JP7367563B2 - Light evaluation device and method - Google Patents

Description

The present invention relates to an illumination evaluation device and an illumination evaluation method for evaluating illumination on a surface to be measured of a measurement object.

Conventionally, the appearance of the surface to be measured has been determined using optical property measuring devices such as a luminance meter, a spectrometer, and a colorimeter, as disclosed in, for example, Patent Document 1. It is expressed and evaluated by the color of color coordinates (chromaticity diagram) such as L ^* a ^* b ^* color system.

JP 2018-4421 Publication

However, in so-called illumination evaluation, there is a situation in which the measurement results of the optical property measuring device and the appearance perceived by the person do not necessarily match. In particular, when the surface to be measured is a surface with a color or texture such as wood grain or real heather grain, the optical property measuring device It is difficult to match the measurement results with the way people perceive things.

The present invention was made in view of the above-mentioned circumstances, and its purpose is to provide a light evaluation device and a light evaluation method that evaluate light using a new evaluation index.

As a result of various studies, the present inventors have found that the above object can be achieved by the following present invention. That is, the illumination evaluation device according to one aspect of the present invention is an apparatus for calculating an evaluation index value representing the degree of illumination on a measured surface of a measurement object, and the illumination evaluation device irradiates the measured surface with illumination light at a predetermined incident angle. first data that is light intensity distribution data at a first acceptance angle in the reflected light of the illumination light that is reflected by the surface to be measured, and a light intensity distribution at a second acceptance angle different from the first acceptance angle; a data acquisition unit that acquires second data that is data, and diffuse reflection data that is light intensity at a third reception angle of the diffuse reflection angle; Determining a first area ratio between a first area and a second area darker than the first threshold, or a first area ratio between a first area brighter than a predetermined first threshold and a second area darker than the first threshold; a second area ratio between a third area that is brighter than a predetermined second threshold and a fourth area that is darker than the second threshold based on the second data, or a third area that is brighter than the predetermined second threshold and the second threshold; A second area ratio with the following dark fourth area is determined, a difference between the determined first area ratio and the second area ratio is determined as difference data, and the determined difference data and the diffuse reflection data are used as the evaluation index. and an evaluation processing unit that takes the value as a value. Preferably, in the illumination evaluation device described above, the data acquisition unit irradiates illumination light onto the surface to be measured of the measurement target at a predetermined angle of incidence, and calculates the amount of light in the reflected light of the illumination light that is reflected by the surface to be measured. a measuring unit that receives and measures intensity at a predetermined light receiving angle; first data that is light intensity distribution data measured by the measuring unit at the incident angle and the first light receiving angle is obtained from the measuring unit; Second data, which is light intensity distribution data measured by the measuring unit at the incident angle and the second acceptance angle, is acquired from the measurement unit, and the light intensity measured by the measurement unit at the incident angle and the third acceptance angle. and an acquisition processing section that acquires diffuse reflection data from the measurement section. Preferably, the measuring section includes a first measuring section that measures the light intensity distribution of the reflected light, and a second measuring section that measures the light intensity of the reflected light. Preferably, in the above-mentioned illumination evaluation device, the data acquisition section is an input section that inputs the first data, the second data, and the diffuse reflection data. Preferably, in the above-mentioned illumination evaluation device, the data acquisition unit acquires the first data from a recording medium (for example, a CD-ROM, a DVD-ROM, etc.) on which the first data, the second data, and the diffuse reflection data are recorded. a reading unit (for example, a CD drive device, a DVD drive device, etc.) that reads the data, the second data, and the diffuse reflection data. Preferably, in the above-mentioned illumination evaluation device, the data acquisition unit acquires the first data, the second data, and the second data from a storage medium (such as a USB memory) that stores the first data, the second data, and the diffuse reflection data. This is an interface unit (for example, a USB interface device, etc.) that reads data and the diffuse reflection data. Preferably, in the above-mentioned illumination evaluation device, the data acquisition unit acquires the first data, the second data, and the second data via a communication network from a server device that has accumulated the first data, the second data, and the diffuse reflection data. and a communication interface unit that receives the diffuse reflection data.

An illumination evaluation method according to another aspect of the present invention is a method for determining an evaluation index value representing the degree of illumination on a surface to be measured of a measurement object, the method comprising: illuminating the surface to be measured with illumination light at a predetermined incident angle. first data that is light intensity distribution data at a first acceptance angle in the reflected light of the illumination light that is reflected by the surface to be measured, and a light intensity distribution at a second acceptance angle different from the first acceptance angle; a data acquisition step of acquiring second data, which is data, and diffuse reflection data, which is light intensity at a third reception angle of the diffuse reflection angle; Determining a first area ratio between a first area and a second area darker than the first threshold, or a first area ratio between a first area brighter than a predetermined first threshold and a second area darker than the first threshold; a second area ratio between a third area that is brighter than a predetermined second threshold and a fourth area that is darker than the second threshold based on the second data, or a third area that is brighter than the predetermined second threshold and the second threshold; A second area ratio with the following dark fourth area is determined, a difference between the determined first area ratio and the second area ratio is determined as difference data, and the determined difference data and the diffuse reflection data are used as the evaluation index. and an evaluation processing step for determining the value.

According to the present invention, the shine evaluation uses the difference data, which is the difference between the first area ratio based on the first data and the second area ratio based on the second data, and the diffuse reflection data as a new gloss evaluation index value. A device and a light evaluation method can be provided. The way the light shines locally changes depending on the viewing angle with respect to the surface to be measured. This tendency is particularly strong when the surface to be measured is a surface with color or texture. Therefore, in the present invention, a change in the area ratio of a relatively bright portion and a relatively dark portion at mutually different first and second acceptance angles, that is, the difference data, is used as one evaluation index value. When you look at the surface to be measured at a specular reflection angle, it appears as a band of light like a mirror surface, making it difficult to see the surface of the measurement surface. On the other hand, when you look at the surface to be measured at a diffuse reflection angle, the surface of the measurement surface is visible. Easy to see. This tendency is particularly strong when the surface to be measured is a surface with color or texture. Therefore, in the present invention, the light intensity at the diffuse reflection angle, that is, the diffuse reflection data is used as another evaluation index value. The above-mentioned illumination evaluation device and illumination evaluation method have evaluation index values set from this perspective, so that illumination can be quantified, and in particular, when the surface to be measured is a surface with color or texture, evaluation is more suitable. can.

In another aspect, the above-mentioned illumination evaluation device includes a display unit that performs display, a coordinate system having an X axis representing the diffuse reflection data and a Y axis representing the difference data, and a The display processing unit further includes a display processing unit that displays coordinate points representing the evaluation index values on the display unit. In another aspect, the above-mentioned illumination evaluation method includes a coordinate system having an X-axis representing the diffuse reflection data and a Y-axis representing the difference data, and a coordinate system representing the evaluation index value obtained in the evaluation processing step . The method further includes a display step of displaying the coordinate points.

These illumination evaluation devices and illumination evaluation methods plot coordinate points of evaluation index values on a coordinate system, so that the evaluation index values of illumination can be visually grasped. In particular, when there are multiple measurement targets, each evaluation index value for the multiple measurement targets can be grasped at a glance, and trends and mutual comparisons are also easy.

In another aspect, in the above-described illumination evaluation device and illumination evaluation method, the first acceptance angle is a diffuse reflection angle, and the second acceptance angle is a specular reflection angle.

According to this, it is possible to provide an illumination evaluation device and an illumination evaluation method in which the first acceptance angle is a diffuse reflection angle and the second acceptance angle is a specular reflection angle.

In another aspect, in the above-mentioned illumination evaluation device and illumination evaluation method, the incident angle is 45°, and the first acceptance angle is any angle within an angle range of 15° to 38°. and the second light receiving angle is 45°.

According to this, the illumination evaluation device has an incident angle of 45°, a first light receiving angle at any angle within the angle range from 15° to 38°, and a second light receiving angle of 45°. and a method for evaluating illumination.

In another aspect, in the illumination evaluation device and illumination evaluation method described above, the third light receiving angle is any angle within an angle range from 15° to 38°.

According to this, it is possible to provide an illumination evaluation device and an illumination evaluation method in which the third light receiving angle is any angle within the angle range from 15° to 38°.

In another aspect, in the above-described shine evaluation apparatus and shine evaluation method, the surface to be measured includes at least one of wood grain and true wood grain.

As described above, such a shine evaluation device and method can reflect the influence of color and texture on the evaluation index, so they can more appropriately evaluate surfaces with at least one of wood grain and real heather grain. can.

According to the present invention, it is possible to provide a light evaluation device and a light evaluation method that evaluate light using a new evaluation index.

It is a block diagram showing the composition of the illumination evaluation device in an embodiment. FIG. 2 is a block diagram showing the configuration of a measuring section that is an example of a data acquisition section in the illumination evaluation device. FIG. 3 is a diagram for explaining a method of calculating first and second area ratios. It is a figure showing an example of diffuse reflection data. 3 is a flowchart showing the operation of the illumination evaluation device. FIG. 3 is a diagram showing an example of a surface to be measured. As an example, it is a diagram showing evaluation index values using coordinate values of a coordinate system. As an example, it is a diagram showing the results of subjective visual evaluation of illumination. FIG. 7 is a diagram showing the relationship between the product of light intensity and difference data and visual evaluation at a light receiving angle of 5° to 20°. FIG. 7 is a diagram showing the relationship between the product of light intensity and difference data and visual evaluation at a light receiving angle of 25° to 40°. FIG. 3 is a diagram showing the relationship between the light receiving angle and the correlation coefficient.

Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. It should be noted that structures with the same reference numerals in each figure indicate the same structure, and the description thereof will be omitted as appropriate. In this specification, when referring to a general term, a reference numeral without a subscript is used, and when referring to an individual configuration, a reference numeral with a suffix is used.

FIG. 1 is a block diagram showing the configuration of the illumination evaluation device in the embodiment. FIG. 2 is a block diagram showing the configuration of a measurement section that is an example of a data acquisition section in the illumination evaluation device. FIG. 3 is a diagram for explaining a method of calculating the first and second area ratios. FIG. 3A shows an example of two-dimensional light intensity distribution data measured on horse chestnut #1000 at an incident angle of 45° and an acceptance angle of 30° (an example of the first acceptance angle), and FIG. 3B shows an example of the two-dimensional light intensity distribution data shown in FIG. 3A. The results of binarizing the light intensity distribution data using a predetermined first threshold value are shown. FIG. 3C shows an example of two-dimensional light intensity distribution data measured on the horse chestnut tree #1000 at an incident angle of 45° and a light receiving angle of 45° (an example of a second light receiving angle), and FIG. The results of binarizing dimensional light intensity distribution data using a predetermined first threshold value are shown. FIG. 4 is a diagram showing an example of diffuse reflection data. The horizontal axis in FIG. 4 represents the light receiving angle (third light receiving angle), and the vertical axis represents the light intensity of the diffusely reflected light.

The illumination evaluation device D in the embodiment is a device that obtains an evaluation index value representing the degree of illumination on the surface to be measured of a measurement object, and for example, as shown in FIG. , an input section 3, a display section 4, an interface section (IF section) 5, and a storage section 6.

The data acquisition unit 1 is configured to obtain light intensity distribution data at a first acceptance angle of the reflected light of the illumination light that is irradiated onto the surface to be measured at a predetermined incident angle and reflected from the surface to be measured. Obtain certain first data, second data that is a light intensity distribution at a second acceptance angle different from the first acceptance angle, and diffuse reflection data that is the light intensity at a third acceptance angle of diffuse reflection. It is a device.

In this embodiment, the data acquisition unit 1 includes, for example, a measurement unit S and an acquisition processing unit 22 that is functionally provided in the control processing unit 2 as described later. The acquisition processing unit 22 will be described later. The measurement unit S is connected to, for example, a control processing unit 2, and under the control of the control processing unit 2, irradiates illumination light onto a surface to be measured at a predetermined angle of incidence and measures the illumination reflected by the surface to be measured. This is a device that measures the intensity of reflected light by receiving it at a predetermined receiving angle. Although the light intensity distribution and the light intensity may be measured with one device, in this embodiment, the measurement section S includes a first measurement section Sa that measures the light intensity distribution of the reflected light, and a first measurement section Sa that measures the light intensity distribution of the reflected light. and a second measurement section Sb that measures light intensity. The first measuring section Sa includes an illuminating section 71, a light receiving section 72a, and a main body section 73a, and the second measuring section Sb includes an illuminating section 71, a light receiving section 72b, and a main body section 73b. Although the light receiving section 72a and main body section 73a and the light receiving section 72b and main body section 73b have different functions, the first and second measuring sections Sa and Sb basically have a lighting section, a light receiving section, and a main body section. For the sake of brevity, they are illustrated in one FIG. 2.

More specifically, the first measurement section Sa includes, for example, as shown in FIG. 2, an illumination section 71, a light receiving section 72a, and a main body section 73a. The illumination section 71 is connected to the main body section 73a, and irradiates a virtual measurement surface HS on which the surface to be measured OS of the measurement object Ob is arranged with predetermined illumination light at a predetermined incident angle θ1 under the control of the main body section 73a. It is a device. The illumination section 71 includes, for example, a light source that is connected to the main body section 73a and emits predetermined illumination light under the control of the main body section 73a, and a light source that collimates the illumination light emitted from the light source and guides it to the measurement surface HS. The illumination unit 71 is arranged such that the optical axis (incident optical axis) AX1 of the illumination optical system is at a predetermined incident angle θ1 with respect to the normal NL of the measurement surface HS. . The illumination light is, for example, D65, which is a CIE (Commission Internationale de l'Eclairage) standard light. The light receiving section 72a receives the reflected light of the illumination light from the measurement surface HS at a predetermined light receiving angle θ2, performs photoelectric conversion, and outputs a signal corresponding to the light intensity of the reflected light of the illumination light to the main body section 73a. It is a device. The light receiving section 72a includes, for example, a light receiving optical system and a light receiving unit, and the light receiving optical system is an optical system that guides the reflected light of the illumination light from the measurement surface HS to the light receiving unit. The unit is connected to the main body part 73a, and according to the control of the main body part 73a, photoelectrically converts the reflected light of the illumination light guided by the light receiving optical system, and outputs a signal as a result of this photoelectric conversion to the main body part 73a. do. More specifically, in this embodiment, the light receiving unit is a so-called image spectrometer (for example, ImSpector V8E type manufactured by JFE Techno Research Co., Ltd.), and includes, for example, a slit member in which a slit-shaped opening is formed, and a hollow It is equipped with a spectroscopic element such as a diffraction grating using a graphic grating and a two-dimensional image sensor such as a CCD type, and the reflected light of the illumination light guided by the light receiving optical system is measured by the opening of the slit member. The slit light corresponding to one horizontal line of the field of view is divided into spectra in the vertical direction by the spectroscopic element, and horizontal spatial data and its spectral data are detected by the two-dimensional image sensor. The detected horizontal spatial data and its spectral data are output to the main body section 73a. The light receiving section 72a is arranged such that the optical axis (light receiving optical axis) AX2 of the light receiving optical system is at a predetermined light receiving angle θ2 with respect to the normal NL to the measurement surface HS. The main body section 73a is connected to the control processing section 2, and obtains light intensity distribution data of the reflected light of the illumination light based on the signal input from the light receiving section 72a, and calculates the light intensity distribution data of the reflected light of the illumination light thus obtained. This is a device that outputs distribution data to the control processing section 2. In this embodiment, since the horizontal spatial data and its spectral data are input as the signal from the light receiving unit, the main body 73a calculates the luminance as the light intensity from the spectral data using a well-known conventional method. Obtain light intensity distribution data for the reflected light. In such a first measuring section Sa, in the measurement of the surface to be measured, as shown in FIG. By scanning in the direction, two-dimensional spectral data for the surface to be measured OS of the object to be measured Ob can be generated, and two-dimensional light intensity distribution data for the surface to be measured OS of the object to be measured Ob can be generated.

In the above description, the light receiving unit is configured to include an image spectrometer, but it is not limited to this as long as it can measure light intensity distribution data. For example, the light receiving unit may include a plurality of photoelectric conversion elements arranged in parallel in one direction. It may be configured to include a linear image sensor equipped with.

On the other hand, the second measurement section Sb includes, for example, as shown in FIG. 2, an illumination section 71, a light receiving section 72b, and a main body section 73b. The illumination section 71 of the second measurement section Sb is the same as the illumination section 71 of the first measurement section Sa, so a description thereof will be omitted. The light receiving section 72b receives the reflected light of the illumination light from the measurement surface HS at a predetermined light receiving angle θ2, performs photoelectric conversion, and outputs a signal corresponding to the light intensity of the reflected light of the illumination light to the main body section 73b. It is a device. The light receiving section 72b includes, for example, a light receiving optical system and a light receiving element, and the light receiving optical system is an optical system that guides the reflected light of the illumination light from the measurement surface HS to the light receiving element, and The element is connected to the main body part 73b, and according to the control of the main body part 73b, photoelectrically converts the reflected light of the illumination light guided by the light receiving optical system, and outputs a signal as a result of this photoelectric conversion to the main body part 73b. do. The light receiving section 72b is arranged such that the optical axis (light receiving optical axis) AX2 of the light receiving optical system is at a predetermined light receiving angle θ2 with respect to the normal NL to the measurement surface HS. The main body section 73b is connected to the control processing section 2, determines the light intensity of the reflected light of the illumination light based on the signal input from the light receiving section 72b, and controls the determined light intensity of the reflected light of the illumination light. This is a device that outputs to the processing section 2. In such a second measurement section Sb, when measuring the surface to be measured, the object to be measured Ob is arranged so that the surface to be measured OS is along the measurement surface HS, as shown in FIG. As such a second measuring section Sb, for example, a three-dimensional variable angle photometer such as GPS-2B manufactured by Murakami Color Research Institute, etc. can be used.

The input section 3 is connected to the control processing section 2, and receives various commands such as commands for instructing calculation of evaluation index values, and various commands necessary for operating the illumination evaluation device D, such as the name of the measurement object. It is a device for inputting data to the light evaluation device D, and is, for example, a plurality of input switches, a keyboard, a mouse, etc. to which predetermined functions are assigned. The display unit 4 is a device that is connected to the control processing unit 2 and displays commands and data input from the input unit 3 and evaluation index values calculated by the illumination evaluation device D under the control of the control processing unit 2. For example, display devices such as a CRT display, a liquid crystal display, and an organic EL display are used.

Note that the input section 3 and the display section 4 may constitute a so-called touch panel. When configuring this touch panel, the input unit 3 is a position input device that detects and inputs an operating position, such as a resistive film type or a capacitive type. In this touch panel, the position input device is provided on the display surface of the display device, one or more input content candidates that can be input are displayed on the display device, and a display displaying the input content that the user wants to input is displayed. When a position is touched, the position is detected by the position input device, and the display content displayed at the detected position is input to the illumination evaluation device D as the user's operation input content. With such a touch panel, it is easy for the user to intuitively understand the input operations, so the illumination evaluation device D is provided that is easy for the user to handle.

The IF section 5 is a circuit that is connected to the control processing section 2 and performs input/output of data with an external device under the control of the control processing section 2, and is, for example, an interface circuit for RS-232C, which is a serial communication method. , an interface circuit using the Bluetooth (registered trademark) standard, an interface circuit that performs infrared communication such as the IrDA (Infrared Data Association) standard, and an interface circuit using the USB (Universal Serial Bus) standard. Further, the IF unit 5 is a circuit that performs communication with an external device, and may be, for example, a data communication card, a communication interface circuit according to the IEEE802.11 standard, or the like.

The storage section 6 is a circuit that is connected to the control processing section 2 and stores various predetermined programs and various predetermined data under the control of the control processing section 2. The various predetermined programs include, for example, a control processing program, and the control processing program controls each section 1 (S (Sa, Sb)), 3 to 6 of the illumination evaluation device D to the function of each section. a control program that controls each according to the above, an acquisition processing program that acquires the first data, the second data, and the diffuse reflection data, and a first area that is brighter than a predetermined first threshold based on the first data; and a second area that is darker than the first threshold, and a third area that is brighter than a predetermined second threshold and a fourth area that is darker than the second threshold based on the second data. an evaluation processing program that calculates a two area ratio, calculates a difference between the calculated first area ratio and second area ratio as difference data, and uses the calculated difference data and the diffuse reflection data as the evaluation index value; A coordinate system having an X-axis representing diffuse reflection data and a Y-axis representing the difference data, and a display processing program for displaying coordinate points representing the evaluation index values obtained by the evaluation processing program on the display unit 4, etc. included. The various kinds of predetermined data include data necessary for executing each of these programs, such as first and second data acquired by the data acquisition unit 1 and diffuse reflection data. Such a storage unit 6 includes, for example, a ROM (Read Only Memory) that is a nonvolatile storage element, an EEPROM (Electrically Erasable Programmable Read Only Memory) that is a rewritable nonvolatile storage element, and the like. The storage unit 6 includes a RAM (Random Access Memory), which serves as a so-called working memory of the control processing unit 2 that stores data generated during execution of the predetermined program. Note that the storage unit 6 may include a hard disk device capable of storing a large capacity in order to store a relatively large capacity of learning data.

The control processing section 2 controls each section 1 (S (Sa, Sb)) and 3 to 6 of the illumination evaluation device D according to the function of each section, and performs an evaluation indicating the degree of illumination on the surface to be measured of the measurement object. This is a circuit for finding index values. The control processing unit 2 includes, for example, a CPU (Central Processing Unit) and its peripheral circuits. The control processing section 2 functionally includes a control section 21, an acquisition processing section 22, an evaluation processing section 23, and a display processing section 24 by executing the control processing program.

The control section 21 controls each section 1 (S (Sa, Sb)), 3 to 6 of the illumination evaluation device D according to the function of each section, and controls the entire illumination evaluation device D.

The acquisition processing unit 22 acquires the first data, the second data, and the diffuse reflection data. More specifically, the acquisition processing unit 22 acquires first data, which is light intensity distribution data measured by the measuring unit S at the incident angle and the first acceptance angle, from the measuring unit S, and Second data, which is light intensity distribution data measured by the measuring unit S at the second light receiving angle, is acquired from the measuring unit S, and the light intensity measured by the measuring unit S at the incident angle and the third light receiving angle. Diffuse reflection data is obtained from the measuring section. More specifically, the acquisition processing unit 22, for example, irradiates illumination light on the surface to be measured OS of the measurement object Ob at the incident angle and receives the first light in the reflected light of the illumination light that is reflected by the surface to be measured OS. The light intensity distribution data at the corner is measured by the first measurement unit Sa, the light intensity distribution data is acquired from the first measurement unit Sa as the first data, and the incident angle is set on the measurement surface OS of the measurement object Ob. The first measurement unit Sa measures the light intensity distribution data at the second acceptance angle of the reflected light of the illumination light reflected by the surface to be measured OS, and the light intensity distribution data is measured by the first measurement unit Sa. The second data is acquired from the first measurement unit Sa, and the second data is obtained from the reflected light of the illumination light that is irradiated onto the surface to be measured OS of the measurement object Ob at the incident angle and reflected by the surface to be measured OS. The second measurement unit Sb measures the light intensity at three light reception angles, and acquires the light intensity from the second measurement unit Sb as the diffuse reflection data.

Two-dimensional light intensity distribution data (an example of the first data) obtained by measuring the surface of a horse chestnut tree (Tochinoki #1000, Tochinoki #1000) with a surface finish of #1000 at a first acceptance angle of 30° using the first measurement unit Sa. ) is shown in FIG. 3A, and two-dimensional light intensity distribution data (an example of the second data) obtained by measuring the surface of this horse chestnut #1000 at a second acceptance angle of 45° is shown in FIG. 3C. In FIGS. 3A and 3C, the incident angle θ1 is 45°, and therefore the specular reflection angle is 45° (second acceptance angle=specular reflection angle). Then, the second measurement unit Sb measures Karin (Karin #1000, Karin #1000) with surface finish #1000, horse chestnut, Merkaba (Merkaba #1000, Each light intensity of each result of measuring each surface of Makaba #1000), ebony (Ebony #1000, Kokutan #1000), Sen (Sen #1000, Sen #1000), and walnut (Walnut #1000, Walnut #1000) is It is shown in FIG. The first and second measurement sections Sa and Sb were calibrated using a so-called white calibration plate. Therefore, these measurement results are based on the light intensity of the reflected light from the white calibration plate. The light intensity of each reflected light on each surface has a peak (maximum value) at the acceptance angle of the specular reflection angle, and has a profile that decreases as the acceptance angle moves away from the specular reflection angle.

The evaluation processing unit 23 calculates a first area ratio between a first area that is brighter than a predetermined first threshold value and a second area that is darker than the first threshold value based on the first data, and a second area ratio between a third area that is brighter than a predetermined second threshold value and a fourth area that is darker than the second threshold value is determined, and the difference between the determined first area ratio and second area ratio is used as difference data. and the obtained difference data and the diffuse reflection data are used as the evaluation index value. More specifically, for example, each pixel of the first data is first binarized using a first threshold value. For example, a pixel that is brighter than the first threshold is set to 0 (black), and a pixel that is darker than the first threshold is set to 1 (white). Then, a first area is determined by summing up the 0 pixels, and a second area is determined by summing up the 1 pixels. Similarly, each pixel of the second data is binarized using a second threshold value, a third area is obtained by summing up pixels of 0, and a fourth area is obtained by summing up pixels of 1. Note that the evaluation processing unit 23 calculates a first area ratio between a first area that is brighter than a predetermined first threshold value and a second area that is darker than the first threshold value based on the first data, and A second area ratio between a third area that is brighter than the threshold and a fourth area that is darker than the second threshold is determined, and a difference between the determined first area ratio and second area ratio is determined as difference data, and The difference data and the diffuse reflection data may be used as the evaluation index value. As can be seen from FIG. 4, the first and second threshold values are set appropriately using the same method depending on the type of object Ob, since the light intensity of the reflected light differs depending on the type of object object Ob. be done.

In the example shown in FIGS. 3 and 4, the first data shown in FIG. 3A is binarized using a first threshold as shown in FIG. 3B, and the first data and A second area is determined. Similarly, the second data shown in FIG. 3C is binarized using a second threshold as shown in FIG. 3D, and the third and fourth areas are determined by summing the 0 pixels and 1 pixels, respectively. The first and second threshold values may be the same value, but in this example, they are different values. For example, the first and second threshold values may be different values from each other. They were set based on the light intensity and the light intensity of the reflected light at the same light receiving angle of 45° as the second light receiving angle of 45° in the second data. Then, a first area ratio (=first area/second area) is calculated, a second area ratio (=third area/fourth area) is calculated, and the second area ratio is subtracted from the first area ratio. By doing so, approximately 80 is obtained as the difference data (see FIG. 7). Furthermore, the light intensity of the reflected light at a light receiving angle (third light receiving angle) of 30°, which is the same as the first light receiving angle of 30° of the first data, is determined as the diffuse reflection data (see FIG. 7). Here, for convenience of explanation, the diffuse reflection data was obtained from FIG. 4 showing the light intensity at each angle in the angle range from about -40° to about 80°. In measuring the reflection data, it is sufficient to measure only the light intensity of the reflected light at the third acceptance angle of 30°.

The display processing unit 24 displays a coordinate system having an X axis representing the diffuse reflection data and a Y axis representing the difference data, and a coordinate point representing the evaluation index value obtained by the evaluation processing unit 23 on the display unit 4. It is to be displayed. More specifically, an XY orthogonal coordinate system having an X axis representing the diffuse reflection data and a Y axis perpendicular to the X axis and representing the difference data is displayed on the display unit 4, and the evaluation processing unit 23 calculates the Coordinate points representing the evaluation index values are plotted on the XY orthogonal coordinate system, and the coordinate points are displayed on the display unit 4.

These control processing unit 2, input unit 3, display unit 4, IF unit 5, and storage unit 6 can be configured by, for example, a desktop computer, a notebook computer, or the like.

Next, the operation of this embodiment will be explained. FIG. 5 is a flowchart showing the operation of the gloss evaluation device. FIG. 6 is a diagram showing an example of a surface to be measured. FIG. 6A is a schematic diagram of a surface image of Sen #1000 with surface finish #1000, and FIG. 6B is a schematic diagram of a surface image of Tochinoki #1000 with surface finish #1000. FIG. 6C is a schematic diagram of a surface image of Walnut #1000 with a surface finish of #1000, and FIG. 6D is a schematic diagram of a surface image of Karin #1000 with a surface finish of #1000. FIG. 6E is a schematic diagram of a surface image of Merkaba (Makaba #1000) with surface finish #1000, and FIG. 6F is a schematic diagram of a surface image of ebony (Kokutan #1000) with surface finish #1000. Each of the images in FIGS. 6A to 6F were generated by measuring each surface with an image spectrometer (imSpector V8E, manufactured by JFE Techno Research Co., Ltd.) at an incident angle of 45° and an acceptance angle of 30°. FIG. 7 is a diagram showing evaluation index values using coordinate values of a coordinate system, as an example. The horizontal axis (X-axis) in FIG. 7 represents diffuse reflection data, and the vertical axis (Y-axis) represents differential data. SC1 to SC6 are evaluation index values for each of the main grains provided in current cars of mutually different car models. FIG. 8 is a diagram showing, as an example, the results of subjective visual evaluation of illumination.

When the illumination evaluation device D having such a configuration is turned on, it initializes the necessary parts and starts its operation. The control processing section 2 functionally includes a control section 21, an acquisition processing section 22, an evaluation processing section 23, and a display processing section 24 by executing the control processing program.

In the operation of determining the evaluation index value, in FIG. 5, the illumination evaluation device D uses the control processing section to acquire the first data, the second data, and the diffuse reflection data using the measurement section S (S1). More specifically, for example, when an operator (user) inputs an instruction to obtain an evaluation index value from the input unit 3, the control processing unit 2 transfers the measured surface OS of the measurement object Ob to the first measurement unit Sa. A message prompting the user to set the settings is displayed on the display section 4, and the system waits for input of an instruction to start measurement. When the operator inputs an instruction to start measurement from the input unit 3, the control processing unit 2 uses the acquisition processing unit 22 to acquire the first and second data. More specifically, the acquisition processing unit 22 causes the first measuring unit Sa to measure at the first light receiving angle, and acquires the two-dimensional light intensity distribution data of this measurement result from the first measuring unit Sa as the first data. and store it in the storage unit 6, cause the first measuring unit Sa to measure at the second light receiving angle, and acquire and store the two-dimensional light intensity distribution data of the measurement result from the first measuring unit Sa as the second data. It is stored in section 6. Subsequently, the control processing section 2 displays a message on the display section 4 prompting to set the surface to be measured OS of the measurement object Ob in the second measurement section Sb, and waits for input of an instruction to start measurement. When the operator inputs an instruction to start measurement from the input unit 3, the control processing unit 2 uses the acquisition processing unit 22 to acquire the diffuse reflection data. More specifically, the acquisition processing unit 22 causes the second measuring unit Sb to measure at the third light receiving angle, acquires the light intensity of this measurement result from the second measuring unit Sb as the diffuse reflection data, and stores it in the storage unit 6. Remember. In one example, the first data, the second data, and the diffuse reflection data are acquired by the measurement unit S (Sa, Sb) in this way.

Next, the illumination evaluation device D uses the evaluation processing unit 23 to obtain an evaluation index value (S2). More specifically, the evaluation processing unit 23 calculates a first and second area based on the first data acquired in process S1, calculates a first area ratio, and calculates a first area ratio based on the second data acquired in process S1. Based on this, the third and fourth areas are determined to determine a second area ratio, the difference between the determined first area ratio and second area ratio is determined as difference data, and this determined difference data and the second area ratio are obtained in the process S1. The diffuse reflection data obtained is set as the evaluation index value, and this evaluation index value is stored in the storage unit 6.

Then, the illumination evaluation device D causes the display processing unit 24 to display this evaluation index value on the display unit 4 (S3), and ends this process. For example, as shown in FIG. 7, the display unit 4 includes a coordinate system having an X axis representing the diffuse reflection data and a Y axis representing the difference data, and the evaluation index value obtained by the evaluation processing unit 23. A coordinate point representing the is displayed.

The measurement conditions for each evaluation index value shown in FIG. is 30°, which is the same as the first light receiving angle.

The shine is a subjective visual evaluation, but as shown in Figure 8, if it is weak, the depth is weak and the impression is not good, and if it is strong, the shine is emphasized and the material is difficult to see and the impression is not good. The stronger it is, the better the impression. Note that the visual evaluation shown in FIG. 7 is the result of aggregating the visual evaluations of five subjects.

Comparing the results shown in FIG. 7 with the results shown in FIG. 8, in FIG. 7, the diffuse reflection data is from about 42 to about 78, and the difference data is from about 48 to about 75, which are indicated by the dashed rectangle. It can be seen that the area within the range gives a good impression of illumination. In the results shown in FIG. 8, for example, it is difficult to distinguish between CS2 and Karin, but as shown in FIG. 7, it is easy to distinguish them in the coordinate system of the diffuse reflection data and the difference data.

As explained above, according to the above, the difference data, which is the difference between the first area ratio based on the first data and the second area ratio based on the second data, and the diffuse reflection data are used as a new illumination evaluation index. A light evaluation device D and a light evaluation method can be provided. The way the partial light shines changes depending on the viewing angle with respect to the surface to be measured OS. This tendency is particularly strong when the surface to be measured OS is a surface with color or texture. Therefore, the change in the area ratio of the relatively bright portion and the relatively dark portion at the first and second light receiving angles that are different from each other, that is, the difference data, was used as one evaluation index value. When the measured surface OS is viewed at a specular reflection angle, it appears as a band of light like a mirror surface, making it difficult to see the surface of the measured surface OS. On the other hand, when the measured surface OS is viewed at a diffuse reflection angle, the measured surface The surface of the OS is easily visible. This tendency is particularly strong when the surface to be measured OS is a surface with color or texture. Therefore, the light intensity at the diffuse reflection angle, that is, the diffuse reflection data was used as another evaluation index value. The above-mentioned illumination evaluation device D and illumination evaluation method have evaluation index values set from this point of view, so that illumination can be quantified, and are particularly suitable when the surface to be measured OS is a surface with color or texture. It can be evaluated as follows. The shine evaluation device D and the shine evaluation method described above can reflect the influence of color and texture on the evaluation index, and therefore, as shown in FIG. 7, it is possible to more suitably evaluate a surface having regular heathered grain. Since the wood grain is substantially the same as the real wood grain, the shine evaluation device D and the shine evaluation method described above can more suitably evaluate surfaces having wood grain.

Since the illumination evaluation device D and the illumination evaluation method plot the coordinate points of the evaluation index values on the coordinate system, the illumination evaluation index values can be visually grasped. In particular, when there are a plurality of measurement objects Ob, each evaluation index value for the plurality of measurement objects Ob can be grasped at a glance, as shown in FIG. 7, and trends and mutual comparisons can be easily made.

According to the above, the first light receiving angle is the diffuse reflection angle and the second light receiving angle is the specular reflection angle. It is possible to provide a light evaluation device D and a light evaluation method in which the angle is 30° and a second light receiving angle is 45°, and a light evaluation device D and a light evaluation method in which the third light receiving angle is 30°.

In addition, in the above embodiment, since the light intensity of the reflected light is generally the strongest, the specular reflection angle is set as the second acceptance angle, and the second area ratio at the specular reflection angle is used as the reference for the difference data (area ratio change). However, the second acceptance angle is not limited to the specular reflection angle, and may be any other angle, and the second area ratio at the other angle is the reference (area ratio) for the difference data. standard of change).

Further, in the above embodiment, the third acceptance angle of the diffuse reflection angle is 30°, but is not limited to 30°, and the third acceptance angle of the diffuse reflection angle is not limited to 30°. Any other angle may be used as long as it is a diffuse reflection angle seen by the surface of the measurement surface.

Further, in the above embodiment, the first acceptance angle was 30°, which is one of the diffuse reflection angles, but it is preferable that it be any angle within the angle range from 15° to 38° from the following. . Similarly, the third acceptance angle of the diffuse reflection angle is preferably any angle within the angle range of 15° to 38°.

FIG. 9 is a diagram showing the relationship between the product of light intensity and difference data and visual evaluation at a light receiving angle of 5° to 20°. FIG. 10 is a diagram showing the relationship between the product of light intensity and difference data and visual evaluation at a light receiving angle of 25° to 40°. Each of the horizontal axes in FIGS. 9 and 10 represents the product of the light intensity at the third acceptance angle θ and the difference data at the second acceptance angle 45° between the first acceptance angle θ and the specular reflection angle. Each vertical axis represents visual evaluation. 9A shows the results when θ is 5°, FIG. 9B shows the results when θ is 10°, FIG. 9C shows the results when θ is 15°, and FIG. 9D shows the results when θ is 15°. shows the results when θ is 20°. 10A shows the results when θ is 25°, FIG. 10B shows the results when θ is 30°, FIG. 10C shows the results when θ is 35°, and FIG. 10D shows the results when θ is 35°. shows the results when θ is 40°. In FIG. 8, by setting the visual evaluation score of weak illumination to 0 points and the visual evaluation point of strong illumination to 5 points, the visual evaluation score of illumination for each measurement target in FIGS. 9 and 10 was determined. FIG. 11 is a diagram showing the relationship between the light receiving angle and the correlation coefficient. The horizontal axis in FIG. 11 represents the light receiving angle θ, and the vertical axis represents the correlation coefficient R.

In the above embodiment, the evaluation index value was expressed by diffuse reflection data and difference data, but in order to evaluate the correlation with visual evaluation, here, the evaluation index value is expressed as the product of diffuse reflection data and difference data, and visual evaluation. The range of acceptance angles was investigated by examining the correlation with In the same case as the first acceptance angle of 30° in the above embodiment, as shown in FIGS. 10B and 11, it is shown that the product of the diffuse reflection data and the difference data has a high correlation with the visual evaluation. Therefore, it can be understood that the first acceptance angle can be evaluated by the product of the diffuse reflection data and the difference data.

As can be seen from Figure 11, within the angle range from 5° to 40°, a certain correlation is observed at other angles except for 40°, and in particular, within the angle range from 25° to 35°. There is a high correlation in terms of acceptance angle. The reason for this is that as the acceptance angle approaches 0°, the light intensity weakens, making it difficult to generate glare, and as the angle of specular reflection approaches 45°, the entire surface shines strongly, making it difficult to recognize the light. It is assumed that this will happen. In actual visual evaluation, the lower limit of the acceptance angle is set to 15° because it becomes easier to recognize illumination from the acceptance angle of 15°, and the correlation coefficient of 38° is the same as the correlation coefficient for the acceptance angle of 15°. Set to the upper limit of the acceptance angle. From the above, the first light receiving angle is preferably any angle within the angular range from 15° to 38°, and more preferably any angle within the angular range from 25° to 35°.

Further, in the above-described embodiment, the data acquisition section 1 is configured to include the measurement section S (Sa, Sb) and the acquisition processing section 22, but the present invention is not limited to this. For example, the data acquisition section 1 irradiates illumination light at a predetermined incident angle onto the surface of the object to be measured, which is measured by a measuring device such as the above-mentioned measuring section S (Sa, Sb) as an example. First data that is light intensity distribution data at a first acceptance angle in the reflected light of the illumination light reflected on the measurement surface, and second data that is light intensity distribution data at a second acceptance angle different from the first acceptance angle. 2 data and diffuse reflection data that is the light intensity at the third light receiving angle of the diffuse reflection angle. Note that the input section may also be used as the input section 3 described above.

Alternatively, for example, the data acquisition unit 1 may irradiate illumination light at a predetermined incident angle onto the surface to be measured of the measurement target, which is measured by a measurement device such as the above-mentioned measurement unit S (Sa, Sb) as an example. First data that is light intensity distribution data at a first acceptance angle in the reflected light of the illumination light reflected by the measured surface, and light intensity distribution data at a second acceptance angle different from the first acceptance angle. The first data and the second data are recorded from a recording medium (for example, a CD-ROM, a DVD-ROM, etc.) on which certain second data and diffuse reflection data, which is the light intensity at a third acceptance angle of the diffuse reflection angle, are recorded. and a reading unit (for example, a CD drive device, a DVD drive device, etc.) that reads the diffuse reflection data.

Alternatively, for example, the data acquisition unit 1 may irradiate illumination light at a predetermined incident angle onto the surface to be measured of the measurement target, which is measured by a measurement device such as the above-mentioned measurement unit S (Sa, Sb) as an example. First data that is light intensity distribution data at a first acceptance angle in the reflected light of the illumination light reflected by the measured surface, and light intensity distribution data at a second acceptance angle different from the first acceptance angle. The first data, the second data, and the diffuse reflection data are stored from a storage medium (for example, a USB memory, etc.) that stores the second data and the diffuse reflection data that is the light intensity at the third acceptance angle of the diffuse reflection angle. It may be an interface section (for example, a USB interface device, etc.) that reads the information. Note that the interface section may also be used as the above-mentioned IF section 5.

Alternatively, for example, the data acquisition unit 1 may irradiate illumination light at a predetermined incident angle onto the surface to be measured of the measurement target, which is measured by a measurement device such as the above-mentioned measurement unit S (Sa, Sb) as an example. First data that is light intensity distribution data at a first acceptance angle in the reflected light of the illumination light reflected by the measured surface, and light intensity distribution data at a second acceptance angle different from the first acceptance angle. The first data, the second data, and the diffuse reflection data are transmitted via a communication network from a server device that has accumulated certain second data and diffuse reflection data that is light intensity at a third acceptance angle of the diffuse reflection angle. It may also be a communication interface unit that receives the information. Note that the communication interface section may also be used as the above-mentioned IF section 5.

In order to express the present invention, the present invention has been adequately and fully described through embodiments with reference to the drawings in the above description, but those skilled in the art will easily be able to modify and/or improve the embodiments described above. It should be recognized that this is possible. Therefore, unless the modification or improvement made by a person skilled in the art does not depart from the scope of the claims stated in the claims, such modifications or improvements do not fall outside the scope of the claims. It is interpreted as encompassing.

D Light evaluation device S Measuring section Sa First measuring section Sb Second measuring section 1 Data acquisition section 2 Control processing section 3 Input section 4 Display section 5 Interface section (IF section)
6 Storage section 21 Control section 22 Acquisition processing section 23 Evaluation processing section 24 Display processing section

Claims (12)

An illumination evaluation device that obtains an evaluation index value representing the degree of illumination on a measured surface of a measurement object,
first data that is light intensity distribution data at a first acceptance angle of reflected light of the illumination light that is irradiated onto the surface to be measured at a predetermined incident angle and reflected by the surface to be measured; a data acquisition unit that acquires second data that is light intensity distribution data at a second light reception angle different from the light reception angle, and diffuse reflection data that is light intensity at a third light reception angle of the diffuse reflection angle;
Based on the first data, a first area ratio of a first area brighter than a predetermined first threshold value and a second area darker than the first threshold value, or a first area brighter than a predetermined first threshold value and the first area A first area ratio between a second area that is darker than a threshold value and a second area that is darker than the second threshold value is calculated, and a second area ratio between a third area that is brighter than a predetermined second threshold value and a fourth area that is darker than the second threshold value based on the second data. Alternatively, a second area ratio between a third area that is brighter than a predetermined second threshold value and a fourth area that is darker than the second threshold value is determined, and the difference between the determined first area ratio and second area ratio is used as difference data. and an evaluation processing unit that uses the obtained difference data and the diffuse reflection data as the evaluation index value.
Light evaluation device. A display section for displaying;
a coordinate system having an X-axis representing the diffuse reflection data and a Y-axis representing the difference data; and a display processing unit that displays coordinate points representing the evaluation index values obtained by the evaluation processing unit on the display unit. further comprising,
The illumination evaluation device according to claim 1. The first acceptance angle is a diffuse reflection angle,
The second acceptance angle is a specular reflection angle.
The illumination evaluation device according to claim 1 or claim 2. The incident angle is 45°,
The first acceptance angle is any angle within an angle range from 15° to 38°,
the second acceptance angle is 45°;
The illumination evaluation device according to claim 1 or claim 2. The third acceptance angle is any angle within an angle range of 15° to 38°.
The illumination evaluation device according to claim 4. The surface to be measured has at least one of wood grain and real wood grain,
The illumination evaluation device according to any one of claims 1 to 5. An illumination evaluation method for obtaining an evaluation index value representing the degree of illumination on a measured surface of a measurement object, the method comprising:
first data that is light intensity distribution data at a first acceptance angle of reflected light of the illumination light that is irradiated onto the surface to be measured at a predetermined incident angle and reflected by the surface to be measured; a data acquisition step of acquiring second data that is light intensity distribution data at a second light reception angle different from the light reception angle, and diffuse reflection data that is light intensity at a third light reception angle of the diffuse reflection angle;
Based on the first data, a first area ratio of a first area brighter than a predetermined first threshold value and a second area darker than the first threshold value, or a first area brighter than a predetermined first threshold value and the first area A first area ratio between a second area that is darker than a threshold value and a second area that is darker than the second threshold value is calculated, and a second area ratio between a third area that is brighter than a predetermined second threshold value and a fourth area that is darker than the second threshold value based on the second data. Alternatively, a second area ratio between a third area that is brighter than a predetermined second threshold value and a fourth area that is darker than the second threshold value is determined, and the difference between the determined first area ratio and second area ratio is used as difference data. and an evaluation processing step in which the obtained difference data and the diffuse reflection data are used as the evaluation index value.
Light evaluation method. Further comprising a coordinate system having an X-axis representing the diffuse reflection data and a Y-axis representing the difference data, and a display step of displaying coordinate points representing the evaluation index values obtained in the evaluation processing step .
The shine evaluation method according to claim 7. The first acceptance angle is a specular reflection angle,
The second acceptance angle is a diffuse reflection angle.
The shine evaluation method according to claim 7 or claim 8. The incident angle is 45°,
The first acceptance angle is 45°,
The second acceptance angle is any angle within an angle range of 15° to 38°.
The shine evaluation method according to claim 7 or claim 8. The third acceptance angle is any angle within an angle range of 15° to 38°.
The shine evaluation method according to claim 10. The surface to be measured has at least one of wood grain and real wood grain,
The shine evaluation method according to any one of claims 7 to 11.

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