JPH03123528A - Compression apparatus for endoscope image data - Google Patents

Abstract

PURPOSE:To enable efficient compression of all observation images with an endoscope along with higher reproducibility of an original image by evaluating at least one of signals compressed by a plurality of compression means to produce an output to an image memory based on the evaluation. CONSTITUTION:A selector 25 outputs data of R, G and B stored in respective memories 24 sequentially to a blocking circuit 26 and an image judging circuit 27 being controlled by a control signal generating section 31. The blocking circuit section processes the data sequentially and the image judging circuit performs an evaluation based on an original image from the selector and a compression image from the blocking circuit section to select a blocking circuit above a specified evaluation value. A selector 28 produces a signal inputted into any one of the blocking circuits to a forecast encoder 29 controlled by a picture quality judging circuit to generate a forecast error, which is outputted to an image memory 22. In this manner, compression is accomplished simultaneously with three kinds of blocking circuits and the images are judged. After a compression by a blocking, further compression is made by a forecast encoding, thereby achieving a higher compression efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of an endoscopic image data compression device that compresses endoscopic images and outputs the compressed endoscopic images to an image recording device.

[Prior Art] In recent years, endoscopes (scopes or fiberscopes), which can diagnose and examine internal organs in body cavities by inserting an elongated insertion section into body cavities, have been widely used. There is. In addition, it is used not only for medical purposes but also for industrial purposes to observe and inspect objects inside pipes of boilers, machines, chemical plants, etc., or inside machines.

Furthermore, electronic endoscopes using solid-state imaging devices such as charge-coupled devices (CODs) as imaging means are also used in various regions.

Furthermore, for example, the video signal of the electronic endoscope device is recorded on a large-capacity storage medium such as an optical disk or a magneto-optical disk,
BACKGROUND ART Image recording devices for use in diagnosis, investigation, etc. after observation have been put into practical use.

For example, FIG. 14 is a schematic diagram of the entire endoscope system including the electronic endoscopy device and the image recording device. An endoscope 91 inserted into a living body 92 is connected to an observation device 93. A viewing monitor 94 and an image recording device 96 including an image data compression device are connected to the viewing device 93 . Further, a suction device 95 is connected to the endoscope 91.

FIG. 15 shows the flow of image signals in the endoscope 91 and observation device Fi93. CC at the tip of endoscopy 1t91
The image signal from D1 enters an amplifier 2 and is amplified to a voltage level of a predetermined frequency. Thereafter, the signal enters the γ circuit 3 and is subjected to γ correction. In the case of the RGB plane sequential method, the signal after γ correction is converted into analog-to-digital by the A/D converter 4, then enters the selector 5, and is sent to the R, G, and B memories 6R, 6G, and 6B, respectively. recorded in RlG
, B. The image signals recorded in the memories 6R, 6G, and 6B are called out at the timing of the TV signal, and
Digital by converters 7R, 7G, 7B respectively.
converted to analog. R, G, B became analog signals
The image signal is a synchronization signal (
SYNC) and is sent to the RGB output terminals R, G, and B. The RGB signals obtained in this manner are displayed on the monitor 94 for internal mirror observation. Also, this RGB
The signal can be recorded with an image recording device@96.

In the light guide 8 of the endoscope 91, the white light from the lamp 10 passes through a rotating filter 9 rotated by a motor 11, so that red, green, and blue color transmission filters forming the rotating filter are placed in the optical path. It is inserted into the wafer and irradiates it with light of each wavelength: red, green, and blue.

Therefore, the image signals captured under the red, green, and blue illumination lights are stored in the R, G, and 8 memories 6R.

Written to 6G and 6B. In addition, motor 11, A/D
Converter 4, selector 5, memory 6R.

6G, 6B, D/A converter 7R, 7G, 7B.

The synchronization signal generation circuit 13 is controlled by the control signal generation section 12.

FIG. 16 shows the flow of image signals in the image recording device 96. RG8 signal output terminals R, G of the observation device 93
, B are input to the input section 97 of the image recording device 96.
is input to. The RGB signals are converted from analog to digital by an A/D converter section 98 via a changeover switch, and then guided to a compression circuit section 99 . The compression circuit section 99 is constructed based on compression theory such as predictive coding. The compressed image data is recorded on a recording system unit 100 such as an optical disk or magneto-optical disk. When reproducing an image, the image data on the recording system section 100 is restored to the original image signal in the decompression circuit section 101. Thereafter, the signal is digital-to-analog converted by the D/Δ converter section 102 and sent to the output section 102. On the other hand, there is a control signal generation unit 104 that controls the destination of the image signal and the transfer timing when transferring the image signal. This is connected to a Δ/D converter section 98, a compression circuit section 99, a recording system section 1001, an expansion circuit section 101, and a D/A converter section 102. In addition, a synchronization signal @ (S
YNC) is sent to the input section 97 and output section 103.

The present applicant has developed an image data compression device, for example, in the patent application filed in 1983.
It is proposed in No. 2-279599.

This performs a single compression process using a single compression circuit. In general, normally observed images are images based on reddish colors, with almost no greenish or blueish colors, and the compression processing described above performs compression based on these characteristics. .

In recent years, methods have been used in which the test area is stained with methylene blue or the like for observation, or a fluorescent agent such as florescen is applied to the test site for observation.

The dyed observation image obtained by dyeing and observing the test area has a blue-based color tone. Also, fluorescent agent applied to the test area? This is an image in which fluorescence excited in the blue wavelength region, that is, blue, is mixed in an image based on IA dormitory image color.

Therefore, a compression method based on the characteristics of an ordinary endoscopic image has a problem in that the compression rate decreases.

Therefore, it has been considered to provide a plurality of compression means and select a compression means with a high compression rate for compression.

[Problems to be Solved by the Invention] However, when a plurality of compression means are used and only a compression means with a high compression ratio is selected, there is a problem that the reproducibility of the original image deteriorates.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide an endoscopic image data compression device that has good reproducibility of original images and efficiently compresses all images observed by an endoscope. It is said that

[Means for solving the problem] A signal of an observation image of an endoscope or a signal obtained by dividing the signal of the observation image into a plurality of wavelength regions is input, the signal is compressed by a compression means, and the compressed signal is An endoscopic image data compression device for outputting to an image recording device includes a plurality of compression means, an evaluation means for evaluating at least one of the signals compressed by the plurality of compression means, and an evaluation means for evaluating at least one of the signals compressed by the plurality of compression means; selecting means for selecting one of the signals compressed by the compressing means, or means for decompressing at least one of the signals compressed by the compressing means and outputting the compressed signal in a displayable manner; and selecting means for selecting one of the selected signals.

[Operation] With the above-described configuration, at least one of the signals compressed by the compression means is evaluated and output to the image recording device based on this evaluation.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1(A) and FIGS. 2 to 4 relate to the first embodiment of the present invention. FIG. 1(A) is a block diagram showing the configuration of an endoscopic image data compression device, and FIG. FIG. 3 is a block diagram showing the configuration of a blocking circuit, and FIG. 4 is an explanatory diagram regarding blocking.

As shown in FIG. 2, the frame-sequential imaging type electronic endoscope device includes a control signal generating section 12 that generates a predetermined control signal for each block, which will be described later, and a COD that is a solid state image carrier that images a subject. (charge-coupled device) 1, an amplifier 2 that amplifies and processes the imaging signal of this CCD 1 and converts it into a video signal, a γ circuit 3 that performs gamma correction on the video signal amplified by this amplifier 2, and the γ circuit 3 described above. An analog-to-digital converter (hereinafter referred to as an A/D converter) 4 converts a video signal, which is a corrected analog signal, into digital signal data using a control signal from the control signal generator 12; A selector 5 that switches and outputs to each memory in the memory section 6 according to a control signal from the signal generating section 12; and an R memory 6R1 provided in the memory section 6 that stores a red wavelength region (hereinafter referred to as R); a green wavelength region; (hereinafter referred to as G) and a B memory 6B that stores blue wavelength region (hereinafter referred to as B), and the control signal generation unit 12 stores the data stored in the memory unit 6. A digital-to-analog converter (hereinafter referred to as a D/A converter) converts a data signal into an analog signal using a control signal, and includes a D/A converter 7R corresponding to the R memory 6R and a D/Δ converter corresponding to the G memory 6G. A D/A converter unit 7 is provided with a D/A converter 7B corresponding to a converter 7G and the B memory 6B, and a horizontal synchronization signal, etc. required by a monitor (not shown) is generated by a control signal from the control signal generator 12. a synchronization signal generation circuit 13 that generates a predetermined synchronization signal;
A lamp 1o that generates illumination light to be supplied to the site to be imaged by the coi, and a lamp 1o that uses R, G, and B light from this lamp 10.
A rotary filter 9 is provided with a filter that separates the light into two parts, a motor 11 rotates the rotary filter 9 according to a control signal from the control signal generating section 12, and the CCD 1 images the divided illumination light. The CCD 1 is connected to the input end of the amplifier 2, and the output end of the amplifier 2 is connected to the input end of the γ circuit 3. 3 is connected to the input terminal of the A/D converter 4, and the output terminal of the D
/Δ] The output end of the inverter 4 is connected to the input end of the selector 50.

The input ends of the R memory 6R, the G memory 6G, and the B memory 6B are each connected to the output end of the selector 5. The output end of the R memory 6R is connected to the input end of the D/A converter 7R, and the input end of an endoscope image data compression system N (hereinafter referred to as image data compression system) is connected to the input end of the D/A converter 7R. It is now connected.

The output terminal of the G memory 6G is connected to the D/A converter 7G.
It is connected to the input end of the image data compression device 20, which will be described later. The output terminal of the B memory 6B is connected to the input terminal of the D/A converter 7B, and is also connected to the input terminal of an image data compression device 20, which will be described later.

The output terminal of the D/A converter 7R is an output terminal 14R.
It is designed to be connected to a monitor, etc. (not shown) via. The output terminal of the D/A converter 7G is connected to a monitor (not shown) or the like via an output terminal 14G. The output terminal of the D/A converter 7B is connected to a monitor (not shown) or the like via an output terminal 14[3. The output end of the synchronization signal generation circuit 13 is connected to a monitor (not shown) or the like via an output terminal 148.

The A/D converter 4, selector 5, memory section 6, D
/A converter 7, motor 11 and Domei signal generation circuit 1
The 3 control signal input terminals are respectively connected to the output terminals of the control 11 signal generating section 12. Further, one output terminal of the control signal generating section 12 is connected to an input terminal of an image data compression device 20, which will be described later.

The image data compression device 20 is provided with an image compression section 21 that compresses the data in the memory section 6.

The image recording unit 23 uses a general recording medium such as an optical disk or a magneto-optical disk to record the image data from the image data compression device 2.
This is to record data compressed with 0.

As shown in FIG. 1(A), the image data compression device 20 includes memories 24R, 24G, 2 for R, G, and B operations.
4Bh<provided memory section 24 and said memory section 24
a selector 25 that selects and outputs each memory; a compression section 26 provided with blocking circuits 26a, 26b, and 26c serving as compression means; and a selector that compares and evaluates the output signal of the compression section 26 with the current signal and that will be described later. 28 and RO for compressed information
An image quality determination circuit 27 that controls the M30, a selector 28 that selects and outputs one of the blocking circuits of the compression unit 26 under the control of the image quality determination circuit 27, and compresses the signal selected by the selector by predictive encoding. The control signal generation section 31 generates a control signal to the memory section 24, selector 25, image quality determination circuit 27, and image recording device 22.

The input terminal of the R memory 24R is connected to the input terminal 23R, the input terminal of the G memory 24G is connected to the input terminal 23G, and the input terminal of the B memory 24B is connected to the input terminal 23B.
It is connected to the.

The R memory 24R, G memory 24G and B memory 24
The output ends of B are connected to the input ends of the selector 25, respectively.

The output terminal of the selector 25 is connected to the blocking circuit 26.
a, 26b, 26c and the original image input terminal of the image quality determination circuit 27.

The output terminals of the blocking circuits 26a, 26b, and 26C are connected to the input terminals of an image determination circuit 27 and a selector 28, respectively.

The first output terminal of the na-recorded image determination circuit 27 is connected to the control terminal of the selector 28, and the second output terminal is connected to the input terminal of the compressed information ROM 30.

The output terminal of the selector 28 is connected to the input terminal of the predictive encoder 29, and the output terminals of the two predictive encoders are connected to the first input terminal of the image recording device 22.

An output end of the compressed information ROM 30 is connected to a second input end of the image recording device 22.

The control signal generating section 31 has its output terminal connected to the control signal input terminals of the memory section 24 , selector 25 , image quality determination circuit 27 , and image recording device 22 .

The blocking circuits 26a, 26b, and 26c each include a main memory 32 for storing input signals, as shown in FIG.
an address counter 37 which is a counter for reading out the pixel of interest in the main memory 32; a matrix counter 35 which generates the address of the pixel of interest based on the address of the address counter 37; and an address of the matrix counter 35. a coefficient ROM 36 in which coefficients are recorded; an accumulative multiplier 33 that multiplies and cumulatively adds coefficients of a matrix frequency centered on the pixel of interest in the main memory 32 and the coefficient ROM 36; and an accumulative multiplier 33 an abnormal value correction circuit 34 that focuses the output result within a predetermined range when it deviates from a predetermined range; and a peripheral detection circuit 38 that detects that the value of the address counter 37 is in the peripheral area of the screen. peripheral area data 39 for generating peripheral area video data by the peripheral area detection circuit 38;
, a data selector 40 that switches the outputs of the normal value correction circuit 34 and the peripheral data ROM 39 under the control of the peripheral detection circuit 38;
0 and a submemory 41 for storing input video data.

The main memory 32 has an input terminal connected to the input terminal 31 and an output terminal connected to the first input terminal of the accumulative multiplier 33 .

The address counter 37 has a first output terminal connected to the matrix counter 35 and a second output terminal connected to the peripheral part detection circuit 38.

A first output terminal of the matrix counter 35 is connected to the address terminal of the main memory 32, and a second output terminal is connected to the coefficient ROM 36.

The output terminal of the coefficient ROM 36 is connected to the cumulative multiplier 33.
is connected to the second input terminal of.

The output terminal of the cumulative multiplier 33 is connected to the abnormal value correction circuit 34.
is connected to the input end of the

An output terminal of the abnormal value correction circuit 34 is connected to a first input terminal of the data selector.

The peripheral part detection circuit 38 has a first output terminal connected to the input terminal of the peripheral part data ROM 39 and a second output terminal connected to the control terminal of the data selector 40 .

An output end of the peripheral ROM 39 is connected to a second input end of the data selector 40.

The output terminal of the data selector 40 is connected to the sub memory 4.
It is connected to the input terminal of 1.

The output end of the sub-memory 41 is connected to an output terminal 42.

The operation of the image data compression device configured as described above will be explained.

As shown in FIG. 2, the rotary filter 9 is rotated by a motor 11 that rotates in synchronization with a control signal from a control signal generator 12, and separates the illumination light from the lamp 10 into R, G, and B. This separated illumination light is guided through the light guide 8 and irradiated onto the subject.

The subject light flux of the subject illuminated by the illumination light described above is imaged on the image carrier of the CCDI by an objective lens system (not shown), photoelectrically converted, and inputted to the amplifier 2 as an imaging signal.

The amplifier 2 removes noise and the like from the carrier signal described above to produce a video signal, amplifies this video signal to a constant voltage range of 0 to 1V, for example, and outputs it to the γ circuit 3.

The γ circuit 3 converts the aforementioned video signal to have gamma characteristics and outputs it to the A/D converter 7.

The A/D converter 7 converts the video signal having the aforementioned gamma characteristic into, for example, an 8-bit digital signal, that is, quantizes it and outputs it to the selector 5.

The selector 5 outputs the digital signal described above to each memory of the memory section 6 in synchronization with the control signal from the control signal generating section 12. When the spectral wavelength range of the illumination light from the rotary filter 9 is red, it is output to the R memory 6R, similarly when it is 8 colors, it is output to the G memory 6G, and similarly when it is blue, it is output to the B memory 6B. That is, it is input and stored in the memory in the same wavelength range as the subject light flux.

Each memory of the memory section 6 is connected to the control signal generating section 12.
The stored data is output to the D/A converter section 7 and the image data compression device 20 according to the control signal. this is,
The data sequentially inputted by the selector 5 are simultaneously D
It outputs to the /A converter section 7, that is, it synchronizes the sequentially imaged object light fluxes in each wavelength range.

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

At the same time, the synchronization signal generation circuit 13 generates a predetermined synchronization signal such as a horizontal synchronization signal required by a monitor (not shown) according to the control signal of the control signal generation section 12, and outputs a predetermined synchronization signal to the output terminal 1.
Output to 43.

A monitor (not shown) displays the subject imaged by the CCD 1 as a color image based on the signals output to the output terminals 14R, 14G, 14B, and 14S.

Further, the data stored in the R memory 6R of the memory section 6 is controlled by a control signal from the control signal generating section 12 as shown in FIG.
), the input terminal 2 of the image data compression device 20
3R and stored in the G memory 6G as in 1] is input to the input terminal 23G, and similarly the data is input to the B memory 6B.
The data stored in is input to the input terminal 23B.

The R data input to the input terminal 24R is stored in the R memory 25R by a control signal from the control signal generator 31.
The G data input to the input terminal 24G is similarly stored in the G memory 25G, and the B data input to the input terminal 24B is stored in the G memory 25G.
The data is similarly stored in the 8 memory 25B.

The selector 25 selects the R memory 24RXG memory 2.
The RlG and B data stored in the 4G and B memory 24B are sent to the blocking circuits 26a, 26b, 26c and the image determination circuit 27 under the control of the control signal generator 31.
, G, B sequentially.

The blocking circuits 26a, 26b, 26c, as shown in FIG.
Process the data of B sequentially.

The signal input to the input terminal 31 is stored in the main memory 32.

Further, the address counter 37 inputs an address for reading out the pixel of interest to the matrix counter 35.
At the same time, it is output to the peripheral detection circuit 38.

As a result, the matrix counter 35 stores peripheral pixels (hereinafter referred to as a matrix) around the pixel of interest in the main memory 3, as shown in FIGS. 4(a) to 4(C).
The main input signal 32 is controlled so that the signal is inputted from 2 to the cumulative multiplier 33.

At the same time, the matrix counter 35 is
) to (C), the coefficients of the matrix are transferred from the coefficient ROM 36 to the cumulative multiplier 33 centering on the pixel of interest.
The coefficient ROM 36 is controlled so that the coefficient is input to the coefficient.

The pixel of interest is, for example, vertically divided by 2 pixels as shown in FIG. 4 (a).
In the case of one pixel horizontally (hereinafter referred to as an iX2 matrix), the upper pixel is the upper pixel, and for example, as shown in Figure 4(b), there are two pixels in both the vertical and horizontal directions (hereinafter referred to as a 2x2 matrix).
For example, as shown in FIG. 4 <C), if there are three pixels in both the vertical and horizontal directions (hereinafter referred to as a 3×3 matrix), the center pixel is used.

Further, the coefficients recorded in the coefficient ROM 36 are, for example, I
In the case of X2 matrix, it is 1/2, in the case of 2X271~RIX, it is 1/4, and in the case of 3X3 matrix, it is 1/9.
It is said that

The cumulative multiplier 33 is connected to the main memory 3 as described above.
A matrix centered on the pixel of interest input from 2,
As described above, the coefficients recorded in the coefficient ROM 36 are multiplied by or subtracted from each other, and cumulative addition is performed and the result is output to the abnormal value correction circuit 34.

As described above, when the input data deviates from a predetermined range, the abnormal value correction circuit 34 corrects the data so that it converges within a predetermined range, and outputs the corrected data to the data selector 40 .

Further, the peripheral area detection circuit 38 detects whether the current pixel of interest is in the center of the screen based on the address value inputted from the address counter 37, and if it is in the peripheral area of the screen, the Controls the peripheral data ROM 39 to output data corresponding to the peripheral part, and
The data selector 40 is connected to the peripheral data ROM 39.
control to output data. This is because the periphery of the pixel of interest is missing in the periphery of the screen, making it impossible to obtain a correct calculation result from the cumulative multiplier 33.

As described above, when the pixel of interest is in the peripheral area of the screen, the data selector 40 selects the peripheral area data ROM3.
9 is output to the sub-memory 41, and in other cases, the data from the abnormal value correction circuit 34 is output to the sub-memory 41.

Roughly speaking, the address counter 37 specifies the address value of interest so that the matrices described above do not overlap, repeats the above-mentioned operation until the end of one screen, and further specifies the R, G
, repeat the above operations until the entire screen of B is completed.

Therefore, the sub-memory 41 stores R, G.

Processed data for three screens of B is recorded.

When matrices are used as described above, for example, in the case of an IX2 matrix, the data amount becomes 1/2, in the case of a 2x2 matrix, the data amount becomes 1/4, and in the case of a 3x3 matrix, the data m becomes 1/9.

Blocking circuits 26a, 26b as described above.

The image compressed by 26c is input to the selector 28 as shown in FIG. 3, and is also input to the image determination circuit 27.

In the image determination circuit 27, the original image manually input from the selector 25 and the blocking circuits 26a, 26b,
For example, the compressed image input from 26c is
Evaluation is made based on the S/N (signal to noise) or entropy described in J, and a blocked circuit having a predetermined evaluation value or more is selected. In addition, when there are multiple blocking circuits having a predetermined evaluation value or more, the blocking circuit with a large matrix, that is, a high compression ratio, is selected. Furthermore, the image determination circuit 27 controls the selector 28 to output the selected blocking circuit as described above, and also controls the compressed information to output information such as which matrix is used. R.O.
Controls M30.

The selector 28 selects the blocking circuits 26a and 26b under the control of the image quality determination circuit 27.

26c is output to the two predictive encoders.

The predictive encoder 29 generates a prediction error using the predictive encoding method described in, for example, "Image Processing Handbook (published by Shokodo) P, 127-P, 129 J,"
Output to the image recording device 22.

The image recording device 22 records the input compressed image and compressed information as described above on a large-capacity storage medium such as an optical disk or a magneto-optical disk.

In this embodiment, three types of blocking circuits perform blocking compression at the same time, and then the image is determined. Therefore, the time required for compression is always constant. Further, after compression by blocking, compression is further performed by predictive coding to improve compression efficiency.

In other words, for images with high correlation between adjacent pixels and few high-frequency components, such as normal observation images, a large matrix is used to improve compression efficiency, and for example, for images with special observation such as staining, a large matrix is used to improve compression efficiency. For images with low correlation between pixels and many high frequency components, a small matrix can be used to prevent deterioration in image quality.

5 to 179 relate to the second practical example of the present invention,
FIG. 5 is an explanatory diagram showing the configuration of the electronic endoscope device, FIG. 6 is an explanatory diagram regarding predictive coding, FIGS. 7 and 8 are explanatory diagrams regarding the frequency distribution of prediction errors of endoscopic images, and FIG. FIG. 9 is a flowchart regarding compression processing. Components similar to those in the first embodiment are designated by the same reference numerals, and description thereof will be omitted.

The image data compression device 250 is provided with an arithmetic processing unit 51, a working memory 52, and an auxiliary storage device 53, as shown in FIG.

The 't4 arithmetic processing device 51 is connected to the working memory 52 and the auxiliary storage device 53, respectively.

Further, the arithmetic processing device 51 is connected to the image recording device 22.

The image data compression device 50 includes a control signal generation section 12.
one of the control signal output terminals, R memory 6R, G memory 6
The output terminals of the G and B memories 6B are connected, and the input terminals of D/A converters 7R, 7G, and 7B are connected.

The operation of the image data compression device configured as described above will be explained.

Usually, the R memory 6R, G memory 6G and B memory 6
In the image data compression device 50, the output terminal of B is
The D/A converters 7R and 7G.

Connected to the input end of 7B.

Therefore, similarly to the first embodiment, the image carried by the CCD 1 is displayed as a color image on a monitor (not shown).

Further, the outputs of the R memory 6R, G memory 6G, and B memory 6B are inputted to the arithmetic processing device 51 by the control signal 1211 of the control signal generating section 12, and the arithmetic processing device 51, the working memory 52, and the auxiliary Image compression processing, which will be described later, is performed by the storage device 53, and the image recording device 22
recorded in

The arithmetic processing device 51 compresses the input image by predictive encoding and outputs it to the image recording device 22.

This predictive encoding will be explained using FIGS. 6 to 8.

FIG. 6 illustrates the signals of a certain n line and its ±1 line. According to this, the ni line has already been read and the value is known, and the n line has the pixel of interest X
The values up to X are known, and the values of all n+1 lines are unknown.

Here, a -1 pixel in the horizontal direction of the pixel of interest When the +1 pixel in the horizontal direction is d, the predicted value X' by the previous value prediction formula (previous value), average prediction formula (average), and composite prediction formula (composite) is as follows.

x' = a (previous value) x
' = 1/2(a+d) (average) x' = 3/4a+ 1/4d+ 1/2cm
1/2d (compound) The prediction error ΔX resulting from this is as follows.

Δx=x−x′ Therefore, by recording the prediction error ΔX, the data X of the original image can be restored from known data. Furthermore, since the prediction error ΔX is generally a smaller value than the original image X, information can be compressed.

FIGS. 7 and 8 show examples of frequency distributions of observed images. If the prediction is performed accurately, the prediction error will be zero; if the predicted value is larger than the true value, the prediction error will be distributed to 10; if it is small, the prediction error will be distributed to -.

Figure 7 shows the frequency distribution of normal observation images, and Figure 7 (
Figure 7(b) shows the case where the previous value prediction formula is used.
shows the case where the average prediction formula is used, and FIG. 7(C) shows the case where the average prediction formula is used.
This shows the case where a composite prediction formula is used. In a normal observation image, the correlation between adjacent pixels is high and there are few high frequency components, so even if the prediction formula is different, the frequency distribution is concentrated in a portion close to zero. Therefore, even if a simple formula such as a previous value prediction formula is used, sufficient compression is possible.

Figure 8 shows the frequency distribution of special view 1 images, and Figure 8 (
Figure 8(b) shows the case where the previous value prediction formula is used.
shows the case where the average prediction formula is used, and FIG. 8(C) shows the case where the average prediction formula is used.
This shows the case where a composite prediction formula is used. In special observed images, the correlation between adjacent pixels is low and there are many high frequency components, so the frequency distribution differs depending on the prediction formula. Therefore, if a simple formula such as a previous value prediction formula is used, sufficient compression cannot be achieved, and a complex prediction formula such as a compound prediction formula cannot be used.

The processing of the arithmetic processing unit 51 will be explained using FIG. 9.

A processing program is called at step (hereinafter referred to as S) 300, and the process is taken over to step 8301.

The above 8301 sets an initial value. This initial value is I
maqe H is any data array of RGB signals,
X 5ize is the number of horizontal pixels, Y sze is the number of vertical pixels,
DPCMO is an array of prediction error data, x and y are working variables that indicate the position of the pixel of interest, case is a working variable that indicates the prediction error formula, and Th is the reference value of the compression rate. 0.0 to compress the image to 30% or less.
3, and Total is a variable that stores the total number of bits of prediction error. After that, it is taken over to 8302.

The above 5302 sets the variables x and y to the initial value of zero, and
Transferred to 303.

The step 8303 sets the variable X to zero, increments the variable y, and takes over to step 5304.

The step 3304 increments the variable X by one and transfers it to step 8305.

5305 is a macro that calculates a prediction error, and C
If aSe is 1, the previous value prediction formula is executed and CaS
If e is 2, the average prediction formula is executed, and if Ca5e is 3, the composite prediction formula is executed. After that, 83
Transferred to 06.

The step 8306 determines whether the pixel of interest has reached the maximum horizontal pixel value, and if the pixel has not reached the maximum value, the step 5304 takes over, and if the pixel has reached the maximum value, the step 8307 takes over.

The step 5307 determines whether the pixel of interest has reached the maximum vertical pixel value, and if the pixel has not reached the maximum value, the step 8303 takes over, and if the pixel has reached the maximum value, the step 8308 takes over.

The above 8308 sets the variables x and y to the initial value of zero, and
Transferred to 309.

The step 5309 sets the variable X to zero, adds 1 to the change y, and takes over to 8310.

The above 5310 adds the variable X and transfers it to 5311.

The above 5311 has DPCtvl (X.

Y), set variable 3it to -, and take over to 3312.

The above 5312 divides the variable WOrk by 2 and calculates the variable Work.
Assign to k and take over to 5313.

The step 5313 determines whether the variable Work is not zero, and if it is not zero, the step 5314 takes over, and if it is zero, the step 5315 takes over.

The above 5314 adds the variable 3it, and the above 5312
Transfer to.

The above 5315 adds the variable [3it to the variable Tota+ and transfers it to 8316.

The step 8316 determines whether the pixel of interest has reached the maximum horizontal pixel value, and if the pixel has not reached the maximum value, the step 5310 takes over, and if the pixel has reached the maximum value, the step 5317 takes over.

The step 5317 determines whether the pixel of interest has reached the maximum vertical pixel value, and if the pixel has not reached the maximum value, the step 8309 takes over, and if the pixel has reached the maximum value, the step 8318 takes over.

The step 8318 divides the aforementioned Total by the total number of pixels, assigns the compression rate to the Rate, and proceeds to step 5319.

The above 5319 is 5320 if the compression ratio is greater than 30% (variable Th is 03) and the variable CaSe is not 3.
Otherwise, take over to 5321.

The above 3320 adds the variable Ca5e, and the above 530
Take over to 2.

The step 5321 ends the execution of the program.

As described above, by calculating the total bits of the prediction error in steps 5301 to 5317 and calculating the compression ratio in step 8318, the optimal prediction formula can be selected, and the prediction formula can be executed from a simple prediction formula. This has the effect of shortening the compression time.

10 and 11 relate to a third embodiment of the present invention; FIG. 10 is a block diagram showing the configuration of an image data compression device, and FIG. 11 is an explanatory diagram regarding filtering.

Note that the same reference numerals are used for the same parts as in the first embodiment, and the description thereof will be omitted. In addition, electronic endoscopy using the screen sequential method
Since the device is the same as that in the first embodiment or the second embodiment, a description thereof will be omitted.

As shown in FIG. 10, the image data compression device includes an R memory 24R, a G memory 24G, and a B memory 24B provided in the memory section 24, a selector 25, and a
A DC king circuit 61 that performs cosine conversion, a first filtering circuit 62 as a first compression means, and an image quality determination circuit (A>63) that determines the image quality of the image compressed by the first filtering circuit 62. A second filtering circuit 64 which is a second compression means, an image quality determination circuit (B) 65 which determines the image quality of the image compressed by the second filtering circuit 64, and a third filtering circuit which is a third compression means. 66, the memory section 24, the selector 25, the DCT circuit 61, and the image quality determination circuit (A) 6
3. The image quality determination circuit (B) 65 and the image recording device 22
and a control signal generating section 67 that supplies control signals to.

The output terminal of the selector 25 is an input terminal of the DCT circuit 61, a first input terminal of the image quality determination circuit (A) 61,
It is connected to the first input terminal of the image quality determination circuit (B) 65.

The output terminal J of the DCT circuit 61 is connected to the input terminal of the first filtering circuit 62, and the output terminal of the first filtering circuit 62 is connected to the image quality determination circuit (Δ) 63.
is connected to the second input terminal of.

The image quality determination circuit (A) 63 has a first output terminal connected to the first input terminal of the image recording device 22 and a second output terminal connected to the second filtering circuit 64.

The output terminal of the second filtering circuit 64 is connected to the second input terminal of the image quality determination circuit (B) 65.

The image quality determination circuit (B) has a first output terminal connected to a second input terminal of the image recording device 22 and a second output terminal connected to the third filtering circuit 66.

The control terminals of the memory section 24, the selector 25, the DCT circuit 61, the image quality determination circuit (A) 63, the image quality determination circuit (B) 65, and the image recording device 22 are connected to the control signal generation section 6.
7 control output terminals, respectively.

The operation of the image data compression device configured as described above will be explained.

The selector 25 selects the R memory 24R and the G memory 2.
The signals of the 4G and B memories 24B are sequentially converted to a DCT circuit 61,
It is output to an image quality determination circuit (A) 63 and an image quality determination circuit (B) 65.

The DCT circuit 25 converts the input signal into, for example, [1''
[:E Trans vol, IC-23P, 90~
For example, a discrete cosine transform of 8×8 size as described in P.39J is performed and output to the first filtering 62.

The first filtering circuit 62 is configured, for example, as shown in FIG.
As shown in a), the pixels of 8×8 size are compressed into 4×4 size with the left end as the origin, and the image quality judgment circuit (A)
Output to 63.

The image quality determination circuit (A) 63 performs inverse discrete cosine transform on the input signal, which has been transformed as described above, and compares it with the original image input from the selector 25. This comparison is performed using S/N, entropy, etc. as explained in the first embodiment. Furthermore, the image quality determination circuit (A>63) determines that when the image quality of the compressed image is below a predetermined standard,
The signal from the first filtering circuit 62 is output to the image recording device 22, and if it exceeds a predetermined standard, the signal is output from the first filtering circuit 62 to the second filtering circuit 64.
Output the signal from.

The second filtering circuit 64 divides the signal input from the image quality determination circuit (A) 63 into 3 pixels with the left end as the origin, as shown in FIG. 11(b), for example. ×3 size, image quality judgment circuit (
B) Output to 65.

The image quality determination circuit (B) 65 is configured such that the image quality determination circuit <A
) 63, and if the image quality of the compressed image is below a predetermined standard, the signal from the second filtering circuit 64 is output to the image recording device 22, and the signal is determined according to the predetermined standard. If the value exceeds 1, the signal from the second filtering circuit 64 is output to the third filtering circuit 66.

The third filtering circuit 66 is configured, for example, as shown in FIG.
As shown in C), a pixel with a medium size of 3×3 is compressed to a size of 2×2 with the left end as the origin, and the image recording device 2
Output to 2.

In addition, if the image quality does not reach a predetermined standard in the image quality determination circuit (A>63), the original image is output; The signal from the first filtering circuit 62 may be output.

That is, there is an effect that the original image can be compressed to a predetermined range without deterioration.

1(B) and 12 relate to the fourth embodiment of the present invention, FIG. 1(B) is a block diagram showing the configuration of an image data compression device, and FIG. 12 is an electronic endoscope device. FIG. 2 is an explanatory diagram showing the configuration of.

As shown in FIG. 12, the field-sequential image transport type electronic endoscope apparatus includes a timing cinerator 216 that generates a predetermined control signal for each block (to be described later), and a charge-coupled device (COD), for example, that transports the subject. ) is the solid element element 203
, an objective lens system 202 that forms an image of a subject light beam on this solid-state image sensor 203, a driver 217 that supplies a drive signal to the solid-state layer I&element, and the solid-state image sensor 203.
a preamplifier 204 that amplifies the image signal of the preamplifier 204, a process circuit 205 that performs gamma correction and chitria removal on the video signal amplified by the preamplifier 204, and
An analog-to-digital converter (hereinafter referred to as an A/D converter) 206 converts a video signal, which is an analog signal that has been corrected, etc., into digital signal data, and this digital signal is switched to each memory in a memory unit 208. The output selector 207 and the memory section 208 ()
R to store the red wavelength region (hereinafter referred to as R)
Memory 208R1 G memory 208G that stores a green wavelength region (hereinafter referred to as G) and a blue wavelength region (hereinafter referred to as B)
A B memory 208B stores the image signal (hereinafter referred to as a D/A converter) and outputs the image signal stored in the memory section 208 or the image signal of the image data compression device 70 described later to a digital-to-analog converter (hereinafter referred to as a D/A converter) 210. 20 display switching circuits, 20 display switching circuits, video signals stored in the memory section, and video signals from an endoscopic image data compression device (hereinafter referred to as image data compression device) 70, which will be described later, are converted from digital signals to analog signals. The D/A converter 210, the screen frame generation circuit 211 that generates a display screen frame for the D/A converter 210, the superimpose circuit 212 that synthesizes information such as patient information on the display screen, and the superimpose circuit 212 that synthesizes information such as patient information on the display screen. Invoice and image files described below?
a character information input circuit 213 for inputting information such as patient information to the file device 80; and a TVVTR 231 for displaying RGB signals from the superimpose circuit 212;
a matrix circuit 214 that converts the RGB signal of the spine pause circuit 212 into, for example, a luminance signal and a color difference signal; an encoder circuit 215 that converts the signal of the matrix circuit 214 into, for example, an NTSC signal; and an NTSC signal from the encoder 215. A VTR 231 that records
a lamp 221 that generates illumination light for supplying an image to a region etc. on which the solid-state image sensor 203 carries an image; and a lamp 22
1, a rotating filter 222 provided with a filter that separates the light from this lamp 221 into R, G, and B, 21 motors that rotate this rotating filter 222, and 21 motors that rotate this rotating filter 222; Cinerator 216
It is composed of a motor driver 218 that supplies driving power to the motor 219 in accordance with the ll signal controlled by the controller, and a light guide 201 that guides the aforementioned separated illumination light to a region to be imaged by the solid-state image sensor 203. .

The lamp 221 is a xenon lamp, a strobe lamp, or the like that can generate illumination light not only in the visible wavelength range but also in the ultraviolet to infrared wavelength range.

Furthermore, the solid-state image sensor 203 has sensitivity not only in the visible light wavelength region but also in the ultraviolet light wavelength region to the infrared light wavelength region.

The exit end face of the light guide 201, the objective lens system 202, and the solid-state image carrier 203 are arranged at the distal end portion 200 of the endoscope.

The solid-state image sensor 203 is arranged at the imaging position of the objective lens system 202.

The solid-state imaging element 203 is connected to the input end of the preamplifier 204, the output end of the preamplifier 204 is connected to the input end of the process circuit 205, and the output end of the process circuit 205 is connected to the Δ/D converter. The output terminal of the A/D converter 206 is connected to the input terminal of the selector 207.

The input terminals of the R memory 208R, the G memory 208G, and the B memory 208B are connected to the selector 207, respectively.
connected to the output end of the The R memory 208R,G
The output terminals of the memory 208G and the B memory 208B are connected to the input terminal of the display switching circuit 209, and also to the input terminal of an image data compression device @70, which will be described later.

The output terminal of the display switching circuit 209 is connected to the input terminal of the D/A converter 210, and the output terminal of the display switching circuit 209 is connected to the input terminal of the D/A converter 210.
The output terminal of 10 is connected to the input terminal of the superimposing circuit 212.

The output terminal of the screen frame generation circuit 211 is connected to the input terminal of the D/A converter 210.

The character information input circuit has a first output terminal connected to the superimpose circuit 212, and a second output terminal connected to an image file device 80, which will be described later.

The output terminal of the superimpose circuit 212 is connected to the TV monitor 230 and the output terminal of the superimpose circuit 212 is connected to the TV monitor 230 and
14.

The output terminal of the matrix circuit 214 is connected to the input terminal of the encoder circuit 215, and the output terminal of the matrix circuit 214 is connected to the input terminal of the encoder circuit 215.
The output terminal of 5 is connected to the input terminal of the VTR 231.

The timing generator 216 has a first output end connected to the driver 217, a second output end connected to the memory section 208, and a third output end connected to the motor driver 218.

The output end of the driver 217 is connected to the solid-state image element 203.
The output end of the motor driver is connected to the motor 219.

An output end of the power source 220 is connected to the lamp 221.

The image data compression device 70 is provided with an image compression section 9o that compresses data in the memory section 208.

The image file device 80 records the data compressed by the image data compression device 90 and the old age information inputted by the character information input circuit 213 using a high-frequency recording medium such as an optical disk or a magneto-optical disk. It is something.

As shown in FIG. 1(B), the image data compression device 70 includes a predictive encoding circuit (A>72, a predictive encoding circuit (B) 73 as a compression means including binarization) as a compression means, and a predictive encoding circuit (B) 73 as a compression means including binarization. A DCT transform circuit 74, which is a compression means using DCT (discrete cosine), and a decoding circuit (A) 75, a decoding circuit (B) 76, and a decoding circuit (C) 77, which are decompression means, switch the compression means to convert the image. It is comprised of a select circuit 78 that outputs to the file device 80 and a select circuit 79 that switches the expansion means and outputs to the display switching circuit 209.

The predictive encoding circuit (A) 72, the predictive encoding circuit (B)
73 and R, G of the DCT conversion circuit 74.

The input ends of B are connected to input terminals 71R, 71G, and 71B, respectively.

The output terminal of the predictive encoding circuit (A>72) is connected to the input terminal of the decoding circuit (A>75), and is also connected to the first input terminal of the select circuit 78.

The output terminal of the predictive encoding circuit (B) 73 is connected to the input terminal of the restoration circuit (B) 76, and is also connected to the second input terminal of the selection circuit 78.

The output terminal of the DCT circuit 74 is connected to the decoding circuit (C) 7.
7, and the select circuit 78
is connected to the third input terminal of.

The output terminal of the decoding circuit (A) 75 is connected to the select circuit 7.
The output terminal of the decoding circuit (B) 76 is connected to the second input terminal of the selection circuit 79, and the output terminal of the decoding circuit (C) 77 is connected to the first input terminal of the selection circuit 79. It is connected to the third input terminal.

The select signal input terminals of the select circuit 78 and the select circuit 79 are connected to the select terminal 82.

The output terminal of the selection circuit 78 is connected to the input terminal of the image file device 80.

The release end of the image file 80 is the release terminal 81
It is connected to the.

The R, G, and B output terminals of the select circuit 79 are connected to output terminals 83R, 83G, and 83B.

The operation of the image data compression device configured as described above will be explained.

The timing generator 216 supplies predetermined timing pulses to the memory section 208, driver 217, and motor driver 218, as shown in FIG.

The driver 217 supplies a drive signal for not reading out the photoelectric conversion and charge conversion signals to the solid-state image carrier 203 using the timing pulse described above.

The lamp 221 generates the above-described illumination light using driving power from a power source 220.

The motor driver 218 generates driving power in synchronization with a control signal from the timing generator 216. This driving power causes the motor to rotate, which causes the rotary filter 222 to rotate and separates the illumination light from the lamp 221 into R, G, and B. This separated illumination light is guided through a light guide 201 and is irradiated onto a subject from an output end face disposed at the end face 200 of the endoscope.

The subject light flux of the subject illuminated by the illumination light described above is imaged by the objective lens system 202 on the imaging surface of the solid-state image sensor 203, photoelectrically converted, and inputted to the preamplifier 204 as an Rt@ signal.

The preamplifier 204 amplifies the above-mentioned imaging signal to a predetermined voltage and outputs it to the process circuit 205.

The process circuit 205 processes the input signal by γ correction and chit7 rear removal, and further applies a bias so that the halation part has a knee characteristic and the dark part has a pedemal level, and A/ Output to D converter 206.

The Δ/D converter 206 converts the aforementioned signal into, for example, an 8-bit digital signal, that is, quantizes it, and outputs it to the selector 207.

The selector 207 outputs the digital signal described above to each memory of the memory section 208. This means that when the spectral wavelength region of the illumination light by the rotation filter 222 is red,
Similarly, if it is green, it is output to the G memory 208G, and similarly, if it is blue, it is output to the B memory 208B.
In other words, it is input to and stored in a memory having a wavelength range equal to that of the subject light beam.

Each memory of the memory unit 208 outputs stored data to the display switching circuit 209 and the image data compression device 70 in response to a control signal from the timing generator 216. This is to output the data sequentially inputted by the selector 5 to the display switching circuit 209 at the same time, that is, to synchronize the subject light fluxes of each wavelength range that are sequentially imaged.

The display switching circuit 209 selects the signal input from the memory section 208 or the signal input from the image data compression device 70 and outputs it to the D/Δ converter 210.

The D/A converter 210 is connected to the display switching circuit 20.
The signal input from 9 and the signal forming the frame of the display screen input from the screen frame generation circuit 211 are combined, and the digital signal is further converted into an analog signal and output to the superimpose circuit 212.

The superimpose circuit 212 applies the character information input circuit 2 to the signal input from the D/A converter 210.
For example, a screen signal is formed by combining patient information from 13, and is output to the TVVTR 231 and matrix circuit 214.

The TV monitor 230 is connected to the superimpose circuit 2.
The signal input from 12 is displayed on the screen.

Further, the matrix circuit 214 converts the signal input from the superimpose circuit 212 into, for example, a luminance signal and a color difference signal, and outputs the signals to the encoder circuit 215.

The encoder circuit 215 converts the input luminance signal and color difference signal into, for example, an NTSC signal, and outputs the signal to the VTR 231.
Output to.

The VTR 231 records the NTSC signal as a moving image on a video tape or the like.

As shown in FIG. 1(B), the image data compression device 70 receives the signal from the R memory 208R at an input terminal 71.
The signal from the G memory 208G is input to the input terminal 71G, and the signal from the B memory 208B is input to the input terminal 71B.

The signals input to the input terminals 71R, 71G, and 71B are processed by a predictive encoding circuit <A> 72 which is a compression circuit, a predictive encoding circuit (B) 73 which is a compression circuit including binarization, and a discrete cosine transform. The signal is input to a DCT circuit 74 which is a compression circuit.

The predictive encoding circuit (A>72, predictive encoding circuit (B)
73 and the DCT circuit 74 compress the input signals using different compression methods, and send them to the predictive coding circuit (A
) 72 outputs to the decoding circuit (△〉75) and also outputs to the first input terminal of the select circuit 78, and the predictive encoding circuit (B
) 73 outputs to the decoding circuit (B) 76 and also outputs to the second input terminal of the select circuit 78, and the DCT circuit 74 outputs to the decoding circuit (C) 77 and the select circuit 78.
output to the third input terminal of.

The decoding circuit (A) 75, the decoding circuit (B) 76, and the decoding circuit (C) 77 expand the input signal as described above, and the decoding circuit (A) 75 is the first one of the select circuit 79.
The decoding circuit (B) 76 outputs it to the second input terminal of the selection circuit 79, and the decoding circuit (C) 77 outputs it to the third input terminal of the selection circuit 79.

The select circuit 78 and the select circuit 79 include:
For example, a select signal is input to the select terminal 82 from a switch or the like provided on the exterior of the endoscope device.

The left circuit 78 selects one of the signals inputted to the first to third input terminals as described above in response to the aforementioned select signal, and outputs it to the Moeki image file 1iso.

At time β1, the select circuit 79 selects - of the signals inputted to the first input terminal to the third input terminal as described above in response to the above-mentioned select signal, and selects the output signal connected to the display switching circuit 209. Output to terminals 83R, 83G, and 83B.

Therefore, the TV monitor 230 displays an image that has been compressed and then decompressed as described above. Further, by switching the display switching circuit 209 using, for example, a switching signal, it is possible to compare the display with the original image.

As a result, the operator, for example a doctor, evaluates the stretched screen, selects an image suitable for recording, operates a switch etc. provided on the exterior of the endoscope device, and
A release signal is input to the release terminal 81.

The above-mentioned release signal causes the image file device 8 to
0 records the signal input from the select i circuit 78 on a large-capacity storage medium such as an optical file or a magneto-optical file.

Although the description has been made using a predictive encoding circuit and a DCT circuit as the compression means, other compression means, such as one based on vector quantization, may be used.

That is, in this embodiment, an operator, for example, a doctor, can select and record an optimal image, and can select a compression means suitable for the image, thereby achieving high image quality and efficiency. This has the effect of being able to record good images.

FIG. 13 is a block diagram showing the configuration of an image data compression apparatus according to a fifth embodiment of the present invention. Note that the same reference numerals are used for the same parts as in the fourth embodiment, and the description thereof will be omitted. Further, since the endoscope apparatus using the field sequential image transport method is the same as that in the fourth embodiment, the explanation thereof will be omitted.

The image data compression device includes a predictive encoding circuit (Δ) 72
, a predictive encoding circuit (B) 73, a DCT conversion circuit 74, a decoding circuit (A) 75, a decoding circuit (B) 76, a decoding circuit (C) 77, a select circuit 78, and a select circuit 7.
9, a compression ratio calculation circuit 85 that calculates the compression ratio of the compression means described above and controls the selection circuit, and a display memory 86 that stores the signal from the selection circuit 79.

The predictive encoding circuit (A) 72, the predictive encoding circuit (B)
73, R of OCT conversion circuit 74 and compression ratio calculation circuit 85
, G, and B are input terminals 71R, 71G, and 7, respectively.
Connected to 1B.

An output end of the predictive encoding circuit (A) 72 is connected to the decoding circuit (A) 75, a first input end of the select circuit 78, and a first input end of the compression lead output circuit 85. There is.

The output end of the predictive encoding circuit (B) 73 is connected to the decoding circuit (B) 76, the second input end of the select circuit 78, and the second input end of the compression ratio calculation circuit 85. .

The output terminal of the DCT circuit 74 is connected to the decoding circuit (C) 7.
7, a third input terminal of the select circuit 78, and a third input terminal of the compressed $4 output circuit 85.

The output terminal of the decoding circuit (A) 75 is connected to the select circuit 7.
9 is connected to the first input terminal of the IA decoding circuit (B) 76.
The output terminal of the head decoding circuit (C) 77 is connected to the second input terminal of the seven select circuits, and the output terminal of the head decoding circuit (C) 77 is connected to the third input terminal of the select circuit 79.

A select signal input terminal of the select circuit 78 is connected to a select terminal 82 .

The select signal input terminal of the select circuit 79 is connected to the output terminal of the compression ratio calculation circuit 85.

The output terminal of the selection circuit 78 is connected to the input terminal of the image file device 80.

The release end of the image file 80 is the release terminal 81
It is connected to the.

The R, G, and B output ends of the select circuit 79 are connected to the input ends of the display memory 86, and the output ends of the display memory 86 are connected to output terminals 83R183G and 83B.

The operation of the image data compression device configured as described above will be explained.

A compression rate calculation circuit 85 calculates the compression rate of each compressed signal in the same manner as in the fourth embodiment.

Furthermore, the compression ratio calculation circuit 85 calculates the decoding circuit (A>7
5. Control the select circuit 79 so as to output the signals of the decoding circuit (B) 76 and the decoding circuit (C) 77, for example, in order of decreasing compression ratio.

The select circuit 79 is controlled as described above, and sequentially outputs the signals of the decoding circuit (A) 75, decoding circuit <8) 76, and decoding circuit (C) 77 to the display memory 86.

The display memory 86 stores the input signal as described above so that it can be displayed on one screen, for example, and outputs the output terminals 83R and 83G connected to the display switching circuit 209.
, 83B.

Therefore, on the TV monitor 230, a plurality of images compressed and then decompressed as described above are displayed in descending order of compression ratio. Further, by switching the display switching circuit 209 using, for example, a switching signal, it is possible to compare the display with the original image.

As a result, a doctor, for example, evaluates the expanded screen, selects an image suitable for recording, operates a switch, etc. provided on the exterior of the endoscope, and
A release signal is input to the release terminal 81.

The above-mentioned release signal causes the image file device Yi
80 records the signal input from the select circuit 78 on a large-scale storage medium such as an optical file or a magneto-optical file.

Although the description has been given using a predictive encoding circuit and a DCT circuit as the compression means, other compression means such as vector m-child conversion may also be used.

That is, in this embodiment, images obtained using a plurality of compression means can be compared and evaluated at the same time, and the operator, for example, a doctor, has the advantage of being able to select and record the optimal image. .

Further, other effects are similar to those of the fourth embodiment.

Although the explanation has been made using a frame-sequential electronic endoscope, it is also possible to provide means for decoding a composite video signal, for example, at the stage before the video signal input terminal of each wavelength region, and input the composite video signal. .

In addition, an external TV can be installed on the inside m 11 using the image guide.
A camera device may be attached and used for this video browser device.

[Effects of the Invention] As explained above, according to the present invention, an original image can be compressed and recorded, or a compressed image can be evaluated and recorded at a time when the image quality does not deteriorate by the image quality determining means, This has the effect of being able to perform optimal image compression.

[Brief explanation of the drawing]

FIG. 1(A) and FIGS. 2 to 4 relate to the first embodiment of the present invention, FIG. 1(△) is a block diagram showing the configuration of an endoscopic image data compression device, and FIG. An explanatory diagram showing the configuration of an electronic endoscope device, FIG. 3 is a block diagram showing the configuration of a blocking circuit, FIG. 4 is an explanatory diagram regarding blocking, and FIGS. 5 to 9 are a second embodiment of the present invention. Regarding the example, the fifth
Figure 6 is an explanatory diagram showing the configuration of the electronic endoscope device, Figure 6 is an explanatory diagram regarding predictive coding, Figures 7 and 8 are explanatory diagrams regarding the frequency distribution of prediction errors in endoscopic images, and Figure 9 is an explanatory diagram showing the configuration of the electronic endoscope device. 10 and 11 are related to the third embodiment of the present invention, FIG. 10 is a block diagram showing the configuration of an image data compression device, FIG. 11 is an explanatory diagram regarding filtering, and FIG. FIG. 1(B) and FIG. 12 relate to the fourth embodiment of the present invention, FIG. 1(B) is a block diagram showing the configuration of an image data compression device, and FIG.
! An explanatory diagram showing the configuration of the mirror device, FIG. 13 is the fifth embodiment of the present invention.
Block diagrams showing the configuration of the image data compression device according to the embodiment, FIGS. 14 to 16, relate to the conventional technology,
FIG. 14 is an explanatory diagram of the endoscope system, FIG. 15 is an explanatory diagram of the endoscope and observation device, and FIG. 16 is an explanatory diagram of the image recording device. 26... Blocking circuit section 27... Image quality determination circuit 28... Selector 72... Predictive coding circuit (A>73... Predictive coding circuit (B) 74... DCT circuit 75... ...Decoding circuit (A) 76...Decoding circuit ([3) 77...Decoding circuit (C) 7...Select circuit Figure 4 (G) (b) (C) Noteworthy mountain range Figure 6 x n+ Line image small unknown Fig. 7 (0) (b) (C) Fig. 8 (0) (b) (C)

Claims (1)

[Scope of Claims] 1. A signal of an observation image of an endoscope or a signal obtained by dividing the observation image signal into a plurality of wavelength regions is input, the signal is compressed by a compression means, and the compressed signal is converted into an image. An endoscopic image data compression device for outputting to a recording device, comprising a plurality of compression means, an evaluation means for evaluating at least one of the signals compressed by the compression means, and an evaluation means for evaluating at least one of the signals compressed by the compression means; 1. An endoscopic image data compression device, comprising: selection means for selecting one of the selected signals. 2. A signal of an observation image of an endoscope or a signal obtained by dividing the observation image signal into a plurality of wavelength regions is input, the signal is compressed by a compression means, and the compressed signal is output to an image recording device. The endoscopic image data compression device includes a plurality of compression means, a means for decompressing at least one of the signals compressed by the compression means and outputting it in a displayable manner, and a means for selecting one of the compressed signals. 1. An endoscopic image data compression device comprising: selection means.