JP2019080325A - Image display method, image display program, and image display device - Google Patents

Abstract

To provide an image display technique which makes it possible to grasp the absolute brightness of an imaging target on the basis of an image.SOLUTION: An image display method comprises processes of: with respect to an image of an imaging target captured by an imaging apparatus which includes an image pickup device without a color filter for color imaging and whose absolute sensitivity is obtained by calibration, setting on the basis of the absolute sensitivity a light volume display scale indicating the correspondence between a light volume expressed with the number of photons per a unit time of light applied from the imaging target and a pixel display state in displaying the image; and displaying the image indicating the absolute light volume of the light applied from the imaging target with the light volume display scale.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image display method, an image display program, and an image display device.

  An image captured using an imaging device such as a CCD camera or a CMOS camera may be displayed automatically or intentionally in a state in which the contrast of the image is adjusted so that the object to be captured can be easily viewed. Such operations are often applied to scientific images.

  As a description of image display, usually, the description of the device and camera used is often finished. Even when the contrast is adjusted, how the contrast is adjusted is not described in relation to the absolute brightness of the object to be photographed.

  Arbitrary contrast adjustments can make the same image appear brighter or darker. Therefore, even if such an image is viewed, it can not be grasped what absolute brightness the object to be photographed has.

  An object of the present invention is to provide an image display technique that enables the absolute brightness of an object to be photographed to be grasped from an image.

According to one aspect of the invention,
Based on the absolute sensitivity, an image of an object to be photographed taken by an image pickup device which is provided with an image pickup element having no color filter for color image pickup and which is calibrated to obtain an absolute sensitivity, light emitted from the object to be photographed Setting a light amount display scale indicating the correspondence between the light amount represented by the number of photons per unit time and the display state of the pixel when the image is displayed;
Displaying an image indicating an absolute light amount of light emitted from the object to be photographed together with the light amount display scale.

According to another aspect of the invention,
Based on the absolute sensitivity, an image of an object to be photographed taken by an image pickup device which is provided with an image pickup element having no color filter for color image pickup and which is calibrated to obtain an absolute sensitivity, light emitted from the object to be photographed Setting a light amount display scale indicating the correspondence between the light amount represented by the number of photons per unit time and the display state of the pixel when the image is displayed;
There is provided an image display program for causing a computer to execute, together with the light amount display scale, an image indicating an absolute light amount of light emitted from the object to be photographed.

According to yet another aspect of the invention,
Based on the absolute sensitivity, an image of an object to be photographed taken by an image pickup device which is provided with an image pickup element having no color filter for color image pickup and which is calibrated to obtain an absolute sensitivity, light emitted from the object to be photographed A function of setting a light amount display scale indicating a correspondence between the light amount represented by the number of photons per unit time and the display state of the pixel when the image is displayed;
There is provided an image display device having a function of displaying an image showing an absolute light amount of light emitted from the object to be photographed together with the light amount display scale.

  By displaying the image of the object to be photographed together with the light amount display scale, it is possible to grasp from the image how much brightness the object to be photographed has, as an absolute light amount.

FIG. 1 is a schematic block diagram of an image display apparatus according to an embodiment of the present invention. FIG. 2 is a flow chart showing a schematic procedure of calibration of an imaging device according to one embodiment. FIG. 3 is a flowchart showing a schematic procedure of photographing and image display of a photographing object according to an embodiment. FIG. 4 is a graph showing an example of relative wavelength sensitivity characteristics. FIG. 5A and FIG. 5B are display examples showing an image showing the light emission state of the object to be photographed (semiconductor multiple quantum well structure) of the example together with the light amount display scale. FIG. 6A and FIG. 6B are display examples showing an image showing the light emission state of the standard light source of the example together with the light amount display scale.

  A schematic configuration of an image display apparatus according to an embodiment of the present invention will be described with reference to FIG. The image display apparatus 1 according to the embodiment is configured to include a holding stand 10, an imaging device 20, a control unit 30, a display unit 40, and an input unit 50.

  The holding stand 10 is configured to hold an object to be photographed 100 that emits light. The imaging device 20 is installed at a position at which the imaging target object 100 held by the holding table 10 can be photographed.

As the imaging device 20, for example, a solid-state imaging device such as a high sensitivity CCD or a CMOS camera can be used. The imaging device 20 is configured to include an iris (iris) mechanism 21, a lens 22, and a solid-state imaging device 23. As the imaging device 23, a (black and white) imaging device having no color filter can be used. The light emitted from the object to be photographed 100 held by the holder 10 is incident on the lens 22 through the diaphragm mechanism 21. (The aperture mechanism 21) opening angle of the lens 22 is theta _0. The lens 22 causes the image of the object to be photographed 100 held on the holder 10 to form an image on the image sensor 23. The imaging device 20 may have a filter that cuts unnecessary wavelength components, as necessary. The filter is disposed between the imaging target 100 and the imaging device 23 (typically, between the imaging target 100 and the lens 22).

  A signal obtained by the light incident on the imaging device 23 is digitized for each pixel by an analog-to-digital converter having a predetermined resolution (for example, 8 bits, 16 bits, etc.) and output as an image. The digitized numerical value for each pixel is called a luminance value. The image data output from the imaging device 20 is input to the control unit 30.

  As the control unit 30, for example, hardware resources such as a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a communication I / F (interface) unit, etc. A computer configured in combination can be used.

  A predetermined program is installed in the control unit 30, and the CPU executes the predetermined program as necessary to realize various functions such as setting of a light amount display scale described later and display of an image and a light amount display scale. Since these functions are realized by the control unit 30, the control unit 30 can be regarded as an image display device. Note that such a predetermined program may be stored and provided in a recording medium readable by the control unit 30 prior to installation, or the control unit through a communication line connected to the control unit 30. 30 may be provided.

  The display unit 40 is configured as an information output unit such as a display device or a printer device, and is controlled by the control unit 30. For example, as described later, an image captured by the imaging device 20, a light intensity display scale, Display Note that various information outputs can be broadly regarded as “display”, including not only electronic display on a display device but also output by printing on a printer device.

  The input unit 50 is configured as an information input unit such as a keyboard and a mouse. The user may input various information by inputting necessary information to the control unit 30 via the input unit 50 or selecting an option presented by the control unit 30 on the display unit 40. it can.

  Next, an image display method using the image display device 1 according to the embodiment will be described. First, calibration of the imaging device 20 is performed. In calibration of the imaging device 20, the absolute sensitivity of the imaging device 20 is acquired. By calibrating the imaging device 20, it is possible to accurately associate the image captured by the imaging device 20 with the amount of light emitted from the imaging target.

  In addition, since the absolute sensitivity of the imaging device 20 can be repeatedly used for image display described later after being obtained once, calibration of the imaging device 20 may be performed once at an initial stage. In addition, you may recalibrate the imaging device 20 at an appropriate opportunity as needed.

  Hereinafter, an example of the calibration procedure of the imaging device 20 will be described. For calibration of the imaging device 20, a standard light source with known emission wavelength, total emission light amount, and emission angle distribution is used. Although the light source used as a standard light source is not particularly limited, it is preferable that the light source has an appropriate amount of light such that the absolute sensitivity of the imaging device 20 can be accurately measured.

  Here, the light quantity is expressed, for example, as the number of photons emitted per unit time (photons / s). The light quantity can also be expressed as power (W) by multiplying this by energy according to the light emission wavelength. The following description exemplifies a case where the light quantity is expressed as the number of photons per unit time (photons / s).

  As a standard light source, for example, it is possible to use a planar semiconductor light emitting element in which a light shielding film having a minute aperture window (for example, a circular aperture window with a diameter of 1 μm to 5 mm) is formed on the surface on the light extraction side. The upper electrode layer of the semiconductor light emitting element can be formed to double as the light shielding film. By adjusting the size of the opening window, the amount of light emitted to the outside of the opening window can be adjusted. Furthermore, by adjusting the ON / OFF pulse ratio (duty ratio) of the drive signal applied to such a semiconductor light emitting element and the lighting cycle, it is possible to precisely adjust the weak light emission amount.

  When the emission wavelength of the standard light source is unknown, the emission wavelength of the standard light source may be, for example, a wavelength-calibrated optical spectrum analyzer device, or a wavelength-calibrated multi-image device such as a spectroscope and a CCD. Measure using a channel analyzer (spectrophotometer).

If the total emitted light amount of the standard light source is unknown, the total emitted light amount of the standard light source is measured using, for example, an integrating sphere method. Let the total amount of light emitted from the standard light source be _ALU .

  When the radiation angle distribution of the standard light source is unknown, the radiation angle distribution of the standard light source is measured, for example, as follows. For example, a photodiode is used as a light detector. First, the photodiode is disposed to face the light emitting portion of the standard light source. Then, the light amount is measured while changing the relative angle of the photodiode with respect to the light emitting portion of the standard light source, and the radiation angle distribution is measured. The radiation angle distribution to be measured may indicate a relative light quantity distribution.

  FIG. 2 is a flowchart showing a schematic procedure of calibration of the imaging device 20. The control unit 30 performs various data processing, calculations, and the like performed in each procedure (steps S11 to S13).

  First, in step S11, a standard light source is photographed by the imaging device 20. More specifically, a standard light source is held on the holding stand 10 as the object to be photographed 100 shown in FIG. 1, and the standard light source is photographed by the imaging device 20. Photographing is performed such that the entire light emitting unit of the standard light source (the entire opening window in the above standard light source example) fits within the image. In addition, photographing is performed with an appropriate light amount and exposure time such that the luminance value of each pixel is not saturated.

Next, in step S12, the incident light amount _PLU is calculated. The incident light amount _PLU is an absolute light amount corresponding to the amount of light incident on the imaging device 20 out of the total emitted light amount _ALU emitted from the standard light source.

First, the light collection efficiency η _L of the imaging device 20 with respect to the standard light source is calculated. The collection efficiency η _L indicates the ratio of the incident light amount P _LU to the total emitted light amount A _LU emitted from the standard light source. In other words,
Light collection efficiency _{L L} = incident light amount P _LU / total radiation amount A _LU
It is expressed as

When the radiation angle distribution of the standard light source is used, the light collection efficiency η _L is within a solid angle corresponding to the opening angle θ ₀ of the imaging device 20 with respect to the value obtained by integrating the radiation angle distribution in all solid angles In the above, it is expressed as a percentage of the integrated value of the radiation angle distribution. In other words,
It is expressed as: collection efficiency 放射_L = radial angular distribution integral value in solid iris angle / radial angular distribution integral value in full solid angle.

For example, when the radiation angle distribution of the standard light source is represented by a Lambert distribution, the collection efficiency η _L can be analytically represented as follows. Here, NA is the numerical aperture (of the diaphragm mechanism 21) of the lens 22 of the imaging device 20.

The incident light amount P _LU is obtained by the collection efficiency η _L and the total emission light amount A _LU
Incident light amount P _LU = Total emitted light amount A _LU × Condensing efficiency η _L
It can be calculated as

If the radiation angle distribution is known as the absolute light amount distribution, the incident light amount _PLU can be obtained by integrating the radiation angle distribution within the iris aperture solid angle.

The calculation of the amount of incident light P _LU is available in step S12, may not be performed after the photographing of the standard light source at step S11, be performed before the standard light source shooting, be performed simultaneously with imaging of standard light source Good.

  Next, in step S13, the absolute sensitivity S of the imaging device 20 is calculated. The absolute sensitivity S indicates the relationship between the unit luminance value and the number of incident photons in imaging with the imaging device 20, and is shown here as the number of incident photons per unit luminance value.

First, with regard to the image of the standard light source output from the imaging device 20, the luminance values of the pixels are integrated over the entire surface of the image to calculate the sum of the luminance values. Then, the sum of the luminance values, divided by the exposure time in shooting, calculates the total sum I _L of the luminance value per unit time.

Absolute sensitivity S can be expressed relative to the sum I _L of the luminance value per unit time, as a ratio of the incident light amount P _{LU (i.e.} the number of incident photons per unit time) to the imaging device 20. In other words,
Absolute sensitivity S = incident light amount P _LU / sum of luminance values per unit time I _L
It is expressed as Thus, calibration of the imaging device 20 is performed, and the absolute sensitivity S is obtained.

  Next, using the imaging device 20 that has been calibrated and the absolute sensitivity S is obtained, the imaging target object to be observed is photographed, and the photographed image is displayed.

  FIG. 3 is a flowchart showing a schematic procedure of photographing and image display of a photographing object to be observed. Various data processing, calculations, and the like performed in each procedure (steps S21 to S23) are performed in the control unit 30. In the present embodiment, a light emitter is illustrated as an object to be photographed.

  First, in step S21, a light emitter is photographed by the imaging device 20. More specifically, the light emitter is held on the holder 10 as the object to be photographed 100 shown in FIG. 1, and the light emitter is photographed by the imaging device 20. Photographing is performed so that the entire light emitting portion of the light emitting body fits within the image. Also, imaging is performed with an appropriate exposure time that does not saturate the luminance value of each pixel. If the light emitter is a variable light amount, the luminance value of each pixel may not be saturated by appropriately selecting the light amount.

  Next, in step S22, a light amount display scale is set based on the absolute sensitivity S for the photographed image of the light emitter. The light amount display scale indicates the correspondence between the luminance value and the light amount, and also displays the pixel through the correspondence between the luminance value and the display state of the pixel in the display image (for example, the brightness in gray scale image display). The correspondence between the state and the light amount is shown. The light amount display scale is displayed together with the image as described in the subsequent step S23.

The correspondence relationship between the luminance value L and the light amount Q is set as follows. When the absolute sensitivity S is used, the luminance value L is converted into the number of photons LS. Furthermore, when the exposure time T _EXP for photographing is used, the luminance value L is converted into the number of photons per unit time, that is, the light quantity, and is expressed as LS / T _EXP .

In this way, a light amount display scale that makes the luminance value L correspond to the light amount LS / T _EXP is obtained. In this light amount display scale, L _SUM S / T _{EXP obtained} by converting the sum L _SUM of luminance values on the entire surface of the image into light amount is equal to the amount of light incident on the imaging device 20 out of all light emitted from the light emitter. Become. Such a light amount display scale is referred to as an incident light amount-based light amount display scale.

  Although the light amount display scale based on the incident light amount can represent the light amount corresponding to the light incident on the imaging device 20, that is, how bright the light is emitted toward the direction of the imaging device 20, the light emitter It can not be expressed about how bright the light is emitted as a whole.

Therefore, in the image display method according to the present embodiment, as described below, the light amount display scale is set such that the sum L _SUM of the luminance values on the entire image represents the total amount of light emitted from the light emitter. Such a light amount display scale is referred to as a light amount display scale based on the total radiation amount.

When setting the light amount display scale based on the total radiation amount, assuming the radiation angle distribution of the light emitter, the light collection efficiency 効率_S of the imaging device 20 with respect to the light emitter is calculated based on the radiation angle distribution. The light collection efficiency η _S is, as described for the light collection efficiency η _L of the standard light source, divided by the radiation angle distribution integral value in the solid angle of the iris aperture by the radiation angle distribution integral value in all the solid angle It can be determined by

For example, if the light emitter is composed of light emitting molecules of random orientation, an isotropic distribution can be assumed as the radiation angle distribution, and the collection efficiency η _S corresponding to the isotropic distribution is
It is expressed as

In the light amount display scale based on the incident light amount, the luminance value L was made to correspond to the light amount LS / T _EXP . In the light amount display scale based on the total radiation amount, the light amount in the light amount display scale based on the incident light amount is divided by the collection efficiency η _S to make the luminance value L correspond to the light amount LS / (T _EXP η _S ). In other words, the light quantity at the light quantity display scale based on the incident light quantity is multiplied by (1 / η _S ). As a result, L _SUM S / (T _EXP η _S ) obtained by converting the total sum L _SUM of the luminance values on the entire surface of the image into light quantity becomes equal to the total light quantity emitted from the light emitter. In this way, the light amount display scale based on the total radiation amount is set.

The radiation angle distribution of the light emitter (or the corresponding collection efficiency 発 光_S ) can be set, for example, by the user inputting from the input unit 50 to the control unit 30. Further, for example, the control unit 30 presents a plurality of radiation angle distribution candidates such as Lambert distribution and isotropic distribution on the display unit 40, and the user selects the appropriate distribution via the input unit 50 to set. You may do so.

  Next, in step S23, the image of the light emitter is displayed together with the light amount display scale. The control unit 30 controls the display unit 40 so that the image is displayed together with the light amount display scale. Here, the case where the image is displayed as a light and dark image (gray scale image) is illustrated.

For grayscale image display, pixels having the maximum luminance value L _M capable of displaying becomes white display. The light amount display scale, which indicates the correspondence between the luminance value and the light amount, also indicates the correspondence between the pixel display state and the light amount through the correspondence between the luminance value and the display state of the pixel. More specifically, the light amount display scale can be displayed, for example, in the form of adding a scale or a numerical value indicating the light amount for a predetermined color (gray) to a gray scale represented by a gradation from black to white. For example, at the end on the white side, the numerical value of the light amount L _M S / (T _EXPに_S ) corresponding to the maximum luminance value L _M is attached. A specific display example of the light amount display scale is shown in an example described later (FIG. 5A, FIG. 5B, etc.).

  As described above, according to the present embodiment, the image of the light emitter can be displayed together with the light amount display scale. As a result, it can be grasped from the image how much brightness the light emitter has, as an absolute light amount.

  As the light amount display scale, it is possible to set a light amount display scale based on the total radiation amount. As a result, it is possible to grasp from the image how much brightness the light emitting body as a whole has, as an absolute light amount.

  In addition to the image of the light emitter and the light amount display scale, the total emitted light amount obtained as the sum of the luminance values on the entire surface of the image may be displayed. Thereby, the total amount of light emitted from the light emitter can be grasped at a glance.

  Next, an image display method according to a first modification of the image display method according to the above-described embodiment will be described. In the first modification, a step of contrast adjustment is added in step S22 of setting the light amount display scale. The other procedures are the same as in the above-described embodiment.

  When the image photographed in step S21 is not displayed as it is, for example, too dark when it is displayed as it is, the contrast adjustment of the image may be performed as described in this modification.

Hereinafter, an example of the procedure of contrast adjustment will be described. Contrast adjustment is performed by changing the maximum luminance value that can be displayed on the pixel from the value L _M before contrast adjustment to the value L _M / α after contrast adjustment obtained by dividing this by the contrast adjustment coefficient α. be able to. As a result, for example, in gray scale display, a pixel having a luminance value L _M / α and displayed in gray in the image before contrast adjustment is displayed in white after contrast adjustment. Quantity display scale, such that the maximum luminance value corresponding to the end portion is changed from L _M to L _{M /} alpha, is set.

  As described above, by changing the correspondence between the luminance value and the display state of the pixel, the contrast of the image is adjusted, and the light amount display scale is set corresponding to the contrast adjustment. Note that, even if the contrast adjustment is performed, the correspondence between the luminance value and the light amount does not change, and the light amount corresponding to the pixel does not change. A specific display example of the light amount display scale in the case where the contrast adjustment is performed will be shown in an example described later (FIGS. 5A, 5B, etc.).

  The contrast adjustment coefficient α can be set, for example, by the user inputting from the input unit 50 to the control unit 30. Alternatively, for example, the control unit 30 may present candidates for a plurality of contrast adjustment coefficients α on the display unit 40, and the user may set them by selecting an appropriate coefficient α through the input unit 50.

  According to the first modification, the contrast can be adjusted so that the image can be viewed more easily, and the light amount display scale can be set so that accurate light amount display can be maintained even if the contrast adjustment is performed.

  Next, an image display method according to a second modification of the image display method according to the above-described embodiment will be described. In the second modification, in step S22 of setting the light amount display scale, a procedure of wavelength sensitivity correction is added. The other procedures are the same as in the above-described embodiment.

  When the light emission wavelength of the light emitter captured in step S21 is different from the light emission wavelength of the standard light source, wavelength sensitivity correction may be performed as described in this modification. When wavelength sensitivity correction is performed, the relative wavelength sensitivity characteristic of the imaging device 20 is acquired in advance.

  The relative wavelength sensitivity characteristic of the imaging device 20 is obtained, for example, as follows. As a light source for relative wavelength sensitivity characteristic measurement, for example, a white light source is prepared. Of the light emitted from the white light source, the light of wavelength λ transmitted through the band pass filter is coupled to the optical fiber.

The total light quantity P _λ of the light of wavelength λ emitted via the optical fiber is measured, for example, by a photodiode. More specifically, the following measurement is performed. For example, in a measurement system using a macro lens, a collimator is attached to the end of the optical fiber on the output side, and the total amount of light emitted from the collimator is measured by a photodiode. For example, in a measurement system using an objective lens, an optical fiber having a smaller NA than that of the objective lens is used to measure the total amount of light emitted from the optical fiber with a photodiode.

Then, the light emitting unit of light of wavelength λ is photographed by the imaging device 20. In the example of the measurement system described above, an image of a collimator or an image of a fiber end is acquired. Then, from the obtained image, the sum I _λ of the luminance values of the light emitting unit is obtained.

From the total light amount P _λ and the sum I _λ of the luminance values of the image, the wavelength sensitivity at the wavelength λ is
Wavelength sensitivity at wavelength λ = sum of luminance values I _λ / total light amount P _λ
Is required.

The wavelength sensitivity at each wavelength λ can be obtained by changing the transmission wavelength λ of the band pass filter and performing the above-mentioned measurement. Assuming that the wavelength sensitivity at an appropriate reference wavelength is 100%, relative wavelength sensitivity RS _λ is obtained as the relative wavelength sensitivity of each wavelength λ. The relative wavelength sensitivity to the wavelength between the measurement wavelengths can be interpolated by an appropriate method.

  FIG. 4 shows an example of the relative wavelength sensitivity characteristic. Note that the measurement shown in FIG. 4 is performed experimentally, and it is considered that more accurate characteristics can be obtained by performing the measurement again.

Next, an example of the procedure of performing wavelength sensitivity correction based on the relative wavelength sensitivity characteristic of the imaging device 20 will be described. Using the relative wavelength sensitivity that represents the emission wavelength of the standard light source as the reference wavelength (100%), the absolute sensitivity of the light emitter to the emission wavelength λ corresponds to the absolute sensitivity S obtained for the standard light source at the wavelength λ It is _calculated as S / RS _λ divided by the relative wavelength sensitivity RS _λ .

Therefore, when wavelength sensitivity correction is performed, the light amount display scale is set by correlating the luminance value L with the light amount LS / (T _EXP η _S RS _λ ).

  According to the second modification, when the light emission wavelength of the standard light source used for calibration of the imaging device 20 and the light emission wavelength of the light emitter to be observed are different, more accurate light amount display can be performed by performing wavelength sensitivity correction. You can set the scale.

  Although the above embodiment exemplifies the case of using the light quantity display scale based on the total radiation quantity, the light quantity display scale based on the incident light quantity may be used as needed.

When a distribution in which light is emitted only in one direction toward the lens of the imaging device is used as the emission angle distribution of the light emitter, the light collection efficiency η _S is 1 (100%), and the light amount based on the total emitted light amount As a result, the display scale will coincide with the light intensity display scale based on the incident light intensity.

  In the above-described embodiment, the gray scale display in which the magnitude of the luminance value is expressed in grayscale is illustrated in step S23. However, the manner in which the magnitude of the luminance value is represented is not particularly limited. . For example, it is possible to display an image and a light amount display scale in pseudo color display in which the magnitude of the brightness value is expressed in pseudo color.

  In addition, as shown to FIG. 6 (A) and FIG. 6 (B) in the below-mentioned Example, you may display the image of the standard light source used for the calibration of an imaging device with a light quantity display scale.

  In addition, although the light-emitting body is illustrated as an imaging | photography target object in the above-mentioned embodiment and the below-mentioned Example, a imaging | photography target object is not limited to a light-emitting body. When photographing an object to be photographed that reflects or scatters light, the light intensity display scale is set for the image and displayed in the same manner as the procedure described for photographing of the light emitter. It becomes possible to grasp how much brightness the object to be photographed has, as an absolute light amount. Here, in order to avoid complexity of expression, radiation (from light emission), reflection, scattering and the like can be collectively referred to as “radiation” for light traveling outward from the object to be photographed.

  Next, an experiment in which a semiconductor multiple quantum well structure is photographed by using an imaging device calibrated using a standard light source to investigate light emission characteristics will be described.

  As a standard light source, a planar light emitting diode (LED) having an emission wavelength of about 630 nm was manufactured using an AlGaInP based semiconductor. This standard light source has a minute circular aperture with a diameter of 100 μm, and can emit light with a weak light quantity of mW to pW. When the standard light source was operated, uniform light emission was observed only from the aperture window, and the radiation angle distribution had a substantially Lambert distribution. The total emitted light quantity was estimated to be 0.044 nW from the total light quantity measurement using the optical power meter. In addition, it is verified by measurement using an integrating sphere that sufficient accuracy can be obtained even by simple total light amount measurement using an optical power meter.

A 10 period GaAs / Al _0.3 Ga _0.7 As multiple quantum well structure (12 nm thick GaAs layer, 10 nm thick Al _0.3 Ga _0.7 As layer) as a light emitter to be observed A device was produced. This device was photoluminescent (PL) light emission (measurement temperature 77 K) and photographed with an image pickup device calibrated with the above standard light source.

  FIG. 5A and FIG. 5B are display examples showing an image showing a light emission state of a light emitter (semiconductor multiple quantum well structure) together with a light quantity display scale based on a total radiation light quantity. The total amount of emitted light obtained as the sum of the luminance values on the entire surface of the image is also displayed (in W) (3.9 nW). FIG. 5A and FIG. 5B show the same light emission state displayed with different contrasts. The light amount display scale is also adjusted according to the adjustment of the contrast.

FIGS. 5A and 5B assume a Lambert distribution as the radiation angle distribution of the light emitter (semiconductor multiple quantum well structure). From the total PL intensity obtained as the sum of the luminance values over the entire image, using the excitation light intensity, the light absorption amount, and the PL light extraction efficiency, the external and internal light emitting quantum yields at 77 K are respectively 3.8 × It was determined to be 10 ^-3 and 0.18.

  FIGS. 6A and 6B are display examples showing an image showing the light emission state of a standard light source together with a light amount display scale based on the total radiation amount. The total amount of emitted light obtained as the sum of the luminance values on the entire surface of the image is also displayed (in W) (0.044 nW). FIG. 6A and FIG. 6B show the same light emission state displayed with different contrasts. The light amount display scale is also adjusted according to the adjustment of the contrast.

  In FIGS. 5A, 5B, 6A, and 6B, the positions of pixels as the vertical and horizontal axes of the image, that is, the positions in the vertical and horizontal directions. Although (Pixel) is shown, for example, they may be displayed in length units to indicate actual dimensions of the light emitter.

  Although the present invention has been described above according to the embodiments and examples, the present invention is not limited to these. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

Reference Signs List 1 image display device 10 holding base 20 imaging device 21 aperture mechanism 22 lens 23 imaging element 30 control unit 40 display unit 50 input unit

Claims (9)

Based on the absolute sensitivity, an image of an object to be photographed taken by an image pickup device which is provided with an image pickup element having no color filter for color image pickup and which is calibrated to obtain an absolute sensitivity, light emitted from the object to be photographed Setting a light amount display scale indicating the correspondence between the light amount represented by the number of photons per unit time and the display state of the pixel when the image is displayed;
Displaying an image indicating an absolute light amount of the light emitted from the object to be photographed together with the light amount display scale.   The calibration of the imaging device is performed by photographing the standard light source, which emits light with a weak light quantity of mW to pW order by having an aperture window of a predetermined size, and the radiation source has a Lambertian distribution, using the imaging device. The image display method according to claim 1, which is performed.   In the step of setting the light amount display scale, a radiation angle set from among a plurality of radiation angle distributions including Lambert distribution and isotropic distribution as radiation angle distribution assumed for light emitted from the object to be photographed The image display method according to claim 1, wherein the light amount display scale is set based on a distribution such that a sum of luminance values of the image represents a total emitted light amount of light emitted from the object to be photographed. 4. The method according to claim 1, further comprising the step of causing the user to select the radiation angle distribution assumed for the light emitted from the photographing object from a plurality of radiation angle distributions including a Lambert distribution and an isotropic distribution. The image display method according to any one of the items. The image is displayed by changing the correspondence between the luminance value of the image and the display state of the pixel when the image is displayed, which is determined according to the amount of light emitted from the object to be photographed. The image display method according to any one of claims 1 to 4, further comprising the steps of adjusting the contrast at the same time and resetting the light amount display scale in accordance with the contrast adjustment.   The image display method according to any one of claims 1 to 5, wherein in the step of setting the light amount display scale, the light amount display scale is set based on relative wavelength sensitivity characteristics of the imaging device.   The image display method according to any one of claims 1 to 6, wherein, in the step of displaying the image together with the light amount display scale, the image and the light amount display scale are displayed in pseudo color. Based on the absolute sensitivity, an image of an object to be photographed taken by an image pickup device which is provided with an image pickup element having no color filter for color image pickup and which is calibrated to obtain an absolute sensitivity, light emitted from the object to be photographed Setting a light amount display scale indicating the correspondence between the light amount represented by the number of photons per unit time and the display state of the pixel when the image is displayed;
An image display program for causing a computer to execute a procedure of displaying an image indicating an absolute light amount of light emitted from the object to be photographed together with the light amount display scale. Based on the absolute sensitivity, an image of an object to be photographed taken by an image pickup device which is provided with an image pickup element having no color filter for color image pickup and which is calibrated to obtain an absolute sensitivity, light emitted from the object to be photographed A function of setting a light amount display scale indicating a correspondence between the light amount represented by the number of photons per unit time and the display state of the pixel when the image is displayed;
An image display device having a function of displaying an image indicating an absolute light amount of light emitted from the object to be photographed together with the light amount display scale;