JP3842944B2 - Electric endoscope generator for electronic endoscope - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric mask generating apparatus for an electronic endoscope, and more particularly to a zoom mask generating process for changing a mask size in accordance with an image scaling function of an electronic endoscope.
[0002]
[Prior art]
An electronic endoscope apparatus images an object to be observed with an imaging element, for example, a CCD (Charge Coupled Device) disposed at the tip of a scope (electronic endoscope), and a video signal (image signal) obtained by the CCD. Is subjected to predetermined image processing, whereby an object image is displayed on the monitor. In the monitor screen, an electric mask is provided around the screen, and the above-described object image is displayed in, for example, a circular opening set by the electric mask.
[0003]
FIG. 6 shows a circuit of an electric mask generation unit of the electronic endoscope apparatus. In this mask generation unit, a mask signal having a predetermined mask shape is written in the mask generation memory 1, and this mask signal is converted into a mask mix. The circuit 2 mixes the video signal. For example, a video signal input to the mask mix circuit 2 is an R (red), G (green), or B (blue) signal formed from the output of the CCD, and a mask signal for these RGB signals. Is mixed and given.
[0004]
FIG. 7 shows the mixing process of the electric mask signal, and FIG. 7A is an original image input to the mask mix circuit 2 before applying a mask, which is an object image to be observed. F is projected on the screen 4 together with the lens barrel 3. In this image, a small uneven portion of the lens barrel frame 3 is projected, and surrounding vignetting is generated. On the other hand, as shown in FIG. 7B, a mask (image) M ₁ that shields the periphery and has a circular opening is formed based on the mask signal of the mask generation memory 1, and the mask mix circuit 2 7A and 7B are mixed to form an easy-to-see screen 4 in which the lens barrel frame 3 and the vignetting are hidden, as shown in FIG. 7C.
[0005]
[Problems to be solved by the invention]
However, the conventional electric mask process has a problem that a necessary image may not be displayed by the mask when the image is enlarged. That is, recent electronic endoscopes are provided with an optical zoom function for optically enlarging and imaging an object to be observed and an electronic zoom function for electronically enlarging after imaging, for example as shown in screen 4 in FIG. As shown in FIG. 8A, when the target part Q is present in the normal display image of FIG. 8A, a part of the target part Q is hidden in the mask M ₁ in the enlarged display image of FIG. .
[0006]
The mask generation process has a problem that it takes time to generate a mask. That is, the mask generation memory 1 of FIG. 6 described above stores, for example, the quarter data M _1a divided into four as shown by the dotted line in the mask M ₁ of FIG. 7B, and the mask data M _1a is stored in the mask data M _1a . One mask image can be formed by sequentially reading four times while changing the reading direction. Conventionally, as shown in FIG. 7D in which a part of the mask in FIG. 7B is enlarged, one pixel (pixel) P of the mask image M ₁ is represented by 1-byte data. Is done.
[0007]
Here, when the time for writing the quarter data M _1a to the mask generation memory 1 is calculated, for example, in the NTSC system, 768 horizontal pixels and 525 vertical lines are set, and the clock frequency of the microcomputer is 10 MHz, 1 clock = 1 instruction. When a microcomputer capable of processing is used, assuming that the necessary number of clocks (steps S0 to S8) are multiplied according to the flowchart of the memory write operation in FIG.
T = (1/10 ⁷ ) × (768/2) × (525/2) × 8 + (1/10 ⁷ )
≒ 0.08064 [sec]
And the time to generate one screen is four times the time T,
0.08064 × 4 = 0.32256 [sec]
It becomes. In the case of this NTSC system display, since 1 frame takes 1/30 second, the number of frame configurations necessary for mask generation is
0.32256 / (1/30) = 9.6768 [sheets]
It becomes.
[0008]
The writing time T of the data M _1a is a time required for the initial process of image formation (when the power is turned on), but about 9.7 frames are required to form one screen. Therefore, it is not possible to display images quickly, and it is desired to shorten the initial processing time including writing of mask data. In particular, the present application proposes to enlarge / reduce (magnify) the mask in accordance with the enlarged / reduced image. In this case, a new mask process is performed together with the image scaling process. There arises a problem that the switching of the mask during the zooming operation is not performed smoothly.
[0009]
The present invention has been made in view of the above problems, and an object of the present invention is to prevent a part of the enlarged image from being hidden by the mask and to reduce the time required for the mask generation process and to provide the mask. Another object of the present invention is to provide an electric mask generator for an electronic endoscope that can quickly display an object image to be observed.
[0010]
[Means for Solving the Problems]
To achieve the above object, an electric mask generating apparatus for an electronic endoscope according to the invention of claim 1 includes a mask generating memory for storing an electric mask signal for covering a predetermined portion of a screen, and the mask signal. In an electronic endoscope electric mask generating device that mixes the image signal obtained by the solid-state image sensor with the image scaling of the electronic endoscope device having an image scaling function, A variable-magnification mask signal of a bit string in which one pixel is represented by 1-bit information is formed for ¼ of the variable-magnification mask image , and this bit string ¼ mask signal is stored in the mask generation memory. reads the bit string 1/4 mask signal in parallel from the variable power mask generating circuit for reading the entire zooming mask image while changing the reading direction of the 1/4 mask signal, said mask generation A shift register for converting parallel mask signal read out from the memory to the serial mask signal, based on the mask signal of 1 pixel 1 bit configuration of serial converted, mask mixing circuit for forming a scaled image signal imparted with zooming mask And is provided.
The invention of claim 2 is a read-only memory for storing a program and data for generating a bit string of a scaling mask in which one pixel is represented by 1-bit information, and a reading for expanding the bit string data of the scaling mask. And a free memory.
[0011]
According to the above configuration, when an enlargement / reduction operation is performed by the zoom switch, the mask itself is also enlarged. That is, the mask generation data corresponding to the image enlargement ratio is read out by a microcomputer or the like, and a mask signal (image signal) in which one pixel is represented by 1-bit information is generated based on the read mask generation data. Once written to memory. Thereafter, the mask signal of 1 pixel 1 bit configuration is mixed and output to the original image signal formed using the solid-state imaging device using a shift register or the like, so that a new enlarged image is displayed on the monitor or the like as an enlarged mask ( The mask is displayed together with a mask in which the opening is enlarged.
[0012]
The writing speed to the mask generation memory is reduced to 1/8 compared with the conventional one-pixel 1-byte configuration, and the mask is formed in a short time, so that the mask displayed when the magnification is changed is displayed smoothly. become.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a configuration of an electric mask generator for an electronic endoscope according to an embodiment, and FIG. 2 shows a configuration in a mask mix circuit. This device is incorporated in, for example, a processor device of an electronic endoscope, and the microcomputer 11 that performs overall control of this processor device also functions as a mask generation circuit. The microcomputer 11 includes a ROM (read only memory) 12 that stores bit sequence generation data (program, etc.) of an electric mask in which one pixel (pixel) is represented by 1 bit, and a RAM (read / write) for expanding the mask bit sequence data. A control signal for a zoom switch SW1 that is operated in the enlargement direction (N) and the reduction direction (F) is input.
[0014]
That is, the microcomputer 11 reads out the mask generation data corresponding to the magnification set by the magnification switch SW1 from the ROM 12, and develops the bit string corresponding to the pixel of the mask image in the RAM 13. The zoom switch SW1 is an optical zoom function switch for optically enlarging an image using a movable lens or the like, an electronic zoom function switch for enlarging an image captured by a CCD by signal processing, or both switches. It becomes.
[0015]
A mask generation memory 15 is connected to the microcomputer 11, and a mask signal having a 1-bit pixel configuration is written in the mask generation memory 15 based on the data developed in the RAM 13. FIG. 3A shows one mask image M _2. For example, upper left data M _{2a obtained} by dividing the mask image M ₂ into four is generated in the mask generation memory 15. Then, the mask generation memory 15 is read and controlled by the microcomputer 11 to output one mask image M _{2 shown} in FIG.
[0016]
For example, the same data M _2a is read in the reverse direction from the upper right side for each horizontal line while sequentially reading the _¼ mask data M _2a in accordance with the scanning line from the upper left side, so that the upper right side in FIG. forming a top half of the mask image M ₂ containing 1/4 data M _2b, for then the lower half of the mask image M _2, forms a lower left quarter data M _2c reads data M _2a from the lower left side However, at this time, the same data M _2a is read out from the lower right side in the reverse direction for each horizontal line to obtain the lower right quarter data M _2d .
[0017]
Further, a mask mix circuit 16 is provided for mixing the output signal of the mask generating memory 15 and the original pixel signal of the object image to be observed, and this pixel signal is obtained from a CCD disposed at the tip of the electronic endoscope. For example, it is a signal for each color of R (red), G (green), and B (blue).
[0018]
In FIG. 2, the internal structure of a mask mix circuit 16 is shown, the counter 18 the mask mixing circuit 16 for inputting a clock signal, a latch circuit 19 for latching the bit data D ₀ to D ₇ of the mask signal, A shift register 20 that converts parallel signals Q _{0 to} Q ₇ output from the latch circuit 19 into serial signals based on a shift clock, and signal mixing units 21R, 21G, and 21B that mix mask signals for each of RGB signals are provided. ing. Each of the signal mixing units 21R, 21G, and 21B has eight logic circuits 22, whereby a mask signal is mixed for each pixel.
[0019]
The embodiment is configured as described above, and the operation thereof will be described next. First, when the power is turned on, a mask M ₂ having a standard size as shown in FIG. 4A is formed. That is, the microcomputer 11 in FIG. 1 reads out the mask bit string generation data having a 1-pixel 1-bit configuration from the ROM 12, develops a bit string for forming a standard mask image in the RAM 13, and sequentially stores the bit string in a mask generation memory. Write to 15. As a result, for example, the ¼ mask data M _{2a shown} in FIG. _3A is formed. In the mask data M _2a , as shown in FIG. 3B in which a part of the mask image M ₂ is enlarged, one pixel is represented by one bit. “Through without pixel data” is set to “0”.
[0020]
The mask data M _2a in the mask generation memory 15 is read out four times by the above-described reading method. This mask data is data D ₀ every 8 bits as shown in FIG. It is supplied in parallel to the mask Mick circuit 16 as to D _7. In the mask mix circuit 16, the parallel bit data is converted into serial bit data through the latch circuit 19 and the shift register 20, and the bit data of the mask signal is supplied to the signal mixing units 21R, 21G, and 21B.
[0021]
For example, in the signal mixing unit 21R, the logical circuit 22 calculates the logical product of the red pixel signals R _{0 to} R ₇ and the inverted signal of the bit data of the mask signal. That is, the mask bit data “1” indicating black shown in FIG. 3B is inverted to “0”, so that the red signal R _{0 to} R ₇ is “1” or “0”. The data “ 0 ” indicating through is inverted and becomes “1”, so that when the red signals R _{0 to} R ₇ are 1, it becomes “1”. The same applies to the green pixel signals G _{0 to} G ₇ and the blue pixel signals B _{0 to} B _{7. When} all of RGB are “0”, a black pixel is formed. The signal is output through. In this way, an image signal to which the mask signal is added is formed, and as shown in FIG. 5A, an object image whose periphery is covered with the standard mask M ₂ is displayed on the monitor screen 4. The
[0022]
On the other hand, if the enlargement operation is performed by the zooming switch SW1 in FIG. 1, according to the enlargement ratio by the microcomputer 11, for example, 4-bit string generation data of one pixel 1-bit configuration of the mask M ₃ of (D) is Read from the ROM 12 and write ¼ mask data M _3a of the bit string to the mask generation memory 15. Then, the read control of the mask generation memory 15, as shown in the FIG. 4 (B) → (C) → (D), will be the larger the mask M ₃ is generated, it is formed immediately before The mask M ₃ is displayed on the screen 4 in the form of rewriting the mask M ₂ from the upper side.
As a result, as shown in FIG. 5B, an enlarged image can be displayed in the enlarged mask M ₃ , and a part of the attention site Q is not hidden by the mask M ₃ .
[0023]
In the above embodiment, the mask data M _2a and M _3a written in the mask generation memory 15 is composed of 1 bit per pixel, so that it is 8 than in the conventional case where it is composed of 1 byte per pixel. The data amount is 1 / minute. That is, in the case of 1 byte per pixel, the 1/4 mask data M _2a is (768/2) × (525/2) = 100800 bytes. 1 {(768/2) × (525/2)} / 8 = 12600 bytes.
[0024]
Therefore, the number of frames to be written in the memory 15 is 9.6768 / 8 = 1.2096, which is about 1.2, and an electric mask can be generated in a short time, and can be switched when the magnification ratio is changed. There is an advantage that the display of the mask becomes smooth. Note that the mask switching process time, that is, the mask formation time period between FIGS. 4A to 4D can be blacked out. In this case, the mask generation process [FIG. B) and (C)] are not displayed on the image 4. In addition, if an address that can be automatically generated in the mask generation memory 15 is used, an address for memory writing becomes unnecessary.
[0025]
【The invention's effect】
As described above, according to the present invention, a bit string 1/4 scaling mask signal representing one pixel information in one bit is formed corresponding to the scaling process of image enlargement / reduction, and this bit string 1 / 4 writes a mask signal to the mask generation memory, to form a whole zooming mask image from the 1/4 mask signal, while converting a parallel mask signal read out from the mask generation memory to the serial mask signal Since a variable magnification mask is provided, it is possible to prevent part of the enlarged image from being hidden by the electric mask and to shorten the time required for the mask switching generation process, and to display the object image to which the mask is applied. And there is an advantage that observation is performed quickly.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an electric mask generating apparatus for an electronic endoscope according to an embodiment of the present invention.
FIG. 2 is a diagram showing a configuration in the mask mix circuit of FIG. 1;
FIG. 3 is a diagram illustrating a mask image [FIG. (A)] and an enlarged image [part (B)] of a part of the mask according to the embodiment.
FIG. 4 is a diagram illustrating an operation at the time of mask switching in the embodiment.
FIGS. 5A and 5B show changes in the screen during a scaling operation in the embodiment, and FIG. 5A is a standard screen and FIG. 5B is an enlarged screen.
FIG. 6 is a block diagram showing a partial circuit of conventional electric mask generation.
7A and 7B are images processed by the circuit of FIG. 6, in which FIG. (A) is an original image before masking, FIG. (B) is a mask image, FIG. (C) is a masked image, and FIG. ) Is a diagram showing an enlarged image of a part of the mask.
FIGS. 8A and 8B show changes in the screen during a conventional scaling operation, where FIG. 8A is a standard screen and FIG. 8B is an enlarged screen.
FIG. 9 is a flowchart showing a memory write operation when generating an electric mask.
[Explanation of symbols]
1,15 ... memory for mask generation,
2,16 ... Mask mix circuit,
4 ... screen,
11: Microcomputer,
20 ... shift register,
21R, 21G, 21B... Signal mixing unit SW1.

Claims (2)

In an electric mask generator for an electronic endoscope that includes a memory for generating a mask for storing an electric mask signal for covering a predetermined portion of a screen, and mixes the mask signal with an image signal obtained by a solid-state imaging device.
A mask scaling process is performed in accordance with image scaling of an electronic endoscope apparatus having an image scaling function, and a scaling mask signal of a bit string in which one pixel is represented by 1-bit information is set to 1/4 of the scaling mask image. formed per, stores this bit sequence 1/4 mask signal to the mask generation memory, reads out the bit string 1/4 mask signal from the mask generation memory in parallel, changing the reading direction of the 1/4 mask signal A scaling mask generation circuit that reads out the entire scaling mask image ,
A shift register that converts the parallel mask signal read from the mask generation memory into a serial mask signal is formed, and a scaled image signal with a scaling mask is formed based on the serially converted mask signal of one pixel and one bit. And an electric mask generating device for an electronic endoscope, comprising: A read-only memory for storing a program and data for generating a bit string of a magnification / reduction mask in which one pixel is represented by 1-bit information, and a readable / writable memory for expanding the bit string data of the magnification / reduction mask are provided. 2. The electric mask generating apparatus for an electronic endoscope according to claim 1, wherein:

Images