JP2000341499A - Color reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color reproducing apparatus which can reproduce with accuracy colors of all objects contained in an image. SOLUTION: A color reproducing device is provided with an object recognizing section 201, which divides an inputted image into a plurality of areas and selects appropriate input profiles from a plurality of input profiles by every divided area, a device independent color converting section 202 which converts the images in each area into device independent color images by using an input profile selected from among the plurality of input profiles, and an image compositing section 203 which composites the device independent color images converted at every area into one device independent color picture. The device is also provided with a device value converting section 204, which converts the composite device independent color image into an output image by using a prescribed output profile.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color reproducing apparatus, and more particularly to a color reproducing apparatus for accurately reproducing the color of an image of an object input by an image input device.

[0002]

2. Description of the Related Art FIG. 23 is a diagram showing a configuration of a conventional color reproducing apparatus. In FIG. 23, an input image from the image input device 10 is input to a device independent color conversion unit 11A of the color correction unit 11. The device independent color conversion unit 11A converts the color of the input image into a device independent color image with reference to the input profile 111A, and outputs the device independent color image to the device value conversion unit 11B. The device value converter 11B outputs the output profile 1
11B, the device-independent color image is converted into a device value that matches the characteristics of the output device, and output to the image output device 12 as an output image.

[0003] Japanese Patent Publication No. 2678007 discloses that in reading a color image, a plurality of pieces of read information indicating respective color components of a plurality of colors are read based on color correction parameters. A color information correction device for correcting recording information is disclosed.

[0004] Japanese Patent Publication No. 2681181 discloses a color data correction apparatus including a calculation means for performing a matrix calculation on color data obtained by digitizing an input signal and performing color correction.

[0005]

In the conventional color reproduction method of the above-described color reproduction apparatus, one set of an appropriate input profile and output profile is selected and processed for one input image. However, since color reproduction is performed using the same subject characteristic data for all of the images, that is, the object spectrum statistical data, the conversion accuracy decreases when a plurality of objects are photographed in the image. .

[0006] Also, Japanese Patent Publication No. 2678007 described above.
In Japanese Patent Application Laid-Open No. H08-218181 and Japanese Patent Publication No. 2681181, a matrix is selected in accordance with the color of RGB values. However, only a color correction is performed, and a color is not converted into a color under illumination light on the observation side. Further, since the subject characteristic data is not used, color reproduction cannot be performed accurately.

The present invention has been made in view of such a problem, and an object thereof is to divide an image into a plurality of regions and perform appropriate color conversion for each of the divided regions. Accordingly, an object of the present invention is to provide a color reproduction device capable of accurately performing color reproduction for all objects in an image.

Another object of the present invention is to provide a color reproducing apparatus capable of accurately recognizing an object in a captured image and performing color conversion with high accuracy by performing color conversion suitable for the object. is there.

Further, the present invention captures a color chart having a known spectral reflectance and calculates subject characteristics from a spectral reflectance of a color chart close to a signal value at the time of capturing an object, thereby obtaining subject characteristic information. It is an object of the present invention to provide a color reproduction device capable of performing color reproduction with high accuracy without previously having a color reproduction device.

[0010]

In order to achieve the above object, a color reproducing apparatus according to a first aspect of the present invention provides a color reproducing apparatus which performs a predetermined color correction on an image input by an image input apparatus and outputs the corrected color. A reproducing apparatus, which divides an input image into a plurality of regions, an object recognition unit that selects an appropriate input profile from a plurality of input profiles for each of the divided regions, and the plurality of input profiles. A device-independent color conversion unit that converts an image of each area into a device-independent color image using an input profile selected from among the device-independent color image, and a device-independent color image that is converted for each area. An image synthesizing unit for synthesizing with a device independent color image,
A device value conversion unit that converts the synthesized device independent color image into an output image using a predetermined output profile.

According to a second aspect of the present invention, there is provided a color reproducing apparatus for performing a predetermined color correction on an image input by an image input apparatus and outputting the corrected image, wherein the input image is divided into a plurality of areas, Selects an appropriate input / output profile from multiple input / output profiles for each divided area, and selects from multiple input / output profiles created by integrating input and output profiles A device value conversion unit that converts an image of each area into an output image using the input / output profile, and an image synthesis unit that synthesizes the output image converted for each area into one output image.

According to a third aspect of the present invention, there is provided a color reproducing apparatus for performing a predetermined color correction on an image input by an image input apparatus and outputting the corrected image, the input apparatus including information necessary for creating a plurality of input profiles. An object recognizing unit that divides an image into a plurality of regions and selects a subject characteristic for each of the divided regions; and a format that performs format conversion based on the selected subject characteristics and outputs variable illumination image data for each region. A conversion unit for selecting an input profile calculated from the illumination variable image data from a plurality of input profiles, and converting an image of each region into a device independent color image using the selected input profile; Independent color conversion unit and device independent color image converted for each area Comprising an image synthesizing unit for synthesizing the down de independent color image, a combined device-independent color image by using a predetermined output profile and the device value converter for converting the output image.

According to a fourth aspect of the present invention, there is provided a color reproducing apparatus for performing predetermined color correction on an image input by an image input device and outputting the corrected image, wherein the input image is divided into a plurality of areas. A dividing unit, a device-independent color conversion unit that converts each of the images of the divided regions into a device-independent color image in parallel using a plurality of input profiles, and a plurality of device-independent converted images. A conversion result selection unit that compares the dent color images and selects a device independent color image for each area, and combines the selected device independent color image for each area into one device independent color image An image synthesis unit that converts the synthesized device-independent color image into an output image using a predetermined output profile. Comprising a device value conversion unit that.

According to a fifth aspect of the present invention, there is provided a color reproducing apparatus for performing a predetermined color correction on an image input by an image input device and outputting the corrected image, wherein the input image is divided into a plurality of areas. A dividing unit, a first device-independent color conversion unit that converts an image of each of the divided regions into a device-independent color image using one input profile, and a device-independent color conversion unit. A second device-independent color conversion unit that converts an image of each area into a device-independent color again using an input profile selected from a plurality of input profiles based on the conversion result; An image synthesizing unit for synthesizing a device-independent color image for each area, and a synthesized device-independent color Comprising a device value converter for converting the output image by using a predetermined output profile image.

According to a sixth aspect of the present invention, there is provided a color reproducing apparatus for performing a predetermined color correction on an image input by an image input apparatus and outputting the corrected image, wherein the input image is divided into a plurality of areas. A dividing unit, a first device-independent color conversion unit that converts an image of each divided region into a device-independent color image using one input profile, and information on spectral reflectances of a plurality of types of objects , A conversion result determination unit that determines a conversion result in the first device-independent color conversion unit with reference to the spectral reflectance database, and a result of the conversion result determination unit. A subject characteristic information calculation unit that selects information of the spectral reflectance database based on and calculates subject characteristic information; and a determination result of the conversion result determination unit. A second device-independent color for converting an image of each area into a device-independent color again using an input profile selected from a plurality of input profiles created using the subject characteristic information calculated in the second step; A conversion unit, an image synthesis unit that synthesizes the converted device independent color image for each area, and a device value conversion that converts the synthesized device independent color image into an output image using a predetermined output profile Part.

According to a seventh aspect of the present invention, there is provided a color reproducing apparatus for performing a predetermined color correction on an image input by an image input device and outputting the corrected image, wherein a plurality of color patches having known spectral reflectances are used. An object recognizing unit that selects an input profile to be used based on the signal value of the image captured by the user from a plurality of input profiles, and an image of each area using the input profile selected from the plurality of input profiles. A device-independent color image that converts the device-independent color image into a device-independent color image, an image synthesis unit that synthesizes the device-independent color image converted for each region into one device-independent color image, Value conversion unit for converting the converted device-independent color image into an output image using a predetermined output profile Comprising a.

According to an eighth aspect of the present invention, there is provided a color reproducing apparatus for performing a predetermined color correction on an image input by an image input device and outputting the corrected image, wherein the spectral reflectance having spectral reflectance data of a color chart is provided. A database, a signal value of an image captured using a plurality of color patches having known spectral reflectances, and a subject characteristic information calculation unit that calculates subject characteristic information from the color patch captured image using data of the spectral reflectance database And an object recognition unit that divides the region of the object photographed image and selects an input profile to be used from among a plurality of input profiles created using the calculated object characteristic information; and A device-independent color conversion unit that converts an image of each area into a device-independent color image using an input profile selected from among them, An image synthesizing unit that synthesizes the device-independent color image converted for each area into one device-independent color image, and converts the synthesized device-independent color image into an output image using a predetermined output profile And a device value conversion unit.

In a ninth aspect based on any one of the first to eighth aspects, the input profile includes information relating to a photographing characteristic of the image input device used for photographing and a setting state of the image input device. , Illumination light information when photographing an image of the object to be photographed by the image input device, observation illumination light information of a place where the image of the object to be photographed is to be observed, and an object to be photographed. At least one of the object characteristic information indicating the statistical property of the spectral reflectance of the object
One is created based on one.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a diagram showing a configuration of a color reproducing apparatus according to a first embodiment of the present invention. Color correction unit 2 that performs correction on the image to generate an output image
00 and an image output device 300.

In the color correction section 200, the object recognition section 2
01 recognizes an object in the input image. That is, the area dividing unit 201-1 of the object recognizing unit 201 performs a process of dividing the input image into a plurality of areas. The input profile selection unit 201-2 selects an appropriate input profile from the plurality of input profiles for each of the divided areas by switching the switch 205. The device independent color conversion unit 202 has a storage unit for storing a plurality of input profiles 1 to N (2021 to 202N), and the input profile selection unit 201
-2, a plurality of input profiles 1 to N (2021 to N
202N), the image of each area is converted into a device-independent color image using the input profile selected from the input profile. The image synthesizing unit 203 synthesizes the device-independent color image converted for each area into one device-independent color image. The device value conversion unit 204 converts the synthesized device independent color image into an output image with reference to the output profile 2040.

FIG. 2 is a diagram showing a detailed configuration of the device independent color conversion unit 202. In addition to the above-mentioned storage unit for storing a plurality of input profiles 1 to N (2021 to 202N), the device independent color conversion unit 202 is used for photographing. Observe the characteristics and settings of the image input device that was used (image input device information), the spectral data of the illumination light when the image of the target object is captured by the image input device (photographing illumination light information), and the captured image of the target object. Spectral data of the illumination light at the place you want (observation illumination light information)
And at least one of information (subject characteristic information) such as statistical properties of the spectral reflectance of the photographed object,
Input profile creation unit 2 for calculating an input profile
031, an input profile operation unit 2030 that converts the created input profile to an input image divided for each area and converts it into a device independent color image
Consists of

FIG. 3 is a diagram showing a detailed configuration of the device value conversion unit 204. The device value conversion unit 204 is configured to convert an input image output device information (image output device information) into an output profile 2042.
And an output profile operation unit 2041 that operates the device-independent color image to convert the generated output profile 2042 into an output image.

By using the above-mentioned image input device information, an input image can be converted into a device independent color image in consideration of differences in individual characteristics of various image input devices and differences in settings at the time of photographing. Even if the image input device 100 is a multispectral camera that captures a plurality of spectral images, or a digital camera, accurate color reproduction can be performed.

Further, by using the photographing illumination light information, the influence of the illumination light at the time of photographing can be canceled. That is, even if the object is photographed under any illumination light (for example, a fluorescent lamp, an incandescent lamp, or sunlight), an accurate spectral reflectance of the object itself can be calculated.

Further, by using the observation illumination light information, it is possible to convert the photographed object into a color under an arbitrary illumination. For example, it is possible to display a color as if there is an object at the observation place by remotely reproducing the color at the observation place where the illumination light is different.

Further, by using the subject characteristic information, a color reproduction image can be accurately estimated even if the input image has only a small amount of spectrum information. In other words, the spectral reflectance of the object can be accurately estimated not only by a multispectral camera in which the image input device can capture a plurality of spectral images, but also by a digital camera that captures a color image in three RGB bands. The subject characteristic information may be a correlation matrix representing a statistical property of the spectral reflectance or a basis function.

Further, by using the image output device information, a device independent color image can be accurately converted into an output image suitable for the image output device 300. This enables color reproduction taking into account differences and variations in characteristics between monitors and printers.

As described above, in the present embodiment, the input image is divided into a plurality of regions, and which input profile is used for each of the divided regions is selected from the plurality of input profiles. Then, using the selected input profile, the input image is converted into a device independent color image. As described above, the object to be photographed in the image can be accurately determined, and an input profile suitable for the characteristics of the subject according to the object can be used. Therefore, color reproduction can be accurately performed over the entire image.

FIG. 4 is a modification of the first embodiment, and shows an example of an image processing apparatus in which a plurality (1 to N) of input profiles are prepared using subject characteristic information.
Usually, it is difficult to photograph only the object that the user wants to photograph, and the background and other objects are also included in the image. If the color reproduction process is performed using only an input profile using one piece of subject characteristic information, the color of the desired object is converted with high accuracy, but the color of the background and other objects becomes inaccurate.

The color correction unit 200 shown in FIG.
A plurality of input profiles 2021 to 202N using animals, plants, and various types of subject characteristic information are prepared.
The object recognizing unit 201 determines from the signal values of the input image what is being photographed in a certain area in the image, and selects an appropriate input profile from a plurality of input profiles. Device independent color converter 2
No. 02 creates a device independent color image by applying an input profile selected from a plurality of input profiles 2021 to 202N to an input image. Note that a plurality of subject characteristic information classified according to the color of the target object or according to the constituent substances may be prepared.

It is assumed that the spectral reflectance space of the subject is distributed in the multidimensional space of the spectrum as shown in FIG.
In FIG. 5, h (λ) is the spectral sensitivity of the camera. h
In (λ), the spectral reflectance of the object taking the value of the signal value p1 is
Represents all points on a vertical line from h (λ). When only one piece of subject information is used as in the related art, p2 of the subject A and p3 of the subject B have the same signal value. Therefore, estimation of the spectral reflectance of the subject from the signal value results in the same result. I will.

Therefore, as in this embodiment, if two sets of subject characteristic information are used for subject A and subject B, spectral reflectances p2 and p3 can be estimated from the same signal value p1. As described above, the spectral reflectance of the subject can be accurately estimated by using the plurality of subject characteristics.

(Second Embodiment) FIG. 6 is a diagram showing the configuration of a color reproduction apparatus according to a second embodiment of the present invention. Color correction unit 2 that performs correction on the image to generate an output image
20 and an image output device 300.

In the color correction section 220, the object recognition section 2
21 recognizes an object in the input image. That is, the region dividing unit 221-1 of the object recognizing unit 221 performs a process of dividing the input image into a plurality of regions. The input / output profile selection unit 221-2 selects an appropriate input / output profile by switching the switch 224 from a plurality of input / output profiles for each of the divided areas. The device value conversion unit 222 has a storage unit for storing a plurality of input / output profiles 1 to N (2221 to 222N), and a plurality of input / output profiles 1 to N (2221 to 222) by an input / output profile selection unit 221-2. 222
The image of each area is converted into a device independent color image using the input / output profile selected from N). The image combining unit 223 combines the device-independent color image converted for each area into one device-independent color image. The device value conversion unit 204 converts the synthesized device independent color image into an output image with reference to the output profile 2040.

FIG. 7 is a diagram showing a detailed configuration of the device value conversion section 222. The image input device 100 uses the characteristics and settings (image input device information) of the image input device used for photographing and the image of the object by the image input device 100. The spectral data of the illumination light at the time of photographing (photographing illumination light information), the spectral data of the illumination light at the place where the image of the photographed object is to be observed (observation illumination light information), and the spectral reflectance of the photographed object An input profile creation unit 2270 that calculates an input profile from at least one of information such as statistical properties (subject characteristic information) and an output profile from information (image output device information) about an input image output device. An output profile creation unit 2260 for calculating, and an input for creating an input / output profile by combining the created input profile and output profile. Power profile creating section 2240
And an input / output profile operation unit 223 that operates the generated input / output profile on the input image and converts it into an output image.
Consists of zero.

By using the input / output profile obtained by synthesizing the input profile and the output profile of the first embodiment, it is possible to convert the input image into an output image in which the color is reproduced at a higher speed.

FIG. 8 shows a modification of the second embodiment. Usually, it is difficult to photograph only the object that the user wants to photograph, and the background and other objects are also included in the image. When color reproduction processing is performed using only an input / output profile using one object characteristic information as in the related art, the color of the desired object is accurately converted, but the color of the background and other objects is inaccurate. turn into.

The color correction unit 220 shown in FIG.
A plurality of input / output profiles 2221 to 222N using animals, plants, and various types of subject characteristic information are prepared. The object recognition unit 221 determines from the signal values of the input image what is being photographed in a certain area in the image, and selects an appropriate input / output profile from a plurality of input / output profiles. Input / output profile operation section 22
2 creates a device independent color image by applying an input / output profile selected from a plurality of input / output profiles 2221 to 222N to an input image.

(Third Embodiment) FIG. 9 is a diagram showing a configuration of a color reproduction apparatus according to a third embodiment of the present invention. Illumination conversion image data (illumination variable image data for each area) 2
A color correction pre-processing unit 240 for converting the image into an input profile from the variable illumination image data, converting the input profile to a device independent color image, and then converting the image to an output image suitable for an image output device. And an image output device 300 that outputs (displays and prints) an output image.

The third embodiment is characterized in that an input image has information necessary for creating a plurality of input profiles, and has a data structure capable of performing illumination conversion using another input profile according to a region in the image. And That is, the input image has any one of image input device information, photographing illumination light information, observation illumination light information, and a plurality of subject characteristic information necessary for creating an input profile in addition to the image data of the subject.

In the pre-color correction processing section 240, the area dividing section 241 of the object recognizing section 241 performs a process of dividing the input image into a plurality of areas. Subject characteristic selection unit 24
1-2 selects a specific subject characteristic among a plurality of subject characteristics included in the input image. The format conversion unit 242 performs format conversion based on the selection result of the photographing illumination light spectrum data selection unit 243, and outputs the converted data as illumination variable image data 244 for each area.

In the color correction section 245, the input profile calculation section 251 calculates an input profile from the illumination variable image data for each area. The device independent color conversion unit 246 converts a plurality of input profiles 1 to N (2461 to 246) corresponding to the calculated input profiles.
By switching the switch 250 from among N), the variable illumination image data 244 for each area is converted into a device independent color image using the input profile selected. The image synthesizing unit 248 synthesizes a device independent color image for each area. The device value conversion unit 249 uses the output profile 2490 to convert to an output image suitable for the image output device.

FIG. 10 is a diagram showing an example of the format of the above-mentioned area-specific illumination variable image data 244. The header includes information such as a marker, a format version, an image size, an image dimension, and an image area. 244-
1, shooting characteristic information 244-2 such as camera spectral sensitivity, shooting shutter speed, and shooting aperture information; shooting illumination light information 244-3 such as a start wavelength, an end wavelength, a wavelength interval, and spectrum data; An area table 244-4 storing information on whether the object belongs to an area (which object spectrum statistical data is to be used), and object characteristic information 1 (244) including an object basis function and eigenvalue data 1
-5), subject characteristic information 2 (244-6) including the object basis function and the eigenvalue data 2, and subject characteristic information 3 (244-) including the object basis function and the eigenvalue data 3.
7), and image data 244-8 of monochrome image × number of image dimensions. In the present embodiment, processing is performed in parallel using three pieces of subject characteristic information, but more pieces of subject characteristic information may be used.

(Fourth Embodiment) FIG. 11 is a view showing a configuration of a color reproducing apparatus according to a fourth embodiment of the present invention. An image input apparatus 100 for photographing an image of an object and a color correction section 26 are shown.
0 and an image output device 300 that outputs (displays and prints) an output image.

The fourth embodiment is characterized in that after an input image is divided into a plurality of regions, the image in each region is converted into a device-independent color image in parallel using a plurality of input profiles. .

In the color correcting section 260, the area dividing section 26
1 divides an input image into a plurality of regions. The device independent color conversion unit 262 converts the image data for each area into a plurality of input profiles 1 to 3 (2621 to 2611).
2623) to convert to a device independent color image. The conversion result selection unit 263 selects one device independent color image by comparing the results 1, 2, and 3 of the device independent color images converted by the plurality of input profiles. The image synthesizing unit 264 synthesizes a device independent color image selected for each area.

The device value converter 265 uses the output profile 2650 to convert the output image into an output image suitable for the image output device.

For example, the color of the human skin and the cloth
As shown in FIG. 12, when viewed from the color space of various objects in the natural world, it is a limited small space. Therefore, even if a specific subject is reproduced using comprehensive subject characteristic information of an object in the natural world, the color reproduction error is small, but conversely, if other objects are reproduced using the specific subject characteristic information, The color reproduction error increases.

FIG. 13 is a flowchart showing details of an algorithm for performing the processing of this embodiment. The threshold value used below is an example and is not limited to this. The color difference 3.2 is a color difference in the L * a * b * space, and is a color difference (color difference) that cannot be distinguished from a different color when a person is away. In the present embodiment, processing is performed in parallel using three pieces of subject characteristic information, but more pieces of subject characteristic information may be used.

First, a chromaticity value is calculated from the comprehensive subject characteristic information (step S1). Next, specific subject characteristic information 1
Is used to calculate a chromaticity value (step S2). Next, a chromaticity value is calculated using the specific subject characteristic information 2 (step S3). Next, the color difference between the chromaticity value obtained in step S1 and the chromaticity value obtained in step S2 is a threshold (ΔE3.
2) It is determined whether it is within the range (step S4). If YES, the result of the specific subject characteristic information 1 is used (step S8) to perform image synthesis (step S9).

If the determination in step S4 is NO, it is determined whether or not the color difference between the chromaticity value obtained in step S1 and the chromaticity value obtained in step S3 is within a threshold value (ΔE3.2). Judgment is made (step S5), and in the case of YES, the result of the specific subject characteristic information 2 is used (step S6),
Image synthesis is performed (step S9). Step S
If the determination at 5 is NO, image synthesis is performed using the result of the comprehensive subject characteristic information (step S7) (step S9).

(Fifth Embodiment) FIG. 14 is a view showing the configuration of a color reproduction apparatus according to a fifth embodiment of the present invention. The image processing apparatus includes a color correction unit 280 that performs correction on the image to generate an output image, and an image output device 300 that outputs (displays and prints) the output image.

The fifth embodiment is characterized in that after an input image is divided into a plurality of regions, the image is hierarchically converted into a device independent color image using a plurality of input profiles.

In the color correction section 280, the area dividing section 28
1 divides an input image into a plurality of regions. The device-independent color conversion unit 1 (282) first converts the divided image into one input profile 1 (28).
Convert to a device independent color image using 1). The conversion result determination unit 283 determines which of a plurality of input profiles to use from the conversion result of the device independent color conversion unit 1 (282). The device-independent color conversion unit 2 (284) switches 287 according to the determination result of the conversion result determination unit 283.
By switching the input profiles 2, 3 (28
41, 2842), the region-divided input image is converted again into a device-independent color image. Image synthesis unit 285
Synthesizes a device independent color image for each region.

The device value conversion unit 286 converts the output image into an output image suitable for the image output apparatus using the output profile 2860.

FIG. 15 is a flowchart showing details of the algorithm for performing the processing of this embodiment. First, a chromaticity value is calculated using comprehensive subject characteristic information of a natural object (step S20). Next, it is determined whether or not the calculated chromaticity value is sufficiently close to the chromaticity value of the specific subject 1 (for example, human skin color) (step S21), and in the case of YES, the specific subject characteristic information 1 is used. The chromaticity value is calculated (Step S25). Next, image synthesis is performed using the result of the specific subject characteristic information 1 (step S26) (step S24).

If the determination in step S21 is NO, it is determined whether or not the chromaticity value is sufficiently close to the chromaticity value of the specific subject 2 (step S22). Is used to calculate the chromaticity value (step S27). Next, image synthesis is performed using the result of the specific subject characteristic information 2 (step S28) (step S2).
9).

If the determination in step S22 is NO, the result of the comprehensive subject characteristic information is used (step S23), and image synthesis is performed (step S24).

That is, in the present embodiment, a chromaticity value is calculated using comprehensive subject characteristic information of a natural object, and whether or not the chromaticity value is close to a specific subject 1 (for example, human skin color) is determined. Alternatively, the conversion result determination unit 283 checks whether the chromaticity value of the specific subject 2 (for example, the color of the fabric) is sufficiently close. If the image is sufficiently close to the specific object, the area image is converted again into a device independent color image using the input profile calculated based on the specific object characteristic information corresponding to the specific object. Otherwise, a conversion result using an input profile calculated based on the comprehensive natural object characteristics is used.

In this embodiment, an example is shown in which conversion is performed in two layers using one piece of comprehensive subject information and two pieces of specific subject information.
Further, the processing may be performed hierarchically in several stages.

(Sixth Embodiment) FIG. 16 is a view showing a configuration of a color reproducing apparatus according to a sixth embodiment of the present invention. The image processing apparatus includes a color correction unit 310 that performs correction on the image to generate an output image, and an image output device 300 that outputs (displays and prints) the output image.

The present embodiment is characterized in that a spectral reflectance database is provided, and subject characteristic information is calculated from spectral reflectance data for each input image and used.

In the color correction section 310, the area dividing section 31
1 divides an input image into a plurality of regions. The device independent color conversion unit 1 (312) as the spectral reflectance estimating unit first uses the image divided into the regions as one input profile 1 (3
121), the spectral reflectance is converted into a device-independent color image in which the spectral reflectance is estimated.

The conversion result determination unit 313 stores a spectral reflectance database 317 in which spectral reflectances of various objects are registered.
And the device independent color conversion unit 1 (31
From the result of 2), the hue of the closest data is examined by comparing with the spectral reflectance stored in the spectral reflectance database 317.

The subject characteristic information calculation section 316 selects data from the spectral reflectance database 317 based on the result of the conversion result determination section 313, calculates subject characteristic data, and inputs the data to the device independent color conversion section 2 (315). . The device independent color conversion unit 2 (315) as the spectral reflectance estimating unit 2 calculates an input profile 2 (basis of a red natural object) 3152 and an input profile 3 (blue natural object) from the calculated subject characteristic data. A base unit 3153 and an input profile 4 (base of a green natural object) 3154 are provided, and a storage unit that can store them is provided. By switching the switch 324 according to the determination of the conversion result determination unit 313, the input image that has been region-divided using the input profile selected from the plurality of input profiles 2 to 4 (3152 to 3154) is again device indexed. Pendant color image 1
Convert to This is input profile 2, 3, or 4
Is the spectral reflectance estimated by

Here, the above four input profiles 1
(3151), 2 (3152), 3 (3153), 4
(3154) is created based on the settings from the photographing-side illumination light setting unit 314 and the image input device characteristic setting unit 318, and subject characteristic information calculated from data in the spectral reflectance DB.

The device independent color conversion unit 3 (319) as an illumination conversion unit
Referring to (illumination conversion), the device-independent color image 1 is converted into a device-independent color image 2 which is a chromaticity value subjected to illumination conversion by the input profile 5.
Convert to Here, the input profile 5 is created from input profile calculation data from the observation-side illumination light setting unit 320.

The image synthesizing unit 322 synthesizes the device independent color image 2 for each input area. The device value conversion unit 323 converts the synthesized image into an output image suitable for the device with reference to the output profile 3230. Here, the output profile 3230 is created based on output profile calculation data set from the image output device characteristic setting unit 321. Device value converter 323
Is output to the image output device 300.

The subject characteristic information may be a correlation matrix representing the statistical property of the spectral reflectance or a basis function.

(Seventh Embodiment) FIG. 17 is a view for explaining a seventh embodiment of the present invention. In the seventh embodiment,
A color chart 400 having a known spectral reflectance is transferred to a digital camera 40.
The input profile selection unit 402 inputs the color chart photographed image 401 photographed in Step 6, selects an input profile 403 to be used at the time of illumination conversion of the photographed object image from the signal value thereof, and inputs the selected input profile to the input profile action unit 404. At the same time, an object photographed image 407 obtained by photographing the object 405 by the digital camera 406 is input to the input profile action unit 404. Input profile action section 4
Reference numeral 04 denotes an input profile 403 of the object photographed image 4
07 to convert to a device independent color image.

FIG. 18 is a diagram showing a configuration of a color reproduction apparatus according to a seventh embodiment of the present invention. The image input apparatus 100 captures an image of an object and a color chart, a color correction section 330, and an output image. And an image output device 300 that outputs (displays and prints) the image.

In the color correction section 330, the image type selection section 331 selects the type of the image. Object recognition unit 332
Divides the region of the object photographed image and selects an input profile to be used from a plurality of input profiles by referring to the signal values of the color chip photographed image and the object photographed image. The input profile creation unit 336 of the device independent color conversion unit 333 creates a plurality of input profiles 3351 to 335N to be selected by the object recognition unit 332. The input profile operation unit 334 operates the input profile selected by switching the switch 332-1 among the plurality of input profiles 1 to N (3351 to 335N) on the object photographed image to convert the device independent color image. create. Image synthesis unit 33
7 synthesizes a device independent image for each area. The device value converter 338 outputs the output profile 3
Referring to 380, the output image is converted to an output image suitable for the device.

Here, it is assumed that the spectral reflectance space of the subject is distributed in the multidimensional space of the spectrum as shown in FIG. At this time, the spectral reflectance of the object taking a certain signal value at the spectral sensitivity h (λ) of the camera represents all points on a line perpendicular to h (λ).

In the case where one conversion matrix is used in the whole range of the signal value of the camera as in the related art, after projecting the spectral reflectance space of the subject onto one axis having poor linearity, the spectral It will project on the sensitivity h (λ). Therefore, in the present embodiment, by exchanging the conversion matrix to be used depending on the signal value, the projection is performed on a plurality of axes having good linearity, so that the accuracy is improved.

(Eighth Embodiment) FIG. 20 is a view for explaining an eighth embodiment of the present invention. In the eighth embodiment,
A color chart 500 having a known spectral reflectance is transferred to a digital camera 508.
Is input to the subject characteristic information calculation unit 503. The subject characteristic information calculation unit 503 calculates subject characteristic information based on the data of the color chart spectral reflectance database (DB) 502. The input profile creation unit 504 converts the illumination of the captured object image 509 based on the calculated object characteristic information.
05 is created. Here, the object photographed image 509 is obtained by photographing the object 506 with the digital camera 508. The input profile operation unit 507 applies the input profile 505 to the object photographed image 509 and outputs a device independent color image.

FIG. 21 is a diagram showing the configuration of a color reproduction apparatus according to the eighth embodiment of the present invention. The image input apparatus 100 for photographing an image of an object, a color correction section 430, and an output image are output ( (Display and print).

In the color correction section 430, an image type selection section 431 selects an image type. The object recognition unit 432 divides the object photographed image into regions and selects an input profile to be used from a plurality of input profiles based on the divided object photographed images. The input profile creation unit 436 of the device independent color conversion unit 433 creates the input profiles 1 to N (4351 to 435N) to be selected by the object recognition unit 432. Here, in the present embodiment, the image type selection unit Subject characteristic information is calculated based on the color chart photographed image selected in 431 and the data in the spectral reflectance database 438, and is provided to the input profile creating unit 436.
Is provided.

The input profile operation section 434 operates the input profile selected by switching the switch 432-1 among the created input profiles 1 to N (4351 to 435N) on the photographed image of the object, and performs device independence. Create a dent color image. The image synthesizing unit 439 synthesizes a device independent color image for each area. The device value conversion unit 440 converts the synthesized image into an output image suitable for the device with reference to the output profile 4400.

In this embodiment, the signal value of the color chart photographed image is checked, and if the signal value is close to the signal value of the object photographed image, object characteristic information is calculated from the spectral reflectance of the color chart. Since the subject characteristics are calculated for each input image without the subject characteristic information, the color reproduction process can be performed with high accuracy. Note that the subject characteristic information may be a correlation matrix representing a statistical property of the spectral reflectance or a basis function.

(Ninth Embodiment) A ninth embodiment of the present invention will be described below with reference to FIG. The ninth embodiment is characterized in that color reproduction is performed using a program for realizing an area-specific illumination conversion process as one function of digital camera image processing software.

In FIG. 22, first, the digital camera 60
0, read the image file taken and display screen 601
And a predetermined area is designated with a mouse or the like to perform area division. Alternatively, the area may be automatically divided using the RGB value ratio. Thereafter, the user selects information such as subject characteristic information and observation illumination light, and performs appropriate illumination conversion at each pixel in the image. By repeatedly performing such area designation and illumination conversion on the same image to perform illumination conversion for each area, and combining images of the respective areas, accurate color correction can be realized.

[0083]

According to the present invention, an image is divided into a plurality of regions, and appropriate color conversion is performed for each of the divided regions, so that color reproduction can be accurately performed for all objects in the image. A color reproduction device that can be performed is obtained.

Further, since the object in the photographed image is accurately recognized and the color conversion is performed according to the object, a color reproducing apparatus capable of performing color reproduction with high accuracy can be obtained.

Further, a color chart whose spectral reflectance is known is photographed,
Since the subject characteristics are calculated from the spectral reflectance of the color chip close to the signal value at the time of photographing the target object, a color reproduction device that can accurately perform color reproduction without having the subject characteristic information in advance is provided. can get.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a color reproduction device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a color reproduction device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a detailed configuration of a device value conversion unit 204.

FIG. 4 is a diagram showing a configuration of a modification of the first embodiment.

FIG. 5 is a diagram showing a distribution of a spectral reflectance space of a subject in a multidimensional space of a spectrum.

FIG. 6 is a diagram illustrating a configuration of a color reproduction device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a detailed configuration of a device value converter 222.

FIG. 8 is a diagram illustrating a configuration of a modification of the second embodiment.

FIG. 9 is a diagram illustrating a configuration of a color reproduction device according to a third embodiment of the present invention.

FIG. 10 is a diagram showing a format of region-specific illumination variable image data 244.

FIG. 11 is a diagram illustrating a configuration of a color reproduction device according to a fourth embodiment of the present invention.

FIG. 12 is a diagram showing a distribution of a specific color space in a color space of various objects in the natural world.

FIG. 13 is a flowchart showing details of an algorithm for performing the processing of the fourth embodiment.

FIG. 14 is a diagram illustrating a configuration of a color reproduction device according to a fifth embodiment of the present invention.

FIG. 15 is a flowchart showing details of an algorithm for performing the processing of the fifth embodiment.

FIG. 16 is a diagram illustrating a configuration of a color reproduction device according to a sixth embodiment of the present invention.

FIG. 17 is a diagram for explaining a seventh embodiment of the present invention.

FIG. 18 is a diagram illustrating a configuration of a color reproduction device according to a seventh embodiment of the present invention.

FIG. 19 is a diagram showing a distribution of a spectral reflectance space of a subject in a multidimensional space of a spectrum.

FIG. 20 is a diagram for explaining an eighth embodiment of the present invention.

FIG. 21 is a diagram illustrating a configuration of a color reproduction device according to an eighth embodiment of the present invention.

FIG. 22 is a diagram illustrating a ninth embodiment of the present invention.

FIG. 23 is a diagram showing a configuration of a conventional color reproduction device.

[Explanation of symbols]

 Reference Signs List 100: image input device, 200: color correction unit, 201: target object recognition unit, 201-1: area division unit, 201-2: input profile selection unit, 202: device independent color conversion unit, 203: image synthesis Unit, 204: device value conversion unit, 205: switch, 300: image output device, 2021 to 202N: input profiles 1 to N, 2030: input profile operation unit, 2031: input profile creation unit, 2040: output profile, 2041 ... Output profile operation unit, 2042 ... output profile, 2043 ... output profile creation unit.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04N 9/64 H04N 1/40 D 5C079 9/73 1/46 Z F term (reference) 5B057 BA02 BA19 CA01 CA08 CA12 CA16 CB01 CB08 CB12 CB16 CC03 CE08 CE17 CE20 CH18 DA08 DA17 DB02 DB06 DB09 DC25 DC36 5C065 AA03 BB01 CC01 CC08 DD01 GG13 GG50 5C066 AA01 AA03 CA11 CA13 EA13 EC01 EE01 FA01 GB01 KE09 KM01 KM11 5C076 AA13A26A26AA13A26A26A20 PP28 PP37 PP47 PP65 PP71 PP74 PQ08 RR14 TT09 5C079 HB08 JA10 KA20 LA06 LA07 LA10 LA31 LA39 LA40 LB02 MA01 MA10 MA11 NA03

Claims (9)

[Claims] 1. A color reproduction device for performing predetermined color correction on an image input by an image input device and outputting the image, wherein the input image is divided into a plurality of regions, and each of the divided regions is An object recognition unit that selects an appropriate input profile from a plurality of input profiles; and converts an image of each region into a device-independent color image using the input profile selected from the plurality of input profiles. A device-independent color image, an image synthesizing unit that synthesizes the device-independent color image converted for each area into one device-independent color image, and a device-independent color image that is synthesized. And a device value conversion unit that converts the output image into an output image using a predetermined output profile. That color reproduction apparatus. 2. A color reproduction device for performing predetermined color correction on an image input by an image input device and outputting the image, wherein the input image is divided into a plurality of regions, and each of the divided regions is The object recognition unit that selects an appropriate input / output profile from a plurality of input / output profiles and an input / output profile selected from a plurality of input / output profiles created by integrating the input and output profiles A color reproduction device comprising: a device value conversion unit that converts an image of each area into an output image using the image processing unit; and an image synthesis unit that synthesizes the output image converted for each area into one output image. apparatus. 3. A color reproduction device for performing predetermined color correction on an image input by an image input device and outputting the image, wherein an input image including information necessary for generating a plurality of input profiles is stored in a plurality of areas. An object recognition unit that divides and selects a subject characteristic for each of the divided regions; a format conversion unit that performs format conversion based on the selected subject characteristics and outputs variable illumination image data for each region; A device independent color conversion unit that selects an input profile calculated from the variable image data from a plurality of input profiles, and converts an image of each area into a device independent color image using the selected input profile And the device-independent color image converted for each area into one device-independent Color reproduction device comprising an image combining unit for combining the color image, and the device value conversion section for converting an output image synthesized device-independent color image by using a predetermined output profile, that comprises a. 4. A color reproduction device for performing predetermined color correction on an image input by an image input device and outputting the color corrected image, comprising: an area dividing unit that divides the input image into a plurality of areas; A device-independent color conversion unit that converts each of the images in each region into a device-independent color image in parallel using a plurality of input profiles, and compares the converted device-independent color images. A conversion result selection unit that selects a device-independent color image for each region by using a combination, and an image combination unit that combines the device-independent color image for each selected region into one device-independent color image. Device value for converting the converted device independent color image into an output image using a predetermined output profile Color reproduction apparatus characterized by comprising a section, a. 5. A color reproduction device for performing a predetermined color correction on an image input by an image input device and outputting the image, comprising: an area dividing unit that divides an input image into a plurality of areas; A first device-independent color conversion unit that converts the image of each of the regions into a device-independent color image using one input profile, based on a conversion result obtained by the device-independent color conversion unit. A second device independent color conversion unit for converting an image of each area into a device independent color again using an input profile selected from a plurality of input profiles; and a device independent color conversion unit for each area. An image synthesizing unit for synthesizing a pendant color image; and Color reproduction apparatus characterized by comprising a device value conversion section for converting an output image using the profile, the. 6. A color reproduction device for performing predetermined color correction on an image input by an image input device and outputting the image, comprising: an area dividing unit that divides an input image into a plurality of areas; A device-independent color conversion unit that converts the image of each region into a device-independent color image using one input profile, and a spectral reflection storing information on spectral reflectances of a plurality of types of objects. Rate database; a conversion result determination unit that determines a conversion result in the first device independent color conversion unit with reference to the spectral reflectance database; and the spectral reflectance based on a result of the conversion result determination unit. A subject characteristic information calculation unit that selects information in the database to calculate subject characteristic information; and a calculation unit that calculates the subject characteristic information in accordance with a determination result of the conversion result determination unit. A second device-independent color conversion unit that converts an image of each area into a device-independent color again using an input profile selected from a plurality of input profiles created using subject characteristic information; An image synthesizing unit for synthesizing the device-independent color image for each of the regions, and a device value converting unit for converting the synthesized device-independent color image into an output image using a predetermined output profile. A color reproduction device. 7. A color reproduction device for performing predetermined color correction on an image input by an image input device and outputting the image, wherein a signal of an image photographed using a plurality of color patches whose spectral reflectances are known is provided. An object recognition unit for selecting an input profile to be used based on the value from a plurality of input profiles; and a device-independent color image of each region using the input profile selected from the plurality of input profiles. A device-independent color conversion unit that converts the image into an image, an image synthesis unit that synthesizes the device-independent color image converted for each area into one device-independent color image, and the synthesized device-independent A device value conversion unit that converts a color image into an output image using a predetermined output profile. Color reproduction apparatus according to claim. 8. A color reproduction device for performing a predetermined color correction on an image input by an image input device and outputting the image, comprising: a spectral reflectance database having spectral reflectance data of color patches; A subject characteristic information calculation unit that calculates subject characteristic information from the color patch photographed image using the signal values of the image photographed using a plurality of known color patches and the data of the spectral reflectance database, And an object recognition unit for selecting an input profile to be used from among a plurality of input profiles created using the calculated subject characteristic information, and an input selected from among the plurality of input profiles. Device-independent color conversion unit that converts the image of each area to a device-independent color image using a profile, and conversion for each area An image synthesizing unit for synthesizing a combined device independent color image into one device independent color image, and a device value conversion for converting the synthesized device independent color image into an output image using a predetermined output profile A color reproduction device, comprising: 9. The input profile includes image input device information including information on a photographing characteristic of the image input device used for photographing and information on a setting state of the image input device, and an image of an object to be photographed, At least one of photographing illumination light information at the time of photographing, observation illumination light information of a place where an image of an object to be photographed is to be observed, and subject characteristic information indicating a statistical property of a spectral reflectance of the object to be photographed. The color reproduction device according to claim 1, wherein the color reproduction device is created based on a color image.