JP2974249B2 - Endoscope image data compression device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an endoscope image data compression device that compresses an endoscope image and outputs the image to an image recording device.

[Prior art] In recent years, by inserting an elongated insertion portion into a body cavity,
2. Description of the Related Art Endoscopes (scopes or fiberscopes) capable of diagnosing and examining internal organs and the like are widely used. In addition to medical use, it is used for observing and inspecting objects in pipes of boilers, machines, chemical plants, etc., or in machines, etc. for industrial use.

Further, various types of electronic endoscopes using a solid-state imaging device such as a charge-coupled device (CCD) as an imaging unit have been used.

The endoscope includes, for example, an elongated endoscope that can be inserted into a body cavity, and a light source device that is connected to the endoscope and supplies illumination light to a distal end component of the endoscope. Is configured. Further, an external TV camera device detachably attached to the endoscope, a video processor device for converting an image signal of the TV camera device into a video signal, and an image output from the video processor device such as a part in a body cavity. An endoscope apparatus including a monitor for projecting a subject is also used.

Further, the electronic endoscope apparatus includes, for example, an electronic endoscope having an imaging unit at a distal end component formed in an elongated shape so as to be inserted into a body cavity, and supplies illumination light to the distal end component of the endoscope. A video processor for converting an imaging signal from the imaging means into a video signal, which is integrated with or separate from the light source device; and a monitor for projecting a subject such as a body cavity portion by the video output of the video processor. And is composed of

Further, the imaging signal or video signal of the above-mentioned endoscope device or electronic endoscope device is recorded on a large-capacity storage medium such as an optical disk or a magneto-optical disk, and is used for diagnosis, investigation, etc. after the end of observation. Image recording devices have been put to practical use.

However, if the above-described image pickup signal or video signal is converted from analog signal to digital signal data and recorded as it is, the data amount increases, and the amount of images that can be stored in one storage medium is limited. There was a problem.

Therefore, the present applicant has proposed a data compression apparatus for compressing the above-mentioned data and reducing the amount of data before recording on the storage medium, for example, in Japanese Patent Application No. 62-279599. In this technique, analog signals are compressed, and the compressed analog signals are converted into digital signals.

[Problems to be Solved by the Invention] In recent years, it has become easy to perform signal processing using digital technology such as a microprocessor.

The present invention has been made in view of the above points, and has as its object to provide an endoscope image data compression apparatus having high compression efficiency using digital technology.

[Means and Actions for Solving the Problems] An endoscope image data compression device according to the present invention includes predetermined color information of the subject obtained by imaging the subject with an imaging unit provided in the endoscope. An endoscope image data compression device having an image data input end to which endoscope image data is input, and capable of compressing the endoscope image data input from the image data input end and recording the compressed endoscope image data in image recording means An average color signal output means for outputting an average color signal corresponding to an average color in the endoscope image data including the predetermined color information; and an internal color signal including the predetermined color information input from the image data input terminal. Calculating means for calculating information relating to a difference between the endoscope image data and the average color signal output from the average color signal output means; and a calculation result of the calculation means being input and including the predetermined color information. Image compression means for generating compressed image data which can be recorded in the image recording means in which the data amount of the endoscope image data is compressed.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 to 4 relate to a first embodiment of the present invention,
1 is an explanatory diagram showing a configuration of an endoscope image data compression device, FIG. 2 is a block diagram showing a configuration of an endoscope image data compression device, FIG. 3 is an explanatory diagram of coordinate conversion based on an average color,
FIG. 4 is an explanatory diagram of requantization in RGB color coordinates.

As shown in FIG. 1, the electronic endoscope apparatus of the field sequential imaging system includes a control signal generation unit 12 that generates a predetermined control signal for each block described later, and a CCD (solid-state image sensor) that captures an object. A charge-coupled device) 1, an amplifier 2 for amplifying and processing the imaging signal of the CCD 1 to convert it into a video signal, a gamma circuit 3 for gamma-correcting the video signal amplified by the amplifier 2, and An analog-to-digital converter (hereinafter, referred to as an A / D converter) 4 for converting a video signal, which is an analog signal, into digital signal data in accordance with a control signal of the control signal generating unit 12; A selector 5 for switching and outputting to each memory of the memory unit 6 according to a control signal of the unit 12, an R memory 6R provided in the memory unit 6 for storing a red wavelength region, and storing a green wavelength region A G memory 6G and a B memory 6B for storing a blue wavelength region; and a digital-to-analog converter (hereinafter, referred to as a digital-to-analog converter) for converting data stored in the memory unit 6 from a digital signal to an analog signal according to a control signal of the control signal generating unit 12. A D / A converter 7R corresponding to the R memory 6R, a D / A converter 7G corresponding to the G memory 6G, and a D / A converter 7B corresponding to the B memory 6B. A D / A converter unit 7; a synchronization signal generation circuit 13 for generating a predetermined synchronization signal such as a horizontal synchronization signal required by a monitor (not shown) based on a control signal of the control signal generation unit 12; A lamp 10 for generating illumination light for supplying to the
A rotary filter 9 provided with a filter for dispersing the light of the lamp 10 in a red wavelength region, a green wavelength region, and a blue wavelength region, and a motor 11 for rotating the rotary filter 9 by a control signal of the control signal generator 12 And a light guide 8 that guides the above-mentioned spectrally illuminated light to a portion where the CCD 1 captures an image.

The CCD 1 is connected to an input terminal of the amplifier 2, an output terminal of the amplifier 2 is connected to an input terminal of the γ circuit 3,
An output terminal of the γ circuit 3 is connected to an input terminal of the A / D converter 4.

The R memory 6R, the G memory 6G, and the B memory 6B
Are connected to the output terminal of the selector 5, respectively. The output terminal of the R memory 6R is connected to the D / A converter 7R.
And an input terminal of an endoscope image data compression device (hereinafter referred to as an image data compression device) 20 to be described later. G memory 6G
Is connected to an input terminal of the D / A converter 7G and to an input terminal of an image data compression device 20 described later. An output terminal of the B memory 6B is connected to an input terminal of the D / A converter 7B and to an input terminal of an image data compression device 20 described later.

The output terminal of the D / A converter 7R is connected to a monitor (not shown) via an output terminal 14R.
The output terminal of the D / A converter 7G is connected to a monitor (not shown) via an output terminal 14G. The output terminal of the D / A converter 7B is connected to a monitor (not shown) via an output terminal 14B. An output terminal of the synchronization signal generating circuit 13 is connected to a monitor (not shown) or the like via an output terminal 14S.

A / D converter 4, selector 5, memory unit 6, D / A
The control signal input terminals of the converter 7, the motor 11, and the synchronization signal generation circuit 13 are connected to the output terminal of the control signal generation unit 12, respectively. One output terminal of the control signal generator 12 is connected to an input terminal of an image data compression device 20 described later.

The image data compression device 20 includes an average color calculation unit 21 for calculating an average color from the data in the memory unit 6, and an image compression unit 22 for compressing the data of the average color calculation unit 21.

The image recording unit 23 uses a large-capacity recording medium such as an optical disk or a magneto-optical disk to
This is to record the data compressed by.

The image data compression device 20 includes, as shown in FIG.
An R memory 25R, which is a working memory for storing the input data in the red wavelength region, and similarly a G memory 2 in the green wavelength region.
5G and similarly a B memory 25B in the blue wavelength region, the above-described average color calculation unit 21, and an image compression unit 22.

The average color calculation unit 21 includes a cumulative adder 26R for cumulatively adding the input data of the red wavelength region, and a cumulative adder 2R.
A divider 27R for dividing the data accumulated by 6R by a predetermined number of pixels; and a divider 27R from the data in the R memory 25R.
A difference circuit 28R that calculates the difference between the results of R, and similarly a cumulative adder 26G in the green wavelength region, a divider 27G, and a difference circuit 28G,
Similarly, it comprises a cumulative adder 26B, a divider 27B, and a difference circuit 28B in the blue wavelength region.

The image compression unit 22 includes a requantization circuit 29R for requantizing data of the difference circuit 28R, which is difference data in a red wavelength region, and an abnormal value correction circuit for correcting an abnormal value of the requantized data. 30R, similarly, a green wavelength region requantization circuit 29G and an abnormal value correction circuit 30G, and similarly a blue wavelength region requantization circuit 29B and an abnormal value correction circuit 30B, and the abnormal value correction circuit 30R, 30G, And a selector 31 for sequentially switching to output the output of 30B to the image recording unit 23.

The input terminals of the R memory 25R and the accumulator 26R are connected to an input terminal 24R, the input terminals of the G memory 25G and the accumulator 26G are connected to an input terminal 24G, and the B memory 25B and the The input terminal to the accumulator 26B is connected to the input terminal 24B.

An output terminal of the accumulator 26R is connected to an input terminal of the divider 27R, and an output terminal of the accumulator 26G is connected to the divider 2R.
The output terminal of the accumulator 26B is connected to the input terminal of the divider 27B.

A first input terminal of the difference circuit 28R is connected to an output terminal of the R memory 25R, and a second input terminal is connected to an output terminal of the divider 27R. A first input terminal of the difference circuit 28G is connected to an output terminal of the G memory 25G, and a second input terminal is connected to an output terminal of the divider 27G. The difference circuit 28B
Is connected to the output terminal of the B memory 25B,
The second input terminal is connected to the output terminal of the divider 27B.

An output terminal of the difference circuit 28R is connected to an input terminal of the requantization circuit 29R, and an output terminal of the requantization circuit 29R is connected to an input terminal of the abnormal value correction circuit 30R. An output terminal of the difference circuit 28G is connected to an input terminal of the requantization circuit 29G, and an output terminal of the requantization circuit 29G is connected to an input terminal of the abnormal value correction circuit 30G. The difference circuit 28B
Is connected to the input terminal of the requantization circuit 29B,
The output end of the requantization circuit 29B is connected to the outlier correction circuit 30B.
Is connected to the input terminal of

The first input terminal of the selector 31 is connected to the abnormal value correction circuit 30.
The second input terminal is connected to the output terminal of the abnormal value correction circuit 30G, and the third input terminal is connected to the output terminal of the abnormal value correction circuit 30B.

An output terminal of the selector 31 is connected to the image recording unit 23.

The operation of the thus configured image data compression device will be described.

As shown in FIG. 1, the rotation filter 9 is rotated by a motor 11 that rotates in synchronization with a control signal of a control signal generator 12, and separates the illumination light of the lamp 10 into red, green, and blue wavelength regions. . The split illumination light is guided through the light guide 8 and illuminates the subject.

The subject luminous flux of the subject illuminated by the illumination light described above is
An image is formed on the imaging surface of CCD1 by an objective lens system (not shown),
The signal is photoelectrically converted and input to the amplifier 2 as an imaging signal.

The amplifier 2 removes noise and the like from the above-described image pickup signal to form a video signal, amplifies the video signal so as to have a constant voltage range of, for example, 0 to 1 V, and outputs the amplified video signal to the γ circuit 3.

The γ circuit 3 converts the above-mentioned video signal so as to have a gamma characteristic, and outputs it to the A / D converter 4.

The A / D converter 4 converts the video signal having the above-described gamma characteristic into, for example, an 8-bit digital signal, that is, quantizes and outputs the digital signal to the selector 5.

The selector 5 outputs the above-described digital signal to each memory of the memory unit 6 in synchronization with the control signal of the control signal generation unit 12. This is because when the spectral wavelength region of the illumination light by the rotation filter 9 is red, the illumination light is output to the R memory 6R,
Similarly, when the color is green, the data is output to the G memory 6G, and when the color is blue, the data is output to the B memory 6B.

Each memory of the memory unit 6 includes the control signal generation unit 12
The stored data is output to the D / A converter unit 7 and the image data compression device 20 in accordance with the control signal. This is to output the data sequentially input by the selector 5 to the D / A converter unit 7 at the same time, that is, to synchronize the subject light flux of each wavelength region sequentially imaged.

The D / A converter 7R of the D / A converter unit 7 converts a digital signal of data stored in the R memory 6R into an analog signal and outputs the analog signal to an output terminal 14R, and the D / A converter 7G is connected to the G memory 6G. The digital signal of the stored data is converted to an analog signal and output to the output terminal 14G, and the D / A converter
7B converts the digital signal of the data stored in the B memory 6B into an analog signal and outputs it to an output terminal 14B.

At the same time, the synchronization signal generation circuit 13
A predetermined synchronizing signal such as a horizontal synchronizing signal required by a monitor (not shown) is generated by the
Output to

The subject imaged by the monitor CCD1 (not shown) is displayed as a color image by the signals output to the output terminals 14R, 14G, 14B, and 14S.

The data stored in the R memory 6R of the memory unit 6 is input to the input terminal 24R of the image data compression device 20 by the control signal of the control signal generation unit 12, as shown in FIG. The data stored in the memory 6G is input terminal 24
The data input to G and similarly stored in the B memory 6B are input to the input terminal 24B.

The data in the red wavelength region input to the input terminal 24R is
The data is stored in the R memory 25R and input to the accumulator 26R.

The accumulator 26R accumulates the input data for one screen as described above, and outputs the sum thereof to the divider 27R.

The divider 27R calculates the total sum of the data of one screen by the accumulator 26R as, for example, the total number of pixels of one screen (512
If it is a pixel, it is divided by 262,144) to calculate an average color R 'in the red plane.

Similarly, the data in the green wavelength region input to the input terminal 24G is stored in the G memory 25G and the accumulator 2
6G, the average color G 'in the green plane is calculated by the divider 27G, and the data in the blue wavelength region input to the input terminal 24B is stored in the B memory 25B and the accumulator 26B.
B, the average color B 'in the blue plane is calculated by the divider 27B.

The average color R 'from the divider 27R is input to a difference circuit 28R.

The difference circuit 28R subtracts the average color R 'for one screen obtained by the divider 27R from the data for one screen in the red wavelength region stored in the R memory 25R as described above, and subtracts the difference. Data is obtained and output to the requantization circuit 29R.

The requantization circuit 29R requantizes the difference data described above according to the difference data, and outputs the result to the abnormal value correction circuit 30R.

The abnormal value correction circuit 30R, when the requantized data is out of the recordable data range, for example, the upper limit data when exceeding the upper limit, and the lower limit data when below the lower limit Then, the difference data converged on the data recording range is output to the selector 31.

Similarly, the data for one screen in the green wavelength region is difference data converged in the data recording range by the G memory 25G, the divider 27G, the difference circuit 28G, the requantization circuit 29G, and the abnormal value correction circuit 30G, and the selector The data for one screen output in the blue wavelength region is converted into difference data converged in the data recording range by the B memory 25B, the divider 27B, the difference circuit 28B, the requantization circuit 29B, and the abnormal value correction circuit 30B. It is output to the selector 31.

The selector 31 outputs, for example, in the order of red wavelength region, green wavelength region, and blue wavelength region, the difference data converged in the data recording range as described above to the image recording unit 23 which is an image recording device.

The image recording unit 23 records data input to a large-capacity recording medium such as an optical disk or a magneto-optical disk.

FIG. 3A shows, for example, the three-dimensional data and average color of each wavelength region described above. When a normal observation is made in the body cavity, since the inside of the body cavity is substantially flesh color, the red wavelength region (R) of the video signal is at a high luminance level, and the green wavelength region (G) and the blue wavelength region (B) are low. The brightness level. Therefore, the color space of the video signal has a substantially cylindrical shape extending from the low luminance level in the green wavelength region (G) and the blue wavelength region (B) toward the red wavelength region (R). That is, the coordinates of the average color of the video signal are also shifted in the red wavelength region (R).

Further, as described above, the difference between the data of each wavelength region of the video signal described with reference to FIG. 3A is obtained from the average color of each wavelength region, thereby obtaining the video signal as shown in FIG. 3B. The average color is located on the center position of the coordinates. That is, the distribution of each wavelength region of the video signal becomes average, and the color space of the above-mentioned video signal is also distributed around the average color located on the center position of the coordinates. That is, it becomes video signal data having a color space suitable for requantization described later.

As described above, the data of the video signal whose color space has been converted is requantized and recorded. This requantization is performed in the red wavelength region (R), the green wavelength region (G), and the blue wavelength region (B). ) Each with a different signal range, each with a different quantization
Requantization to bit data. This will be described for the red wavelength region (R) and the green wavelength region (G).
For example, as shown in FIG.
The signal range of -127 to 127 is quantized to 6 bits, and the signal range of -31 to 31 in the green wavelength region (G) is quantized to 3 bits. Blue wavelength region (B) is green wavelength region (G)
And so on. FIG. 4 (a)
FIG. 4B shows the linear quantization in which the signal ranges are equally divided and the above-described requantization is performed. As shown in FIG. Coarse nonlinear quantization may be used.

That is, attention is paid to the fact that the wavelength region of the in-vivo observation image is within a very limited wavelength region, and the image quality of the recorded image is increased by increasing the information amount of the signal in the red wavelength region having a wide range of signal levels. There is an effect that the compression rate of the recorded image is improved by reducing the information amount of the signals in the green wavelength region and the blue wavelength region which are the signal levels in the narrow range.

5 to 8 relate to a second embodiment of the present invention.
FIG. 5 is an explanatory diagram showing the configuration of the endoscope image data compression device, FIG. 6 is a block diagram showing the configuration of the endoscope image data compression device, and FIGS. 7 and 8 are requantization in the color difference signal. FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 5, the electronic endoscope apparatus of the frame sequential imaging system has the same configuration as that of the first embodiment, and the R data 6R,
The data of the G memory 6G and the B memory 6B and the control signal from the control signal generator 12 can be output.

The image data compression device 40 includes a color space conversion unit 41,
An average color calculation unit 42 and an image compression unit 43 are provided,
The image recording unit 23 is connected.

The color space conversion unit 41 of the image data compression device 40
As shown in the figure, an R memory 44R, which is a working memory for storing the input data in the red wavelength region, a G memory 44G in the green wavelength region, and a B memory 44B in the blue wavelength region, similarly, The matrix circuit 45 converts a signal in a wavelength region into, for example, a luminance signal and a color difference signal of the NTSC standard.

The average color calculation unit 42 includes a cumulative adder 46RY for cumulatively adding the data of the input color difference signal RY area, and a divider for dividing the data accumulated by the cumulative adder 46RY by a predetermined number of pixels. 47RY, a difference circuit 48RY for calculating the difference between the results of the divider 47RY from the data in the R memory 44R, and similarly, a cumulative adder 46BY for the color difference signal BY area and a divider 47BY.
And a difference circuit 48BY.

The image compression unit 43 includes a re-quantization circuit 49RY for re-quantizing data of the difference circuit 48RY, which is difference data of a color difference signal RY area, and an abnormality for correcting an abnormal value of the re-quantized data. Similarly to the value correction circuit 50RY, the color difference signal BY
The region requantization circuit 49BY and the abnormal value correction circuit 50BY, and the abnormal value correction circuits 50RY and 50BY and the matrix circuit 45
And a selector 51 that sequentially switches to output the luminance signal Y to the image recording unit 23.

The input end of the R memory 44R is connected to the input terminal 24R,
The input terminal of the G memory 44G is connected to the input terminal 24G, and the input terminal of the B memory 44B is connected to the input terminal 24B.

The output terminal of the accumulator 46RY is connected to the input terminal of the divider 47RY, and the output terminal of the accumulator 46BY is connected to the input terminal of the divider 47BY.

The first input terminal of the difference circuit 48RY is the matrix circuit
The second input terminal is connected to the output terminal of the divider 47RY. A first input terminal of the difference circuit 48BY is connected to an output terminal of the color difference signal BY of the matrix circuit 45, and a second input terminal is connected to the divider 47BY.
It is connected to the output terminal of BY.

The output terminal of the difference circuit 48RY is connected to the input terminal of the requantization circuit 49RY, and the output terminal of the requantization circuit 49RY is connected to the input terminal of the abnormal value correction circuit 50RY. An output terminal of the difference circuit 48BY is connected to an input terminal of the requantization circuit 49BY, and an output terminal of the requantization circuit 49BY is connected to an input terminal of the abnormal value correction circuit 50BY.

The first input terminal of the selector 51 is connected to the matrix circuit 45.
The second input terminal is connected to the output terminal of the abnormal value correction circuit 50RY, and the third input terminal is connected to the output terminal of the abnormal value correction circuit 50BY.

The output end of the selector 51 is connected to the image recording unit 23.

The operation of the thus configured image data compression device will be described.

Similarly to the first embodiment, the data stored in the R memory 6R of the memory unit 6 shown in FIG. 5 is controlled by the control signal of the control signal generator 12 as shown in FIG.
Is input to the input terminal 24R, and the data similarly stored in the G memory 6G is input to the input terminal 24G.
The data stored in B is input to input terminal 24B.

The data in the red wavelength region input to the input terminal 24R is
The data in the green wavelength region stored in the R memory 44R and input to the input terminal 24G is stored in the G memory 44G, and the data in the blue wavelength region input to the input terminal 24B is stored in the B memory 4G.
Stored in 4B.

The matrix circuit 45 reads data stored in the R memory 44R, the G memory 44G, and the B memory 44B, and reads NT data.
SC standard luminance signal data Y, color difference signal data R-Y, B-
Convert to Y The luminance signal Y is output to the selector 51, the chrominance signal RY is output to the accumulator 46RY and the difference circuit 48RY, and the chrominance signal BY is output to the accumulator 46BY and the difference circuit 48BY.

The accumulator 46RY accumulates the input data for one screen as described above, and outputs the sum to the divider 47RY.

The divider 47RY calculates the total sum of the data for one screen by the accumulator 46RY as, for example, the total number of pixels of one screen (both vertically and horizontally).
Divide by 262,144) for 512 pixels to calculate the average color difference RY 'in the color difference RY.

Similarly, the average color difference BY ′ of the color difference BY is calculated by the accumulator 46BY and the divider 47BY from the data of the color difference signal data BY described above.

The difference circuit 48RY subtracts the average color difference RY 'of one screen obtained by the divider 47RY from the data of one screen of the color difference signal data RY from the matrix circuit 45 as described above. Then, the difference data is obtained and output to the requantization circuit 48RY.

The requantization circuit 49RY requantizes the difference data described above according to the difference data, and outputs the result to the abnormal value correction circuit 50RY.

The abnormal value correction circuit 50RY includes upper limit data when the requantized data is out of the recordable data range, for example, when the upper limit is exceeded, and lower limit data when the requantized data falls below the lower limit. Thus, the difference data converged on the data recording range is output to the selector 51.

Similarly, data for one screen in the green wavelength region is divided by a divider
47BY, the difference circuit 48BY, the requantization circuit 49BY, and the abnormal value correction circuit 50BY become difference data converged in the data recording range and output to the selector 51.

The selector 51 sends, for example, the luminance signal Y, the difference data of the chrominance RY converged to the data recording range, and the difference data of the chrominance BY converged to the data recording range to the image recording unit 23 which is an image recording device in the order. Output.

The image recording unit 23 records data input to a large-capacity recording medium such as an optical disk or a magneto-optical disk.

The color region of the color difference signal described above, when performing normal observation,
For example, it is as shown in FIG. This is because, since the inside of the body cavity is substantially flesh color, the red wavelength region (R) of the video signal has a high luminance level, and the green wavelength region (G) and the blue wavelength region (B) have the low luminance level. Therefore, the color area of the color difference signal is located in the substantially elliptical second quadrant where the signal level of the color difference signal RY is high and the signal level of the color difference signal BY is low.

Further, as described above, the seventh color difference is calculated based on the average color difference of each color difference signal.
By obtaining the difference between the data of each color difference signal of the video signal described with reference to FIG. 7A, the color area of the color difference signal is located at the center position of the coordinates as shown in FIG.
That is, the color difference signals are distributed on both color regions on average. That is, the data is color difference signal data having a color area suitable for requantization described later.

As described above, the data of the color difference signal whose color region has been converted is requantized and recorded. In this requantization, for example, the color difference signal RY is quantized to 3 bits, and the color difference signal BY is
In order to quantize to 4 bits, requantization is performed to data of different quantization bits.

In addition, when a test portion or the like is stained and observed, for example,
The result is as shown in FIG. This is because the inside of the body cavity is stained, the red wavelength region (R) of the video signal has a low luminance level, and the green wavelength region (G) and the blue wavelength region (B) have a high luminance level. Therefore, the color area of the color difference signal is based on the signal level of the color difference signal RY and the color difference signal B-
The signal levels of both Y are high, and are substantially elliptical and located at the second polar quadrant and the fourth quadrant around the first quadrant.

Further, as described above, the average color difference of each color difference signal is the eighth color difference signal.
By obtaining the difference between the data of each color difference signal of the video signal described with reference to FIG. 8A, the color area of the color difference signal is located at the center position of the coordinates as shown in FIG. 8B.
That is, the color difference signals are distributed on both color regions on average. That is, the data is color difference signal data having a color area suitable for requantization described later.

As described above, the data of the color difference signal whose color area has been converted is requantized and recorded. In this requantization, for example, both the color difference signal RY and the color difference signal BY are quantized to 5 bits. Like that.

As described above, the requantization in the case of performing normal observation and the requantization in the case of performing observation by staining are switched by, for example, a changeover switch (not shown).

That is, attention is paid to the fact that the region of the color difference signal of the in-vivo observation image is within an extremely limited region, and recording the luminance signal without compressing it has the effect of improving the image quality of the recorded image.

Also, by changing the number of data bits for requantization when performing normal observation and for requantization when performing observation by staining, the compression ratio is improved when performing normal observation. In addition, when observation is performed by staining, there is an effect that the quality of a recorded image is improved.

9 and 10 relate to a third embodiment of the present invention, and FIG. 9 is an explanatory diagram showing a configuration of an endoscope image data compression apparatus.
FIG. 10 is a block diagram showing a configuration of an endoscope image data compression device. Note that the same components as those in the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 9, the electronic endoscope apparatus of the frame sequential imaging system has the same configuration as that of the first embodiment, and the R data 6R,
The data of the G memory 6G and the B memory 6B and the control signal from the control signal generator 12 can be output.

The image data compression device 60 includes a color space conversion unit 61,
An image compression unit 62 is provided, and the image recording unit 23 is connected.

The color space conversion unit 61 of the image data compression device 60
As shown in the figure, the R memory 63R, which is a working memory for storing the input data in the red wavelength region, the G memory 63G in the green wavelength region, and the B memory 63B in the blue wavelength region, similarly, An L ^* a ^* b ^* conversion circuit 64 for converting a signal in the wavelength region into a signal based on, for example, the CIE (International Commission on Illumination) CIE1976 (L ^* , a ^* , b ^* ) specification.

The image compression unit 62 includes, for example, an average color ROM 65A in which the average color a ^* 'of the color signal a ^* calculated based on the distribution state of the color signal a ^* of the representative observed image, and the L ^* a ^* b
^* A difference circuit 66A for calculating a difference between ROM65A for the average color from the data of the input color signal a ^* region from the converting circuit 64,
A requantization circuit 67A for requantizing data of the difference circuit 66A, which is difference data of the color signal a ^* area, and an abnormal value correction circuit 68A for correcting an abnormal value of the requantized data.
And the average color ROM 65B in which the average color b ^* 'of the color signal b ^* is recorded in the same manner as the color signal a ^* , the difference circuit 66B, and the requantization circuit 6.
7B and an abnormal value correction circuit 68B, and the abnormal value correction circuits 68A and 68
8B and the output of the L ^* a ^* b ^* conversion circuit 64 to an image recording unit.
And a selector 69 that switches sequentially to output the data to 23.

The input end of the R memory 63R is connected to the input terminal 24R,
The input terminal of the G memory 63G is connected to the input terminal 24G, and the input terminal of the B memory 63B is connected to the input terminal 24B.

A first input terminal of the difference circuit 66A is connected to the L ^* a ^* b ^*.
The output terminal of the color signal a ^* of the conversion circuit 64 is connected, and the second input terminal is connected to the average color ROM 65A.

The first input terminal of the difference circuit 66B is connected to the L ^* a ^* b ^*.
The conversion circuit 64 is connected to the output terminal of the color signal b ^* , and the second input terminal is connected to the average color ROM 65B.

An output terminal of the difference circuit 66A is connected to an input terminal of the requantization circuit 67A, and an output terminal of the requantization circuit 67A is connected to an input terminal of the abnormal value correction circuit 68A. An output terminal of the difference circuit 66B is connected to an input terminal of the requantization circuit 67B, and an output terminal of the requantization circuit 67B is connected to an input terminal of the abnormal value correction circuit 68B.

A first input terminal of the selector 69 is connected to an output terminal of the L ^* a ^* b ^* conversion circuit 64 luminance signal L ^*, a second input terminal is connected to an output terminal of the abnormal value correction circuit 68A, The input terminal is connected to the output terminal of the abnormal value correction circuit 68B.

The output terminal of the selector 69 is connected to the image recording unit 23.

The operation of the thus configured image data compression device will be described.

Similarly to the first embodiment, the data stored in the R memory 6R of the memory unit 6 shown in FIG. 9 is transmitted by the control signal of the control signal generator 12 as shown in FIG.
Is input to the input terminal 24R, and the data similarly stored in the G memory 6G is input to the input terminal 24G.
The data stored in B is input to input terminal 24B.

The data in the red wavelength region input to the input terminal 24R is
The green wavelength data stored in the R memory 63R and input to the input terminal 24G is stored in the G memory 63G, and the blue wavelength data input to the input terminal 24B is stored in the B memory 6G.
Stored in 3B.

The L ^* a ^* b ^* conversion circuit 64 includes the R memory 63R,
The data stored in the G memory 63G and the B memory 63B is read, and the luminance signal L specified by CIE1976 (L ^* , a ^* , b ^* ) is read.
^* , Color signals a ^* , b ^* . The luminance signal L ^* is output to the selector 69, the color signal a ^* is output to the difference circuit 66A, and the color signal b ^* is output to the difference circuit 66B.

The difference circuit 66A subtracts the data of the average color a ^* 'of the average color ROM 65A from the data of the color signal a ^* for one screen input from the L ^* a ^* b ^* conversion circuit 64 to obtain difference data. And outputs it to the requantization circuit 67A.

The requantization circuit 67A requantizes the difference data described above according to the difference data, and outputs the result to the abnormal value correction circuit 68A.

The abnormal value correction circuit 68A, when the requantized data is out of the recordable data range, for example, data of the upper limit when exceeding the upper limit, and data of the lower limit when below the lower limit Then, the difference data converged on the data recording range is output to the selector 69.

Similarly, the data for one screen of the color signal b ^* is obtained by the difference circuit
66B, the difference data converged in the data recording range by the requantization circuit 67B and the abnormal value correction circuit 68B, and the selector
Output to 69.

The selector 69 sends the L ^* signal, the difference data of the color signal a ^* converged to the data recording range, and the difference data of the color signal b ^* converged to the data recording range to the image recording unit 23, which is an image recording device, in this order. Output.

The image recording unit 23 records data input to a large-capacity recording medium such as an optical disk or a magneto-optical disk.

Note that a plurality of sets of average color ROMs may be prepared and appropriately switched depending on a difference in observation method such as observation by staining or a difference in observation site.

Also, while the L ^* a ^* b ^* uniform color space has been described,
Other color spaces may be used.

That is, attention is paid to the fact that the area of the color difference signal of the in-vivo observation image is within an extremely limited area, and the luminance signal L
Recording of ^* without compression has the effect of improving the image quality of the recorded image.

Although the description has been made using the electronic endoscope apparatus of the frame sequential imaging method, a means for decoding, for example, a composite video signal is provided before the video signal input terminal of each wavelength region, and the composite video signal is input. Is also good.

Further, an external TV camera device may be mounted on an endoscope using an image guide and used in the video processor device.

[Effects of the Invention] As described above, according to the present invention, an observation image can be compressed based on the average color of the observation image, and efficient recording of the observation image according to the observation image can be performed. There is an effect that can be.

[Brief description of the drawings]

1 to 4 relate to a first embodiment of the present invention, and FIG. 1 is an explanatory diagram showing a configuration of an endoscope image data compression device;
FIG. 2 is a block diagram showing a configuration of the endoscope image data compression device, FIG. 3 is an explanatory diagram of coordinate conversion based on average color, FIG.
5 is a diagram illustrating requantization in RG color coordinates. FIGS. 5 to 8 relate to a second embodiment of the present invention, and FIG. 5 is a diagram illustrating a configuration of an endoscope image data compression device. , FIG. 6 is a block diagram showing a configuration of an endoscope image data compression device, FIGS. 7 and 8 are explanatory diagrams of requantization in a color difference signal,
9 and 10 relate to a third embodiment of the present invention.
The figure is an explanatory diagram showing the configuration of the endoscope image data compression device,
FIG. 10 is a block diagram showing the configuration of the endoscope image data compression device. 20 image data compression device 21 average color calculation unit 22 image compression unit 23 image recording unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazunari Nakamura 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside O-limpus Optical Industry Co., Ltd. (72) Inventor Shinichiro Hattori 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Industry Co., Ltd. Jury President Kunio Matsumoto Judge Koichi Itsubo Judge Keiji Fujiwara (56) References JP-A-63-290091 (JP, A) JP-A-59-104886 (JP, A)

Claims (1)

(57) [Claims] An image data input end for inputting endoscope image data including predetermined color information of the subject obtained by capturing an image of the subject by an imaging means provided in the endoscope; An endoscope image data compression device capable of compressing the endoscope image data input from an image data input end and recording the compressed endoscope image data in an image recording unit, wherein the average color in the endoscope image data including the predetermined color information is Average color signal output means for outputting a corresponding average color signal; endoscope image data including the predetermined color information input from the image data input terminal; and average color signal output from the average color signal output means. Calculating means for calculating information relating to the difference between the image data, and a pressure recordable in the image recording means, which receives the calculation result of the calculating means and compresses the data amount of the endoscope image data including the predetermined color information. Endoscopic image data compression apparatus characterized by comprising an image compressing means for generating image data.