JP6147097B2 - Endoscope and endoscope system - Google Patents

Description

  The present invention relates to an endoscope and an endoscope system having an image sensor to which a color filter is attached.

  The endoscope system includes an endoscope that captures a color image, and a processor that receives the color image from the endoscope and performs image processing. The endoscope obtains a color image by providing a color filter on the imaging surface of the imaging device. The color filter has a plurality of colors corresponding to a specific color space, and an image signal constituting the color image takes a value corresponding to the color space. Since the type of color filter varies depending on the endoscope, the color space of the image signal to be output varies depending on the type of endoscope. Further, since the processor is designed to process only an image signal in a specific color space, when an image signal defined by a color space different from the color space that can be processed by the processor is processed, the obtained image has a color. It will collapse and become difficult to observe. That is, if an endoscope having a different color space is connected to a processor, an observable image cannot be obtained. In order to solve this problem, the processor acquires model information from the endoscope, specifies the type of color filter according to the model information, and performs color space correction processing on the image signal according to the specified type of color filter. The structure to apply is known (patent document 1).

JP 2006-115963 A

  However, spectral sensitivity characteristics differ depending on the type of color filter. More specifically, the color filter is composed of pixels of a plurality of colors, and the sensitivity to the wavelength of light differs for each color. Therefore, if the color space is simply corrected without considering the spectral sensitivity characteristics, the luminance of each color forming the image obtained by the correction is different from the image before correction. Therefore, there is a possibility that the color of the image obtained by the correction may be lost and difficult to observe. Furthermore, when model information that is not stored in the processor is received, the type of the color filter cannot be specified, and the color space may not be corrected.

  The present invention has been made in view of these problems, and an object thereof is to obtain an endoscope and an endoscope system that create an image that is faithful to an original image and that corresponds to a different color space. And

  An endoscope according to a first invention of the present application is an endoscope that can be attached to a processor that processes an image signal captured using a first filter that outputs transmitted light defined by a first color space. A second filter that transmits reflected light from the observation target and outputs transmitted light defined by a second color space different from the first color space; An image sensor that outputs an image signal, and a color conversion unit that converts the second image signal into the first image signal defined by the first color space, the color conversion unit including the first filter spectrum The second image signal is converted into the first image signal based on the sensitivity characteristic and the spectral sensitivity characteristic of the second filter.

  When the endoscope is connectable to the processor, further includes a determination unit that determines a color space that can be processed by the processor, and the determination unit determines that the color space that can be processed by the processor is the first color space Furthermore, it is preferable that the color conversion unit converts the second image signal into the first image signal and outputs the first image signal.

  When the endoscope is connectable to the processor, further includes a determination unit that determines a color space that can be processed by the processor, and the determination unit determines that the color space that can be processed by the processor is the second color space In addition, it is preferable that the color conversion unit does not convert the second image signal, and the endoscope outputs the second image signal to the processor.

  The spectral sensitivity characteristic has a sensitivity characteristic for each of a plurality of color components constituting each color space, and the color conversion unit uses one color component among the plurality of color components constituting the first color space, Other color components constituting the second color space by normalizing other color components constituting one color space and using one color component among a plurality of color components constituting the second color space It is preferable that the second image signal is converted into the first image signal by using the value obtained by normalizing and normalizing.

  The first filter is a complementary color system filter, the second filter is a primary color system filter, the first color space is a complementary color system color space, and the second color space is a primary color system color space. Is preferred.

  An endoscope system according to a second invention of the present application includes a processor that processes an image signal imaged using a first filter that outputs transmitted light defined by a first color space, and reflected light from an observation target. And a second filter that outputs transmitted light defined by a second color space different from the first color space, and an imaging element that images the transmitted light and outputs a second image signal A color conversion unit that converts the second image signal into a first image signal defined by the first color space, and an endoscope that can be attached to the processor. The second image signal is converted into the first image signal based on the spectral sensitivity characteristic of the first filter and the spectral sensitivity characteristic of the second filter.

  According to the present invention, an endoscope and an endoscope system for creating images corresponding to different color spaces are obtained.

It is a figure which shows an endoscope system. It is the figure which showed roughly about pixel interpolation. It is the figure which showed roughly about conversion of a color space. It is the graph which showed the spectral sensitivity characteristic of the primary color system filter. 3 is a graph showing spectral sensitivity characteristics of a complementary color filter. It is the flowchart which showed the color system conversion process.

  Hereinafter, an endoscope system 100 according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  First, the outline of the endoscope system 100 will be described with reference to FIG. The endoscope system 100 includes an endoscope 200, a processor 300, and a monitor 306.

  The endoscope 200 mainly includes a photographing optical system 201, an illumination optical system 202, an image sensor 211, a primary color system filter (second filter) 212, and a drive / process circuit 220.

  The illumination optical system 202 receives illumination light described later from the processor 300 via the illumination optical fiber 204 and irradiates the observation target. The illumination light is reflected by the observation object. The imaging optical system 201 includes one or more optical lenses, and transmits reflected light from the observation target toward the primary color filter 212 and the image sensor 211 and forms an image on the image sensor 211. The primary color filter 212 includes a plurality of red filters, a plurality of green filters, and a plurality of blue filters defined by a primary color system color space (second color space). Each color filter transmits only light in a specific wavelength band toward the image sensor 211. The imaging element 211 has a plurality of imaging pixels, images the transmitted light from the primary color filter 212, and outputs an image signal composed of the primary color system color space to the drive / process circuit 220. An image signal composed of a primary color space is called a primary color image signal (second image signal). The primary color image signal is composed of luminance values respectively indicating red, green, and blue luminances.

  The drive / process circuit 220 mainly includes a color conversion unit 221, a signal processing unit 222, and a system determination unit (determination unit) 223.

  The system determination unit 223 specifies the color space of the image signal that can be processed by the processor 300. The endoscope system 100 according to the present embodiment corresponds to two color spaces, a primary color system color space and a complementary color system color space. In other words, the system determination unit 223 specifies which of the primary color system color space and the complementary color system color space the processor 300 corresponds to. Details will be described later.

  The color conversion unit 221 performs pixel interpolation processing, which will be described later, and converts the image signal output from the image sensor 211 into an image signal defined by the color space specified by the system determination unit 223. That is, when the color space specified by the system determination unit 223 is a complementary color system color space, the primary color system image signal is converted into an image signal defined by the complementary color system color space and transmitted to the signal processing unit 222. On the other hand, when the color space specified by the system discrimination unit 223 is a primary color system color space, the primary color system image signal is transmitted to the signal processing unit 222 without being converted. An image signal defined by the complementary color space is referred to as a complementary color image signal (first image signal). The complementary color image signal is composed of luminance values indicating the luminances of magenta, cyan, yellow, and green. The process of converting the primary color system image signal to the complementary color system image signal is called color system conversion process.

  The signal processing unit 222 is electrically connected to the color conversion unit 221, the system determination unit 223, and the processor 300, and controls communication between the endoscope 200 and the processor 300.

  The processor 300 mainly includes a system control circuit 301, a video signal processing unit 302, a ROM 303, a panel switch 304, a lamp control circuit 311, and an aperture drive unit 313, and a complementary color system color space (first color Complementary color system image signals captured using a complementary color system filter (first filter) that outputs transmitted light defined by (space) are processed.

  The system control circuit 301 is electrically connected to the video signal processing unit 302, the lamp control circuit 311, the aperture control unit, the ROM 303, and the panel switch 304, and operates by reading the firmware stored in the ROM 303. To control the operation.

  The video signal processing unit 302 is configured to perform image processing on the complementary color system image signal, receives the complementary color system image signal from the signal processing unit 222, performs predetermined processing, and transmits the created display image to the monitor 306. To do.

  The lamp control circuit 311 controls the light amount of the lamp 312 according to an instruction from the system control circuit 301. The lamp 312 emits illumination light in accordance with an instruction from the lamp control circuit 311 and changes the amount of light. The aperture drive unit 313 controls the opening and timing of the aperture 314 in accordance with an instruction from the system control circuit 301. The aperture 314 changes the opening and timing according to an instruction from the aperture controller. Thereby, the light emission timing and light emission period of illumination light are adjusted. The lamp lens 315 causes the illumination light to enter the illumination optical fiber 204.

  The panel switch 304 includes a plurality of switches. The switch is operated by the user and transmits a signal corresponding to the operated switch to the system control circuit 301. The system control circuit 301 controls the processor 300 according to the received signal.

  The monitor 306 displays a display image. Thereby, the user can observe the observation target.

  Next, pixel interpolation processing will be described with reference to FIG. A part of the primary color filter 212 is shown in the array 21. The primary color system filter 212 is an optical filter in which a red filter, a green filter, and a blue filter are arranged in a so-called Bayer array. Each of the red filter, the green filter, and the blue filter corresponds to each imaging pixel. Therefore, in a signal output from the image sensor 211, one pixel has only a luminance value of one color. On the other hand, in a display image, one pixel needs to have luminance values of red, green, and blue. Therefore, it is necessary to interpolate the luminance values using the luminance values of adjacent pixels. The process of interpolating the luminance value is called pixel interpolation process.

Processing for interpolating red luminance values using the array 22 will be described. The array 22 shows red pixels R11, R13, R31, R33 and the like that are actually imaged, and red pixels R12, R21, R22, and the like that are not actually imaged. Before executing the pixel interpolation process, the red pixel that is actually imaged has a luminance value obtained by imaging, but the red pixel that is not actually imaged does not have a luminance value. The red pixels R11, R13, R31, and R33 have luminance values BR11, BR13, BR31, and BR33, respectively. Using these red pixels, luminance values BR12, BR21, and BR22 of red pixels R12, R21, and R22 are created. This process is called interpolation. The luminance values BR12, BR21, and BR22 are obtained by the following formula.
BR12 = (BR11 + BR13) / 2
BR21 = (BR11 + BR31) / 2
BR22 = (BR11 + BR13 + BR31 + BR33) / 4

A process of interpolating the green luminance value using the array 23 will be described. The array 23 indicates green pixels G12, G21, G23, and G32 that are actually captured, and green pixels G11 and G22 that are not actually captured. Before the pixel interpolation process is executed, the green pixel that is actually captured has a luminance value obtained by imaging, but the green pixel that is not actually captured does not have a luminance value. Green pixels G12, G21, G23, and G32 have luminance values BG12, BG21, BG23, and BG32, respectively. Using these green pixels, the luminance values BG11 and BG22 of the green pixels G11 and G22 are created. The luminance values BG11 and BG22 are obtained by the following formula.
BG11 = (BG12 + BG21) / 2
BG22 = (BG12 + BG21 + BG23 + BG32) / 4

A process of interpolating blue luminance values using the array 24 will be described. The array 24 shows blue pixels B22, B24, B42, and B44 that are actually captured, and blue pixels B23, B32, and B33 that are not actually captured. Before executing the pixel interpolation process, the actually captured blue pixel has a luminance value obtained by imaging, but the blue pixel that is not actually captured does not have a luminance value. Blue pixels B22, B24, B42, and B44 have luminance values BB22, BB24, BB42, and BB44, respectively. Using these blue pixels, luminance values BB23, BB32, and BB33 of blue pixels B23, B32, and B33 are created. The luminance values BB23, BB32, and BB33 are obtained by the following formula.
BB23 = (BB22 + BB24) / 2
BB32 = (BB22 + BB42) / 2
BB33 = (BB22 + BB24 + BB42 + BB44) / 4

  Accordingly, all the pixels included in the display image have red, green, and blue luminance values. That is, a primary color image signal is created.

  The color system conversion process will be described with reference to FIGS. The color system conversion process is a process of converting a primary color image signal into a complementary color image signal based on the spectral sensitivity characteristic of the primary color system filter 212 and the spectral sensitivity characteristic of the complementary color system filter.

A part of the complementary color filter is shown in an array 31 in FIG. The complementary color filter is an optical filter in which a magenta filter Mg, a cyan filter Cy, a yellow color filter Ye, and a green color filter Gn are arranged. When reading the luminance value from the image sensor 211 to which the complementary color filter is attached, interlace reading is performed. In interlace reading, the first field and the second field are read alternately. In the first field, the combined luminance value Wr and total luminance value Gb in the N1 line, and the combined luminance value Wb and total luminance value Gr in the N2 line are read. Here, the combined luminance value Wr is a value obtained by adding the luminance value BMg of the magenta pixel of the N1 line and the luminance value BYe of the yellow pixel, and the combined luminance value Gb is the luminance value BGn of the green pixel of the N1 line. The value obtained by adding the luminance value BCy of the cyan pixel, the combined luminance value Wb is the value obtained by adding the luminance value BMg of the magenta pixel of the N2 line and the luminance value BCy of the cyan pixel, and the combined luminance value Gr is N2. This is a value obtained by adding the luminance value BGn of the green pixel of the line and the luminance value BYe of the yellow pixel. In the next second field, the combined luminance value Wb and total luminance value Gr in the N2 line, and the combined luminance value Wr and total luminance value Gb in the N3 line are read. The combined luminance value Wr is a value obtained by adding the luminance value BMg of the magenta pixel in the N2 line and the luminance value BYe of the yellow pixel, and the combined luminance value Gb is the luminance value BGn and cyan pixel of the green pixel in the N2 line. The combined luminance value Wb is a value obtained by adding the luminance value BMg of the magenta pixel of the N3 line and the luminance value BCy of the cyan pixel, and the combined luminance value Gr is the green value of the N3 line. This is a value obtained by adding the luminance value BGn of the color pixel and the luminance value BYe of the yellow color pixel. Then, the total luminance value is read for all lines. Here, the luminance value BMg of the magenta pixel, the luminance value BCy of the cyan pixel, the luminance value BYe of the yellow pixel, and the luminance value BGn of the green pixel are the red luminance value RB, the green luminance value GB, and It is expressed by the following equation using the blue luminance value BB.
BMg = BR + BB
BCy = BB + BG
BYe = BR + BG
BGn = BG
Therefore, the combined luminance value Wr, the total luminance value Gb, the combined luminance value Wb, and the total luminance value Gr are represented by the following expressions.
Wr = BMg + BYe = (BR + BB) + (BR + BG) = 2BR + BG + BB
Gb = BGn + BCy = BG + (BB + BG) = 2BG + BB
Wb = BMg + BCy = (BR + BB) + (BB + BG) = BR + BG + 2BB
Gr = BGn + BYe = BG + (BR + BG) = R + 2BG
That is, the luminance value of the complementary color system color space can be obtained by adding the luminance value of the primary color system color space.

  FIG. 4 is a graph showing the spectral sensitivity characteristics of the primary color filter 212. A red spectral sensitivity characteristic is represented by a red spectral sensitivity characteristic Rp (λ), a green spectral sensitivity characteristic is represented by a green spectral sensitivity characteristic Gp (λ), and a blue spectral sensitivity characteristic is represented by a blue spectral sensitivity characteristic Bp (λ). λ indicates a wavelength. The spectral sensitivity characteristics of each color form a mountain shape having substantially the same shape centered on a predetermined wavelength.

  FIG. 5 is a graph showing the spectral sensitivity characteristic of the complementary color filter. The cyan spectral sensitivity characteristic is the cyan spectral sensitivity characteristic Cyc (λ), the magenta spectral sensitivity characteristic is the magenta spectral sensitivity characteristic Mgc (λ), and the yellow spectral sensitivity characteristic is the yellow spectral sensitivity characteristic Yec (λ). The green spectral sensitivity characteristic is indicated by a green spectral sensitivity characteristic Gc (λ). The spectral sensitivity characteristics of each color have different shapes.

  Since the spectral sensitivity characteristic of the primary color system filter 212 is different from the spectral sensitivity characteristic of the complementary color system filter, in order to realize high color reproducibility when converting the primary color system color space to the complementary color system color space, the primary color system filter and the complementary color are used. The spectral sensitivity characteristics of the system filter must be taken into account. As described above, the luminance value of the complementary color can be obtained by simply adding the luminance values of the primary colors. However, since the spectral sensitivity characteristic of the primary color filter 212 is different from the spectral sensitivity characteristic of the complementary color filter, simply adding the luminance values is not sufficient. High color reproducibility cannot be realized. Therefore, the sensitivity ratio of other colors is calculated based on one of the colors of the primary color filter and the complementary color filter, the conversion coefficient is obtained using the sensitivity ratio, and the luminance value of each color is calculated using the conversion coefficient. to correct. As a result, the difference in spectral sensitivity characteristic between the filters is corrected to realize high color reproducibility. This will be described in detail below.

First, the sensitivity ratio of other colors is calculated using one of the colors of the primary color filter and the complementary color filter as a reference. That is, the spectral sensitivity characteristics of other colors are normalized using the green color of the primary color system filter 212 and the green color of the complementary color system filter. The value thus obtained is the sensitivity ratio. Hereinafter, a red sensitivity ratio Ratio_p (R / G) that is a red sensitivity ratio and a blue sensitivity ratio Ratio_p (B / G) that is a blue sensitivity ratio in the primary color filter 212 are shown.

Next, the magenta sensitivity ratio Ratio_c (Mg / Gn), which is the magenta sensitivity ratio in the complementary color filter, the yellow sensitivity ratio Ratio_c (Ye / Gn), which is the sensitivity ratio of yellow, and the sensitivity ratio of cyan. A certain cyan sensitivity ratio Ratio_c (Cy / Gn) is shown.

Next, a correction coefficient is obtained using the normalized sensitivity ratio. Correction coefficient W_r2 mg used when converting a red luminance value into a magenta luminance value, correction coefficient W_b2 mg used when converting a blue luminance value into a magenta luminance value, and a red luminance value as a yellow luminance value Correction coefficient W_r2ye used when converting to green, a correction coefficient W_g2ye used when converting a green luminance value to a yellow luminance value, a correction coefficient W_g2gn used when converting a green luminance value to a green luminance value, The calculation formulas of the correction coefficient W_b2cy used when converting the blue luminance value into the cyan luminance value and the correction coefficient W_g2cy used when converting the green luminance value into the cyan luminance value are shown below.
W_r2mg = k (Ratio_c (Mg / Gn) / Ratio_p (R / G)
W_b2mg = k (Ratio_c (Mg / Gn) / Ratio_p (B / G)
W_r2ye = k (Ratio_c (Ye / Gn) / Ratio_p (R / G)
W_g2ye = k.Ratio_c (Ye / Gn)
W_g2gn = k
W_b2cy = k (Ratio_c (Cy / Gn) / Ratio_p (B / G)
W_g2cy = k · Ratio_c (Cy / Gn)
Here, k is a sensitivity ratio between G and Gn of the image sensors 211 and is obtained by the following equation.

Next, the luminance value of each color is corrected by multiplying the luminance value of each color by the correction coefficient. Then, using the corrected luminance value, a combined luminance value Wr, a total luminance value Gb, a combined luminance value Wb, and a total luminance value Gr are obtained. The resultant luminance value Wr, total luminance value Gb, synthetic luminance value Wb, and total luminance value Gr obtained in this way are expressed by the following equations.
Wr = BMg + BYe = (W_r2mg · BR + W_b2mg · BB) + (W_r2ye · BR + W_g2ye · BG)
Gb = BGn + BCy = W_g2gn · BG + (W_b2cy · BB + W_g2cy · BG)
Wb = BMg + BCy = (W_r2mg · BR + W_b2mg · BB) + (W_b2cy · BB + W_g2cy · BG)
Gr = BGn + BYe = W_g2gn · BG + (W_r2ye · BR + W_g2ye · BG)

  As a result, the difference in spectral sensitivity characteristics between the filters is corrected to convert the luminance value of the primary color space into the luminance value of the complementary color space, thereby realizing high color reproducibility.

  The flow of the color system conversion process will be described with reference to FIG. The color system conversion process is a process executed by the endoscope 200 and is executed when the endoscope 200 is connected to the processor 300.

  In the first step S61, the system determination unit 223 specifies the color space of the image signal that can be processed by the processor 300. If it is determined that the processor 300 corresponds to the complementary color space, the process proceeds to step S62. If it is determined that the processor 300 corresponds to the primary color space, the process proceeds to step S65.

  If it is determined in step S61 that the processor 300 corresponds to the complementary color system color space, in step S62, the image sensor 211 captures the transmitted light from the primary color system filter 212 and converts the primary color system image signal into a color conversion unit. Output to 221.

  In the next step S63, the color conversion unit 221 executes pixel interpolation processing. Thereby, luminance values are obtained for all the pixels.

  In the next step S64, the color conversion unit 221 executes a color system conversion process. As a result, the primary color image signal is converted into an image signal defined by the complementary color space and is transmitted to the signal processing unit 222.

  If it is determined in step S61 that the processor 300 corresponds to the primary color system color space, in step S65, the imaging device 211 captures the transmitted light from the primary color system filter 212 and converts the primary color system image signal into a color conversion unit. Output to 221.

  In the next step S66, the color conversion unit 221 executes pixel interpolation processing. Thereby, luminance values are obtained for all the pixels.

  In the next step S <b> 67, a primary color image signal or a complementary color image signal is transmitted to the processor 300.

  In the next step S68, the video signal processing unit 302 processes the complementary color image signal, and the monitor 306 displays the display image obtained thereby. Then, the process ends.

  According to the present embodiment, even if the color space of the image signal captured by the image sensor 211 included in the endoscope 200 is different from the color space of the image signal that can be processed by the processor 300, the endoscope 200 is processed by the processor 300. It can be used by connecting to. In addition, by taking into consideration the spectral sensitivity characteristics of the filter attached to the image sensor 211 and the spectral sensitivity characteristics of the filter assumed by the processor 300, an image that is faithful to the color of the subject image and has high color reproducibility can be obtained. It can be displayed on the monitor 306.

  Note that the image signal output from the image sensor 211 is not limited to the primary color image signal, and may be an image signal defined by a complementary color space or another color space.

  Further, the color space of the image signal that can be processed by the processor 300 is not limited to the complementary color space, and may be another color space. At this time, the endoscope 200 converts the image signal output from the image sensor 211 into an image signal defined by a color space suitable for the processor 300 and outputs the image signal.

  When the image sensor 211 outputs an image signal defined by a complementary color system color space, the image sensor 211 may convert the complementary color image signal into a primary color image signal by using the inverse conversion formula of the above-described formula. Is possible.

  The arrangement of primary color filters is not limited to the Bayer arrangement, and the arrangement of color system filters is not limited to the aforementioned arrangement.

DESCRIPTION OF SYMBOLS 100 Endoscope system 200 Endoscope 201 Image | photographing optical system 202 Illumination optical system 204 Illumination optical fiber 211 Imaging element 212 Primary color system filter 220 Drive / process circuit 221 Color conversion part 222 Signal processing part 223 System discrimination | determination part 300 Processor 301 System control circuit 302 Video signal processing unit 303 ROM
304 Panel Switch 306 Monitor 311 Lamp Control Circuit 312 Lamp 313 Aperture Drive Unit 315 Lamp Lens

Claims (4)

An endoscope attachable to a processor configured to process an image signal imaged using a first filter that outputs transmitted light defined by a first color space,
A second filter that transmits reflected light from the observation target and outputs transmitted light defined by a second color space different from the first color space;
An image sensor that images the transmitted light and outputs a second image signal;
A color conversion unit for converting the second image signal into a first image signal defined by the first color space ;
A determination unit that determines a color space that can be processed by the processor ;
When said processor is capable of processing a color space has the determination unit is determined to be the first color space, the color conversion unit spectroscopy of the second filter and the spectral sensitivity characteristic of the prior Symbol first filter Converting the second image signal into the first image signal based on a sensitivity characteristic and outputting the first image signal;
When the determination unit determines that the color space that can be processed by the processor is the second color space, the color conversion unit does not convert the second image signal, but converts the second image signal. Endoscope to output . The spectral sensitivity characteristic has a sensitivity characteristic for each of a plurality of color components constituting each color space,
The color conversion unit normalizes other color components constituting the first color space using one color component among a plurality of color components constituting the first color space, and the second color component. The second color space is normalized using a value obtained by normalizing another color component constituting the second color space using one color component of a plurality of color components constituting the second color space, and using the value obtained by normalization. the endoscope according to claim 1 for converting an image signal into the first image signal. The first filter is a complementary color system filter, the second filter is a primary color system filter, the first color space is a complementary color system color space, and the second color space is a primary color system color. The endoscope according to claim 1 , wherein the endoscope is a space. A processor configured to process an image signal captured using a first filter that outputs transmitted light defined by a first color space;
A second filter that transmits reflected light from the observation target and outputs transmitted light defined by a second color space different from the first color space; An image sensor that outputs an image signal, a color conversion unit that converts the second image signal into a first image signal defined by the first color space, and a color space that can be processed by the processor And when the determination unit determines that the color space that can be processed by the processor is the first color space, the color conversion unit determines the spectral sensitivity characteristic of the first filter and the first color space . The second image signal is converted into the first image signal based on the spectral sensitivity characteristic of the second filter and the first image signal is output, and the color space that can be processed by the processor is the second image signal. When the determination unit determines that the color space is The conversion unit without converting the second image signal, an endoscopic system including an endoscope which is attachable to said processor for outputting the second image signal.

Images