JP7491039B2 - Color change degree estimation system, color change degree estimation method and program - Google Patents

Description

The present invention relates to a color change degree estimation system, a color change degree estimation method, and a program for estimating the degree of color change of an object.

It is known that the color of each object changes as a result of the components contained in the inks, pigments, dyes, base materials, materials, etc. that make up the object undergoing chemical changes in response to environmental factors such as temperature and light.
Moreover, by observing the change in color of an object, the degree of deterioration of the object, that is, the degree of functional decline, can be determined.
However, because the color change occurs continuously and gradually as a result of fading over time, it is difficult for the human eye to detect the change during normal observation.

As a countermeasure to this, a user can recognize that the color has changed from the initial state due to the environment by comparing it with an identical object in an undegraded state (e.g., a new item).
Regarding the recognition of color changes over time, there is a technology that visualizes the state of an oil painting as the oil paint deteriorates over time based on the change in the spectral reflectance of the oil paint over time (see, for example, Patent Document 1).

JP 2004-078598 A

In the technology described in Patent Document 1, when checking for color changes in an object, each time a color change is detected in the target object (e.g., an article), it is necessary to obtain an object in its initial state that is colored in the same color as the target object and has no color change.
However, if it is no longer possible to obtain an identical object in its initial state with no color change due to, for example, the production of the object being discontinued, it becomes impossible to detect the change in color of the target object.

Furthermore, when comparing the color with a new product, it is possible to detect whether the color has changed from the initial state, but it is not possible to detect the quantitative degree of change (hereinafter referred to as the degree of change) of the color.
In addition, the technology described in Patent Document 1 can visualize the changes in an oil painting over time and allow the user to recognize the gradual change in color, but it cannot be used to quantitatively detect the degree of change in the color of an object.

Furthermore, when detecting whether or not the color has changed from the initial state, it is difficult for a typical user to visually recognize a subtle change in color by themselves.
For this reason, it is necessary to request a professional with specialized knowledge to determine the deterioration of the object, which incurs costs and effort for the user.

The present invention has been made in consideration of such circumstances, and provides a color change degree estimation system, a color change degree estimation method, and a program that can quantitatively detect color changes in an object (e.g., an article) due to the environment, and easily and inexpensively estimate the degree of color change to be used in determining functional deterioration of the object.

In order to solve the above-mentioned problems, the color change degree estimation system of the present invention is characterized in that it comprises a pixel value acquisition unit that acquires pixel values of a predetermined region in an object image in which an object is captured from the object image; a reference pixel value calculation unit that calculates reference pixel values for each of the predetermined regions corresponding to each piece of color change characteristic information based on color change characteristic information, which is color characteristic information that has been acquired in advance for each of the predetermined regions in response to a degree of color change in the regions; and a change degree estimation unit that compares each of the reference pixel values with the pixel value, extracts the color change characteristic information corresponding to the pixel value, and estimates the degree of change corresponding to the extracted color change characteristic information as the degree of color change of the object.

The color change degree estimation system of the present invention is characterized in that the predetermined area is set as at least two or more target areas having different change characteristics of the color characteristic information.

The color change degree estimation system of the present invention is characterized in that the change degree estimation unit extracts the color change characteristic information used to calculate the reference pixel value that has the closest combination of ratios between the pixel value and the reference pixel value of each of the two or more target regions.

The color change degree estimation system of the present invention is characterized in that the reference pixel value calculation unit calculates the reference pixel value based on the change color characteristic information, imaging device spectral sensitivity information, which is spectral sensitivity information of the imaging device that captured the object image, and each of the light source spectral distributions of the emitted light of a plurality of light sources, and the change degree estimation unit estimates the light source spectral distribution of the light source of the environment in which the object image was captured, together with the change color characteristic information, by comparing each of the reference pixel values with the pixel value.

The color change degree estimation system of the present invention is characterized in that the changed color characteristic information is information indicating the spectral reflectance of the area corresponding to the degree of change.

The color change degree estimation system of the present invention is characterized in that it further comprises an item deterioration information database which indicates, for each item , the correspondence between the degree of change and the deterioration information indicated by the degree of change, and a deterioration information providing unit which extracts the deterioration information of the item corresponding to the degree of change from the item deterioration information database and provides it to a user.

The color change degree estimating method of the present invention is characterized in that it includes a pixel value acquisition step in which a pixel value acquisition unit acquires pixel values of a predetermined region in an object image in which an object is imaged, from the object image in which the object is imaged; a reference pixel value calculation step in which a reference pixel value calculation unit calculates reference pixel values for each of the predetermined regions corresponding to each piece of changed color characteristic information, based on changed color characteristic information, which is color characteristic information acquired in advance for each of the predetermined regions in response to a degree of change in color of the regions; and a change degree estimation step in which a change degree estimation unit compares each of the reference pixel values with the pixel value, extracts the changed color characteristic information corresponding to the pixel value, and estimates the degree of change corresponding to the extracted changed color characteristic information as the degree of change in color of the object.

The program of the present invention causes a computer to operate as: pixel value acquisition means for acquiring pixel values of a predetermined region in an object image in which an object is captured, from the object image; reference pixel value calculation means for calculating reference pixel values for each of the predetermined regions corresponding to each piece of color change characteristic information, which is color characteristic information that has been acquired in advance for each of the predetermined regions in response to a degree of color change in the regions; and change degree estimation means for comparing each of the reference pixel values with the pixel value, extracting the color change characteristic information corresponding to the pixel value, and estimating the degree of change corresponding to the extracted color change characteristic information as the degree of color change of the object.

As described above, the present invention provides a color change degree estimation system, a color change degree estimation method, and a program that can quantitatively detect color changes in an object (e.g., an article) due to the environment and easily and inexpensively estimate the degree of color change to be used in determining functional deterioration of the object.

1 is a block diagram showing an example of the configuration of an article color change information providing system using a color change degree estimation system according to an embodiment of the present invention. 1 is a diagram showing an example of the configuration of a changed color characteristic information database showing the spectral reflectance for each degree of change in each target area of an article in this embodiment (hereinafter, changed spectral reflectance). FIG. 11A to 11C are diagrams illustrating the acquisition of changed spectral reflectance for each degree of change in a target area of an article according to the present embodiment. 4 is a diagram showing an example of the configuration of an image capture device spectral sensitivity table in the image capture device spectral sensitivity database 109 according to the present embodiment. FIG. 4 is a diagram showing an example of the configuration of a light source spectral distribution table in a light source characteristic information database 110 in the present embodiment. FIG. 10 is a conceptual diagram illustrating a process of detecting a degree of change from pixel values of a target area of an article in a captured image, performed by a change degree estimation unit 105 in this embodiment. FIG. 10 is a flowchart showing an example of the operation of a process of estimating the degree of change in a color change degree estimating system in the present embodiment.

A first embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the degree of color change of an object (a numerical value that quantitatively indicates a change in color characteristic information such as the spectral reflectance of the object, which will be described later) is estimated.
FIG. 1 is a block diagram showing an example of the configuration of an article color change information providing system using a color change degree estimating system according to an embodiment of the present invention.
In FIG. 1, an article color change information providing system 1 includes a color change degree estimating system 100 and a user terminal 200.

Moreover, the color change degree estimating system 100 and the user terminal 200 are connected to each other via a data communication network 300 including the Internet or the like.
An application program for transmitting and receiving data used to detect the degree of color change between the user terminals 200 and the color change degree estimation system 100 is installed.

In FIG. 1, the color change degree estimation system 100 includes a data input/output unit 101, an image area recognition unit 102, a pixel value acquisition unit 103, a reference pixel value calculation unit 104, a change degree estimation unit 105, a deterioration information provision unit 106, a memory unit 107, an item deterioration information database 108, an imaging device spectral sensitivity database 109, and a light source characteristic information database 110.
When the data of a captured image is supplied from the user terminal 200, the data input/output unit 101 writes and stores the captured image together with user identification information in the storage unit 107.
The image area recognition unit 102 reads out captured image data from the storage unit 107, and extracts an image area to be evaluated (hereinafter, referred to as a target image area) for estimating the deterioration of an item in the captured image.

The pixel value acquisition unit 103 extracts each target pixel value (e.g., each of the color components RGB) of the target image area of the article from the target image area, and writes and stores them in the memory unit 107 in correspondence with the above-mentioned user identification information.
The reference pixel value calculation unit 104 calculates the reference pixel value of each target image region of the above-mentioned article from the spectral reflectance (a type of color characteristic information) measured in advance, the spectral sensitivity of the imaging device that captured the captured image (hereinafter referred to as the imaging device spectral sensitivity), and the spectral distribution of the light source (hereinafter referred to as the light source spectral distribution) (described in detail later).

FIG. 2 is a diagram showing an example of the configuration of an article deterioration information database showing the spectral reflectance for each degree of change in each target area of an article (hereinafter, referred to as changed spectral reflectance).
2A shows an example of the configuration of an item table. The item table has columns for item identification information and a change degree table index for each record. The item identification information is identification information for identifying each item. The change degree table index is an index such as an address indicating an area in which a change degree table of the item indicated by the item identification information is stored.

2B shows an example of the configuration of the change degree table. The change degree table has columns for each record: the change degree, the spectral reflectance for each target area (changed color characteristic information), and the functional deterioration state of the product corresponding to the change degree. The change degree is a numerical value (a numerical value added to the spectral reflectance included in a predetermined spectral reflectance range) that indicates a quantized change state in the process of the change in the spectral reflectance.
For example, the degree of change is determined by dividing the spectral reflectance that has changed over time by the initial value of the peak of the spectral reflectance.

Alternatively, the color of each target area of the article may be faded (changed) while the article is irradiated with light, and the change in the peak value of the spectral reflectance may be measured every predetermined time. The point at which the differential value of the curve of the change in the spectral reflectance is equal to or greater than a predetermined value may be determined from the curve of change in the spectral reflectance, and the calculated value at the point of change may be used as the degree of change.
The functional degradation state of the article corresponding to the degree of change is information indicating the functional degradation state of the article that can be estimated from the degree of change in the color of the target area, for example, in the case of a building material, the degree of degradation of functions such as waterproofness, water repellency, heat resistance, weather resistance, fire resistance, oxidation prevention, etc. Here, multiple columns of the functional degradation state of the article corresponding to the degree of change may be provided for each degree of change and for each cause of deterioration.

3 is a diagram for explaining acquisition of the change in spectral reflectance for each degree of change in a target area of an article. Here, measurements are taken for each degree of change (degree of deterioration) of the article, and the objects that change are the components contained in each of the inks, pigments, dyes, base materials, materials, etc. used in the article.
3, light is irradiated onto an article 500, and a test is performed to determine the degree of change in the spectral reflectance of a target image area 501, a target image area 502, a target image area 503, and a target image area 504. Each of the target image areas 501, 502, 503, and 504 is set in advance based on experimental results as an area where deterioration is likely to be estimated.

Also, in FIG. 3 , the change rates of changed spectral reflectance 501A, changed spectral reflectance 502A, changed spectral reflectance 503A, and changed spectral reflectance 504A in each of target image area 501, target image area 502, target image area 503, and target image area 504 of item 500 are obtained in units of change degree 1.0 (initial state), change degree 0.8, change degree 0.6, and change degree 0.4.
In this embodiment, the smaller the degree of change, the greater the degree of functional deterioration (deterioration of characteristics) of the item. However, the greater the degree of change, the greater the degree of functional deterioration (deterioration of characteristics) of the item.

FIG. 4 is a diagram showing an example of the configuration of an image capture device spectral sensitivity table in the image capture device spectral sensitivity database 109. As shown in FIG.
In FIG. 4, the imaging device spectral sensitivity table has columns for imaging device identification information and spectral sensitivity information for each record.
The imaging device identification information is identification information for identifying each imaging device (model), and the spectral sensitivity information is data on the spectral sensitivity of the imaging device, which is the spectral sensitivity of the imaging device.

FIG. 5 is a diagram showing an example of the configuration of a light source spectral distribution table in the light source characteristic information database 110. As shown in FIG.
In FIG. 5, the light source spectral distribution table has columns for light source identification information and spectral distribution information (data on the spectral distribution of radiation from a light source) for each record.
The light source identification information is identification information for identifying each light source (for example, a product number or information on the type of light source such as a fluorescent lamp, an LED (light emitting diode) lamp, an incandescent lamp, or sunlight). The spectral distribution information is data on the spectral distribution of light emitted from the light source.

Returning to FIG. 1, the reference pixel value calculation unit 104 refers to an imaging device spectral sensitivity table in an imaging device spectral sensitivity database 109 using imaging device identification information supplied by a user, and reads out the imaging device spectral sensitivity of the imaging device that captured the captured image.
The reference pixel value calculation unit 104 reads, from the item table of the item deterioration information database 108, a change degree table index of the change degree table corresponding to the specified item identification information.
The reference pixel value calculation unit 104 refers to the change degree table in the article deterioration information database 108 in response to the change degree table index.

Furthermore, the reference pixel value calculation unit 104 reads out data on the spectral distribution from the light source spectral distribution table, and reads out the change in spectral reflectance for each target image region from the change degree table.
Then, the reference pixel value calculation unit 104 calculates pixel values (each of the RGB color components) of pixels in each predetermined target image region from the imaging device spectral sensitivity, the varying spectral reflectance, and the spectral distribution, and sets the calculated pixel values as reference pixel values.

The change degree estimation unit 105 reads out the target pixel value and each of the reference pixel values for each degree of change from the memory unit 107, compares the target pixel value acquired by the pixel value acquisition unit 103 with each of the reference pixel values for each degree of change, and detects the reference pixel value having the degree of change closest to the target pixel value.
Here, the change degree estimation unit 105 calculates the ratio of each of the color components R (Red), G (Green), and B (Blue) in the target pixel value and the reference pixel value for each target image region.

FIG. 6 is a conceptual diagram illustrating the process performed by the change degree estimation unit 105 to detect the degree of change from pixel values of a target area of an article in a captured image.
Here, the change degree estimation unit 105 reads the target pixel values RGB of each of the target image areas 601 , 602 , and 603 of the item 600 from the storage unit 107 .
Here, in a target image region 601, the target pixel value R is R601, the target pixel value G is G601, and the target pixel value B is B601.
In the target image region 602, the target pixel value R is R602, the target pixel value G is G602, and the target pixel value B is B602.
In the target image region 603, the target pixel value R is R603, the target pixel value G is G603, and the target pixel value B is B603.

Furthermore, the change degree estimation unit 105 compares the target pixel value with the reference pixel values of the target image area 601, the target image area 602, and the target image area 603, which are calculated from the changed spectral reflectance for each degree of change.
Here, in the reference pixel values corresponding to the target image region 601, the reference pixel value R is R601r, the target pixel value G is G601r, and the target pixel value B is B601r.
For the reference pixel values corresponding to the target image region 602, the target pixel value R is R602r, the target pixel value G is G602r, and the target pixel value B is B602r.
In the reference pixel values corresponding to the target image region 603, the target pixel value R is R603r, the target pixel value G is G603r, and the target pixel value B is B603r.

Then, the change degree estimation unit 105 calculates an RGB ratio combination S601 (R601/R601r, G601/G601r, B601/B601r) in the target image region 601.
Furthermore, the change degree estimation unit 105 calculates an RGB ratio combination S602 (R602/R602r, G602/G602r, B602/B602r) in the target image region 602.
Furthermore, the change degree estimation unit 105 calculates an RGB ratio combination S603 (R603/R603r, G603/G603r, B603/B603r) in the target image region 603.

Returning to Figure 1, the change degree estimation unit 105 detects the degree of change in the combination of changed spectral reflectances calculated by calculating the reference pixel values that have the closest ratios of the pixel values R, B, and G of each of the RGB ratio combinations S601, S602, and S603, as the degree of change in the target image area in the captured image.
Here, it is desirable that the target image area 601, the target image area 602, and the target image area 603 each have different characteristics of change in spectral reflectance.
Then, the change degree estimation unit 105 writes and stores in the memory unit 107 the calculated (estimated) RGB ratio combination for each combination of the change degree of the target image region and the light source identification information (spectral distribution data).

In this way, by using the ratio between the target pixel value RGB and the reference pixel value RGB, the influence of lighting intensity and the like can be eliminated.
In addition, in this embodiment, three target image areas, target image area 602 and target image area 603, are used, but the degree of change may also be detected using two or more target image areas each having different change characteristics of spectral reflectance.

The degradation information providing unit 106 reads out from the storage unit 107 the degree of change corresponding to the combination of the light source identification information and the degree of change.
Then, the deterioration information providing unit 106 refers to the change degree table in the item deterioration information database 108 in correspondence with the combination of the user identification information and the item identification information.
The deterioration information providing unit 106 reads out a description of the deteriorated state of the product corresponding to the read-out degree of change, and transmits the description to the user terminal 200 .

FIG. 7 is a flowchart showing an example of the operation of the process of estimating the degree of change in the color change degree estimating system in this embodiment.
Step S201:
A user purchases items (such as building materials) when building a new house or renovating a house.

Step S202:
For example, the user may receive a notification from a company from which the user purchased an item that it is time to check the degree of change in the purchased item (for example, building materials).
Then, the user captures an image of a specified part of the item (a part corresponding to the target image area) using an imaging device that the user owns, and transmits the captured image (e.g., the image in Figure 10) and the imaging device identification information of the imaging device used for the image capture from the user terminal 200 to the color change degree estimation system 100.
At this time, the user terminal 200 transmits the user ID used when starting the application as user identification information to the color change degree estimating system 100 together with the captured image and imaging device identification information.

Step S203:
When the data input/output unit 101 receives an image of a specific location, imaging device identification information, and user identification information from the user terminal 200, it writes and stores each of the image of the specific location and the imaging device identification information in the memory unit 107 in correspondence with the user identification information.

Step S204:
The image area recognition unit 102 reads out captured image data from the storage unit 107, and extracts a target image area from the captured image.
Then, the pixel value acquisition unit 103 extracts the target pixel values R, G, and B from each of the target image areas extracted by the image area recognition unit 102, and writes and stores them in the memory unit 107 in correspondence with the above-mentioned user identification information.

Step S205:
The reference pixel value calculation unit 104 reads the image capture device identification information corresponding to the user identification number from the storage unit 107 .
Then, the reference pixel value calculation unit 104 reads out the spectral sensitivity information (imaging device spectral sensitivity) corresponding to the imaging device identification information from the imaging device spectral sensitivity table of the imaging device spectral sensitivity database 109 .

Step S206:
The reference pixel value calculation unit 104 determines whether or not the spectral distribution information corresponding to all the light source identification information in the light source spectral distribution table of the light source characteristic information database 110 has been read out.
Here, the reference pixel value calculation unit 104 sequentially reads out the spectral distribution information from the top row of the light source spectral distribution table to the bottom row, and determines whether or not the spectral distribution information corresponding to all of the light source identification information in the light source spectral distribution table has been read, depending on whether or not the bottom row of the light source spectral distribution table has been read.

At this time, if the reference pixel value calculation unit 104 has not read out the spectral distribution information corresponding to all the light source identification information in the light source spectral distribution table, the process proceeds to step S207.
On the other hand, if the reference pixel value calculation unit 104 has read out the spectral distribution information corresponding to all of the light source identification information in the light source spectral distribution table, the process proceeds to step S211.

Step S207:
The reference pixel value calculation unit 104 reads out the next row (the top row the first time) of spectral distribution information (light source information) from the light source spectral distribution table of the light source characteristic information database 110 .
Here, the reference pixel value calculation unit 104 reads out the item identification information corresponding to the user identification information from the storage unit 107 .
The reference pixel value calculation unit 104 selects a change degree table corresponding to the read-out item identification information from the item table of the item deterioration information database 108 (this process is performed only the first time).
Furthermore, the reference pixel value calculation unit 104 reads out the changed spectral reflectance from the top row in the change degree table.

Step S208:
Then, the reference pixel value calculation unit 104 judges whether or not the changed spectral reflectance for each target image region corresponding to all the degrees of change in the change degree table of the article deterioration information database 108 has been read out.
Here, the reference pixel value calculation unit 104 sequentially reads out the changed spectral reflectance for each target image area from the top row of the change degree table to the bottom row, and determines whether or not the changed spectral reflectance for each target image area corresponding to all degrees of change in the change degree table has been read depending on whether or not the bottom row of the change degree table has been read.

At this time, if the reference pixel value calculation unit 104 has not yet read out the changed spectral reflectance for each target image region corresponding to all the degrees of change in the change degree table, the process proceeds to step S209.
On the other hand, if the reference pixel value calculation unit 104 has read out the changed spectral reflectance for each target image region corresponding to all the degrees of change in the light source spectral distribution table, the process proceeds to step S206.

Step S209:
The reference pixel value calculation unit 104 reads out the change in spectral reflectance (change in color characteristic information) for each target image region in the next row (the top row the first time) from the change degree table of the light source characteristic information database 110 .

Step S210:
The reference pixel value calculation unit 104 calculates reference pixel values Rr, Gr, and Br of each of the target image regions based on the spectral distribution information, the imaging device spectral sensitivity, and the spectral reflectance change for each target image region.
Then, the reference pixel value calculation unit 104 writes and stores in the memory unit 107 each of the calculated reference pixel values Rr, Gr, Br of the target image region in correspondence with each combination of light source identification information and degree of change.
Furthermore, the reference pixel value calculation unit 104 advances the process to step S208.

Step S211:
The change degree estimation unit 105 sequentially reads out from the memory unit 107 reference pixel values Rr, Gr, Br corresponding to each target image area and target pixel values R, G, B of each target image area in accordance with each combination of light source identification information and degree of change.
Then, the change degree estimation unit 105 calculates the ratio between each of the reference pixel values Rr, Gr, Br of the read target image area and the target pixel values R, G, B of each target image area, and calculates the RGB ratio combinations (R/Rr, G/Gr, B/Br) described in Figure 6 for each combination of light source identification information and degree of change for each target image area.
In addition, the change degree estimation unit 105 writes and stores in the memory unit 107 the calculated RGB ratio combinations (R/Rr, G/Gr, B/Br) of each target image area for each combination of light source identification information and change degree.

Step S212:
The change degree estimation unit 105 extracts combinations of light source identification information and change degrees that provide the most similar RGB ratio combinations (R/Rr, G/Gr, B/Br) between the target image regions.
Then, the change degree estimation unit 105 determines the degree of change in the combination of the extracted light source identification information and the degree of change as the estimation result of the degree of change of the item in the chart image area of the captured image.
Furthermore, the change degree estimation unit 105 determines the spectral distribution indicated by the light source identification information in the combination of the light source identification information and the change degree as an estimation result of the light source environment in which the captured image was captured.
Then, the change degree estimation unit 105 writes and stores the data of the change degree and the spectral distribution in the storage unit 107 in association with the combination of the user identification information and the item identification information.

Step S213:
The degradation information providing unit 106 reads out the degree of change in the combination of the light source identification information and the degree of change from the storage unit 107 .
Then, the deterioration information providing unit 106 refers to the change degree table in the item deterioration information database 108 in correspondence with the combination of the user identification information and the item identification information.
The deterioration information providing unit 106 reads out a description of the deteriorated state of the product corresponding to the read-out degree of change, and transmits the description to the user terminal 200 .
At this time, if the degree of change of the item indicated by the item identification information falls outside the unusable threshold range of the degree of change previously set for each item, the deterioration information providing unit 106 notifies information indicating the need to replace the item.

According to this embodiment, the above-described configuration makes it possible to estimate the degree of change in an item owned by a user based on the target image area of the item in the captured image taken by the user, and when the user requests a contractor to investigate the deterioration of the item's functionality, there is no need for the contractor to visit the user's home to observe the item and directly observe the item to diagnose the deterioration of functionality, so the user can easily and inexpensively recognize the deterioration in functionality that corresponds to the degree of change in the item.
Furthermore, according to this embodiment, the target pixel values of each target image area are compared with reference pixel values calculated corresponding to each target image area, so that the degree of change can be estimated with an accuracy that even a professional cannot visually detect, and therefore the deterioration of the functionality of an item can be estimated with high accuracy.

In the embodiment described above, the image capture device identification information is obtained from the user. However, when calculating the reference pixel value, the spectral distribution of the light source in the imaging environment and the image capture device spectral sensitivities of the image capture device may be estimated together with the degree of change in the chart as parameters that change the multiple image capture device spectral sensitivities as well as the spectral distribution of the light source.
Furthermore, if the above-mentioned application is for a smartphone, it is clear that the user terminal 200 is a smartphone, so by preparing an imaging device that is used in a representative smartphone, the range of estimation of the imaging device spectral distribution can be narrowed.

In addition, in this embodiment, all the degrees of change in the change degree table are calculated, but if the degree of change is not being checked for the first time, the configuration may be such that the reference pixel value is calculated using the change in spectral reflectance since the previous degree of change, thereby reducing the load of estimating the degree of change.
Similarly, the search range for the degree of change for starting estimation measures may be narrowed based on the purchase date, manufacturing date and time, and usage environment of the item whose deterioration level is to be estimated.

Furthermore, in the present embodiment, the spectral distribution of the imaging environment is estimated, but when imaging a chart, the pixel values of each pixel of an image captured without using a strobe may be subtracted from the pixel values of each pixel of an image captured using a strobe to obtain data of an image captured using only a strobe, thereby omitting the estimation of the spectral distribution of the light source.
In addition, in this embodiment, the color characteristic information (or changing color characteristic information) has been described as spectral reflectance (or changing spectral reflectance), but any information indicating the spectral reflectance of the target image area corresponding to the degree of change may be used, and for example, a function of spectral reflectance, a numerical value of the coefficient of a base function of a function curve indicating the spectral reflectance, a rate of change or difference from an initial value of spectral reflectance, or a measured value (discrete value) of the spectral reflectance may be used.

It should be noted that a program for implementing the functions of the color change degree estimation system 100 of the present invention may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed to estimate the degree of deterioration of an article from the degree of color change. Note that the term "computer system" here includes hardware such as an OS and peripheral devices.
Additionally, "computer system" includes a WWW system equipped with a homepage providing environment (or display environment). Furthermore, "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Furthermore, "computer-readable recording medium" also includes devices that hold a program for a certain period of time, such as volatile memory (RAM) within a computer system that becomes a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line.

The above program may also be transmitted from a computer system in which the program is stored in a storage device or the like to another computer system via a transmission medium, or by transmission waves in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has the function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The above program may also be one that realizes part of the above-mentioned functions. Furthermore, it may be a so-called difference file (difference program) that can realize the above-mentioned functions in combination with a program already recorded in the computer system.

Reference Signs List 100: Color change degree estimation system 101: Data input/output unit 102: Image area recognition unit 103: Pixel value acquisition unit 104: Reference pixel value calculation unit 105: Change degree estimation unit 106: Deterioration information provision unit 107: Storage unit 108: Product deterioration information database 109: Imaging device spectral sensitivity database 110: Light source characteristic information database 200: User terminal 300: Data communication network

Claims (8)

a pixel value acquiring unit that acquires pixel values of a predetermined area in an object captured image from the object captured image;
a reference pixel value calculation unit that calculates a reference pixel value for each of the predetermined regions based on changing color characteristic information, which is color characteristic information previously acquired for each of the predetermined regions in response to a degree of color change in the region; and
a change degree estimation unit that compares each of the reference pixel values with the pixel value, extracts the change color characteristic information corresponding to the pixel value, and estimates a degree of change corresponding to the extracted change color characteristic information as a degree of change in color of the object. 2. The color change degree estimating system according to claim 1, wherein the predetermined area is set as at least two or more target areas having different change characteristics of the color characteristic information. The change degree estimation unit,
The color change degree estimation system according to claim 2, characterized in that the change color characteristic information used in calculating the reference pixel value having the closest combination of ratios between the pixel value and the reference pixel values of each of the two or more target regions is extracted. The reference pixel value calculation unit
calculating the reference pixel value based on the change color characteristic information, imaging device spectral sensitivity information that is spectral sensitivity information of an imaging device that captured the object image, and each of light source spectral distributions of light emitted from a plurality of light sources;
4. The color change degree estimation system according to claim 1 , wherein the change degree estimation unit estimates the light source spectral distribution of a light source in an environment in which the object image was captured, together with the changed color characteristic information, from a comparison between each of the reference pixel values and the pixel value. The color-changing characteristic information is
The color change degree estimating system according to claim 1 , wherein the information indicates a spectral reflectance of the region corresponding to the degree of change. an article deterioration information database indicating, for each article , the correspondence between the degree of change and deterioration information indicated by the degree of change;
The color change degree estimation system according to any one of claims 1 to 5, further comprising a deterioration information providing unit that extracts the deterioration information of the item corresponding to the degree of change from the item deterioration information database and provides it to a user. a pixel value acquisition step in which a pixel value acquisition unit acquires pixel values of a predetermined area in an object image from an object image in which an object is captured;
a reference pixel value calculation step in which a reference pixel value calculation unit calculates a reference pixel value for each of the predetermined regions in accordance with each of the change color characteristic information, the change color characteristic information being color characteristic information previously acquired for each of the predetermined regions in accordance with a degree of change in color of the region;
a change degree estimation process in which a change degree estimation unit compares each of the reference pixel values with the pixel value, extracts the changed color characteristic information corresponding to the pixel value, and estimates a degree of change corresponding to the extracted changed color characteristic information as a degree of change in color of the object. Computer,
a pixel value acquiring means for acquiring pixel values of a predetermined region in an object captured image from the object captured image;
a reference pixel value calculation means for calculating a reference pixel value for each of the predetermined regions in accordance with each of the changing color characteristic information, the changing color characteristic information being color characteristic information previously acquired for each of the predetermined regions in accordance with a degree of color change in the region;
a program that operates as a change degree estimation means for comparing each of the reference pixel values with the pixel value, extracting the change color characteristic information corresponding to the pixel value, and estimating the degree of change corresponding to the extracted change color characteristic information as the degree of change in color of the object.

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