JP4575537B2 - Electronic endoscope device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic endoscope apparatus that displays an image obtained by inserting a scope including a CCD (imaging device) into an organ of a human body and taking an image on a monitor via a processor.
[0002]
[Prior art]
In a conventional electronic endoscope apparatus, a captured image is displayed on a monitor as a moving image, and a captured image can be printed (hard copy) as a still image by connecting a video printer. In such an endoscope apparatus, when an operator operates a dedicated switch during an inspection or the like, a video signal of a captured image is output to a video printer, thereby printing the captured image. Based on the printed captured image, the state of the affected area is diagnosed.
[0003]
[Problems to be solved by the invention]
Usually, the resolution of the captured image depends on the number of pixels of the CCD provided in the scope, and the higher the number of pixels, the higher the resolution of the captured image that is printed. However, when a captured image obtained by imaging with a scope is displayed on a monitor as a moving image, the number of CCD pixels that can be used as a video is determined according to the color television system of the monitor. For example, when the NTSC system is applied as the color television system, the number of usable effective pixels is about 410,000 pixels. Also in the conventional electronic endoscope apparatus, a CCD having a number of pixels of about 20 to 410,000 pixels is mainly provided in the scope for reasons such as restrictions on displaying captured images on a monitor by the NTSC method. Yes.
[0004]
In order to obtain a clear image equivalent to the image recorded on the silver salt film by imaging with the CCD, it is necessary to use a CCD having several million pixels. Therefore, even if a captured image obtained by imaging with a CCD having about 410,000 pixels or less is printed by a printer, only a low-resolution image with low resolution can be obtained. If the affected area is diagnosed based on the low-quality captured image, the image around the affected area is unclear, so the state of the affected area cannot be accurately confirmed and there is a risk of misdiagnosis.
[0005]
On the other hand, when a megapixel CCD having a pixel number of 1 million pixels or more is provided in the scope, the number of pixels is larger than the effective number of pixels that can be used in the NTSC system, so only a part of the captured image is displayed on the monitor. End up.
[0006]
The present invention displays a captured image as a moving image on a monitor according to the color television system of the monitor regardless of the number of CCD pixels in the scope, and a high-resolution still image when a megapixel CCD is provided in the scope. An object of the present invention is to obtain an electronic endoscope apparatus capable of obtaining the above.
[0007]
[Means for Solving the Problems]
An electronic endoscope apparatus according to the present invention is connected to a scope having an imaging element on which a subject image is formed, and a scope and a monitor for displaying the subject image, and to the imaging element for displaying the subject image on the monitor. An electronic endoscope apparatus including a processor that processes an image signal corresponding to a generated subject image, to an external still image data processing system that can convert the image signal into still image data and receive still image data A signal output means for outputting, and a pixel number adjusting means for adjusting the number of pixels constituting the subject image. When the subject image is displayed on the monitor, the pixel number adjusting means is an effective pixel corresponding to the monitor. When the still image data is output to the outside, the subject image is configured by the total number of pixels of the image sensor. As a result, a subject image composed of the number of effective pixels or less is displayed on the monitor, and still image data corresponding to the subject image composed of the total number of pixels is output. Furthermore, the electronic endoscope apparatus preferably includes a pixel number determining unit that determines whether or not the total number of pixels of the image sensor is larger than the effective pixel number corresponding to the monitor. In this case, the pixel number adjusting unit includes When the number of pixels of the image sensor is larger than the number of effective pixels, it is desirable to adjust the number of pixels constituting the subject image. As a result, when the number of pixels of the image sensor is larger than the number of effective pixels, a subject image composed of the number of effective pixels or less can be obtained, so that the entire captured image is displayed on the monitor and when still image data is output, Still image data from which a high-resolution captured image composed of the total number of pixels of the element is obtained is output to the outside.
Since the number of pixels is adjusted based on the number of effective pixels in this way, both a scope having an image sensor having an effective number of pixels and a scope having an image sensor having an effective number of pixels or less can be effectively used. The effective pixel number is, for example, the number of pixels according to the color television system of the monitor. Preferably, the pixel number adjusting unit displays a subject image including the effective pixel number on the monitor. As a result, the subject image is displayed on the entire monitor.
[0008]
When displaying the subject image on the monitor, it is desirable that the pixel number adjusting unit performs the thinning process on the subject image composed of the total number of pixels of the image sensor, thereby configuring the subject image with the effective number of pixels. Through such thinning processing, the entire captured image is displayed on the monitor according to the resolution of the monitor. When adjusting the number of pixels by thinning-out processing, the pixel number adjusting means reads an image signal corresponding to the subject image composed of the effective number of pixels from the image sensor when displaying the subject image on the monitor, and obtains still image data. In the case of outputting, it is desirable to read out from the image sensor an image signal corresponding to a subject image composed of the total number of pixels of the image sensor. By adjusting the number of pixels in the scope in this way, a processor that can handle a scope having a megapixel CCD can be easily obtained without changing the circuit configuration of the processor.
[0009]
When displaying the subject image on the monitor, it is desirable that the pixel number adjusting unit performs the average operation method on the subject image composed of the total number of pixels of the image pickup device, thereby configuring the subject image with the effective number of pixels. . By such an average operation method, a subject image without aliasing distortion can be displayed on the monitor. When adjusting the number of pixels by the average operation method, the pixel number adjusting means reads the image signal corresponding to the subject image composed of the total number of pixels of the image sensor from the image sensor, and then displays the subject image on the monitor In this case, the read image signal is converted into an image signal corresponding to the subject image composed of the effective number of pixels and sent to the processor, and when the still image data is output, the read image signal is directly sent to the processor. It is desirable to send. By adjusting the number of pixels within the scope, it is possible to easily obtain a processor that can support a scope having a megapixel CCD without changing the circuit configuration of the processor.
[0010]
When the number of pixels of the image sensor is smaller than the number of effective pixels, the pixel number adjusting unit preferably does not adjust the number of pixels constituting the subject image. Thus, when displaying on a monitor and when outputting still image data Also, an image signal corresponding to a subject image composed of the total number of pixels of the image sensor is always read out. Therefore, even if a scope having an image sensor with a small number of pixels is connected to the processor, a subject image composed of the total number of pixels is displayed on the monitor without converting the number of pixels. Is displayed.
[0011]
The still image data processing system is preferably a processing system including a computer system to which a printer capable of printing a high-resolution image is connected and an image recording apparatus capable of receiving still image data and recording it in an auxiliary storage device. By executing printing based on still image data sent to the computer system, a high-resolution captured image composed of the total number of pixels of the image sensor is obtained. Moreover, a high-resolution captured image can be obtained by displaying the captured image on a high-resolution monitor based on the still image data stored in the auxiliary storage device.
[0012]
The processor of the electronic endoscope apparatus according to the present invention is connected to a scope having an image sensor on which a subject image is formed and a monitor for displaying the subject image, and is generated in the image sensor to display the subject image on the monitor. An external endoscope image data processing system capable of converting an image signal into still image data and receiving still image data, which is a processor of an electronic endoscope apparatus including a processor that processes an image signal corresponding to a subject image Signal output means for outputting to the monitor and a pixel number adjusting means for adjusting the number of pixels constituting the subject image. When the subject image is displayed on the monitor, the pixel number adjusting means reduces the subject image to less than the effective number of pixels. When the still image data is output to the outside, the subject image is composed of the total number of pixels of the image sensor, so that the subject image composed of less than the effective number of pixels is monitored. Is displayed on the still image data corresponding to the constructed object image by the total number of pixels is equal to or to be output. When the number of pixels of the image sensor is greater than the number of effective pixels, a subject image composed of the number of effective pixels is obtained, so that the entire captured image is displayed on the monitor, and when outputting still image data, all pixels of the image sensor Still image data from which a high-resolution captured image composed of numbers is obtained is output to the outside.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an electronic endoscope apparatus according to an embodiment of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a block diagram of the entire electronic endoscope apparatus according to the first embodiment. The electronic endoscope apparatus includes an electronic scope 10 and a processor 20, and a television monitor 50 for displaying an image is connected to the processor 20. The electronic scope 10 is detachably connected to the processor 20. When performing surgery or examination, the electronic scope 10 is connected to the processor 20 and inserted into a human organ or the like. The operation of the entire electronic endoscope apparatus is controlled by a CPU (Central Processing Unit) 36 provided in the system control circuit 34 in the processor 20.
[0015]
Light emitted from a light source 29 such as a halogen lamp enters the incident end 13 a of the light guide 13 via the condenser lens 31. The light guide 13 is a fiber bundle (light beam) for guiding the light emitted from the light source 29 from the connection end to the distal end of the electronic scope 10. The light incident on the incident end 13 a of the light guide 13 is emitted from the emission end 13 b of the light guide 13 and is emitted from the distal end of the electronic scope 10 through the light distribution lens 14. Thereby, the observation site S is irradiated with light. The connection end of the electronic scope 10 indicates a connection side with the processor 20, while the distal end of the electronic scope 10 indicates a distal end side inserted into the body cavity of the electronic scope 10.
[0016]
When the observation site S is irradiated with light, the light reflected by the observation site S passes through the objective lens 11 in the electronic scope 10, and thereby a subject image is formed on a CCD (imaging device) 12. On the light receiving surface of the CCD 12 on which the subject image is formed, photodiodes (not shown) which are photoelectric conversion elements and serve as pixels of the CCD 12 are arranged.
A complementary color filter, which will be described later, is arranged on the photodiode. When the subject image is formed on the light receiving surface of the CCD 13, an analog image signal (charge) corresponding to the color passing through the complementary color filter is generated for each pixel by photoelectric conversion.
[0017]
In FIG. 1, a CCD 12 provided in the electronic scope 10 is an imaging device having a number of pixels of about 1.6 million, and is a so-called megapixel CCD. The EEPROM 15 stores data related to the characteristics of the scope 10 (such as the number of pixels of the CCD 12) in advance. When the scope 10 is connected to the processor 20, data related to the characteristics of the electronic scope 10 is sent to the system control circuit 34. Sent.
[0018]
When the subject image is displayed on the monitor 50 as a moving image, the image signal generated in the CCD 12 is processed as described below. In this embodiment, the NTSC system is applied as the color television system. Therefore, the resolution of the monitor 50 follows the NTSC system.
[0019]
The CCD driver 16 is a circuit for driving the CCD 12, and a drive signal output from the CCD driver 16 is sent to the CCD 12 via the pixel number adjustment circuit 17. As will be described later, the pixel number adjusting circuit 17 reads out only about 410,000 pixel image signals corresponding to the NTSC system out of about 1.6 million pixels of the CCD 12 from the CCD 12 as necessary. That is, by controlling the drive signal so that the transfer path (not shown) in the CCD 12 thins out the pixels as appropriate, it is composed of about 410,000 pixels, which is the maximum number of pixels that can be used as an image in the NTSC system. An image signal corresponding to the subject image of the frame is sent to the pixel number adjustment circuit 17. The pixel number adjusting circuit 17 outputs the drive signal sent from the CCD driver 16 to the CCD 12 in accordance with the control signal sent from the system control circuit 34.
[0020]
An image signal corresponding to a subject image composed of about 410,000 pixels is read from the CCD 12 and input to the pixel number adjusting circuit 17, and then sent to the CCD process circuit 21 in the video processor 20. In this embodiment, since the NTSC system is applied, the image signal generated in the CCD 12 is read at 1/30 second intervals for each frame. In the following, the number of pixels of about 410,000 according to the NTSC system corresponding to the resolution of the monitor 50 is referred to as the effective pixel number.
[0021]
In the CCD process circuit 21, processing such as noise removal is performed on the image signal corresponding to the number of effective pixels read from the CCD 12. Further, the image signals read out for one frame are separated into image signals corresponding to red, blue, and green colors, respectively. When the image signal corresponding to each color is sent to the A / D conversion circuit 22, it is converted from an analog signal to a digital signal. The digitized image signal is temporarily stored in the image memory 23.
[0022]
The stored digital image signal is read from the image memory 23 and sent to the D / A converter 25. In the D / A converter 25, the digital image signal is converted into an analog signal and sent to the video process circuit 26. In the video process circuit 26, an analog image signal is converted into a video signal such as an NTSC (composite video) signal, a Y / C separation signal, or an analog RGB component signal. The video signals are sequentially output to the monitor 51 in accordance with the NTSC system, whereby the captured image is displayed on the monitor 50 as a moving image. At this time, the captured image is displayed on the entire screen of the monitor 50 because all the pixels that can be used in the NTSC system are used.
[0023]
On the other hand, when outputting an image signal as still image data to an external device, the following processing is performed. However, in this embodiment, a personal computer 54 and an image recording device 55 dedicated for digital data are connected to the processor 20 as external devices.
[0024]
When the recording switch 18 provided in the scope 10 is pressed by the operator, a control signal is sent from the system control circuit 34 to the pixel number adjusting circuit 17, and a drive signal sent from the pixel number adjusting circuit 17 to the CCD 12 is controlled. . Thereby, all the image signals (charges) generated in all pixels in the CCD 12 are read out from the CCD 12. That is, an image signal for one frame corresponding to about 1.6 million pixels is read from the CCD 12 and sent to the pixel number adjusting circuit 17. The read image signal is subjected to signal processing in the CCD process circuit 21, digitized in the A / D conversion circuit 22, and then sent to the image memory 23.
[0025]
A digital image signal corresponding to the total number of pixels of the CCD 12 temporarily stored in the image memory 23 is sent to the system control circuit 34. In the system control circuit 34, the image signal is converted into digital still image data corresponding to a predetermined format, and a still image such as an external personal computer 54 or image recording device 55 is provided via an interface circuit (not shown). Output to the data processing / management system. Here, still image data is serially transferred. While still image data is output, no image signal is stored in the image memory 23, and the captured image is displayed on the monitor 50 in a frozen state (still image).
[0026]
The personal computer 54 is connected to a printer 54P capable of printing a high-resolution image. When a predetermined operation is performed on the computer, a high-resolution captured image is printed on a print sheet based on the received still image data. Printed. The image recording device 55 is a device for recording digital still image data in an auxiliary storage device such as a magneto-optical disk. When still image data is sent from the processor 20, the captured image is auxiliary stored as a still image. Recorded on the device. Further, the image recording device 55 also has a function for reproducing and displaying the recorded image on the monitor. By outputting an image signal to the high resolution monitor 56 connected to the image recording device 55, the high resolution The captured image is displayed on the monitor 56. The monitor 56 is a monitor corresponding to the UXGA standard for personal computer video signals, and is effective up to about 2 million pixels as the number of pixels that can be used for CCD video.
[0027]
When the keyboard 51 or the panel switch 35 is operated by an operator, a signal related to the operation is input to the system control circuit 34 via an interface circuit (not shown). The system control circuit 34 is provided with a CPU 36, a ROM 37, and a RAM 38, and data read from the EEPROM 15 is temporarily stored in the RAM 38.
[0028]
The timing generator 28 outputs clock pulses, synchronization signals, and the like to the CCD driver 16, the CCD process circuit 21, the A / D conversion circuit 22, the image memory 23, the D / A converter 25, and the video process circuit 26. . Thereby, the input / output timing of the image signal in each circuit is adjusted.
[0029]
In the CCD process circuit 21, a luminance signal is generated from the image signal read from the CCD 12, and sent to the system control circuit 34 via the A / D converter 22. In the system control circuit 34, a control signal for controlling the diaphragm 30 is sent to the diaphragm control circuit 33 based on the transmitted luminance signal. When a drive signal for driving the motor 32 is sent from the aperture control circuit 33 to the motor 32, the motor 32 rotates and the aperture 30 opens and closes in conjunction with the rotation of the motor. The diaphragm 30 opens and closes so that the amount of light applied to the observation site S is appropriate.
[0030]
With reference to FIG. 2, a thinning process when displaying a moving image on a monitor will be described.
[0031]
FIG. 2 is a diagram schematically showing a part of the pixel array. The complementary color filter CC is a mosaic filter composed of four color filter elements of cyan Cy, magenta Mg, yellow Ye, and green G, and is configured by repeatedly arranging pixel blocks B each of which is an element. The The arrangement of the complementary color filters CC corresponds to the pixel arrangement on the CCD 12, that is, the arrangement of photodiodes. In the present embodiment, the interline transfer method is applied as the charge transfer method, and in the vertical direction of the CCD 13, a vertical transfer unit (not shown) is provided between each row of photodiodes. A horizontal transfer unit (not shown) to which charges transferred to the vertical transfer unit are transferred is also provided. FIG. 2 shows a state in which the array of complementary color filters CC is provided on the pixel array, and 8 × 8 = 64 pixel arrays, which are part of the pixel array, are shown.
[0032]
As described above, when a moving image is displayed on the monitor 50, the number of pixels constituting the subject image is the number of effective pixels (about 410,000 pixels) according to the NTSC system. Since the total number of pixels of the CCD 12 is about 1.6 million pixels, here, only one pixel is selected from four pixels corresponding to the positions of four adjacent filter elements of the same color, and stored in that pixel. Only charge is transferred to the vertical transfer path. That is, the subject image is converted into an image having a reduction ratio of 1/4 in both the vertical and horizontal directions. For the remaining three pixels not selected, the accumulated charge is not transferred. By repeatedly executing the process of extracting one pixel from the four pixels for each color, the subject image is configured with the number of effective pixels. That is, thinning processing (down sampling) is performed on the subject image.
[0033]
Each pixel in the pixel array shown in FIG. _ji And each pixel selected by the thinning process is represented by P ′ _ji In this case, the pixel P ′ selected by the thinning process _ji Is obtained by any one of the following four formulas ((1) to (4)). However, the subscript j (0 to 7) is the pixel P _ji , P ' _ji The subscript i (0 to 7) represents the pixel P _ji , P ' _ji Indicates the horizontal position.
[0034]
P ' _ji = P _ji (J <2, i <2) (1)
P ' _ji = P _{j + 2, i} (J ≧ 2, i <2) (2)
P ' _ji = P _{j, i + 2} (J <2, i ≧ 2) (3)
P ' _ji = P _{j + 2, i + 2} (J ≧ 2, i ≧ 2) (4)
[0035]
For example, cyan Cy, which is four adjacent filter elements of the same color ₁₁ , Cy ₁₂ , Cy _{twenty one} , Cy _{twenty two} Pixel P at the position of ₀₀ , P ₀₂ , P ₂₀ , P _{twenty two} Cyan Cy ₁₁ Pixel P according to ₀₀ Is a pixel P ′ according to equation (1). ₀₀ Extracted as Similarly, yellow Y, which is the four adjacent filter elements ₃₃ , Ye ₃₄ , Ye ₄₃ , Ye ₄₄ The pixel P at the position of ₅₄ , P ₅₆ , P ₇₄ , P ₇₆ Yellow Ye from the inside ₃₃ Pixel P according to ₅₄ Is a pixel P ′ according to equation (4). ₃₂ Extracted as
[0036]
By performing such a thinning process on the subject image formed on the CCD 12, that is, the subject image composed of the total number of pixels, the subject image composed of about 1.6 million pixels is about 1/4. It is converted into a subject image composed of a certain 410,000 effective pixels. That is, the subject image formed on the CCD 12 is composed of about 1.6 million pixels, but the image signal actually read out from the CCD 12 is an effective pixel when the captured image is displayed on the monitor 50 as a moving image. The image signal corresponds to a subject image composed of a number (about 410,000 pixels).
[0037]
In FIG. 2, the number of pixels of the CCD 12 as a megapixel CCD is about 1.6 million pixels, and the number of pixels constituting the subject image is converted to the number of effective pixels of about 410,000 pixels by thinning processing. Even in a scope 10 having several megapixel CCDs, it is possible to construct an image with the effective number of pixels. When the number of pixels of the CCD 12 is U, when the number of effective pixels is D, thinning processing may be performed so that an image composed of all the pixels becomes an image with a reduction ratio of D / U times in the vertical and horizontal directions. At this time, the expressions (1) to (4) vary depending on the reduction ratio and the arrangement of the filter elements of the complementary color filter. Note that thinning processing of integer multiples and advantageous multiples is conventionally known.
[0038]
FIG. 3 is a flowchart showing the entire operation of the endoscope apparatus executed by the CPU 22 in the system control circuit 34.
[0039]
In step 101, when the power is turned on, the set values relating to the aperture 30, the light source 29, and the like are set to initial values. In step 102, processing related to the scope 10 is performed. Although the number of pixels of the scope 10 shown in FIG. 1 is about 1.6 million pixels, in this embodiment, the processor 20 is also connected to a type of scope 10 having a CCD 12 having a conventional number of pixels equal to or less than the number of effective pixels. Is possible.
[0040]
In step 103, processing relating to the operation of the keyboard 51 is performed. In step 105, other processing, for example, processing for the operation of the panel switch 35 is performed.
[0041]
Such an operation of the entire endoscope apparatus is repeatedly performed until the power is turned off, and a subroutine is executed in each of steps 102 to 104.
[0042]
FIG. 4 is a diagram showing a subroutine of step 102 in FIG.
[0043]
In step 201, it is determined whether or not the scope 10 has been replaced. That is, it is determined whether or not the scope 10 that has been connected so far has been removed and another scope 10 has been newly connected to the processor 20. If it is determined that the scope 10 is newly connected to the processor 20, the process proceeds to step 202. If it is determined that the scope 10 is not newly connected to the processor 20, this subroutine ends and the process returns to step 102. If the process proceeds to step 201 for the first time after the execution of step 101 in FIG. 3 (the process proceeds to step 201 only after the power is turned on), the process proceeds to step 202. In step 202, it is determined whether or not the number of pixels of the CCD 12 is greater than the number of effective pixels based on the data related to the number of pixels of the CCD 12 read from the EEPROM 15 of the scope 10 connected to the processor 20.
[0044]
If it is determined in step 202 that the number of pixels of the CCD 12 is larger than the number of effective pixels, the process proceeds to step 203. In step 203, a thinning process is performed. That is, image signals corresponding to the subject image constituted by the effective number of pixels are sequentially read out from the CCD 12. In step 204, video signals corresponding to the number of effective pixels are sequentially output to the monitor 50, whereby the captured image is displayed on the monitor 50 as a moving image. When step 204 is executed, the subroutine ends.
[0045]
On the other hand, if it is determined in step 202 that the number of pixels of the CCD 12 is not larger than the number of effective pixels, the process proceeds to step 206. In step 206, since the number of pixels of the CCD 12 is equal to or less than the number of effective pixels, image signals corresponding to the subject image constituted by the total number of pixels of the CCD 12 are sequentially read from the CCD 12. For example, if the number of pixels of the CCD 12 in the connected scope 10 is about 300,000 pixels, an image signal generated in all pixels is read from the CCD 12. In step 206, a video signal corresponding to a captured image composed of all the pixels of the CCD 12 having the number of effective pixels or less is output to the monitor 50, whereby the captured image is displayed on the monitor 50 as a moving image. At this time, the captured image is displayed in a partial area of the screen of the monitor 50. When step 206 is executed, the subroutine ends.
[0046]
FIG. 5 is an interrupt routine showing a still image output operation for outputting the subject image to the outside as still image data. When the recording switch 18 (see FIG. 1) of the scope 10 is pressed, the interruption routine is started by interrupting the main routine of FIG.
[0047]
In step 301, charges accumulated in all pixels of the CCD 12 in the scope 10 are read from the CCD 12. Here, regardless of the number of pixels of the CCD 12 in the scope 10 connected to the processor 20, an image signal corresponding to the subject image composed of the total number of pixels is read from the CCD 12.
[0048]
In step 302, the read image signal is temporarily stored in the image memory 23 as a digital signal via the CCD process circuit 21 and the A / D converter 22. When a digital image signal is read from the image memory 23, it is converted into still image data by the system control circuit 34 and output to the personal computer 54 and the image recording device 55. When step 302 is executed, the interrupt routine ends. Thereby, the captured image is again displayed on the monitor 50 as a moving image.
[0049]
As described above, according to the first embodiment, when the number of pixels of the CCD 12 in the scope 10 is larger than the number of effective pixels according to the NTSC system, when the captured image is displayed on the monitor 50, the number of effective pixels is used. When only the image signal corresponding to the subject image to be read is read from the CCD 12 and the captured image is output to the outside as still image data, the image signal corresponding to the subject image composed of the total number of pixels is read from the CCD 12. As a result, the captured image can be displayed on the monitor 50 in accordance with the resolution (color television system) of the monitor 50, and a subject image composed of the total number of pixels can be sent to the personal computer 54 and the image recording device 55 as still image data. it can. By executing printing based on the image data sent from the personal computer 54, a captured image composed of all the pixels, that is, a high-resolution image can be obtained. A high-resolution captured image can be displayed on the high-resolution monitor 56 based on the still image data recorded in the storage device. By obtaining a high-resolution captured image, the affected area can be accurately diagnosed.
[0050]
Since the pixel number adjusting circuit 17 is provided in the scope 10, the scope 10 having a megapixel CCD and the scope 10 having a CCD with a small number of pixels as in the conventional case without changing the configuration in the existing processor 20. It is possible to easily manufacture the processor 20 corresponding to both.
[0051]
In the present embodiment, as shown in the subroutine of FIG. 4, it is determined whether or not the number of pixels of the CCD 12 provided in the scope 10 connected to the processor 20 is the effective number of pixels. If the number of pixels is equal to or greater than the number of effective pixels, a thinning process is performed, and a subject image based on the number of effective pixels is displayed on the entire screen of the monitor 50. The image signal of the total number of pixels is read from the CCD 12 as it is. As a result, when the scope 10 of the CCD 12 having a small number of pixels is used, since the thinning process is not performed, the subject image can be displayed on the monitor 50 with the maximum resolution of the CCD 12. Thus, in the present embodiment, the captured image can be displayed with the maximum resolution corresponding to both the megapixel CCD and the conventional CCD having the number of effective pixels or less. In the present embodiment, when the number of pixels is larger than the number of effective pixels, the subject image is configured by the number of effective pixels, that is, the subject image is displayed on the entire screen of the monitor 50. The subject image may be displayed on the screen. In this case, when the number of pixels is larger than the number of effective pixels, the subject image is configured with the number of pixels equal to or less than the number of effective pixels corresponding to the area.
[0052]
In the present embodiment, the NTSC system is applied as the color television system of the monitor 50, but a PAL system, high vision system, or clear vision system monitor may be applied instead. In this case, in the processor 20, a subject image is formed with the effective number of pixels corresponding to the applied television system (for example, about 1.8 million pixels in the case of high vision), and a video signal corresponding to the effective number of pixels is generated. Generated. In addition, a printer capable of directly receiving digital still image data and printing a high resolution image with a built-in printer driver may be connected as an external device.
[0053]
The pixel number adjustment is not limited to the configuration in which only the image signal corresponding to the subject image composed of the effective number of pixels is sent to the pixel number adjustment circuit 17, but the image signal for all pixels is sent to the pixel number adjustment circuit 17, The pixel number adjusting circuit 17 may be configured to send only the image signal corresponding to the subject image constituted by the effective number of pixels to the CCD process circuit 21. Alternatively, as shown in FIG. 6, the pixel number adjusting circuit 17 is provided on the output side of the image memory 23 in the processor 20, and an image signal corresponding to the captured image constituted by the total number of pixels of the CCD 12 is output from the image memory 23. The pixel number adjustment circuit 17 may adjust the number of pixels. In this case, when the recording switch 18 is pressed, an image signal corresponding to the total number of pixels is sent from the pixel number adjusting circuit 17 to the system control circuit 34.
[0054]
Next, an electronic endoscope apparatus according to the second embodiment will be described with reference to FIGS. In the second embodiment, unlike the first embodiment, the number of pixels is converted by an average operation method instead of the thinning process (downsampling) shown in FIG.
[0055]
FIG. 7 is a block diagram of an electronic endoscope apparatus according to the second embodiment. As in the first embodiment, a scope 10 having a CCD 12 with about 1.6 million pixels is connected to the processor 20.
[0056]
When displaying a captured image on the monitor 50, image signals of all the pixels generated in the CCD 12 are read from the CCD 12. That is, an image signal corresponding to the subject image composed of the total number of pixels (about 1.6 million pixels) is sent to the pixel number adjustment circuit 17.
[0057]
As will be described later, the pixel number adjusting circuit 17 performs pixel conversion so as to form a subject image by an average operation method. The number of pixels constituting the converted subject image is the number of effective pixels (about 410,000 pixels) according to the NTSC system. An image signal corresponding to a subject image composed of converted pixels and composed of effective pixels is sent to the CCD process circuit 21. Pixel conversion is executed based on a control signal sent from the system control circuit 34.
[0058]
When the recording switch 18 is pressed, the image signal input to the pixel number adjusting circuit 17 is sent to the CCD process circuit 21 as it is without being subjected to pixel conversion. Then, an image signal corresponding to the subject image composed of the total number of pixels is output to the outside via the system control circuit 34. Other configurations are the same as those in the first embodiment.
[0059]
FIG. 8 is a diagram showing an average operation method executed in the pixel number adjusting circuit 17. The pixel array shown in FIG. 8 is the same as the pixel array shown in FIG. 3, and the complementary color filter CC is also the same. 8 × 8 = 64 pixels are arranged.
[0060]
In the second embodiment, in order to change a subject image composed of about 1.6 million pixels into a subject image composed of about 410,000 pixels, an average of four pixels corresponding to four adjacent same color filter elements is obtained, A method (average operation method) for constructing a subject image from the average pixels is applied. Each pixel calculated by the average operation method is expressed as P ′ _ji When expressed as a pixel P ′ _ji Is calculated by the following equations ((5) to (8)). However, the subscripts j and i indicate the pixel P as in the first embodiment. _ji , P ' _ji The vertical and horizontal positions are shown.
[0061]
P ' _ji = (P _{j, i} + P _{j, i + 2} + P _{j + 2, i} + P _{j + 2, i + 2} ) / 4
(I <2, j <2) (5)
P ' _ji = (P _{j, i + 2} + P _{j, i + 4} + P _{j + 2, i + 2} + P _{j + 2, i + 4} ) / 4
(I ≧ 2, j <2) (6)
P ' _ji = (P _{j + 2, i} + P _{j + 2, i + 2} + P _{j + 4, i} + P _{j + 4, i + 2} ) / 4
(J ≧ 2, i <2) (7)
P ' _ji = (P _{j + 2, i + 2} + P _{j + 2, i + 4} + P _{j + 4, i + 2} + P _{j + 4, i + 4} ) / 4
(J ≧ 2, i ≧ 2) (8)
[0062]
For example, pixel P ′ ₁₃ Is green G, which is four adjacent filter elements of the same color ₁₃ , G ₁₄ , G _{twenty three} , G _{twenty four} 4 pixels P according to ₁₅ , P ₁₇ , P ₃₅ , P ₃₇ It is the average of and is calculated | required by (6) Formula. Alternatively, the pixel P ′ _{twenty two} Is cyan Cy, which is four adjacent filter elements of the same color ₃₃ , Cy ₃₄ , Cy ₄₃ , Cy ₄₄ 4 pixels P according to ₄₄ , P ₄₆ , P ₆₄ , P ₆₆ It is the average of and is calculated | required by (8) Formula.
[0063]
By performing such pixel conversion processing on the subject image composed of the total number of pixels formed in the CCD 12, the subject image is composed of the average pixels, and the number of pixels constituting the subject image is effective. Converted to the number of pixels.
[0064]
Here, as in the first embodiment, the number of pixels of the CCD 12 as a megapixel CCD is about 1.6 million pixels, and the number of pixels constituting the subject image is converted to an effective number of pixels of about 410,000 pixels by the average operation method. However, even in the scope 10 having megapixel CCDs with various numbers of pixels, an image can be configured with the number of effective pixels. When the number of pixels of the CCD 12 is U, when the number of effective pixels is D, as is conventionally known, an image composed of all pixels is averaged so as to obtain an image with a reduction ratio of D / U times in the vertical and horizontal directions. An operation method may be applied. At this time, the expressions (5) to (8) vary depending on the reduction ratio and the arrangement of the filter elements of the complementary color filter.
[0065]
As described above, according to the second embodiment, the number of pixels constituting the subject image is converted into the number of effective pixels by the average operation method. By applying the average operation method, aliasing is not generated in the converted captured image, and a high-quality captured image is displayed on the monitor 50 as compared with the captured image obtained by the thinning process. Is done. In addition, since the high-quality captured image composed of the total number of pixels is displayed on the monitor 50, the state of the affected area can be accurately diagnosed.
[0066]
【The invention's effect】
As described above, according to the present invention, the captured image is displayed on the monitor as a moving image according to the color television system of the monitor regardless of the number of CCD pixels in the scope, and the megapixel CCD is provided in the scope. Can obtain high-resolution still images.
[Brief description of the drawings]
FIG. 1 is a block diagram of an electronic endoscope apparatus according to a first embodiment.
FIG. 2 is a diagram showing a thinning process.
FIG. 3 is a main routine showing the operation of the entire electronic endoscope apparatus.
FIG. 4 is a subroutine at step 102 in FIG. 3;
FIG. 5 is an interrupt routine showing a still image output operation of a captured image.
6 is a block diagram of an electronic endoscope apparatus when a pixel number adjustment circuit is provided in a processor 20. FIG.
FIG. 7 is a block diagram of an electronic endoscope apparatus according to a second embodiment.
FIG. 8 is a diagram showing an average operation method.
[Explanation of symbols]
10 Scope
12 CCD (imaging device)
17 Pixel number adjustment circuit
20 processors
36 CPU
50 monitors
54 Personal Computer
55 Image recording device

Claims (11)

And a scope having an imaging device an object image is formed, a monitor for the scope to view the object image is connected detachably connected, generated in the imaging device for displaying an object image on the monitor An electronic endoscope apparatus comprising a processor that processes an image signal corresponding to a subject image,
When outputting a video signal so that the subject image is displayed as a moving image on the monitor and outputting the subject image as a still image to the outside, the image signal can be converted into still image data and still image data can be received. Signal output means for outputting to an external still image data processing system;
A number-of-pixels determining unit that is provided in the processor and determines whether or not the total number of pixels of the connected imaging device of the scope is larger than the number of effective pixels according to the monitor;
Pixel number adjusting means for adjusting the number of pixels constituting the subject image,
When the number of pixels of the image sensor is greater than the number of effective pixels, the pixel number adjusting means performs a thinning process or an average operation method on a subject image composed of the total number of pixels of the image sensor, thereby The subject image displayed on the screen is configured with the number of effective pixels or less corresponding to the monitor, and when the subject image is output to the outside as a still image, the subject image output to the outside is configured with the total number of pixels of the image sensor. An electronic endoscope apparatus characterized by:   The said pixel number adjustment means comprises the to-be-photographed image displayed on the said monitor by the total pixel number of the said image pick-up element, when the pixel number of the said image pick-up element is less than the effective pixel number. Electronic endoscope device.   The electronic endoscope apparatus according to claim 1, wherein the effective pixel number is a pixel number according to a color television system of the monitor.   When the pixel number adjusting means displays the subject image on the monitor, the subject image is composed of effective pixels by performing a thinning process on the subject image composed of the total number of pixels of the image sensor. The electronic endoscope apparatus according to claim 1.   When the pixel number adjusting means displays the subject image on the monitor, the subject image is composed of effective pixels by performing an average operation method on the subject image composed of the total number of pixels of the image sensor. The electronic endoscope apparatus according to claim 1.   When the pixel number adjusting means displays the subject image on the monitor, the image signal corresponding to the subject image constituted by the effective pixel number is read from the image sensor, and when the still image data is output, the imaging is performed. The electronic endoscope apparatus according to claim 1, wherein an image signal corresponding to a subject image constituted by the total number of pixels of the element is read from the imaging element.   When the pixel number adjusting unit reads an image signal corresponding to a subject image formed by the total number of pixels of the image sensor from the image sensor and then displays the subject image on the monitor, the read image is displayed. The signal is converted into an image signal corresponding to a subject image composed of effective pixels and sent to the processor. When still image data is output, the read image signal is sent to the processor as it is. The electronic endoscope apparatus according to claim 1.   When the number of pixels of the image sensor is smaller than the number of effective pixels, the pixel number adjusting unit does not adjust the number of pixels constituting the subject image, so that it always responds to the subject image composed of the total number of pixels of the image sensor. The electronic endoscope apparatus according to claim 1, wherein a read image signal is read from the image sensor.   The still image data processing system is a computer system to which a printer capable of printing a high-resolution image is connected, and a processing system including an image recording device capable of receiving still image data and recording it in an auxiliary storage device. The electronic endoscope apparatus according to claim 1. A scope having an image sensor on which a subject image is formed is detachably connected and a monitor for displaying the subject image is connected , and the subject image generated on the image sensor is displayed in order to display the subject image on the monitor. A processor of an electronic endoscopic apparatus for processing an image signal,
When outputting a video signal so that the subject image is displayed as a moving image on the monitor and outputting the subject image as a still image to the outside, the image signal can be converted into still image data and still image data can be received. Signal output means for outputting to an external still image data processing system;
A pixel number determination means for determining whether or not the total number of pixels of the imaging device of the connected scope is larger than the effective pixel number according to the monitor;
Pixel number adjusting means for adjusting the number of pixels constituting the subject image,
When the number of pixels of the image sensor is greater than the number of effective pixels, the pixel number adjusting means performs a thinning process or an average operation method on a subject image composed of the total number of pixels of the image sensor, thereby The subject image displayed on the screen is configured with the number of effective pixels or less corresponding to the monitor, and when the subject image is output to the outside as a still image, the subject image output to the outside is configured with the total number of pixels of the image sensor. A processor for an electronic endoscope apparatus, characterized in that:   The electronic endoscope apparatus according to claim 1, wherein the pixel number adjusting unit is provided in the scope.

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