JP4477517B2 - Color adjustment method and color adjustment apparatus - Google Patents

Description

  The present invention relates to a color adjustment method and a color adjustment apparatus capable of performing adjustment while reducing variation in adjustment due to individual differences among color adjustment apparatuses.

  An imaging system of a general digital camera often includes an imaging lens group, an IR (infrared) cut filter as an optical low-pass filter, and a CCD unit. In such a configuration, the light incident through the imaging lens group passes through the IR cut filter, and after removing harmful infrared components, is imaged on the CCD unit. The CCD unit is composed of a microlens array, a color filter, and a CCD element, and the light collected for each pixel by the microlens array is applied to the CCD element via, for example, a primary color Bayer array color filter. Imaged.

  Here, among the imaging lens group, the IR cut filter, and the micro lens array and the color filter of the CCD unit, the IR cut filter and the color filter have large variations in spectral sensitivity characteristics, respectively, and the color reproduction of the image by the digital camera. It will have a big influence on.

  In order to minimize this effect in the digital camera, it is necessary to adjust the correction values for white balance and color correction for each digital camera. Conventionally, such adjustment is performed based on the result obtained by photographing a specific color chart using a light source that is actually desired for photographing.

In Patent Document 1, a rotary band-pass filter disk that allows light of a plurality of specific wavelength bands to pass is installed between a light source and a digital camera. With such a configuration, it is possible to perform accurate white balance and color adjustment with respect to other light sources that do not actually exist only by performing adjustment work using one type of light source.
JP 2001-320716 A

  However, in the method of Patent Document 1, in order to perform adjustments related to a plurality of types of light sources, it is necessary to perform imaging for the number of times corresponding to the types of the light sources, so that adjustment takes time.

  In addition, when the adjustment of the method of Patent Document 1 is performed by a plurality of adjustment devices, there may be variations in the adjustment results for each device due to, for example, manufacturing variations of components such as adjustment disks.

  The present invention has been made in view of the above circumstances, and provides a color adjustment method and a color adjustment apparatus that do not take time for adjustment and can be adjusted in consideration of individual differences in components of the adjustment apparatus. The purpose is to provide.

In order to achieve the above object, in the color adjustment method according to the first aspect of the present invention, at least one digital camera is selected from among a plurality of digital cameras to be subjected to color adjustment. A plurality of image data is obtained by photographing a predetermined light source of the color adjustment device a plurality of times using a digital camera, and the components of the color adjustment device are based on the plurality of image data obtained by the digital camera individual differences to create a color adjustment apparatus for a coefficient which reflects the, save the color adjusting device for coefficients above created, have rows color adjustment of the digital camera by using the stored color adjustment device coefficient, The plurality of times of photographing are performed without interposing an infrared cut filter that is one of the constituent members of the color adjustment device between the predetermined light source and the digital camera, and the predetermined light source. Serial interposed the infrared cut filter between the digital camera characterized in that it comprises a shooting and performed.

The color adjustment method according to the second aspect of the present invention obtains a plurality of image data by photographing a predetermined light source of the color adjustment device a plurality of times using a plurality of digital cameras to be subjected to color adjustment. Then, based on a plurality of image data acquired by the plurality of digital cameras, a plurality of color adjustment device coefficients reflecting individual differences of the constituent members of the color adjustment device are created, and the plurality of created Based on the color adjustment device coefficient, the optimum digital camera for creating the color adjustment device coefficient is selected, the color adjustment device coefficient corresponding to the selected digital camera is stored, and the stored color Color adjustment of the plurality of digital cameras is performed using the adjustment device coefficient.

  The color adjustment apparatus according to the third aspect of the present invention is configured to freely advance and retract between the A light source, a digital camera that captures the A light source and acquires image data, and the A light source and the digital camera. An infrared cut filter that removes an infrared light component of light from the A light source, a spectral sensitivity characteristic of the A light source, a spectral sensitivity characteristic of a reference digital camera, and a reference infrared cut filter A reference data storage unit that stores at least spectral sensitivity characteristics as reference data, image data acquired by imaging performed without interposing the infrared cut filter between the A light source and the digital camera, and Image data acquired by photographing performed with the infrared cut filter interposed between the A light source and the digital camera, and the reference data Color adjustment device coefficient for creating a color adjustment device coefficient reflecting individual differences of the infrared cut filter for each color adjustment device when color adjusting the digital camera from the reference data stored in the storage unit And a color adjusting device coefficient storage unit for storing the color adjusting device coefficient generated by the color adjusting device coefficient generating unit.

According to these 1st- 3rd aspects, color adjustment can be performed using the coefficient for color adjustment apparatuses reflecting the individual difference of the structural member of a color adjustment apparatus.

  According to the present invention, it is possible to provide a color adjustment method and a color adjustment apparatus that do not take time for adjustment and can perform adjustment in consideration of individual differences of components of the adjustment apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram of a color adjustment apparatus 10 according to an embodiment of the present invention.
Referring to the configuration of FIG. 1 schematically, a viewer 13 having a light source 12 and a digital camera for adjusting the color adjusting device 10 (hereinafter simply referred to as “light-shielding member 11” which shields outside light from entering). (Referred to as a digital camera) 14 and the viewer 13 can be photographed by the digital camera 14. Here, the digital camera 14 in FIG. 1 is a camera selected from a plurality of digital cameras to be adjusted by the color adjustment apparatus 10. As the light source 12, for example, an A light source is used. The spectral sensitivity characteristic of the A light source is shown as characteristic L21 in FIG.

  In FIG. 1, an equipment IR cut filter 15 is disposed between the viewer 13 and the digital camera 14 so as to be freely inserted or retracted. Here, the equipment IR cut filter 15 is attached to the attachment member 16, and the attachment member 16 is further attached to the filter moving device 17.

  FIG. 3 is a front view of the equipment IR cut filter 15, the attachment member 16, and the filter moving device 17. As shown in FIG. 3, the attachment member 16 is movably attached to the filter moving device 17, and the equipment IR cut filter 15 is moved by sliding the attachment member 16 in the direction of the arrow shown in the figure. It is inserted between the viewer 13 and the digital camera 14 to remove a specific wavelength component (infrared component) of light incident through the viewer 13, or the equipment IR cut filter 15 is inserted between the viewer 13 and the digital camera 14. It can be evacuated. Here, the spectral sensitivity characteristic of a general IR cut filter has a characteristic as shown in FIG. 4, for example.

  In FIG. 1, the digital camera 14 and the filter moving device 17 are connected to a personal computer 20 via connection cables 18 and 19, respectively. A memory 21 and a CPU 22 are provided in the personal computer 20 as a reference data storage unit, a color adjustment device coefficient creation unit, and a color adjustment device coefficient storage unit. The memory 21 is a memory including an adjustment program storage unit 21a for storing an adjustment program, a reference data storage unit 21b for storing reference data to be described later, and the like. The CPU 22 controls the adjustment of the color adjusting device 10 by controlling the digital camera 14 and the filter moving device 17 to operate at a desired timing based on data stored in the memory 21.

  FIG. 5 is a configuration diagram of an imaging system used in the digital camera 14. As shown in the figure, the light incident through the imaging lens group 30 passes through an IR cut filter 31 as an optical low-pass filter and is removed from the harmful infrared component, and then incident on the CCD unit 32. The Here, as the equipment IR cut filter 15 attached to the filter moving device 17 via the attachment member 16, an infrared cut wavelength having a shorter wavelength than the cut wavelength of the IR cut filter 31 of the digital camera 14 is used. To.

  The CCD unit 32 includes a microlens array 32a, a color filter 32b, and a CCD element 32c. The light collected for each pixel by the microlens array 32a of the CCD unit 32 is imaged on the CCD element 32c via, for example, a color filter 32b having a primary color Bayer arrangement. Here, the primary color Bayer array color filter is a color filter having four pixels of R, Gr, Gb, and B as one pixel array unit.

  FIG. 6 is a flowchart showing the entire processing contents for obtaining the color adjusting device coefficient reflecting the individual difference of the color adjusting device 10 set as shown in FIG. The processing in FIG. 6 is executed by the CPU 22 in accordance with a program stored in the adjustment program storage unit 21a in the personal computer 20 in FIG. In FIG. 6, an example in which a characteristic parameter for correcting variation due to individual differences of the equipment IR cut filter 15 is calculated as the color adjustment device coefficient will be described.

  In FIG. 6, first, the CPU 22 acquires the circuit board number of the digital camera 14 set as shown in FIG. 1 (step S1). Here, the circuit board number is identification information set for each digital camera to be adjusted, and is configured by a storage unit (for example, an EEPROM or the like) for storing various adjustment values of the digital camera. ) Is stored. Hereinafter, the circuit board number is expressed as MC_cam.

Next, the CPU 22 causes the digital camera 14 to photograph the viewer 13 in a state where the equipment IR cut filter 15 is not interposed between the viewer 13 and the digital camera 14, and the light from the light source 12 is emitted from the digital camera 14. (Step S2). Then, the CPU 22 acquires image data obtained by photographing with the digital camera 14 (step S3). Here, the image data acquired in step S3 is actually the white level of the image data. As shown in FIG. 7, the white level is obtained by calculating an average value of R, Gr, Gb, and B color components of 32 pixels in the center × 32 pixels in the center of the image obtained by photographing. Regarding Gb,
G = (Gr + Gb) / 2 (Formula 1)
To obtain. In this case, the R and B components are the average of 256 pixels, and the G component is the average of 512 pixels. Hereinafter, the white level R component and the G component obtained in step S3 in this way are denoted as White_r_get and White_g_get, respectively.

  Next, the CPU 22 causes the digital camera 14 to photograph the viewer 13 with the equipment IR cut filter 15 interposed between the viewer 13 and the digital camera 14, and the light from the light source 12 is transmitted to the equipment IR cut filter. The digital camera 14 receives light through 15 (step S4). And CPU22 acquires the white level of the image data obtained by imaging | photography with the digital camera 14 similarly to step S3 (step S5). Hereafter, the white level R component and G component obtained in step S5 are denoted as White_ir_r_get and White_ir_g_get, respectively.

  Next, the CPU 22 calculates the color for calculating the characteristic parameter of the equipment IR cut filter 15 from the white level of the image data acquired in steps S3 and S5 and the reference data stored in the reference data storage unit 21b. An adjustment device coefficient calculation operation is performed (step S6). After completion of the color adjustment device coefficient calculation calculation, the processing of FIG.

Next, the color adjustment device coefficient calculation calculation in step S6 will be described.
First, reference data stored in the reference data storage unit 21b will be described. This reference data is reference data having a fixed value used in later calculations.

  The first reference data stored in the reference data storage unit 21b is the spectral sensitivity characteristic of the A light source shown in FIG. Hereinafter, the spectral characteristic of the A light source is expressed as HGVWR_spct_ref_x. Here, x indicates the wavelength value of FIG. 2, and is a value that changes every 1 [nm] within a range of 380 ≦ x ≦ 720. In the following, it is assumed that x represents a wavelength value that changes every 1 [nm] within a range of 380 ≦ x ≦ 720.

  The second reference data is a spectral sensitivity characteristic of an IR cut filter (hereinafter referred to as a reference IR cut filter) serving as a predetermined reference. This characteristic is indicated by L41 in FIG. Hereinafter, the spectral sensitivity characteristic of the reference IR cut filter is denoted as IR_spct_ref_x.

  The third reference data is a long wavelength band of a CCD element used in a digital camera serving as a predetermined reference, that is, a reference spectral sensitivity characteristic of an R component. This characteristic is indicated by L81 in FIG. Hereinafter, the R reference spectral sensitivity characteristic is expressed as R_ccd_ref_x.

  The fourth reference data is an intermediate wavelength band of a CCD element used in a digital camera serving as a predetermined reference, that is, a G component reference spectral sensitivity characteristic. This characteristic is indicated by L82 in FIG. Hereinafter, the G reference spectral sensitivity characteristic is expressed as G_ccd_ref_x.

  Here, the R reference spectral sensitivity characteristic L81 and the G reference spectral sensitivity characteristic L82 shown in FIG. 8 are each normalized so that the maximum spectral sensitivity of the G reference spectral sensitivity characteristic L82 is 100.

  As for the fifth reference data, the R reference spectral sensitivity characteristic L81 and the spectral sensitivity characteristic L41 of the reference IR cut filter are integrated every 1 [nm] in the visible wavelength band (380 [nm] to 720 [nm]). It is the spectral sensitivity characteristic obtained by this. This characteristic is indicated by L84 in FIG. Hereinafter, this data is expressed as R_ir_ccd_ref_x.

  The sixth reference data is obtained by integrating the product of the R reference spectral sensitivity characteristic L81 and the spectral sensitivity characteristic L21 of the light source 12 every 1 [nm] in the visible wavelength range (380 [nm] to 720 [nm]). This is the integrated value obtained by calculating the sum. Hereinafter, this data is expressed as White_r_ref.

  The seventh reference data is obtained by integrating the product of the G reference spectral sensitivity characteristic L82 and the spectral sensitivity characteristic L21 of the light source 12 every 1 [nm] in the visible wavelength range (380 [nm] to 720 [nm]). This is the integrated value obtained by calculating the sum. Hereinafter, this data is expressed as White_g_ref.

  The eighth reference data includes an R reference spectral sensitivity characteristic L81, a spectral sensitivity characteristic L21 of the light source 12, and a spectral sensitivity characteristic L41 of the reference IR cut filter in the visible wavelength range (380 [nm] to 720 [nm]). It is an integrated value obtained by integrating every [nm] and calculating the sum thereof. Hereinafter, this data is expressed as White_ir_r_ref.

  The ninth reference data includes a G reference spectral sensitivity characteristic L82, a spectral sensitivity characteristic L21 of the light source 12, and a spectral sensitivity characteristic L41 of the reference IR cut filter in the visible wavelength range (380 [nm] to 720 [nm]). It is an integrated value obtained by integrating every [nm] and calculating the sum thereof. Hereinafter, this data is expressed as White_ir_g_ref.

  Although not used in the color adjustment device coefficient calculation calculation, in order to perform color adjustment of a digital camera using the color adjustment device 10, the short wavelength band of the CCD element shown in L83 in FIG. The product of the reference spectral sensitivity characteristic B_ccd_ref_x, the B reference spectral sensitivity characteristic L83 and the spectral sensitivity characteristic L21 of the light source 12 is integrated every 1 [nm] in the visible wavelength band (380 [nm] to 720 [nm]). The integrated value White_b_ref obtained by calculating the sum thereof must also be stored as reference data.

FIG. 9 is a flowchart showing the processing for calculating the color adjusting device coefficient.
In FIG. 9, first, the R sensitivity coefficient k_R_get is obtained from the white level obtained without passing through the equipment IR cut filter 15 in step S3 of FIG.
k_R_get = White_r_get / White_g_get (Formula 2)
(Step S11).

Next, from the white level obtained in step S3 and step S5 in FIG. 6, the change amount of the white level obtained before and after the installation of the equipment IR cut filter 15 is set as a G component IR cut coefficient k_ir_g_get.
k_ir_g_get = White_ir_g_get / White_g_get (Formula 3)
(Step S12). Next, from the reference data White_ir_g_ref and White_g_ref, the G component IR cut coefficient k_ir_g_ref of the reference IR cut filter is
k_ir_g_ref = White_ir_g_ref / White_g_ref (Formula 4)
(Step S13). Next, from k_ir_g_get obtained in step S12 and k_ir_g_ref obtained in step S13, an IR cut filter correction coefficient k_adj_ir is obtained as follows:
k_adj_ir = k_ir_g_get / k_ir_g_ref (Formula 5)
(Step S14).

  Next, the spectral sensitivity characteristic R_cam_cal1_x of the R component and the spectral sensitivity characteristic G_cam_cal1_x of the G component of the digital camera 14 are calculated from the white level obtained by photographing with the digital camera 14 (step S15).

For this purpose, first, from the white level acquired in step S3 of FIG.
kR = (White_r_get / White_g_get) / (White_r_ref / White_g_ref) (Formula 6)
Ask from.

Next, R spectrum first detection data R_ccd_est1_x and G spectrum first detection data G_ccd_est1_x are respectively obtained.
R_ccd_est1_x = R_ccd_ref_x × kR (380 ≦ x ≦ 720)
G_ccd_est1_x = G_ccd_ref_x × 1 (380 ≦ x ≦ 720) (Formula 7)
Ask from. Furthermore, a value sR_ccd_est1 obtained by integrating R_ccd_est1_x in the range of 380 ≦ x ≦ 720 is obtained.
sR_ccd_est1 = R_ccd_est1_380 + R_ccd_est1_381 +… + R_ccd_est1_720 (Formula 8)
It asks like this.

Here, the influence of the spectral sensitivity characteristic of the IR cut filter 31 inside the digital camera 14 on the spectral sensitivity characteristic of the R component is corrected. For this purpose, the relative sensitivity coefficient kIRR of R with respect to G through the equipment IR cut filter 15 is determined from the white level acquired in step S5 of FIG.
kIRR = (White_ir_r_get / White_ir_g_get) / (White_ir_r_ref / White_ir_g_ref) (Formula 9)
Ask from.

Next, the relative spectral sensitivity characteristic R_IR_ccd_est_x through the equipment IR cut filter 15 is
R_IR_ccd_est_x = R_IR_ccd_ref_x × kIRR (380 ≦ x ≦ 720) (Equation 10)
Ask from.

Next, paying attention to the spectral sensitivity at the cut wavelength 620 [nm] of infrared light, the actual R spectral relative sensitivity coefficient kR_h is
kR_h = R_IR_ccd_est_620 / R_ccd_ref_620 (Formula 11)
Ask from. Based on the R spectral relative sensitivity coefficient kR_h, the R spectral second detection data R_ccd_est2_x is
R_ccd_est2_x = R_ccd_ref_x (380 ≦ x ≦ 540)
R_ccd_est2_x = R_ccd_ref_x × kR_h (541 ≦ x ≦ 720) (Formula 12)
Ask from. The R spectral second detection data R_ccd_est2_x is shown in a characteristic L85 in FIG. Next, the integrated value sR_ccd_est2 is calculated from the R spectrum second detection data thus obtained.
sR_ccd_est2 = R_ccd_est2_380 + R_ccd_est2_381 +… + R_ccd_est2_720 (Formula 13)
It asks like this.

  Using the values obtained as described above, the spectral sensitivity characteristics of the R component and the G component are calculated according to the procedure of FIGS.

  First, the CPU 22 obtains a difference dR = sR_ccd_est2-sR_ccd_est1 between the integrated value sR_ccd_est2 of the R spectral second detection data and the integrated value sR_ccd_est1 of the R spectral first detection data (step S21). Next, it is determined whether the difference dR obtained in step S21 is positive or negative (step S22). If it is determined in step S22 that dR is positive, the process proceeds to step 23. If negative, the process proceeds to step S33.

  If the difference dR is positive in the determination in step S22, initialization is performed by substituting the R_ccd_est2_x 621 [nm] spectral sensitivity R_ccd_est2_621 for the R spectral movement amount calculation integrated value diff (step S23). Next, initialization is performed by substituting 0 for the count value n of a counter (not shown) (step S24).

  Next, the R spectral movement amount calculation integrated value diff initialized as described above is compared with the difference dR to determine whether or not diff> dR is satisfied (step S25). If it is determined in step S25 that diff ≦ dR, the value of R_ccd_est2_ (622 + n) is added to diff (step S26). Since n = 0 at the first time, the value of R_ccd_est2_622 is added. Subsequently, n is incremented (step S27), and the process returns to step S25. That is, in the determination of step S25, the operation from step S25 to step S27 is repeated while adding the value after 622 [nm] of R_ccd_est2_x in increments of 1 [nm] until diff> dR.

  If it is determined in step S25 that diff> dR, the process proceeds to step S28, and R spectral third detection data R_ccd_est3_x indicated by the characteristic L87 in FIG. 13 is obtained (step S28). This R_ccd_est3_x is the characteristic of the section of 621 ≦ x ≦ 700 of the R spectral second detection data R_ccd_est2_ (x + n) shifted from 621 [nm] to the long wavelength side by n [nm]. Further, R_ccd_est3_x is clipped to 0 within the range of 701 ≦ x ≦ 720 (step S29).

  Next, the validity of the value of n is confirmed by determining whether or not the count value n is less than or equal to the predetermined value Max_shift (step S30). Here, it is assumed that Max_shift is 20, for example. If n exceeds Max_shift in the determination in step S30, it is determined that there is an error in the calculation of the spectral characteristic, and that is output, and the spectral calculation calculation is terminated.

On the other hand, if it is determined in step S30 that n is equal to or smaller than Max_shift, n is substituted into the R spectral shift amount shift (step S31). Subsequently, the x coordinate a and the y coordinate b of the point P82 shown in FIG. 13 and the x coordinate c and the y coordinate d of the point P83 shown in FIG.
a = 640-shift
b = R_ccd_est3_640
c = 620
d = R_ccd_est3_620 (Formula 14)
(Step S32).

  Here, a point P82 (characteristic point after the shift) in FIG. 13 is a point P81 (characteristic point before the shift) indicating the spectral sensitivity at the wavelength 640 [nm] of R_ccd_est3_x laterally shifted by the R spectral movement amount shift to the short wavelength side. This is the shifted point. A point P83 in FIG. 13 is a point indicating the spectral sensitivity of R_ccd_est3_x at a wavelength of 620 [nm]. The wavelength 640 [nm] is the wavelength at the inflection point of the R reference spectral sensitivity characteristic shown in the characteristic L81 of FIG. 8, and the wavelength 620 [nm] is the IR cut wavelength of a general IR cut filter.

  In the determination of step S22, if dR is negative, initialization is performed by substituting a value obtained by multiplying the spectral sensitivity R_ccd_est_621 at the wavelength 621 [nm] of R_ccd_est2_x by −1 in diff (step S33). n is initialized to 0 as in step S24 (step S34).

  Next, the R spectral movement amount calculation integrated value diff initialized as in step S33 is compared with the difference dR to determine whether or not diff <dR (step S35). If diff ≧ dR in the determination in step S35, the value of R_ccd_est2_ (622 + n) is subtracted from diff (step S36). Since n = 0 at the first time, the value of R_ccd_est2_622 is subtracted. Subsequently, n is incremented (step S37), and the process returns to step S35. That is, in the determination in step S35, the operations in steps S35 to S37 are repeated until diff <dR.

  If it is determined in step S35 that diff <dR, the process proceeds to step S38. Then, it is determined whether n is 0 (step S38). If it is determined in step S38 that n is 0, R_ccd_est2_x is substituted into R_ccd_est3_x within a range of 621 ≦ x ≦ 700 (step S39). Thereafter, the process proceeds to step S42.

  On the other hand, if it is determined in step S38 that n is not 0, first, 1 is added to n (step S40), and then R_ccd_est3_x is shifted from 621 [nm] to the short wavelength side by n [nm]. Spectral second detection data R_ccd_est2_ (xn) is substituted in a range of 621 ≦ x ≦ 700 (step S41). Next, R_ccd_est3_x is clipped to 0 in the range of 701 ≦ x ≦ 720 (step S42).

  Next, the validity of the value of n is confirmed by determining whether or not the count value n is less than or equal to the predetermined value Max_shift (step S43). If n exceeds Max_shift in the determination in step S43, it is determined that there is an error in spectral prediction, and that is output, and the spectral calculation calculation ends.

On the other hand, if it is determined in step S43 that n is equal to or smaller than Max_shift, n is substituted into the R spectral shift amount shift (step S44). Subsequently, the above a, b, c, d are respectively
a = 640 + shift
b = R_ccd_est3_640
c = 620
d = R_ccd_est3_620 (Formula 15)
(Step S45). The point P82 in this case is a point obtained by laterally shifting the point P81 indicating the spectral sensitivity at the wavelength 640 [nm] of R_ccd_est3_x indicated as the characteristic L86 to the long wavelength side by the R spectral movement amount shift.

  After a, b, c, and d are obtained in step S32 or step S45, smooth interpolation is performed between point P82 and point P83 shown in FIG. 13 using the obtained a, b, c, and d. Here, in this embodiment, linear interpolation is performed using the straight line 801 shown in FIG. 13, but curved interpolation may be performed.

Next, in order to obtain the R spectral fourth detection data R_ccd_est4_x including the straight line 801, first, from the above a, b, c, d
R_ccd_est4_x = {(bd) / (ac)} × (xc) + d (621 ≦ x ≦ a-1) (Formula 16)
Is calculated (step S46). This section is a portion of the straight line 801. Next, R_ccd_est4_x from the wavelength at the point P82 to the wavelength 720 [nm] is set as R_ccd_est3_x (step S47).

Thereafter, the R spectral sensitivity characteristic R_cam_cal1_x and the G spectral sensitivity characteristic G_cam_cal1_x are respectively determined based on the R spectral fourth detection data obtained in steps S46 and S47.
R_cam_cal1_x = R_ccd_est2_x (380 ≦ x ≦ 620) + R_ccd_est4_x (621 ≦ x ≦ 720)
G_cam_cal1_x = G_ccd_est1_x (380 ≦ x ≦ 620) (Equation 17)
Ask from. That is, regarding the R spectral sensitivity characteristic, the R spectral second detection data R_ccd_est2_x obtained from the second detection result is used as it is for the spectral sensitivity characteristic from the wavelength 380 [nm] to 620 [nm], and 621 [nm]. To 720 [nm], the R spectral fourth detection data R_ccd_est4_x obtained from the R spectral second detection data R_ccd_est2_x is used. As a result, an appropriate R spectral sensitivity characteristic considering the influence of the spectral sensitivity characteristic of the IR cut filter 31 inside the digital camera 14 can be obtained. Since the G spectral sensitivity characteristic is less affected by the IR cut filter 31 inside the digital camera 14, the spectral first detection data obtained without using the equipment IR cut filter 15 can be used as it is.

  By such a method, the R spectral sensitivity characteristic is obtained as a characteristic L87 obtained by adding the R spectral second detection data and the R spectral fourth detection data in FIG. The G spectral sensitivity characteristic is the G reference spectral sensitivity characteristic L82 itself. FIG. 13 also shows the B spectral sensitivity characteristic L88. The B spectral sensitivity characteristic L88 is obtained by integrating the product of the B reference spectral sensitivity characteristic B_ccd_ref_x, the B reference spectral sensitivity characteristic L83, and the spectral sensitivity characteristic L21 of the light source 12 every 1 [nm] in the visible wavelength range. Can be obtained using the integrated value White_b_ref calculated.

Here, it returns to description of FIG. 9 again. After calculating the R component spectral sensitivity characteristic R_cam_cal1_x and the G component spectral sensitivity characteristic G_cam_cal1_x in step S15 of FIG. The difference dSUM_IR_obj between the integrated value and the integrated value of the spectral sensitivity of the equipment IR cut filter 15 is
SUM_IR_ref = IR_spct_ref_380 +… + IR_spct_ref_720
dSUM_IR_obj = (k_adj_ir-1) × SUM_IR_ref (Formula 18)
(Step S16). Next, the equipment IR cut filter spectral correction data calculated value IR_spct_obj_cal_x (380 ≦ x ≦ 720) as a characteristic parameter,
IR_spct_obj_cal_x = IR_spct_ref_x + {(IR_spct_ref_x / SUM_IR_ref) × dSUM_IR_obj}
(380 ≦ x ≦ 619)
IR_spct_obj_cal_x = IR_spct_ref_x (620 ≦ x ≦ 720) (Formula 19)
(Step S17). A characteristic of the calculated value of the equipment IR cut filter spectral correction data is indicated by L42 in FIG.

Next, a characteristic parameter calculation value of the equipment IR cut filter 15 is obtained (step S18). For this purpose, first, using the equipment IR cut filter spectral correction data calculated value obtained in step S17,
R_spct_ir_obj_x = R_ccd_ref_x × IR_spct_obj_cal_x × HGVWR_spct_ref_x
G_spct_ir_obj_x = G_ccd_ref_x × IR_spct_obj_cal_x × HGVWR_spct_ref_x
(380 ≦ x ≦ 720) (Formula 20)
Thus, an integrated value of the R spectral sensitivity characteristic and the G spectral sensitivity characteristic of the digital camera 14 in a state in which the dispersion of the spectral sensitivity characteristic due to the individual difference of the equipment IR cut filter 15 is corrected is obtained. Then, by calculating the sum of these calculated integrated values, the characteristic parameter calculation values of the color adjustment device 10 (the white level R component and G component in a state where the spectral sensitivity variation of the equipment IR cut filter 15 is corrected) White_ir_r_obj_cal and White_ir_g_obj_cal The
White_ir_r_obj_cal = R_spct_ir_obj_380 + R_spct_ir_obj_381 +… + R_spct_ir_obj_720
White_ir_g_obj_cal = G_spct_ir_obj_380 + G_spct_ir_obj_381 +… + G_spct_ir_obj_720
(Formula 21)
Ask from. Further, the coefficient k_White_ir_obj_cal of the characteristic parameter calculated value obtained as in (Equation 21) is
k_White_ir_obj_cal = White_ir_r_obj_cal / White_ir_g_obj_cal (Formula 22)
Ask from. At the same time, the characteristic parameter reference coefficient k_White_ir_ref
k_White_ir_ref = White_ir_r_ref / White_ir_g_ref (Formula 23)
Ask from. Then, the difference dk_White_ir_obj_cal of the coefficient of the characteristic parameter calculation value from the values obtained as in (Expression 22) and (Expression 23) is
dk_White_ir_obj_cal = ABS {(k_White_ir_obj_cal / k_White_ir_ref) -1} (Formula 24)
Ask from. Here, ABS in (Equation 24) indicates that the absolute value in parentheses is calculated.

  The subsequent calculation is for confirming whether or not the characteristic parameter of the equipment IR cut filter 15 has been properly obtained by verification. For this purpose, the CPU 22 uses the characteristic parameter calculation values White_ir_r_obj_cal and White_ir_g_obj_cal to calculate the R spectral sensitivity characteristic R_cam_cal2_x and the G spectral sensitivity characteristic G_cam_cal2_x of the digital camera 14 by the same method as the spectral calculation in step S15 (step S19). ). However, here, the calculation is performed by replacing White_ir_r_ref and White_ir_g_ref with White_ir_r_obj_cal and White_ir_g_obj_cal, respectively.

After calculating the spectral sensitivity characteristics in step S19, the white level is verified (step S20). In this white level verification, the R spectral sensitivity characteristic R_cam_cal2_x and the G spectral sensitivity characteristic G_cam_cal2_x obtained in step S19 are used.
R_spct_cal2_x = R_cam_cal_2_x × HGVWR_spct_ref_x (380 ≦ x ≦ 720)
G_spct_cal2_x = G_cam_cal_2_x × HGVWR_spct_ref_x (380 ≦ x ≦ 720) (Equation 25)
In this manner, the R spectral sensitivity characteristic and the G spectral sensitivity characteristic are integrated. Then, the sum of these calculated integrated values for each wavelength component is
White_r_cal2 = R_spct_cal2_380 + R_spct_cal2_381 +… + R_spct_cal2_720
White_g_cal2 = G_spct_cal2_380 + G_spct_cal2_381 +… + G_spct_cal2_720 (Formula 26)
It asks like this. Furthermore, the R sensitivity coefficient k_R_cal2 is calculated from the integrated value obtained as in (Equation 26).
k_R_cal2 = White_r_cal2 / White_g_cal2 (Formula 27)
Ask from. Next, the difference dk_R_cal2 between the R sensitivity coefficient k_R_cal2 and the R sensitivity coefficient k_R_get is set to
dk_R_cal2 = ABS {(k_R_cal2 / k_R_get) -1} (Formula 28)
Ask from. Next, the CPU 22 determines whether or not the difference dk_R_cal2 is less than 0.05 (step S21). In the determination of step S21, when the difference dk_R_cal2 is not less than 0.05, that is, when the difference between the R sensitivity coefficient obtained using the reference data and the R sensitivity coefficient obtained using the newly calculated characteristic parameter is large. Finishes the color adjustment device coefficient calculation calculation. In this case, the digital camera 14 is notified that it was inappropriate for adjustment. The determination value 0.05 in step S21 is an example and can be changed.

  On the other hand, if the difference dk_R_cal2 is less than 0.05 in the determination in step S21, the CPU 22 determines that the characteristic parameter has been appropriately obtained, and the CPU 22 determines the color adjustment device coefficient as a predetermined directory in the memory 21. For example, it is saved as a CSV (Comma-Separated Value) format file. Hereinafter, this file is referred to as a characteristic file. Here, since there is a possibility that a characteristic parameter that is more appropriate than the newly calculated characteristic parameter may already be stored in the characteristic file, the CPU 22 prior to storing the newly calculated characteristic parameter. Then, it is determined whether the characteristic file is already stored in the memory 21 (step S22). If it is determined in step S22 that the characteristic file exists, the CPU 22 calculates the difference dk_White_ir_obj_cal of the coefficient of the characteristic parameter calculation value calculated in step S18 and the coefficient of the characteristic parameter calculation value already stored in the characteristic file. The difference dk_White_ir_obj is compared to determine whether dk_White_ir_obj_cal is smaller than dk_White_ir_obj (step S23).

If the characteristic file does not exist in the determination in step S22, or if dk_White_ir_obj_cal is smaller than dk_White_ir_obj in the determination in step S23, it is determined that the newly calculated characteristic parameter is a more appropriate characteristic parameter. The calculated color adjustment device coefficient is stored in a characteristic file (step S24), and the process of FIG. 9 is terminated. Here, in step S24, the characteristic file includes
White_ir_r_obj = White_ir_r_obj_cal
White_ir_g_obj = White_ir_g_obj_cal
dk_White_ir_obj = dk_White_ir_obj_cal
MC_cam_master = MC_cam
IR_spct_obj_x = IR_spct_obj_cal_x
Save. Here, MC_cam_master is a characteristic parameter indicating a circuit board number of a digital camera (hereinafter referred to as a master camera) that is optimal for adjusting the color adjusting device 10. The color adjusting device coefficients may be stored in one file, or may be stored in a plurality of files.

  If it is determined in step S23 that dk_White_ir_obj_cal is greater than or equal to dk_White_ir_obj, the newly calculated characteristic parameter is not stored in the characteristic file, and the process in FIG. 9 is terminated.

  As described above, according to the present embodiment, the characteristic parameter reflecting the individual difference for each color adjustment apparatus is calculated, and the characteristic parameter can be saved as a characteristic file. Thereby, when the color of the digital camera is actually adjusted, it is possible to perform the adjustment not depending on the individual difference of the constituent members of the color adjusting device.

Here, when the color adjustment of the digital camera is performed using the calculated characteristic parameter, the spectral sensitivity 2 of the digital camera is calculated by performing the spectral calculation 2 process of step S19 in FIG. However, in the spectral calculation here, it is necessary to obtain the B spectral sensitivity characteristic in addition to the R and G spectral sensitivity characteristics. In this case, from the B component White_b_get of the white level of the image data obtained before the equipment IR cut filter 15 is interposed, the relative sensitivity coefficient kB of B to G is
kB = (White_b_get / White_g_get) / (White_b_ref / White_g_ref) (Formula 29)
Ask from. And from this relative sensitivity coefficient kB, B spectral sensitivity characteristic (B spectral first detection data) B_CCD_est1_x
B_CCD_est1_x = B_ccd_ref_x × kB (380 ≦ x ≦ 720) (Equation 30)
Ask from. Here, since the B spectral sensitivity characteristic is also less influenced by the IR cut filter 31 inside the digital camera 14, the first spectral detection data obtained without using the equipment IR cut filter 15 can be used as it is.

  After calculating the spectral sensitivity characteristics of the RGB color components as described above, color adjustment can be performed using these spectral sensitivity characteristics. As the color adjustment method, a known method disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-320716 may be used, and the description thereof is omitted here.

  Here, at the time of color adjustment, a parameter set for each color adjustment apparatus may be used without using the characteristic parameter. In this case, a flag for setting whether or not to perform color adjustment using a characteristic parameter is prepared for each color adjustment device. When the color adjustment is performed using the characteristic parameter, the spectral calculation calculation is performed using the characteristic parameters White_ir_r_obj and White_ir_g_obj. On the other hand, when it is not set to perform the color adjustment using the characteristic parameter, the spectral calculation calculation is performed using the reference data White_ir_r_ref and White_ir_g_ref.

  In addition, when the color adjustment device coefficient is calculated using a plurality of digital cameras, a final master camera can be selected from them. FIG. 14 is a flowchart showing processing for selecting a master camera.

  In FIG. 14, the CPU 22 first acquires the circuit board number MC_cam of the digital camera to be selected (step S51). Next, the CPU 22 determines whether or not the characteristic file is stored in a predetermined directory in the memory 21 (step S52). If it is determined in step S52 that the characteristic file has not been saved, it is determined that the characteristic file could not be read, and this is output as a characteristic file reading error, and the process in FIG. 14 ends.

  On the other hand, if it is determined in step S52 that the characteristic file is stored, the characteristic file is read (step S53). Then, the CPU 22 refers to MC_cam_master in the characteristic file to determine whether or not the circuit board number set in MC_cam_master is the MC_cam read in step S51 (step S54). If it is determined in step S54 that Mc_cam_master = Mc_cam, the digital camera selected in step S51 is selected as the master camera (step S55). On the other hand, if it is determined in step S54 that Mc_cam_master = Mc_cam is not satisfied, the digital camera selected in step S51 is not the master camera (step S56), and the processing in FIG.

  The process of FIG. 14 is a process of selecting the digital camera having the circuit board number stored in the characteristic file as the master camera. That is, the characteristic file stores the circuit board number of the digital camera that created the optimal characteristic parameters, so it is possible to select a master camera from a large number of digital cameras by referring to the characteristic file. It is. By selecting a master camera and calculating the color adjustment device coefficient using this master camera, the optimum color adjustment device coefficient can be obtained even when adjustment is performed again thereafter. .

  Although the present invention has been described based on the above embodiments, the present invention is not limited to the above-described embodiments, and various modifications and applications are naturally possible within the scope of the gist of the present invention.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be extracted as an invention.

It is a figure which shows the structure of the whole color adjustment apparatus which concerns on one Embodiment of this invention. It is a figure which shows the spectral sensitivity characteristic of A light source. It is a front view of an equipment IR cut filter, a mounting member, and a filter moving device. It is a figure which shows the spectral sensitivity characteristic of IR cut filter. It is a figure which shows the structure of the general imaging system member of a digital camera. It is a flowchart shown about the flow of the process of the coefficient calculation for color adjustment apparatuses. It is a figure which shows the color component in an image. It is a figure shown about R reference spectral sensitivity characteristic, G reference spectral sensitivity characteristic, and B reference spectral sensitivity characteristic. It is a flowchart shown about the flow of a process of the coefficient calculation calculation for color adjustment apparatuses. It is FIG. 1 of the flowchart shown about the flow of a process of spectral calculation. It is FIG. 2 of the flowchart shown about the flow of a process of spectral calculation. It is FIG. 3 of the flowchart shown about the flow of a process of spectral calculation. It is a figure shown about the spectral sensitivity characteristic calculated by spectral calculation. It is a flowchart shown about the flow of a process of master camera selection.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Color adjusting device, 11 ... Shading member, 12 ... Light source, 13 ... Viewer, 14 ... Digital camera, 15 ... Equipment IR cut filter, 16 ... Mounting member, 17 ... Filter moving device, 18, 19 ... Connection cable, 20 ... Personal computer, 21 ... Memory, 21a ... Adjustment program storage unit, 21b ... Reference data storage unit, 22 ... CPU, 30 ... Imaging lens group, 31 ... IR cut filter, 32 ... CCD unit, 32a ... Micro lens array, 32b ... Color filters, 32c ... CCD elements

Claims (14)

Select at least one digital camera from the multiple digital cameras that are subject to color adjustment.
By photographing the predetermined light source of the color adjustment device a plurality of times using the selected digital camera, a plurality of image data is obtained,
Based on a plurality of image data acquired by the digital camera, to create a color adjustment device coefficient reflecting individual differences of the components of the color adjustment device,
Save the color adjustment device coefficient created above,
There line color adjustment of the digital camera by using the stored color adjustment device coefficient,
The plurality of times of shooting are performed without an infrared cut filter that is one of the components of the color adjustment device between the predetermined light source and the digital camera, the predetermined light source, and the digital camera. A color adjustment method comprising: photographing with the infrared cut filter interposed between the camera and the camera . The color adjustment method according to claim 1, wherein the coefficient for the color adjustment device includes a coefficient for reflecting an individual difference of the infrared cut filter. The coefficient for reflecting the individual difference of the infrared cut filter is predicted to be acquired by photographing performed with the infrared cut filter interposed between the predetermined light source and the digital camera. The color adjustment method according to claim 2, further comprising: a red component and a green component of a white level, and spectral sensitivity characteristics of the infrared cut filter. The color adjustment method according to claim 2, wherein the color adjustment device coefficient further includes identification information for identifying the digital camera used to create the color adjustment device coefficient. 5. The color adjustment method according to claim 1, wherein a white level red component and a green component of the image data are used to create the color adjustment device coefficient. 6. 6. The color adjustment method according to claim 5, wherein the color adjustment device coefficient is generated based on predetermined reference data from a white level red component and a green component of the image data. The color adjustment method according to claim 6, wherein the predetermined reference data includes spectral sensitivity characteristic data of a red component and a green component of a digital camera serving as a predetermined reference. 8. The color adjustment method according to claim 7, wherein the predetermined reference data further includes spectral sensitivity characteristic data of an infrared cut filter serving as a predetermined reference. The predetermined light source is an A light source,
The color adjustment method according to claim 8, wherein the predetermined reference data further includes spectral sensitivity characteristic data of the A light source. After the color adjustment device coefficient is created, whether or not the created color adjustment device coefficient is appropriate is verified. As a result of the verification, the created color adjustment device coefficient is appropriate. 2. The color adjustment method according to claim 1, wherein the color adjustment device coefficient is stored only in some cases. Prior to performing color adjustment of the digital camera using the color adjustment device coefficient, it is determined whether or not to perform color adjustment of the digital camera using the color adjustment device coefficient, and the color adjustment device. 2. The color adjustment according to claim 1, wherein the color adjustment of the digital camera is performed using the color adjustment device coefficient only when it is determined that the color adjustment of the digital camera is performed using an image coefficient. Method. A plurality of image data is acquired by photographing a predetermined light source of the color adjustment device a plurality of times using a plurality of digital cameras to be subjected to color adjustment,
Based on a plurality of image data acquired by the plurality of digital cameras, create a plurality of color adjustment device coefficients reflecting individual differences of the components of the color adjustment device,
Select an optimal digital camera to create the color adjustment device coefficient based on the plurality of color adjustment device coefficients created above,
Save the color adjustment device coefficient corresponding to the selected digital camera,
A color adjustment method, wherein color adjustment of the plurality of digital cameras is performed using the stored coefficient for color adjustment device. A light source;
A digital camera for capturing image data by photographing the light source A;
An infrared cut filter configured to be movable back and forth between the A light source and the digital camera, and for removing an infrared light component of light from the A light source;
A reference data storage unit that stores at least the spectral sensitivity characteristics of the A light source, the spectral sensitivity characteristics of the reference digital camera, and the spectral sensitivity characteristics of the reference infrared cut filter as reference data;
Image data acquired by photographing performed without interposing the infrared cut filter between the A light source and the digital camera, and the infrared cut filter interposed between the A light source and the digital camera. The individual difference of the infrared cut filter for each color adjustment device when color-adjusting the digital camera from the image data acquired by photographing performed and the reference data stored in the reference data storage unit A color adjusting device coefficient creating unit for creating a color adjusting device coefficient that reflects
A color adjusting device coefficient storage unit that stores the color adjusting device coefficient created by the color adjusting device coefficient creating unit;
A color adjusting apparatus comprising: 14. The color adjustment apparatus according to claim 13, wherein the color adjustment apparatus coefficient is stored in a predetermined file format in a predetermined directory of the color adjustment apparatus coefficient storage unit.

Images