values corresponding to the RGB values are transmitted from the server 5 to the color characteristics of the digital camera 2. Since the color characteristic profile of the monitor 1 is created based on the profile, the profile of the monitor 1 can be created via the network without connecting the digital camera 2 to the computer 3.

It is explanatory drawing which shows the outline of a structure of the color management system S which concerns on 1st Embodiment, and a use condition. (A) It is a flowchart which shows the color management whole process of the monitor 1 which concerns on 1st Embodiment. (B) It is a flowchart which shows an imaging | photography process. (C) It is a flowchart which shows a digital camera profile creation process. (D) It is a flowchart which shows a monitor profile creation process. It is explanatory drawing which shows the outline of a structure of the color management system S which concerns on 2nd Embodiment, and a use condition. (A) It is a flowchart which shows the color management whole process of the monitor 1 which concerns on 2nd Embodiment. (B) It is a flowchart which shows an imaging | photography process. (C) It is a flowchart which shows a digital camera profile creation process. (D) Flow chart of data transfer. (E) It is a flowchart which shows a monitor profile creation process.

Explanation of symbols

S Color management system 1 Monitor
2 Digital camera 3 Computer 4 Barcode 5 Server

Claims (3)

A profile creation system comprising a terminal device connected to a monitor and a server device connected to the terminal device,
The server device
Acquisition means for acquiring image data obtained by simultaneously photographing a first chart printed on a print medium and a second chart displayed on a monitor with an electronic camera;
An RGB value of each patch constituting the first chart portion in the image data is obtained, and color characteristics of the electronic camera are obtained based on the RGB value and a colorimetric value of each patch constituting the first chart. First color characteristic profile creation means for creating a profile;
Transmitting means for transmitting the created color characteristic profile of the electronic camera to the terminal device,
The terminal device
Receiving means for receiving a color characteristic profile of the electronic camera transmitted from the server device;
The RGB value of each patch constituting the second chart portion displayed on the monitor in the image data is acquired, and the color characteristic profile of the monitor is obtained based on the RGB value and the color characteristic profile of the electronic camera. Second color characteristic profile creation means for creating,
The profile creation system characterized in that the electronic camera has address transmission means for photographing address information for communication with the terminal device and transmitting it to the server device . The profile creation system according to claim 1,
The server device
Storage means for storing the colorimetric values of each patch constituting the first chart;
The first color characteristic profile creating means includes an RGB value of each patch constituting the first chart portion and a colorimetric value of each patch constituting the first chart acquired from the storage means. A profile creation system that creates a color characteristic profile of the electronic camera based on the profile. The profile creation system according to claim 1 or 2,
The second color characteristic profile creating means obtains a colorimetric value corresponding to the RGB value of each patch constituting the second chart portion displayed on the monitor, as a colorimetric value of the color characteristic profile of the electronic camera. The profile creation system is characterized in that a color characteristic profile of the monitor is created based on each of the RGB values and the calculated colorimetric value, each of which is calculated by performing an interpolation operation on the basis of.

Images