JP2011212150A - Endoscope processor and endoscope unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep uniform visibility of color of an endoscopic image at any place.SOLUTION: An endoscope processor 20 includes: a second video signal processing circuit 22b; a memory 23; and a mask luminance generating circuit 27. The memory 23 stores reference values of first to fourth and sixth to ninth colors. In a mask luminance setting mode, a mask luminance generating circuit 27 calculates visibility attributes of the first to the fourth and the sixth to the ninth colors based on the ambient illuminance, the luminance of a mask image, the white luminance of an observed image, the white tristimulus values of the observed image and the tristimulus values of the first to the fourth and the sixth to the ninth colors. The mask luminance generating circuit 27 corrects the luminance of the mask image so that the visibility attributes of the first to the fourth and the sixth to the ninth colors approximate to the first to the fourth and the sixth to the ninth reference values. A second video signal processing circuit 22b creates a display image including the mask image with the corrected luminance.

Description

  The present invention relates to an endoscope processor that adjusts the color appearance of an image captured by an endoscope.

  2. Description of the Related Art An add-on camera that captures a subject image transmitted by an electronic endoscope or a fiberscope having an image sensor at the tip of an insertion tube with an image sensor is known. A subject image captured by an electronic endoscope or add-on camera is generated as an image signal. The generated image signal is subjected to image processing such as white balance processing, and the color of the subject is kept constant (see Patent Document 1).

  However, even if the color of the subject displayed on the monitor is constant, the color may appear to change depending on the surrounding environment to the eyes of the observer. In an endoscope unit for observing an image captured by an image sensor with a monitor, there are various places where a monitor for observing a subject image is installed. Therefore, the color appearance of the subject image may change depending on where the monitor is installed.

JP 05-031070 A

  Therefore, an object of the present invention is to provide an endoscope processor in which the color of the subject is recognized by the user regardless of the location where the monitor is installed.

  An endoscope processor of the present invention is an endoscope processor that creates a display image having an observation image including at least a part of a subject image observed by an endoscope and a mask image covering the periphery of the observation image. , The reference illuminance that is the illuminance of the reference ambient environment, the reference mask brightness that is the brightness of the reference mask image, the white colorimetric value that is displayed on the monitor that displays the display image, and the reference white colorimetric value that is the brightness The value of the appearance attribute of the first color calculated based on the reference white luminance and the first reference colorimetric value that is the colorimetric value of the first color displayed in the mask image on the monitor is the first reference. A first memory that is stored as an appearance attribute value; an observation illuminance that is an illuminance of an ambient environment in which the subject image is observed using an endoscope; an observation mask brightness that is a luminance of a mask image when the subject image is observed; The A white colorimetric value and luminance that are displayed on the monitor at the time of observation, a white colorimetric value that is observed and a luminance value that is observed and the first colorimetric value that is the colorimetric value of the first color that is displayed inside the mask image on the monitor A reception unit that receives an actual measurement value of the color value, and a first based on the actual measurement values of the observation illuminance, the observation mask luminance, the observation white colorimetry value, the observation white luminance value, and the first observation colorimetry value received by the reception unit. And a mask image corresponding to the observation mask luminance so that the first observation appearance attribute value approaches the first reference appearance attribute value. A correction unit that corrects the mask luminance signal, which is a signal component of the signal, a second memory that stores the mask luminance signal corrected by the correction unit, and an observation mask luminance corresponding to the mask luminance signal stored in the second memory Mask image It is characterized in that it comprises a creation unit that creates a display image using.

  In addition, a first input unit that receives an input for starting a mask setting mode for calculating a first observation appearance attribute value, and when the mask setting mode is started based on an input to the first input unit, the mask image is displayed inside the mask image. A first transmission unit configured to transmit an image signal corresponding to a display image including white and the first color to the monitor, and the reception unit in the mask setting mode, the observation illuminance, the observation mask luminance, the observation white colorimetric value, the observation The measurement value of the white luminance and the first observation colorimetric value can be received, and the calculation unit receives the observation illuminance, the observation mask luminance, the observation white colorimetry value, the observation white luminance, and the first observation measurement measured in the mask setting mode. The first observation appearance attribute value is calculated based on the actual color value, and the correction unit corrects the mask luminance signal so that the first observation appearance attribute value approaches the first reference appearance attribute value in the mask setting mode. To do It is preferred.

  In addition, a control unit that controls operations of the correction unit, the transmission unit, the reception unit, and the calculation unit is provided, and the correction unit performs a mask setting mode when there is a difference between the first observation appearance attribute value and the first reference appearance attribute value. Correction is performed to change the mask luminance signal included in the image signal transmitted to the monitor by a unit change amount, and the transmission unit corresponds to a display image including a mask image having a luminance corresponding to the mask luminance signal corrected by the correction unit. The image signal is transmitted to the monitor, the receiving unit can receive the actual measurement value of the observation mask luminance after transmitting the retransmitted display image to the monitor, and the calculation unit is based on the observation mask luminance received again by the receiving unit. The first observation appearance attribute value is calculated, and the control unit corrects the unit change amount by the correction unit until the difference between the first observation appearance attribute value and the first reference appearance attribute value is minimized, and the transmission unit Send image signal Setting when receiving the observation mask luminance by the receiving unit and calculating the first observation appearance attribute value by the calculation unit to minimize the difference between the first observation appearance attribute value and the first reference appearance attribute value Preferably, the value is stored in the second memory.

  The receiving unit has a second input unit capable of inputting numerical values. By inputting numerical values to the second input unit, the observation illuminance, mask luminance, observation white colorimetric value, observation white luminance, and first observation It is preferable that at least one of the measured values of the colorimetric values is received.

  The receiving unit can be connected to a colorimeter that detects mask luminance, observation white colorimetric value, observation white luminance value, and first observation colorimetric value, and includes mask luminance, observation white colorimetric value, observation white luminance value. It is preferable to receive the actual measurement value of the first observation colorimetric value from the colorimeter.

  The receiving unit can be connected to an image sensor provided in the endoscope or an image sensor provided in an add-on camera connected to the endoscope, and includes a mask luminance, an observed white colorimetric value, an observed white luminance, and a first It is preferable to receive an actual measurement value of the observed colorimetric value as an image signal generated by the image sensor.

  Further, the first memory includes reference illuminance, reference mask luminance, reference white colorimetric value, reference white luminance, and colorimetric values of a second color different from the first color displayed in the mask image on the monitor. The second color appearance attribute value calculated based on the reference colorimetric value of 2 is stored as the second reference appearance attribute value, and the reception unit displays it inside the mask image on the monitor when observing the subject. The measured value of the second observation colorimetric value that is the colorimetric value of the second color to be received is received, and the calculation unit receives the observation illuminance, the observation mask luminance, the observation white colorimetric value, the observation white luminance, and the second observation measurement. A second observation appearance attribute value, which is a value of the second color appearance attribute, is calculated based on the actually measured color value, and the correction unit approaches the second observation appearance attribute value. Thus, it is preferable to correct the mask luminance signal.

  In addition, a third input unit that receives an input for starting an initial setting mode for calculating the first reference appearance color value, and a predetermined luminance when the initial setting mode is started based on an input to the third input unit. A second transmission unit configured to transmit a display image including white and the first color inside the mask image to the monitor, and the reception unit includes a reference illuminance, a reference mask luminance, a reference white colorimetric value, The measured value of the reference white luminance and the first reference colorimetric value can be received, and the calculation unit receives the reference illuminance, the reference mask luminance, the reference white colorimetric value, the reference white luminance, and the first reference received in the initial setting mode. Preferably, the first reference appearance attribute value is calculated based on the actual measurement value of the colorimetric value, and the first memory stores the first reference appearance attribute value calculated in the initial setting mode.

  The endoscope unit of the present invention is an endoscope unit that creates a display image having an observation image including at least a part of a subject image observed by the endoscope and a mask image covering the periphery of the observation image. Reference illuminance that is the illuminance of the reference ambient environment, reference mask brightness that is the brightness of the reference mask image, white colorimetric value that is displayed on the monitor that displays the display image, and reference white color measurement that is the brightness The first color appearance attribute value calculated based on the first reference colorimetric value which is the value, the reference white luminance, and the first colorimetric value displayed in the mask image on the monitor is the first. A first memory for storing the reference appearance attribute value, an observation illuminance that is an illuminance of an ambient environment in which the subject image is observed using an endoscope, and an observation mask luminance that is a luminance of the mask image when the subject image is observed ,subject A white colorimetric value and luminance that are displayed on the monitor when observing the observation white colorimetric value and the observation white luminance and the first observation that is the colorimetric value of the first color displayed inside the mask image on the monitor A receiving unit that receives an actual measurement value of the colorimetric value; and a first unit based on the actual measurement value of the observation illuminance, the observation mask luminance, the observation white colorimetry value, the observation white luminance value, and the first observation colorimetry value received by the reception unit. A calculation unit that calculates a first observation appearance attribute value that is a value of the appearance attribute of one color, and a mask that corresponds to the observation mask luminance so that the first observation appearance attribute value approaches the first reference appearance attribute value A correction unit that corrects the mask luminance signal that is a signal component of the image, a second memory that stores the mask luminance signal corrected by the correction unit, and an observation mask corresponding to the mask luminance signal stored in the second memory Mask picture that is brightness It is characterized in that it comprises a creation unit that creates a display image using.

  According to the present invention, it is possible to make the user perceive the same color as the same color regardless of the place where the monitor is installed.

1 is a block diagram schematically showing an internal configuration of an endoscope unit including an endoscope processor to which a first embodiment of the present invention is applied. FIG. It is a figure which shows notionally the production method of a display image. It is a figure of the chart image for mask setting. It is a flowchart which shows the process which a system controller performs in initial setting mode. It is a flowchart which shows the process which a system controller performs in mask brightness | luminance setting mode. It is a block diagram which shows roughly the internal structure of the endoscope unit containing the endoscope processor to which the 2nd Embodiment of this invention is applied.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram schematically showing an internal configuration of an endoscope unit having an endoscope processor to which the first embodiment of the present invention is applied.

  The endoscope unit 10 includes an endoscope processor 20, an electronic endoscope 30, and a monitor 11. The endoscope processor 20 is connected to the electronic endoscope 30 and the monitor 11.

  Illumination light for illuminating the subject is supplied from the endoscope processor 20 to the electronic endoscope 30. The subject irradiated with the illumination light is imaged by the electronic endoscope 30. An image signal generated by imaging of the electronic endoscope 30 is sent to the endoscope processor 20.

  In the endoscope processor 20, predetermined signal processing is performed on the image signal obtained from the electronic endoscope 30. The image signal subjected to the predetermined signal processing is transmitted to the monitor 11, and an image corresponding to the transmitted image signal is displayed on the monitor 11.

  Next, the configuration of the electronic endoscope 30 will be described. The electronic endoscope 30 is provided with a light guide 31, an image sensor 32, and the like.

  The light guide 31 extends from the connector 33 connected to the endoscope processor 20 to the distal end of the insertion tube 34. Illumination light supplied from the endoscope processor 20 enters the incident end of the light guide 31. The illumination light incident on the incident end is transmitted to the exit end. The illumination light transmitted to the emission end is irradiated to the subject in the distal direction of the insertion tube 34.

  The optical image of the reflected light of the subject irradiated with the illumination light reaches the light receiving surface of the image sensor 32 provided at the distal end of the insertion tube 34. The image sensor 32 is controlled to generate an image signal of one frame every fixed period, for example, 1/60 second.

  Next, the configuration of the endoscope processor 20 will be described. The endoscope processor 20 includes a light source system 21, first and second video signal processing circuits 22a and 22b, a memory 23 (first and second memories), a system controller 24 (control unit), a timing controller 25, and an input. A unit 26 (first to third input units), a mask luminance generation circuit 27 (calculation unit), and the like are provided.

  Illumination light is emitted from the light source system 21. When the electronic endoscope 30 is connected to the endoscope processor 20, the light source system 21 is optically connected to the light guide 31. The illumination light emitted from the light source system 21 is incident on the incident end of the light guide 31.

  When the electronic endoscope 30 is connected to the endoscope processor 20, the image sensor 32 is electrically connected to the first video signal processing circuit 22a. The image signal generated and transmitted by the image sensor is received by the first video signal processing circuit 22a.

  In the first video signal processing circuit 22a, predetermined signal processing such as white balance processing and color interpolation processing is performed. The first video signal processing circuit 22 a is connected to the memory 23. The image signal that has undergone predetermined signal processing is stored in the memory 23.

  The memory 23 is connected to the second video signal processing circuit 22b (creation unit, first and second transmission units). The image signal stored in the memory 23 is transmitted to the second video signal processing circuit 22b. In the second video signal processing circuit 22b, mask processing is performed on the image signal.

  Here, the mask process will be described. There are restrictions on the optical system that can be disposed at the distal end of the insertion tube 34 of the electronic endoscope 30, and the optical image near the periphery of the light receiving surface of the image sensor 32 may cause insufficient light amount or aberration, making it unsuitable for observation. It is common.

  Therefore, as shown in FIG. 2, the signal component corresponding to the image near the center in the entire light receiving surface ES of the image sensor 32 is the observation image OI and the mask image MI which is a black mask covering the periphery of the observation image OI. A display image DI is created in combination. Note that the brightness of the mask image MI is determined in the mask brightness setting mode, as will be described later.

  It is converted into an image signal corresponding to the display image DI by mask processing. The second video signal processing circuit 22b further performs predetermined signal processing on the image signal subjected to the mask processing. An image signal that has undergone predetermined signal processing is transmitted to the monitor 11 as a video signal.

  As described above, an image signal is generated every 1/60 seconds and transmitted to the monitor 11. By switching the image displayed on the monitor 11 every 1/60 seconds, a real-time moving image is displayed on the monitor 11.

  The first and second video signal processing circuits 22a and 22b and the memory 23 are connected to the system controller 24 and the timing controller 25 via the bus 28 (receiving unit) (see FIG. 1). The system controller 24 controls the operations of the first and second video signal processing circuits 22a and 22b and the memory 23. In addition, the timing controller 25 controls the timing of the operations of the first and second video signal processing circuits 22a and 22b and the memory 23.

  The bus 28 is also connected to the input unit 26 and the mask luminance generation circuit 27. Various input operations by the user are possible on the input unit 26, and the system controller 24 controls each part according to the input operation. Further, the mask luminance generation circuit 27 calculates the luminance of the mask image MI in the mask luminance setting mode.

  Next, a method for setting the brightness of the mask image MI by the endoscope processor 20 will be described. In order to set the brightness of the mask image MI, the endoscope processor 20 is provided with a mask initial setting mode and a mask brightness setting mode as operation modes.

  In the mask initial setting mode, the reference value of the color appearance attribute is calculated and stored in the memory 23. The reference value of the color appearance attribute is a value of the color appearance attribute displayed on the monitor 11 as an observation image surrounded by a mask image having a reference luminance in the reference ambient environment.

  In the mask luminance setting mode, a luminance signal component corresponding to the optimal luminance of the mask image MI in the environment where the monitor 11 is installed is calculated and stored in the memory 23. Note that, in the surrounding environment where the monitor 11 is installed, the brightness of the mask image MI that matches the reference value stored in the memory 23 with the value of the appearance attribute of the predetermined color displayed on the monitor 11 as an observation image is the optimal brightness. As a result, the luminance signal component is calculated. The luminance signal component stored in the memory 23 is used to determine the luminance of the mask image when the subject is subsequently observed.

  The mask initial setting mode is started by performing a mode switching operation on the input unit 26. In the mask initial setting mode, the system controller 24 causes the chart image signal stored in the memory 23 to be transmitted to the monitor 11 and causes the monitor 11 to display a mask setting chart image corresponding to the chart image signal.

  In the mask setting chart image CI, as shown in FIG. 3, the display region of the observation image OI is divided into nine 3 × 3 regions A1 to A9. Each of the areas A1 to A9 is a single color and is displayed in a different color for each area.

  The first to fourth areas A1 to A4 are displayed in first to fourth colors that are chromatic colors. The fifth area A5 is displayed in white. The sixth to ninth areas A6 to A9 are displayed in the fifth to ninth colors. Note that the brightness of the mask image MI in the mask setting chart image CI is set to a predetermined brightness as the recommended brightness.

  In the mask initial setting mode, as the ambient illuminance (reference illuminance) at the time of initial setting, an input of the actual measured value Lsw1 of the ambient illuminance at the place where the monitor 11 is installed is obtained.

  The first to fourth and sixth to ninth displayed in the mask setting chart image CI as the tristimulus values of the first to fourth and sixth to ninth colors displayed on the monitor 11 at the initial setting. Input of actual measured values (X11 to X14, Y11 to Y14, Z11 to Z14) and (X16 to X19, Y16 to Y19, Z16 to Z19) of the tristimulus values of the colors are required.

  Further, as the white tristimulus values and luminances displayed on the monitor 11 at the initial setting, the white tristimulus values and the actual luminance values (Xw1, Yw1, Zw1) and Ldw1 displayed in the mask setting chart image CI are input. Is required.

  Further, as the brightness of the mask image MI displayed on the monitor 11 at the time of initial setting, an input of the actual measurement value Yb1 of the brightness of the mask image MI in the mask setting chart image MI is obtained.

  The ambient illuminance is measured by an illuminometer (not shown), and the tristimulus values of each color, the brightness of white, and the brightness of the mask image MI are measured by a colorimeter (not shown). The measured ambient illuminance, tristimulus value, white brightness, and mask image MI brightness can be input by an input operation to the input unit 26.

  Alternatively, at least one of the illuminometer and the colorimeter can be connected to the bus 28 via a connector (not shown) of the endoscope processor 20, and the ambient illuminance, tristimulus value, white luminance, and mask The brightness of the image MI can be input to the endoscope processor 20 as a signal.

  When ambient illuminance, tristimulus values, white luminance, and luminance of the mask image MI are input, the mask luminance generation circuit 27 has eight colors other than white displayed on the mask setting chart image, that is, first to first colors. The values of the appearance attributes of the fourth color and the sixth to ninth colors are calculated as the above-described reference values. The calculation of the color appearance attribute value will be described below.

  In the mask luminance generation circuit 27, the ambient illuminance, the specific color tristimulus value displayed on the monitor 11, the white tristimulus value displayed on the monitor 11, and the monitor 11 are displayed according to the forward model of CIECAM02. The brightness and Cartesian coordinates of a specific color are calculated as the color appearance attributes from the measured values of the white luminance and the luminance of the mask image MI.

  As described above, the endoscope processor 20 includes the ambient illuminance Lsw1 at the time of initial setting, the white tristimulus values (Xw1, Yw1, Zw1) of the monitor 11, the white luminance Ldw1 of the monitor 11, and the mask image. Luminance Yb1 is input. Furthermore, the endoscope processor 20 includes tristimulus values (X11 to X14, Y11 to Y14, Z11 to Z14) and (X16 to X19) of the first to fourth and sixth to ninth colors at the initial setting. Since Y16 to Y19 and Z16 to Z19) are input, the appearance attributes (brightness and Cartesian coordinates) of the first to fourth and sixth to ninth colors in the initial setting are calculated.

  Color appearance attributes in the calculated initial settings, that is, first to fourth and sixth to ninth initial lightness J11 to J14, J16 to J19, first to fourth and sixth to ninth initial Cartesian coordinates ( ac11 to ac14, bc11 to bc14) and (ac16 to ac19, bc16 to bc19) are stored in the memory 23 as reference values for the respective colors.

  Hereinafter, a method of calculating the initial lightness J11 of the first color and the initial Cartesian coordinates (ac11, bc11) of the first color using the tristimulus values of the first color at the initial setting will be described. Note that the appearance attributes of colors based on the tristimulus values of other colors are calculated in the same manner.

  First, the ambient ratio Sr1 at the initial setting is calculated by substituting the ambient illuminance Lsw1 at the initial setting and the white luminance Ldw1 of the monitor 11 at the initial setting into Lsw and Ldw in the equation (1), respectively.

  As shown in Table 1, according to the surrounding ratio Sr1 in the initial setting, the surrounding environment at the time of the initial setting is classified into an average surrounding, a dim surrounding, and a dark surrounding. The observation parameters (c1, Nc1, F1) in the initial setting are determined according to the classified ambient environment.

  Next, by substituting the tristimulus values (X11, Y11, Z11) of the first color at the initial setting into (X, Y, Z) in the equation (2), the primary of the first color at the initial setting Conversion coordinates (R11, G11, B11) are obtained. Further, by substituting the white tristimulus values (Xw1, Yw1, Zw1) displayed on the monitor 11 at the initial setting into (X, Y, Z) in the equation (2), the primary conversion coordinates of the white at the initial setting (Rw1, Gw1, Bw1) is obtained.

  Next, the adaptive luminance La1 in the initial setting is calculated by dividing the white luminance Ldw1 of the monitor 11 at the initial setting by 5. By substituting the adaptation luminance La1 in the initial setting and the observation parameter F1 in the initial setting determined based on Table 1 into La and F in the equation (3), the adaptation coefficient D1 in the initial setting is calculated.

  First primary transformation coordinates (R11, G11, B11), white primary transformation coordinates (Rw1, Gw1, Bw1), white Y stimulus value Yw1 of monitor 11 at the initial setting, and adaptation coefficient D1 at the initial setting, By substituting (R, G, B), (Rw, Gw, Bw), Yw, and D in the equations (4) to (6), respectively, the secondary transformation coordinates (Rc11, Gc11, Bc11) is calculated.

  Next, the first coefficient k1 in the initial setting is calculated by substituting the adaptation luminance La1 in the initial setting into La in the equation (7).

  By substituting the first coefficient k1 in the initial setting calculated by the equation (7) and the adaptation luminance La1 in the initial setting into k and La in the equation (8), respectively, the second coefficient Fl1 in the initial setting is calculated. Is done.

  By substituting the white Y stimulus value Yw1 of the monitor 11 at the time of initial setting and the luminance Yb1 of the mask image MI into Yw and Yb in the equation (9), respectively, the third coefficient n11 for the first color at the initial setting Is calculated.

  The fourth coefficient Nbb11 for the first color in the initial setting is substituted by substituting the third coefficient n11 calculated by the expression (9) for n in the expressions (10) and (11). , Ncb11, z11 are calculated.

  Next, by substituting the secondary transformation coordinates (Rc11, Gc11, Bc11) of the first color in the initial setting into (Rc, Gc, Bc) in the equation (12), the first color of the first color in the initial setting Tertiary transformation coordinates (R′11, G′11, B′11) are calculated.

  Note that the matrix in equation (12) is given by equations (13) and (14).

  The first color cubic transformation coordinates (R′11, G′11, B′11) calculated by the equation (12) and the second coefficient Fl1 calculated by the equation (8) are respectively (15) to By substituting (R ′, G ′, B ′) and Fl in the equation (17), the quaternary transformation coordinates (R′a11, G′a11, B′a11) of the first color in the initial setting are calculated. Is done. In addition, when the cubic transformation coordinates (R′11, G′11, B′11) are negative, the absolute value is used, and the quotient term in the equations (15) to (17) is multiplied by −1. Added to 0.1.

  The quaternary transformation coordinates (R′a11, G′a11, B′a11) of the first color calculated by the equations (15) to (17) are expressed as (R′a, G in the equations (18) and (19). By substituting for “a, B′a), the Cartesian coordinates (a11, b11) of the first color in the initial setting are calculated.

  The hue angle of the first color in the initial setting is assigned by substituting the Cartesian coordinates (a11, b11) of the first color calculated by the equations (18), (19) into (a, b) in the equation (20). h11 is calculated.

  The seventh coefficient et11 for the first color in the initial setting is calculated by substituting the hue angle h11 of the first color calculated by the equation (20) into h in the equation (21).

  Next, the quaternary transformation coordinates (R′a11, G′a11, B′a11) of the first color calculated by the equations (15) to (17) and the first color calculated by the equation (10) By substituting the fourth coefficient Nbb11 for (R′a, G′a, B′a) and Nbb in the equation (22), the achromatic response A11 of the first color in the initial setting is calculated. . Further, the white achromatic response Aw1 in the initial setting is also calculated using the white tristimulus values (Xw1, Yw1, Zw1) instead of the tristimulus values (X11, Y11, Z11) of the first color.

  The achromatic response A11 of the first color calculated by the equation (22), the achromatic response Aw1 of white, the observation parameter c1 determined based on Table 1, and the sixth coefficient calculated by the equation (11) By substituting each of z11 into A, Aw, c, and z in the equation (23), the lightness J11 of the first color in the initial setting is calculated.

  Next, the observation parameter Nc1 determined based on Table 1, the fifth coefficient Ncb11 for the first color calculated in the equation (10), the seventh coefficient for the first color calculated in the equation (21) Coefficients et11, (18), Cartesian coordinates (a11, b11) of the first color calculated by the equations (19), and quaternary transformation coordinates of the first color calculated by the equations (15) to (17) Substituting (R′a11, G′a11, B′a11) for Nc, Ncb, et, (a, b), (R′a, G′a, B′a) in equation (24) Thus, a temporary value t11 for the first color in the initial setting is calculated.

  Next, a temporary value t11 for the first color calculated by the equation (24), the lightness J11 of the first color calculated by the equation (23), and the first value calculated by the equation (9) The chroma C11 for the first color in the initial setting is calculated by substituting the third coefficient n11 for the color into t, J, and n in the equation (25).

  The chroma C11 for the first color calculated by the equation (25) and the hue angle h11 for the first color calculated by the equation (20) are substituted into C and h in the equations (26) and (27), respectively. Thus, Cartesian coordinates (ac11, bc11) for the first color in the initial setting are calculated.

  The appearance attributes (J11, ac11, bc11) of the first color calculated by the equations (23), (26), and (27) are stored in the memory 23 as described above as the first color reference value. The Similarly, reference values for the second to fourth and sixth to ninth colors are also calculated and stored in the memory 23.

  Next, calculation of the brightness of the mask image MI in the mask brightness setting mode will be described. The mask luminance setting mode is started by performing a mode switching operation on the input unit 26. Even in the mask luminance setting mode, the system controller 24 causes the chart image signal stored in the memory 23 to be transmitted to the monitor 11 and causes the monitor 11 to display the mask setting chart image.

  Also in the mask luminance setting mode, the input of the measured value Lsw2 of the ambient illuminance at the place where the monitor 11 is installed is obtained as the ambient illuminance at the time of luminance setting.

  Further, the first to fourth and sixth to ninth displayed in the mask setting chart image CI as the tristimulus values of the first to fourth and sixth to ninth colors displayed on the monitor 11 at the luminance setting. The input of actual measured values (X21 to X24, Y21 to Y24, Z21 to Z24) and (X26 to X29, Y26 to Y29, Z26 to Z29) of the tristimulus values of the colors are required.

  Further, as white tristimulus values and luminances displayed on the monitor 11 at the time of luminance setting, white tristimulus values and actual luminance values (Xw2, Yw2, Zw2) and Ldw2 displayed in the mask setting chart image CI are input. Is required.

  Further, as the luminance of the mask image MI displayed on the monitor 11 at the time of luminance setting, an input of the actual measured value Yb2 of the luminance of the mask image MI in the mask setting chart image CI is obtained.

  As in the initial setting mode, the ambient illuminance is measured by an illuminometer (not shown), and the tristimulus values of each color, the white luminance, and the luminance of the mask image MI are measured by a colorimeter (not shown). Measured. The measured ambient illuminance, tristimulus value, white luminance, and luminance of the mask image MI can be input by an input operation to the input unit 26.

  Similarly to the initial setting mode, the ambient illuminance, the tristimulus value, the white luminance, and the luminance of the mask image MI may be input to the endoscope processor 20 as signals.

  When the ambient illuminance, tristimulus value, white luminance, and luminance of the mask image MI are input, the mask luminance generation circuit 27 performs the first to fourth colors and the sixth to ninth as in the initial setting mode. The color appearance attribute is calculated.

  That is, the lightness J21 to J24 and J26 to J29 of the first to fourth and sixth to ninth colors in the luminance setting, and the Cartesian coordinates (ac21 to ac of the first to fourth and sixth to ninth colors in the luminance setting. ac24, bc21 to bc24), (ac26 to ac29, bc26 to bc29) are calculated.

  Unlike the initial setting mode, in the mask luminance setting mode, when the appearance attributes of the first to fourth colors and the sixth to ninth colors are calculated, a comparison with a reference value is performed. Comparison with the reference value is performed for each color.

  For example, for the first color, the difference between the brightness J21 in the brightness setting and the brightness J11 as the reference value, the difference between the Cartesian coordinate ac21 in the brightness setting and the Cartesian coordinate ac11 as the reference value, and the Cartesian coordinates bc21 in the brightness setting A difference from the Cartesian coordinate bc11 which is a reference value is calculated.

  In the mask luminance generation circuit 27, the geometric average value of the difference between the brightness and the Cartesian coordinates calculated for the first color is calculated as the evaluation value of the first color. Similar calculations are performed for the second to fourth and sixth to ninth colors, and evaluation values for the second to fourth and sixth to ninth colors are calculated.

  Next, the mask luminance generation circuit 27 calculates an arithmetic average value of the evaluation values of the first to fourth and sixth to ninth colors. The calculated evaluation value is temporarily stored in the memory 23 together with the luminance signal component corresponding to the luminance Yb2 of the mask image MI being displayed.

  After storing the evaluation value, the mask luminance generation circuit 27 controls the second video signal processing circuit 22b so as to change the luminance of the mask image MI being displayed on the monitor 11. The luminance is changed by changing the luminance signal component of the component corresponding to the mask image of the chart image signal by a unit change amount that can be adjusted by the endoscope processor 20.

  When the brightness of the mask image MI is changed, the input of the actual measurement value of the brightness of the mask image MI after the change is obtained again.

  When the actual measurement value of the brightness of the mask image MI is re-input, the brightness of the first to fourth and sixth to ninth colors, the first to fourth, and sixth to ninth again at the newly input brightness. The Cartesian coordinates of the color are calculated. The mask luminance generation circuit 27 calculates an evaluation value for the luminance signal component of the mask image MI based on the calculated color brightness and Cartesian coordinates, and stores the evaluation value in the memory 23.

  Thereafter, the change in the brightness of the mask image MI, the input request for the actual measurement value, and the calculation of the evaluation value are repeated until the evaluation value becomes the lowest. The luminance signal component that minimizes the evaluation value is stored in the memory 23. The stored luminance signal component is determined and used as a luminance signal component corresponding to the luminance of the mask image during normal observation.

  Next, the control of the operation of each part executed by the system controller 24 in the initial setting mode will be described with reference to the flowchart of FIG. As described above, the initial setting mode is started when a switching operation to the input unit 26 is input.

  In step S100, the chart image signal stored in the memory 23 is transmitted to the monitor 11 via the second video signal processing circuit 22b, and the mask setting chart image is displayed on the monitor 11. After the chart image signal transmission command, the process proceeds to step S101.

  In step S101, input of the ambient illuminance, the tristimulus value of the color displayed in the observation image OI, the white luminance displayed in the observation image OI, and the measured value of the luminance of the mask image MI is requested. For example, an input request is made by superimposing a message and an input field for requesting input on the mask setting chart image CI. After the input request, the process proceeds to step S102.

  In step S102, it is determined whether or not the numerical values of all input request items have been input. Step S102 is repeated until all the input request items are input. If all input request items have been input, the process proceeds to step S103.

  In step S103, reference values for the first to fourth and sixth to ninth colors are calculated based on the input ambient illuminance, tristimulus value, white luminance, and luminance of the mask image MI. After calculating the reference value, the process proceeds to step S104.

  In step S104, the reference value of each color calculated in step S103 is stored in the memory 23. After the storage in the memory 23, the initial setting mode is terminated.

  Next, the control of the operation of each part executed by the system controller 24 in the mask luminance setting mode will be described with reference to the flowchart of FIG. As described above, the mask luminance setting mode is started when a switching operation to the input unit 26 is input.

  In step S200, the luminance signal component corresponding to the luminance of the mask image MI is initially set. Note that the luminance signal component that is initially set is set to a minimum value that can be set. That is, the luminance signal component in the mask image MI of the chart image signal is changed to a settable minimum value. After the initial setting of the luminance signal component is completed, the process proceeds to step S201.

  In step S201, an evaluation threshold value used for comparison with a newly calculated evaluation value is initially set. Note that the initial setting value of the evaluation threshold value may be any value as long as it is a sufficiently large value. That is, the maximum settable value is set as the evaluation threshold value. After the initial setting of the evaluation threshold, the process proceeds to step S202.

  In step S202, the chart image signal including the mask image MI using the luminance signal component set in step S200 is transmitted to the monitor 11 via the second video signal processing circuit 22b, and the mask setting chart image CI is displayed on the monitor 11. To display. After transmitting the chart image signal, the process proceeds to step S203.

  In step S203, input of actual measurement values of necessary input request items is requested. In the first input request after the mask luminance setting mode is started, the ambient illuminance, the color tristimulus values displayed in the observation area, the white luminance displayed in the observation area, and the luminance of the mask image MI are input. Thereafter, only the luminance of the mask image MI is required to be input. After the input request, the process proceeds to step S204.

  In step S204, it is determined whether or not the numerical values of all input request items have been input. Step S204 is repeated until all the input request items are input. If all input request items have been input, the process proceeds to step S205.

  In step S205, the appearance color attributes of the first to fourth and sixth to ninth colors are calculated based on the input ambient illuminance, tristimulus value, white luminance, and luminance of the mask image MI. That is, the lightness and Cartesian coordinates of each color are calculated. After the appearance color attribute is calculated, the process proceeds to step S206.

  In step S206, an evaluation value is calculated using the reference value stored in the memory 23 and the appearance color attribute calculated in step S205. After calculating the evaluation value, the process proceeds to step S207.

  In step S207, it is determined whether or not the evaluation value calculated in step S206 is less than the set evaluation threshold value. If the evaluation value is less than the evaluation threshold, the process proceeds to step S208. If the evaluation value is greater than or equal to the evaluation threshold, the process proceeds to step S210.

  In step S208, the evaluation value calculated in step S206 is updated to a new evaluation threshold value. After the evaluation threshold is updated, the process proceeds to step S209.

  In step S209, the unit change amount is added to the set value of the luminance signal component to update to a new luminance signal component. After the luminance signal component is updated, the process returns to step S202. Thereafter, the processing in steps S202 to S209 is repeated until the evaluation value becomes equal to or greater than the evaluation threshold value in step S207.

  In step S210, the unit change amount is subtracted from the set value of the luminance signal component and updated to a new luminance signal component. After the luminance signal component is updated, the process proceeds to step S211.

  In step S211, the luminance signal component updated in step S210 is stored in the memory 23 for setting the luminance of the mask image MI at the time of observation. After storing the luminance signal component, the mask luminance setting mode is terminated.

  As described above, according to the endoscope processor to which the first embodiment is applied, the user can perceive that the colors displayed as the observation images are the same regardless of the surrounding brightness. is there.

  For example, in the reference room having the recommended brightness, the appearance color attribute of the color displayed inside the mask image having the recommended brightness is calculated and stored in the initial setting mode. Thereafter, even if the installation location of the monitor 11 is changed or the brightness is changed, the brightness of the mask image MI is newly determined in the mask brightness setting mode with respect to the environment after the change. When the same color as the color displayed inside the recommended mask image MI in the room is displayed, it is perceived by the user.

  Next, an endoscope processor to which the second embodiment of the present invention is applied will be described. The endoscope processor of the second embodiment is different from the first embodiment in that the tristimulus values and the luminance of the color displayed on the monitor can be detected without using a colorimeter. Hereinafter, a description will be given focusing on differences from the first embodiment. In addition, the same code | symbol is attached | subjected to the site | part which has the same function as 1st Embodiment.

  As shown in FIG. 6, the configurations and functions of the electronic endoscope 30 and the monitor 11 in the second embodiment are the same as those in the first embodiment. Further, the configuration and function of the endoscope processor 200 in the second embodiment other than the control of the image sensor 32 by the system controller 240 in the initial setting mode and the mask luminance setting mode of the mask luminance generation circuit 270 are the first This is the same as the embodiment.

  The mask luminance generation circuit 270 in the second embodiment is provided with the same function as the mask luminance generation circuit 27 in the first embodiment. Furthermore, the mask luminance generation circuit 270 according to the second embodiment is provided with a conversion function from primary color signal components to tristimulus values. That is, RGB signal components included in the image signal are converted into tristimulus values XYZ.

  The mask luminance generation circuit 270 is also provided with a function for calculating the luminance signal component from the primary color signal component. That is, the luminance signal component is calculated from the RGB signal components included in the image signal.

  The system controller 240 in the second embodiment controls the image sensor 32 and the mask luminance generation circuit 270 as described below in the initial setting mode and the mask luminance setting mode.

  In both modes, the system controller 240 obtains only the actual measured value of the ambient illuminance as in the first embodiment. As in the first embodiment, the value detected by the illuminometer is input by the user.

  Unlike the first embodiment, in both modes, the system controller 240 requests the first to ninth areas A1 to A9 and the mask image MI (see FIG. 3) to be photographed. For example, a message such as “Please photograph the first area” is superimposed on the mask setting chart image CI.

  By photographing the first to fourth and sixth to ninth regions A1 to A4 and A6 to A9, primary color signals of the first to fourth and sixth to ninth colors are generated. The system controller 240 converts the generated primary color signals of the first to fourth and sixth to ninth colors into tristimulus values of the first to fourth and sixth to ninth colors so as to convert the mask luminance. The generation circuit 270 is controlled.

  By photographing the fifth area A5, a white primary color signal displayed on the monitor 11 is generated. The system controller 240 controls the mask luminance generation circuit 270 so as to calculate a white tristimulus value and luminance based on the generated white primary color signal.

  By photographing the mask image MI, a primary color signal of the mask image MI is generated. The system controller 240 controls the mask luminance generation circuit 270 so as to calculate the luminance of the mask image MI based on the generated primary color signal of the mask image.

  In the mask luminance generation circuit 270, based on the input actual measurement value of ambient illuminance, the calculated tristimulus values of each color, the calculated white tristimulus value and luminance, and the calculated luminance of the mask image MI, The color appearance attribute is calculated in the same manner as in the first embodiment. Accordingly, a reference value is calculated in the initial setting mode, and a luminance signal component is generated and stored in the memory 23 in the mask luminance setting mode.

  As described above, the endoscope processor 200 to which the second embodiment is applied can also allow the user to perceive that the colors displayed as the observation images are the same regardless of the surrounding brightness. is there.

  In the mask luminance setting mode in the first and second embodiments, the luminance of the mask image MI is changed until the evaluation value becomes the lowest. However, the mask luminance setting mode may not be changed until the evaluation value becomes the lowest. . For example, even when the brightness of the mask image MI is changed until the evaluation value becomes less than the threshold value, it is possible to obtain the same effect as in the first and second embodiments. At least, the perceptual color identity can be maintained as compared with the conventional case if the brightness of the mask image MI is changed so that the value of the color appearance attribute calculated in the brightness setting approaches the reference value. It is.

  In the mask luminance setting mode in the first and second embodiments, the luminance signal component corresponding to the luminance of the mask image MI is changed by the unit change amount, but the configuration is not limited thereto. The luminance signal component may be changed by any other method.

  In the first and second embodiments, the initial setting mode is provided, but the initial setting mode may not be provided. Based on the recommended ambient illuminance, the recommended white tristimulus value of the monitor 11, the recommended white luminance, the recommended mask image MI luminance and the tristimulus value of any color assumed. Alternatively, the appearance attribute of any color may be calculated in advance and stored in the memory 23.

  In the first and second embodiments, the brightness of the mask image MI is determined based on the appearance attributes of the first to fourth and sixth to ninth colors, but eight colors are used. It does not have to be. A single color may be used, or two or more colors may be used.

  In the initial setting mode and the mask luminance setting mode in the first and second embodiments, the mask setting chart image CI displaying nine colors is displayed inside the mask image MI, but at least the mask image MI is displayed. If the colors used in the above, white, and other colors are displayed, the same effects as in the first and second embodiments can be obtained.

  In the first and second embodiments, the brightness of the mask image MI is determined using the brightness and Cartesian coordinates as the color appearance attributes, but other color appearance attributes may be used. For example, in CIECAM02, it is also possible to calculate the hue component H, brightness Q, saturation s, and colorfulness M as color appearance attributes in addition to brightness, hue angle, and chroma. The brightness of the mask image MI may be determined. Moreover, the attribute to be used is not limited to three types.

  In the first and second embodiments, the color appearance attribute is calculated by the forward model of CIECAM02, but the color appearance attribute is calculated by another conventionally known color appearance model. There may be.

  In the first and second embodiments, an electronic endoscope is used, but it can also be applied to an add-on camera connected to a fiberscope.

DESCRIPTION OF SYMBOLS 10 Endoscope unit 11 Monitor 20,200 Endoscope processor 22a, 22b 1st, 2nd video signal processing circuit 23 Memory 24, 240 System controller 26 Input part 27, 270 Mask brightness | luminance generation circuit 30 Electronic endoscope A1 A9 First to ninth regions CI Mask setting chart image DI display image MI mask image OI observation image

Claims (9)

An endoscope processor for creating a display image having an observation image including at least a part of a subject image observed by an endoscope and a mask image covering the periphery of the observation image,
Reference illuminance that is the illuminance of the ambient environment that serves as a reference, reference mask brightness that is the brightness of the mask image that serves as a reference, white colorimetric value that is displayed on the monitor that displays the display image, and reference white colorimetric value that is brightness And the reference white luminance, and the value of the appearance attribute of the first color calculated based on the first reference colorimetric value which is the colorimetric value of the first color displayed in the mask image on the monitor A first memory for storing as a first reference appearance attribute value;
Observation illuminance that is the illuminance of the surrounding environment for observing the subject image using the endoscope, observation mask luminance that is the luminance of the mask image when observing the subject image, and the monitor when observing the subject A white colorimetric value and luminance to be displayed on the monitor, and an observation white colorimetric value and observation white luminance to be displayed on the monitor, and a first observational colorimetric value to be displayed on the monitor in the mask image. A receiving unit for receiving the actual measurement value of the color value;
Based on the observation illuminance, the observation mask luminance, the observation white colorimetric value, the observation white luminance value, and the actual measurement value of the first observation colorimetric value received by the reception unit, A calculation unit that calculates a first observation appearance attribute value that is a value of the appearance attribute;
A correction unit that corrects a mask luminance signal that is a signal component of the mask image corresponding to the observation mask luminance so that the first observation appearance attribute value approaches the first reference appearance attribute value;
A second memory for storing the mask luminance signal corrected by the correction unit;
An endoscope processor, comprising: a creation unit that creates the display image using the mask image that is the observation mask brightness corresponding to the mask brightness signal stored in the second memory. A first input unit for receiving an input for activating a mask setting mode for calculating the first observation appearance attribute value;
When the mask setting mode is started based on an input to the first input unit, an image signal corresponding to the display image including white and the first color inside the mask image is transmitted to the monitor. 1 transmission unit,
The receiving unit is capable of receiving the observation illuminance, the observation mask luminance, the observation white colorimetric value, the observation white luminance, and the actual measurement value of the first observation colorimetric value in the mask setting mode,
The calculation unit is configured to determine the first illuminance based on the observation illuminance, the observation mask luminance, the observation white color measurement value, the observation white luminance value, and the actual measurement value of the first observation color measurement value received in the mask setting mode. 1 observation appearance attribute value is calculated,
The correction unit corrects the mask luminance signal so that the first observation appearance attribute value approaches the first reference appearance attribute value in the mask setting mode. Endoscope processor. A control unit that controls operations of the correction unit, the transmission unit, the reception unit, and the calculation unit;
The correction unit uses the mask luminance signal included in the image signal transmitted to the monitor in the mask setting mode as a unit when there is a difference between the first observation appearance attribute value and the first reference appearance attribute value. Make corrections that change by the amount of change,
The transmission unit transmits an image signal corresponding to the display image including a mask image having a luminance corresponding to the mask luminance signal corrected by the correction unit to the monitor,
The receiving unit can receive the measured value of the observation mask luminance after transmitting the retransmitted display image to the monitor;
The calculation unit calculates the first observation appearance attribute value based on the observation mask luminance received again by the reception unit;
The control unit corrects a unit change amount by the correction unit and transmits the image signal by the transmission unit until a difference between the first observation appearance attribute value and the first reference appearance attribute value is minimized. , Receiving the observation mask luminance by the receiving unit, and calculating the first observation appearance attribute value by the calculation unit, and calculating the first observation appearance attribute value and the first reference appearance attribute value. The endoscope processor according to claim 2, wherein the set value when the difference is minimized is stored in the second memory.   The receiving unit includes a second input unit capable of inputting a numerical value, and the observation illuminance, the mask luminance, the observation white colorimetric value, the observation white luminance, by inputting a numerical value to the second input unit, The endoscope processor according to any one of claims 1 to 3, wherein at least one of the measured values of the first observation colorimetric value is received.   The receiving unit is connectable to a colorimeter that detects the mask luminance, the observed white colorimetric value, the observed white color luminance, and the first observed colorimetric value, and the mask luminance, the observed white color The colorimetric value, the observed white luminance, and the actual measured value of the first observed colorimetric value are received from the colorimeter. Endoscopic processor.   The receiving unit is connectable to an image sensor provided in the endoscope or an image sensor provided in an add-on camera connected to the endoscope, and the mask luminance, the observation white colorimetric value, and the observation The endoscope according to any one of claims 1 to 4, wherein white luminance and an actual measurement value of the first observation colorimetric value are received as an image signal generated by the imaging device. Processor. The first memory includes the reference illuminance, the reference mask luminance, the reference white colorimetric value, the reference white luminance, and a second color different from the first color displayed in the mask image on the monitor. Storing the value of the second color appearance attribute calculated based on the second reference colorimetry value, which is a colorimetric value of the second color value, as a second reference appearance attribute value;
The receiving unit receives an actual measurement value of a second observation colorimetric value that is a colorimetric value of the second color to be displayed inside the mask image on the monitor when observing the subject;
The calculation unit is configured to determine an appearance attribute of the second color based on the observation illuminance, the observation mask luminance, the observation white colorimetric value, the observation white luminance value, and an actual measurement value of the second observation colorimetric value. A second observation appearance attribute value that is a value of
The correction unit corrects the mask luminance signal so that the second observation appearance attribute value approaches the second reference appearance attribute value. The endoscope processor according to item. A third input unit for receiving an input for starting an initial setting mode for calculating the first reference appearance color value;
When the initial setting mode is started based on an input to the third input unit, the display image including white and the first color is transmitted to the monitor inside a mask image having a predetermined luminance. A second transmitter,
In the initial setting mode, the receiving unit is capable of receiving the reference illuminance, the reference mask luminance, the reference white colorimetric value, the reference white luminance, and the measured value of the first reference colorimetric value,
The calculation unit is configured to perform the first calculation based on the measured values of the reference illuminance, the reference mask luminance, the reference white colorimetric value, the reference white color luminance, and the first reference colorimetric value received in the initial setting mode. 1 reference appearance attribute value is calculated,
The endoscope processor according to any one of claims 1 to 7, wherein the first memory stores the first reference appearance attribute value calculated in the initial setting mode. . An endoscope unit for creating a display image having an observation image including at least a part of a subject image observed by an endoscope and a mask image covering the periphery of the observation image,
Reference illuminance that is the illuminance of the ambient environment that serves as a reference, reference mask brightness that is the brightness of the mask image that serves as a reference, white colorimetric value that is displayed on the monitor that displays the display image, and reference white colorimetric value that is brightness And the reference white luminance, and the value of the appearance attribute of the first color calculated based on the first reference colorimetric value which is the colorimetric value of the first color displayed in the mask image on the monitor A first memory for storing as a first reference appearance attribute value;
Observation illuminance that is the illuminance of the surrounding environment for observing the subject image using the endoscope, observation mask luminance that is the luminance of the mask image when observing the subject image, and the monitor when observing the subject A white colorimetric value and luminance to be displayed on the monitor, and an observation white colorimetric value and observation white luminance to be displayed on the monitor, and a first observational colorimetric value to be displayed on the monitor in the mask image. A receiving unit for receiving the actual measurement value of the color value;
Based on the observation illuminance, the observation mask luminance, the observation white colorimetric value, the observation white luminance value, and the actual measurement value of the first observation colorimetric value received by the reception unit, A calculation unit that calculates a first observation appearance attribute value that is a value of the appearance attribute;
A correction unit that corrects a mask luminance signal that is a signal component of the mask image corresponding to the observation mask luminance so that the first observation appearance attribute value approaches the first reference appearance attribute value;
A second memory for storing the mask luminance signal corrected by the correction unit;
An endoscope unit, comprising: a creation unit that creates the display image using the mask image that is the observation mask brightness corresponding to the mask brightness signal stored in the second memory.

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