JPH03118025A - Endoscope image data compressing device - Google Patents

Abstract

PURPOSE:To execute the high compression of image data by bringing one color information containing a component of the longest wavelength side in plural color information for constituting an endoscope image to data compression by higher compressibility than that of the other color information. CONSTITUTION:A compressing circuit 34 (represents 34R, 34G and 34B) divides the whole input image by setting a prescribed number of picture elements as one block, and calculates an average value of a density value of the picture element in each block. Subsequently, the average value is recorded in a recording system part 35 together with color discriminating information. The number of picture elements of one block is set to nine picture elements as for an R image, two picture elements as for G image, and four picture elements as for a B image. As for the R image, it is compressed to about 1/9, and as for the G image, it is compressed to about 1/2, and as for the B image, it is compressed to about 1/4, and image data is recorded. An extending circuit 36 (represents 36R, 36G and 36B) reproduces the color discriminating information and the average value of each block, and based on the color discriminating information, the density value of each picture element in the block is set as the average value and the picture elements for constituting the block are restored.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an endoscopic image data compression device that compresses endoscopic image data.

[Prior art and problems to be solved by the invention] In recent years, by inserting an elongated insertion part into a body cavity, it is possible to observe internal organs, etc., and to insert a treatment instrument inserted into a treatment instrument channel as necessary. Endoscopes, which can be used to perform various therapeutic procedures, are widely used.

In addition, an electronic 81 mirror in which a solid-state image element such as a COD is provided at the distal end of the insertion portion has also been put into practical use.

By the way, endoscopic images captured by the electronic endoscope or the television camera connected to the eyepiece of the fiberscope are not only observed on a television monitor, but also recorded on an image recording device.
It may be used later for diagnosis and analysis. When recording endoscopic images in this manner, there is a problem in that a large capacity storage device is required because the image data has a large amount of data. Furthermore, when transmitting images, there is a problem that the transmission speed is slow.

Therefore, it has been proposed to compress image data.

In this case, various compression techniques can be applied; for example, the present applicant has proposed
In this paper, we propose a device that performs γ correction and quantization according to the characteristics of multiple color signals that make up an endoscopic image. The configuration of this device is shown in FIG. 17.

In this device, a light source section 152 and an image data compression section 161 are provided in an observation device 146 to which an electronic endoscope 144 is connected. The light emitted from the lamp 153 in the light source section 152 passes through a rotating filter 155 that is rotationally driven by a motor 154, and is separated in time series into light in the R, G, and B wavelength regions, and is used for electronic endoscopy. The light passes through the light guide 151 of the mirror 144 and is emitted from the tip of the insertion section 143 of the electronic inner cover 11144. The image of the subject illuminated with this light is
An objective lens 157 provided at the distal end of the insertion section 143 forms an image on the imaging surface of the C0D 158 and converts it into an electrical signal. This C0D 58 is driven by a driver 159 in the observation device 146, and the output signal is amplified by an amplifier 162 in the image data compression section 161 and then passed through a changeover switch 163 to γ correction circuits 164, 165.1.
66 is selectively input. This γ correction circuit 164°1
65 and 166 correspond to R, G, and B color signals, respectively, and have γ characteristics that take into account the luminance distribution of each color signal. For example, for the R signal, the slope is increased in the high brightness level part to increase the amount of data in the high brightness level part, and for the B signal, the slope is increased in the low brightness level part to increase the data volume in the low brightness level part. The data opening is increased, and the G signal has normal characteristics. γ correction circuit 164, 165
The outputs of ゜166 are respectively A/D converters 167
．． 168 and 169 and are each digitized with separate vitrification levels, eg 4 bits for R, B and 8 bits for G. Said A/D converter 167.168.1
The outputs of 69 are respectively memory 171R, 171G,
171B. This memory 171R, 171G
, 171B are converted into analog signals by D/A converters 172, 173, and 174. Only R and B signals are converted to inverse γ by inverse γ correction circuits 175 and 176.
The corrected data is output from data output terminals 177, 178, and 179. In addition, memories 171R, 171G, 171B
The signals read from the image recording device 150 are also recorded on the image recording device 150. The control signal generator 181 controls the motor 154 . Driver 159. Changeover switch 163. Memory 171R, 1
It controls the timing of the 71G, 171B0 image recording device@150, etc., and outputs a synchronization signal from the 5YNC output terminal 182.

Thus, the device shown in FIG. 17 has R,G.

B Perform γ correction on each color signal using different γ characteristics and record it on the image recording bag M150, perform reverse γ correction during playback, return to the original signal before γ correction, and display on a monitor etc. is configured to do so.

However, in this case, the characteristics of the inverse γ correction circuit need to match the characteristics of 1/γ0, where γ0 is the characteristic of the γ correction circuit, and it is very difficult to match them accurately. In particular, analog gamma correction.

When performing inverse γ correction, there is a good chance that the characteristics will change due to temperature.

The present invention has been made in view of the above circumstances, and is an endoscopic image data compression device that utilizes the characteristics of endoscopic images to enable high compression of endoscopic image data with a simple configuration. is intended to provide.

[Means for Solving the Problems 1] The endoscopic image data compression device of the present invention converts one color information containing the component on the longest wavelength side out of a plurality of color information constituting an endoscopic image into other color information. In order to compress the data at a higher compression rate than the color information, the color information is provided with means for lowering the resolution of the one color information compared to the other color information.

[Operation] In the present invention, the resolving power of one color information containing the longest wavelength component among the plurality of color information constituting an endoscopic image is made lower than the resolving power of other color information. 1
One color information is compressed at a higher compression rate than other color information. In a normal endoscopic image, color information containing components on the longest wavelength side has fewer high-frequency components than other color information.

Therefore, even if the resolution of this color information is lowered and the compression ratio is increased, the diagnosis will not be affected.

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

1 to 6 are based on the first embodiment of the present invention, and FIG.
The figure is a blog diagram showing the development of the image recording device, Figure 2 is an explanatory diagram showing the entire endoscopic image filing system Q, Figure 3 is a block diagram showing the configuration of the observation device, and Figure 4 is the image recording device. FIG. 5 is a flowchart showing the image recording apparatus σ reproduction operation, and FIG. 6 is an explanatory diagram for explaining the n-way compression operation.

As shown in FIG. 2, the endoscopic image file link system includes an electronic endoscope 1, an observation device 3 and a suction device 6 to which the electronic endoscope ff11 is connected, and the lower device 3. A monitor 4 and an image recording device 5 are provided.

The electronic endoscope 1 includes an elongated, e.g., flexible insertion section 1a that is inserted into a living body 2, and a large-diameter operation section 1b connected to the rear end of the insertion section 1a.

Universal cord 1C extended from this operation part 1b
A connector 1d connected to the observation device 3 is provided at the end of the universal cord 1c.

The distal end of the insertion section 1a of the electronic endoscope 1 is provided with an illumination window and an observation window. A light distribution lens (not shown) is mounted inside the illumination window, and a light guide 18 is connected to the rear end of the light distribution lens. This light guide 18 is inserted through the insertion section 1a, the operating section 1b, and the universal cord 1c, and is connected to the connector 1d.

Further, an objective lens system (not shown) is provided inside the observation window, and a solid-state image carrier, for example, a CCD 8, is disposed at an image forming position of this objective lens system.

The output signal of this CCD 8 is transmitted to the insertion section la, the operation section 1b,
The signal is input to the I detection device 3 via a signal line inserted through the universal cord 1c and connected to the connector 1d.

The observation device 3 is constructed as shown in FIG.

The observation device 3 includes a lamp 19 that emits white light, and a rotary filter 21 that is provided between the lamp 19 and the incident end of the light guide 18 and is rotationally driven by a motor 20. There is. The rotating filter 21 has red (R) and green (G) filters arranged in a circumferential direction.
), and a filter 22 that transmits light in each wavelength range of blue (B).
R, 22G, 22B, and is rotated by the motor 2o to insert a filter 22R22G into the illumination optical path.
, 22B are inserted sequentially. and,
R by this rotary filter 21.

The light separated in time series into each of the G and B wavelength regions is transmitted to the light guide 18. The light is emitted from the distal end of the insertion section 1a of the electronic endoscope UA1 through a light distribution lens.

The observation device 3 also includes an amplifier 9, and the output signal of the CCD 8 is amplified to a voltage level within a predetermined range by the amplifier 9, and subjected to γ correction by a γ correction circuit 11. The γ-corrected signal is converted into a digital signal by the Δ/D converter 12, and then transferred to the memories 14R and 14G corresponding to R, G, and 8, respectively, by the changeover switch 13.
, 14B, and the memories 14R, 14G,
14B stores an R image, a 0 image, and an 8 image, respectively. The memory 14R114G, 1
4B is read out simultaneously with the timing of the TV signal,
D/A converters 15, 15.degree. 15 convert the signals into analog signals, respectively. These analog R, G, and B image signals are output from the RGB signal output terminal 17 together with the synchronization signal 5YNC from the synchronization signal generation circuit 16, and are input to the monitor 41, image recording device 5, etc. There is. Said motor 20. △/D converter 12. Changeover switch 13. Memory 14R114G, 14
B. D/A converter 15. The synchronization signal generation circuit 16 is
It is controlled by a control signal generator 23.

Next, the image recording device 5 including the image data compression device will be explained using FIG.

The R, G, and [3 image signals output from the observation device @3 are
The signals are input from the input unit 31, converted into digital signals by A/D converters 32, 32, and 32, respectively, and temporally stored in the R frame memory 33R, the G frame memory 33G, and the B frame memory 338. It looks like this. The R, G, and B image signals read from each frame memory 33R, 33G, and 33B are transmitted to an R compression circuit 34R, a G compression circuit 34G, and a B compression circuit 34, respectively.
After being compressed at different compression rates by B, the data is recorded on a recording system unit 35 such as an optical disk or a magnetic disk.

Furthermore, when reproducing image data, the recording system unit 35
The R, G, and B image signals are read out from
The R decompression circuit 36R, the G decompression circuit 36G, and the B decompression circuit 36B each decompress and restore the data. The restored R, G, and B image data are temporarily stored in the R frame memory 37R, the G frame memory 37G, and the B frame memory 37B. Then, R, G from these frame memories 37R, 37G, and 37B.

Each B image signal is read out in synchronization with the television signal, converted into an analog signal by a D/A converter 38, 38, 38, and then outputted from an output section 39.

Next, using FIGS. 4 to 6, the compression circuit 34R,
The operations of the expansion circuits 34G and 34B and the expansion circuits 36R, 36G, and 36B will be explained.

As shown in FIG. 4, the compression circuit 34 (34R).

Represents 34G and 34B. ) divides the entire input image into one block of a predetermined number of pixels in step S1,
The average value of the density values of pixels in each block is calculated. Next, in step S2, the average value is recorded in the recording system section 35 together with the color identification information. In this embodiment, the number of pixels in one block is 9 pixels for the RM image, 2 pixels for the 0 image, and 4 pixels for the 8 image. Therefore, 8 images are compressed to approximately 179, 0 images are compressed to approximately 1/2, and 8 images are compressed to approximately 174.
This means that the image data was compressed into .

On the other hand, as shown in FIG.
Represents 6G and 36B. ) reproduces the color identification information and the average value of each block from the recording system unit 35 in step S3, and in step s4, based on the color identification information, the density value of each pixel in the block is set as the average value, Restore the pixels that make up the block.

FIG. 6 shows an example of compression and expansion operations using specific density values. The figure (a) relates to 0 images, the figure (b) relates to 8 images, and the figure (C) relates to 8 images. (a>As shown in the figure, in the 0 image, Pl.

Divide the entire input image into one block with two pixels of P2, and calculate the average value (4) of the density values (3, 5) of the pixels in the block.
is calculated, and this average value (4) is recorded in the recording system unit 35. At the time of reproduction, two pixel density values (4, 4) are created from one average value (4) reproduced from the recording system unit 35. Similarly, as shown in figure (b), in 8 images, Pn.

The four pixels P 12 , P 2t , and P 22 constitute one block, and the density values of the pixels in the block (2, 6, 5,
The average value (5) of 7) is recorded in the recording system unit 35, and during playback, the density values of 4 pixels (5°5.
5.5). Also, as shown in figure (C), 8
In the image, P11 to PI3. P21~. P23゜P31
The nine pixels of ~P33 are taken as one block, and the average value (5) of the density values (2, 5, 6, 6, 4, 7, 4° 3.8) of the pixels in the block is recorded in the recording system section 35. , when playing,
Create density values for 9 pixels from the average value (5).

In the case of such compression and expansion, the greater the number of pixels in one block, the higher the compression rate and the worse the resolution during reproduction. R
, G, and B images, the relationship between the number of pixels in one block, the compression ratio, and the M resolution during reproduction is as shown in the table below.

In this way, in this embodiment, R, which constitutes an endoscopic image,
Of the 8 G images, the 8 images containing the component on the longest wavelength side are compressed at a higher compression rate than the other 8 G images. Generally, the 8 images in the endoscopic image have a so-called flat shape with few high frequency components. Therefore, for displaying the color and shape of a square lesion site for diagnostic purposes,
8 images do not contribute much, rather G and 8 images have important information. Therefore, even if the compression rate of the 8 images is increased and the resolution during playback is decreased to some extent, the diagnosis will not be affected.

Further, since the 0 image has important information for diagnosis, in this embodiment, the compression ratio is kept low by emphasizing the resolution at the time of reproduction for the 0 image.

As described above, according to the present embodiment, by utilizing the characteristics of endoscopic images, it is possible to perform endoscopic images with a simple configuration, while ensuring that deterioration in image quality during playback does not affect diagnosis, and with a high compression rate. Compression of endoscopic image data becomes possible.

7 to 10 relate to a second embodiment of the present invention, FIG. 7 is a block diagram showing the configuration of the compression circuit, FIG. 8 is a block diagram showing the configuration of the prediction error calculation circuit, and FIG. 9 is a block diagram showing the configuration of the prediction error calculation circuit. FIG. 10 is an explanatory diagram for explaining a method for determining prediction errors, and FIG. 10 is an explanatory diagram of a smoothing filter.

This embodiment differs from the first embodiment in that a compression circuit 34 and an expansion circuit 36 are set for R, G, and B image signals.
are different.

As shown in FIG. 7, the compression circuit 34 in this embodiment includes a smoothing circuit 41 and a prediction error calculation circuit 42.
Frame memory 33R, 33G.

The image signal from 33B is smoothed by a smoothing circuit 41, predictively encoded by a prediction error calculation circuit 42, and stored in the recording system section 35.

The smoothing circuit 41 has a size of 3×3 (as shown in FIG. 10).
Smoothing is performed using a two-dimensional filter (pixel). This filter calculates the smoothed m degree value of each pixel by multiplying the density value of that pixel by (1-k) and multiplying the density value of each of the 8 pixels near that pixel by (k/8).
The multiplied value is the added value. In addition, k (Q<k<l
) is a smoothing coefficient; when this value is large, the smoothing effect is large, and when the value is small, the smoothing effect is small. The value of this smoothing coefficient is switched by a compression ratio switching circuit. By arbitrarily setting the value of this smoothing coefficient, the spatial frequency band after smoothing can be determined. That is, the larger k and the greater the smoothing effect, the more the high frequency components of the image deteriorate.

Further, the prediction error calculation circuit 42 converts the input data into one pixel delay line 43 as shown in FIG.
By delaying the data by a pixel and subtracting this data from the original input data by a subtractor 44, the difference with the data one pixel before is obtained. As shown in FIG. 9, when the m degree value of pixel (i, j) is x(i, j>), the prediction error signal Δx(1
゜j) is Δx (i, j)=x (i, j)-x (i-1, j
). Since this prediction error signal has a smaller value than the input data, less data D is recorded in the recording system section 35.

On the other hand, the decompression circuit 36 restores the original data by adding the prediction signal, that is, the data of one pixel before, to the prediction error signal reproduced from the recording system section 35. In this embodiment, unlike the first embodiment, the decompression circuit 36 has R
, G, and B have the same circuit configuration and operation.

Here, if the smoothing coefficient k applied to the smoothing circuit 41 is increased, the high frequency components of the image will deteriorate, but since the smoothing effect is large, the prediction error signal will become smaller overall, and therefore it will not be recorded. There will be less data. In other words, the compression ratio is high. On the other hand, when k is small and the smoothing effect is small, the high frequency components of the image are not degraded, but the prediction error signal becomes larger overall, and therefore less data is recorded. That is, the compression ratio is low. in this way.

By arbitrarily setting the smoothing coefficient k in the smoothing circuit 41, the compression ratio can also be arbitrarily set.

In this embodiment, as in the first example, smoothing is performed in the smoothing circuit 41 in the compression circuit 34 corresponding to each image signal in the order of R, B, and G from the one with the highest compression ratio. coefficient k
has been established. The relationship between the smoothing coefficient k, compression rate, and resolution at the time of reproduction of each R, G, and B image is as shown in the following table.

In this way, in this embodiment, as in the first embodiment, the resolution of the 0 image, which is important for diagnosis, is not reduced, and the M resolution is reduced for the 8 images, for which there is no problem even if the resolution is reduced for diagnosis. The compression ratio is high.

The other functions and effects of the configuration 9 are the same as those of the first embodiment.

11 to 14 relate to the third embodiment of the present invention,
FIG. 11 is a block diagram showing the configuration of the image recording device.
Figure 2 is a block diagram showing the configuration of the prediction error calculation circuit.
Figure 3 shows the configuration of the band limit switching circuit.
FIG. 4 is an explanatory diagram showing the passband of each LPF in FIG. 13.

As shown in FIG. 11, in this embodiment, an R band limit switching circuit 51R and a G band limit switching circuit 51G are connected between the input section 31 and the A/D converter 32°32.32 in the first embodiment. , B band limit switching circuit 51B is provided.

Further, as shown in FIG. 12, the compression circuit 34 in this embodiment has a prediction error calculation circuit 42 similar to that in the second embodiment, but unlike the second embodiment,
They have the same circuit configuration and operation. In addition, the expansion circuit 3
6 is for restoring the original data by adding the prediction signal, that is, the data of one pixel before, to the prediction error signal reproduced from the recording system unit 35, as in the second embodiment. , B has the same circuit configuration and was created by vJ.

The band limit switching circuits 51R, 51G, and 51B are constructed as shown in FIG.

The input terminals of each of the band limit switching circuits 51R, 51G, and 51B are connected to a one-horn, two-output switch 53R,
It is connected to the input terminals of 53G and 53B. One output end of each of the changeover switches 53R, 53G, and 53B is provided with an R low-pass filter (hereinafter referred to as LPF).
It is connected to the input terminals of LPF 54G for 54R and G, and LPF 54B for B. The output end of each LPF 54R, 54G, and 54B is a two-man power one-output selector switch 55R.
, 55G, and 55B. Moreover, the said changeover switch 53R, 53G.

53B's other output end and selector switches 55R, 55G,
55B is connected to the other input terminal.

The outputs of the changeover switches 55R, 55G, and 55B are the outputs of the band limit switching circuits 51R, 51G, and 51B. Each of the above LPF54R.

The pass bands of 54G and 54B are as shown in FIG. That is, the R LPF 54R removes high frequency components, the G LPF 54G hardly removes high frequency components, and the B LPF 54B has characteristics in between.

The changeover switches 53R, 53G, and 53B and the changeover switches 55R, 55G, and 55B are configured to be changed over by a signal from the stained image signal generation circuit 52. This stained image signal generation circuit 52 has a switch 57, one end of which is applied a power supply voltage via a resistor 58, and the other end of which is grounded. Then, depending on the voltage at one end of the switch 57, the selector switch 53
R, 53G, 53B and selector switch 55R, 55G, 5
5B is switched.

Next, the operation of this embodiment will be explained.

When recording a normal image, the stained image signal generation circuit 5
Turn off the switch 57 of No.2. Then, receiving that signal, the changeover switches 53R and 53G are activated.

The 53B1 changeover switches 55R, 55G, and 55B select the LPFs 54R, 54G, and 54B, respectively. As a result, each R, G, and B image signal is transmitted to each LPF.
Pass through 54R, 54G, and 54B. Therefore, the high frequency components of the 8 images are removed, and the data base of the prediction error signal produced by the compression circuit 34R is reduced. In the B signal, higher frequency components are removed than in the case of the R signal, and the data base of the prediction error signal becomes slightly smaller. Furthermore, since high frequency components of the G signal are hardly removed, there is a large amount of prediction error signal data, but the resolution is not degraded.

In the second embodiment, the band limitation of the R, G, and B signals is performed digitally by the smoothing circuit 41 in the compression circuits 34R, 34G, and 348, but in this embodiment, the band limitation switching circuits 51R, 51G, and , LPF54R in 51B, 54
G, 54B is used in an analog manner.

Next, when recording a stained image, the switch 57 of the stained image signal generation circuit 52 is turned off. Then, receiving the signal, the changeover switches 53R, 153G, 53B, and the changeover switches 55R, 55G.

55B selects the circuit side that bypasses the LPFs 54R, 54G, and 54B, respectively. As a result, R, G, and B image signals are transmitted to each LPF 54R, 54G, and 54B.
It is output as is without passing through it, and is not band-limited. Therefore, the compression rate in the compression circuit 34 is lower than that for normal images.

The reason why band limitations are not provided during stained images is as follows.

For normal images, R, G, and B images, especially 8 images,
There are few high frequency components, so even if band limitation is applied, the difference from the original image can hardly be discerned.

On the other hand, in a dyed image, detailed shapes are clearly visible, so if band limitation is applied, the deterioration in image quality compared to the original image will be clearly discernible.

In this way, according to this embodiment, depending on the characteristics of the image,
Image resolution and compression rate can be changed.

Other functions and effects of the configuration 1 are the same as those of the first embodiment.

In the first and second embodiments as well, when a dyed image is used, the original image may be recorded as it is without performing block compression or smoothing compression.

15 and 16 relate to a fourth embodiment of the present invention, FIG. 15 is a block diagram showing the configuration of an image recording device, and FIG. 16 is a block diagram showing the configuration of an image recording device.
The figure is an explanatory diagram for explaining thinning.

This embodiment is an example in which compression is performed by thinning out sample points.

As shown in FIG. 15, in this embodiment, the output terminals of the frame memories 33R, 33G, and 33B in the first actual case are respectively connected to the J terminal of each switch 61 for one output for three inputs. ing. The output end of this changeover switch 61 is connected to a thinning circuit 62.The output of this thinning circuit 62 is recorded in the recording system unit 35.

The output end of the recording system section 35 is connected to an expansion circuit 63, and the output end of this expansion circuit 63 is connected to the input end of a changeover switch 64 for one-manpower three outputs. Each output terminal of this changeover switch 64 is connected to the frame memories 37R, 37G, and 37B in the first embodiment, respectively.

The frame memories 33R, 33G, 33B.

37R, 37G, 37B, changeover switches 61, 64, thinning circuit 62. Recording system section 35. The expansion circuit 63 is
It is controlled by a control circuit 66.

In this embodiment, frame memories 33R and 33G.

33B are sequentially read out, and the R, G, and B signals are input to the thinning circuit 62 in time series through a changeover switch 61 that is switched for each R, G, and B signal. This thinning circuit 62 is
By changing the number of pixels to be thinned out according to the input signal, R, G
, 8 Shintan are processed in chronological order. For example, as shown in FIG. 16 (a), the R signal has 4×4 pixels (
One pixel is recorded every 166 pixels, and as shown in FIG. 16(b), 8 signals are recorded one pixel per 2×2 pixels (4 pixels)
All G signals are recorded without being thinned out. In FIG. 16, black circles indicate pixels to be recorded, and white circles indicate pixels to be thinned out.

Further, the recording system unit 35 sequentially reproduces R, G, and 8 Shintan, and the expansion circuit 63 to which this signal is input changes the number of expansion pixels according to the input signal, and reproduces R, G, and B. The signal is processed in chronological order. That is, for the R signal, 166 pixel data is created from one data, for the B signal, 4 pixel data is created from 1 pixel data, and for the G signal, it is output as is without being expanded. R output from this expansion circuit 63 in time series,
The G and B signals are transferred to each frame memory 37R, 37G, 37 via a changeover switch 64 that can be switched for each R, G, and B.
It is stored in B.

As described above, even if the R signal is recorded and reproduced with sample points thinned out, the image quality of the reproduced image hardly deteriorates. Therefore, in this embodiment, the thinning rate of the R signal, that is, the data compression rate, is set higher than that of other signals.

Other functions and effects of the configuration 1 are the same as those of the first embodiment.

Note that the present invention is not limited to a frame-sequential electronic endoscope using RGB signals, but can also be applied to a single-panel electronic endoscope that decodes a composite video signal. Further, the endoscope may be of a type having an image pickup element at the tip thereof, or may be of the type that guides an image to the outside of the object to be observed via an image guide using an optical fiber and then receives the image with an R81 element.

[Effects of the Invention] As explained above, according to the present invention, by utilizing the characteristics of an endoscopic image, one color information containing the component on the longest wavelength side among the plurality of color information forming the endoscopic image is By lowering the resolution of color information compared to the resolution of other color information,
Since one color information is data compressed at a higher compression rate than other color information, the advantage is that endoscopic image data can be highly compressed with a simple configuration.

[Brief explanation of drawings]

Figures 1 to 6 relate to the first embodiment of the present invention.
The figure is a block diagram showing the configuration of the image recording device, FIG. 2 is an explanatory diagram showing the entire endoscopic image filing system, FIG. 3 is a block diagram showing the configuration of the observation device, and FIG. 4 is the image recording device. 5 is a flowchart showing the reproduction operation of the image recording device, FIG. 6 is an explanatory diagram for explaining the compression operation of the compression circuit, and FIGS. 7 to 10 are flowcharts showing the reproduction operation of the image recording device. Regarding the second embodiment, FIG. 7 is a block diagram showing the configuration of the compression circuit, FIG. 8 is a block diagram showing the configuration of the prediction error calculation circuit, and FIG. 9 is an explanation for explaining the method of calculating n of the prediction error. 10 is an explanatory diagram of the smoothing filter, FIGS. 11 to 14 relate to the third embodiment of the present invention, FIG. 11 is a block diagram showing the configuration of the image recording unit 5A, and FIG. FIG. 13 is a block diagram showing the configuration of the prediction error calculation circuit, FIG. 13 is a block diagram showing the configuration of the band IQ limit switching circuit, FIG. 14 is an explanatory diagram showing the passband of each LPF in FIG. FIG. 16 relates to a fourth embodiment of the present invention, FIG. 15 is a block diagram showing the configuration of an image recording device, FIG. 16 is an explanatory diagram for explaining thinning, and FIG. 17 includes an image data compression device. FIG. 1 is a block diagram showing an example of an endoscope system. 1...Electronic endoscope 5...Image recording device 34R
, 34G, 34B... Compression circuit 35... Recording system section 36R1 36G. 36B... Expansion circuit Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 (0) (b) (C) Figure 7 Figure 9 Figure 10 Procedure Nerti original book (self-produced) q″r Director-General of the Office of Permissions 1, Indication of the case 2, Title of the invention 3, Consideration for amendment (Relationship with 1990, 1999 Patent Application No. 258051 Endoscopic image data compression device patent Letter of first appearance 5 JI 1st day Representative Mr. Toshibe Shimoyama Name 5 Date of amendment order 6 Subject of amendment 7 Contents of amendment ” Column As shown in Attachment 1, in box 23, page 23 of the statement, line 15, “...Turn off switch 57.”
Turn on 7. ..." will be corrected.

Claims (1)

[Claims] In an endoscopic image data compression device that compresses image data of an endoscopic image obtained by an endoscope, one piece of color information that includes the component on the longest wavelength side among the plurality of color information that constitutes the endoscopic image is used. An endoscope comprising means for lowering the resolution of the one color information compared to the other color information in order to compress the data at a higher compression rate than other color information. Image data compression device.