JP2710404B2 - Color shift prevention device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color misregistration prevention apparatus provided with a means for re-freezing when a detected color misregistration amount is equal to or more than a set value.

[Prior Art] In recent years, imaging means using a solid-state imaging device has been widely used in television cameras and endoscopes.

The use of the image pickup means makes it easy to record, reproduce, or perform image processing on an image displayed on the monitor screen to make the feature of interest noticeable.

For example, when used for an endoscope or the like, an operation of freezing an image to make a still image may be performed in order to make a detailed diagnosis. In this case, an image having a color shift may freeze.

For this reason, for example, in Japanese Patent Application Laid-Open No. 61-717191, a color shift of a still image is corrected, a color shift of the image is detected based on a difference between images captured at different times, and the correction amount is determined by the photographer. , And a photographer discloses a conventional example in which color shift is corrected based on the warning.

Further, Japanese Patent Application Laid-Open No. 63-167576 discloses an image freeze apparatus which does not freeze when an image is shifted and can freeze only when the image is not shifted.

[Problems to be Solved by the Invention] In the above-mentioned Japanese Patent Application Laid-Open No. 61-717191, the photographer must perform correction every time the color misregistration is excessive, which is inconvenient.

On the other hand, Japanese Patent Application Laid-Open No. 60-26986 discloses a freeze system having a frame memory for storing a freeze image signal, a control circuit for controlling the frame memory, and an operation panel provided with a switch for operating the control circuit. The circuit was proposed.

Therefore, when the observer who observes the monitor wants to freeze, when the freeze switch on the operation panel is turned on,
Even if there is much shift in the image on the monitor, the image is frozen, and the observer must restart the freeze, which is troublesome.

On the other hand, in Japanese Patent Application Laid-Open No. 63-167576, a freeze is applied after an image shift is detected, so that a still image actually frozen and an image determined to have no image shift are different from each other. A still image without image shift cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a color misregistration preventing apparatus capable of reliably obtaining a still image with a small image misregistration with a simple configuration.

[Means for Solving the Problems and Action] In the present invention, the image signal is temporarily frozen in the image storage means based on the freeze instruction signal, and when the color shift amount of the frozen image signal is within a set value, the freeze is performed. Is held, and if it is more than the set value, the freeze is released,
Next, by providing a re-freezing means for performing the same operation on the frozen image signal, it is possible to reliably display the color-shifted image signal as a still image.

EXAMPLES Hereinafter, the present invention will be described specifically with reference to the drawings.

1 to 3 relate to a first embodiment of the present invention, FIG. 1 is a block diagram showing a configuration of an endoscope apparatus provided with the first embodiment, and FIG. 2 is a configuration of the first embodiment. A block diagram showing the
FIG. 3 is an overall view of the endoscope apparatus.

Endoscope apparatus 1 having a first embodiment as shown in FIG.
Is a video processor 5 including an electronic endoscope 2 provided in an imaging means, a light source device 3 for supplying illumination light to the electronic endoscope 2 and a signal processing circuit 4, and a connection to the video processor 5. The video processor 5 comprises a color monitor 6 as a display means and a color misalignment prevention unit 7 of the first embodiment connected to the video processor 5.

The electronic endoscope 2 has an elongated, for example, flexible insertion portion 8.
A large-diameter operation section 9 is connected to the rear end of the insertion section 8. A flexible cable 11 extends laterally from the operation unit 9.
Is extended, and a connector 12 is provided at a distal end portion of the cable 11. The electronic endoscope 2 can be connected to the video processor 5 via the connector 12.

On the distal end side of the insertion portion 8, a rigid distal end portion 13 and a bending portion 14 that can bend rearward and adjacent to the distal end portion 13 are sequentially provided. By rotating a bending operation knob 15 provided on the operation section 9, the bending section 14 is rotated.
Can be bent in the horizontal direction or the vertical direction. The operation section 9 is provided with an insertion port 16 communicating with a treatment instrument channel provided in the insertion section 8.

As shown in FIG. 1, a light guide 17 for transmitting illumination light is inserted into the insertion section 8 of the electronic endoscope 2. The light guide 17 is inserted through the cable 11 shown in FIG. 3 and is connected to the video processor 5 so that color-sequential illumination light is supplied from the light source device 3 to the end face of the light guide 71 on the incident side. Is done.

Illumination light of the lamp 10 which emits light by power supplied from the power supply 18 passes through a rotary filter 22 which is driven to rotate by a motor 21, so that each color of red, green and blue attached in the circumferential direction of the rotary filter 22. Transmission filters 23R, 23G, 23
Light of each wavelength of red, green, and blue sequentially passing through B, that is, light of color sequence, is passed through a condenser lens 24 to a light guide.
Irradiated on the 17 end faces.

The lamp 19 emits light in a wide band from ultraviolet rays to infrared rays, and a xenon lamp, a strobe lamp, or the like can be used.

The driving of the motor 21 is controlled by the motor driver 25 so that the rotation speed thereof is constant.

The illumination light transmitted by the light guide 17 is emitted forward from the end face on the distal end side of the insertion section 8. The object illuminated with the illumination light is imaged by a CCD 28 as a solid-state imaging device disposed on a focal plane of the object by an objective lens 27 attached to the distal end side of the insertion section 8.

The CCD 28 has sensitivity in a wide wavelength range from the ultraviolet region to the infrared region including the visible region, and photoelectrically converts an optical image formed on the CCD 28 to accumulate it as signal charges.

Thus, the signal charge of the CCD 28 is read out from the driver 29 in the signal processing circuit 4 by the drive pulse transmitted via the signal line 30b, and the signal charge of the CCD 28 is read out via the signal line 30a.
Is input to the preamplifier 31 in the inside. The operation unit 9 of the electronic scope 2 is provided with a freeze / freeze release button 32 for giving a freeze instruction / freeze release instruction.

The video signal amplified by the preamplifier 31 is input to a process circuit 33, subjected to signal processing such as γ correction and white balance, and converted into a digital signal by an A / D converter. The digital video signal is converted into three R signals corresponding to, for example, red (R), green (G), and blue (B) by the selection circuit 35.
The memory 36R, the memory 36G for G, and the memory 36B for B are selectively stored. The signal data stored in the memories 36R, 36G, and 36B are simultaneously read, converted into analog signals by a D / A converter 37, output as R, G, and B color signals, and input to an encoder 38. The signal is output from the encoder 38 as an NTSC composite signal.

The composite video signal or RGB signal output from the encoder 38 is input to the color monitor 6 and displays the subject image in color. For example, before or after the D / A converter 37, a superimpose circuit (not shown) for superimposing data such as patient data and date on the video signal is provided.

In the signal processing circuit 4, a timing generator 39 for generating the timing of the entire system is provided, and the output signals of the timing generator 39 synchronize the circuits of the motor driver 23, the driver 29, and the memory controller 40. In addition, a synchronization signal SYNC of the RGB signal can be output to the outside.

The memory controller 40 includes R, G, B memories 36R, 36R.
G / 36B is controlled to read / write color signal data.

The memory controller 40 is provided with a freeze command signal / freeze release command signal FC / FCC input through a terminal 41.
Thus, the freeze / freeze control of the memories 36R, 36G, 36B is performed.

The freeze / freeze release button 32 is connected to the signal line 30c.
Is connected to the terminal 42 via the.

Thus, by connecting the connector 43 of the color shift prevention unit 7 to the video processor 5, the color shift prevention unit 7 has, for example, two color signals G and B and a synchronization signal SYNC,
Button 32 freeze / freeze release signal FD / FCD
Is input, and a freeze command / freeze release command signal FC / FCC can be output to the memory controller 40.

When a freeze instruction is given by the freeze / freeze release button 32, the color misregistration prevention unit 7 outputs a freeze command signal FC to the temporary memory controller 40 and obtains a correlation amount between the two color signals G and B to obtain a color. The shift amount is detected, and when the color shift amount is equal to or smaller than the set value, the memory controller 40 causes the freeze command signal FC to be held. If the detected color misregistration amount is equal to or greater than the set value, a freeze release command signal FCC is output, and then the freeze command signal FC is temporarily output again to perform the same operation.
(Unless the freeze release instruction signal FCD is input), the image processing apparatus has a function of finally freezing an image in which the detected color shift amount is equal to or less than the set value.

Next, the color misregistration prevention unit 7 will be described with reference to FIG.

The synchronization signal SYNC is input to the timing generation circuit 51,
A mask pulse MP, a clamp pulse CP, and a reset pulse RP are generated as timing signals required in each circuit.

In addition, the color signals R, G, and B have a high correlation as an endoscope image.
The two color signals G and B are input to buffer circuits 52a and 52b, respectively.

The respective color signals output from the buffer circuits 52a and 52b are input to inverse γ correction circuits 53a and 53b which perform inverse γ correction, and after the inverse γ correction is performed, the mask circuits 54a and 54, respectively.
Entered in b. As shown in FIG. 3, each mask circuit 54a, 54b has a data area such as a patient name and other data and a date.
A mask pulse MP for masking 6A and passing the video signal portion of the endoscope image 6B is applied, and the video signal portion of the endoscope image 6B is cut out in synchronization with the mask pulse MP. Are input to the next-stage AGC circuits 55a and 55b.

The AGC circuits 55a and 55b perform a function of matching the video levels of the two color signals G and B, and the signals whose levels are matched are input to the clamp circuits 56a and 56b, respectively. Each clamp circuit 56a, 56b includes a timing pulse generation circuit 51.
The pedestal level of each signal is clamped by the clamp pulse CP generated in step (1), and the pedestal levels are aligned.

The output signals of the clamp circuits 56a and 56b are
, The difference between the two signals is detected, and the absolute value circuit 58 at the next stage calculates the absolute value of the difference.

In a normal endoscope image, the correlation between the G and B image components is high, so the output value of the absolute value circuit 58 is small when the amount of color shift is small, while the absolute value is large when the amount of color shift is large. circuit
The output value of 58 becomes smaller.

That is, the output value of the absolute value circuit 58 becomes a color shift amount detection signal indicating the color shift amount of the corresponding two pixels.

The output signal of the absolute value circuit 58 is input to a mask circuit 59, cut by a mask pulse MP for removing a noise component other than a required video signal, and input to an integration circuit 60.

This integration circuit 60 is controlled by the detection control circuit 61.
An operation is performed in which the color shift amount for one screen is integrated to obtain the color shift amount for one screen and output to the comparison circuit 62 in the next stage.

The reset pulse RP from the timing generation circuit 51 is input to the detection control circuit 61, and the reset pulse RP
Is output to the integration circuit 60 to reset the color misregistration amount previously integrated by the integration circuit 60, and perform an operation of integrating the color misregistration signal for the next one screen.

The comparison circuit 62 to which the output signal of the integration circuit 60 is input further receives a reference value voltage corresponding to the upper limit of the color shift amount permitting the freeze from the reference value setting circuit 64, and the color shift from the integration circuit 60. Compare with quantity. Thus, the integration circuit 60
Is compared with the amount of color misregistration. When the color shift amount from the integrating circuit 60 is within the reference value, that is, within the allowable color shift amount, the comparison circuit 62 outputs an "H" level freeze permission signal. Outputs an "L" level signal and a signal for releasing the freeze.

The output of the comparison circuit 62 is input to a freeze & freeze release circuit 63.

The freeze / freeze release circuit 63 is further provided with a freeze / freeze release button 32 via the signal processing circuit 4.
Instruction / freeze instruction signal FD / FCD is input. The freeze & freeze release circuit 63 is provided with a freeze instruction signal FD by the freeze / freeze release button 32.
Is input, the freeze command signal FC is output once to the memory controller 40, and the R, G, and B memories 36R, 36G, 36B
Is temporarily set to the frozen state. That is, writing is prohibited, and updating to new image data is prohibited (stopped). Next, a signal is sent to the detection control circuit 61, the integration circuit 60 is reset, and the color shift amount with respect to the temporarily frozen image signal is integrated for one screen. Then
The integration signal of the integration circuit 60 with respect to the frozen image signal is compared with a reference value by a comparison circuit 62.
Is at the "H" level, the freeze permission signal or the freeze command signal FC is continuously output from the freeze & freeze release circuit 63, and the temporary freeze image is held in the freeze state. On the other hand, when the output of the comparison circuit 62 is at "L" level, the freeze & freeze release circuit 63 outputs the freeze release command signal FCC, and the memories 36R, 36G, 36B are in the freeze release state via the memory controller 40. And outputs the freeze command signal FC again. That is, writing of new image data is performed. When the freeze is released, the detection control circuit 61 outputs a reset pulse RP to the integration circuit 60, and stops the color shift detection operation until the color shift detection operation for the next frozen image is performed. When one frame of new image data is stored in the R, G, and B memories 36R, 36G, and 36B by the freeze command signal FC, the amount of color misregistration for the frozen image and the result of the freeze are determined. The state is temporarily set to the freeze state until the determination as to whether or not it is present is completed.

Then, as described above, the color misregistration amount of the frozen image is detected, and the frozen image is kept frozen if the value is equal to or less than the reference value, and the frozen image is released and released if the value is equal to or more than the reference value. An image is captured and the same operation is repeated.

Therefore, some time after giving the freeze instruction,
A frozen image with a small amount of color shift can be obtained.

To return the frozen image to a moving image, press the freeze / freeze release button 32 to output the freeze release instruction signal FCD, and the freeze & freeze release circuit circuit 63 will use the memory controller 40 for R, G, B Memory 36R, 36G, 36
Release the freeze state of B and switch to movie mode.

According to the first embodiment, after the physician as the user determines the framing of the portion where the frozen image is considered to be obtained, and presses the freeze / freeze release button 32 to output the freeze instruction signal FD, Is temporarily frozen, the amount of color misregistration of the image is detected, and if the amount of color misregistration is determined to be small, the freeze is held. If the amount of color misregistration is large, the freeze release output is not output. As long as the freeze is canceled (unless a freeze stop instruction is given), the operation of detecting an image with a color shift amount equal to or smaller than the reference value for a new image is repeated, and a frozen image with a small color shift amount is held. Will be.

Therefore, according to the first embodiment, the image whose color shift amount is determined to be small by the color shift amount determining means can be reliably held as a frozen image.

Further, according to the first embodiment, a still image (freeze image) with a small amount of color shift can be obtained with a simple circuit configuration without newly providing a memory unit. A freeze image with a small amount of color shift can be obtained by one freeze instruction operation.

Therefore, it is possible to improve the operability of the frame sequential endoscope, and to contribute to the improvement of the diagnostic performance with a still image having a small color shift amount.

FIG. 4 shows a color misalignment prevention unit 71 according to a second embodiment of the present invention.
Is shown.

This second embodiment differs from the first embodiment shown in FIG.
The output signals of the clamp circuits 56a and 56b are input to the division circuit 72, and the ratio between the two color signals G and B is calculated. Of the calculated ratios, the denominator is a noise level, that is, a black level in the original image or a level close to the black level causes an error in the calculation result. The level of the video signal ratio is controlled and sent to the mask circuit 59.

The output of the mask circuit 59 is input to the integration circuit 60,
The output of the integration circuit 60 is input to the comparison circuit 62. The output of the comparison circuit 62 is a freeze & freeze release circuit 63
And input to the timer circuit 74. When the output of the comparison circuit 62 is at the “L” level, the timer circuit 74 delays the signal output from the freeze and freeze release circuit 63 and outputs the delayed signal to the freeze and freeze release circuit 63. When the output signal is at "H" level, the delay operation is stopped.

That is, when the amount of color misregistration is large, the timer circuit 74 causes the moving image and the still image to be displayed temporarily at regular intervals. Then, in the case of this still image, it is determined whether or not the color misregistration amount is equal to or less than the reference value. If the color misregistration amount is equal to or greater than the reference value, the moving image and the still image are continuously displayed. In this case, the delay operation of the timer circuit 74 is stopped, and the freeze command signal FCC is output from the freeze & freeze release circuit 63 to hold the freeze state.

 The schematic operation of the second embodiment is as shown in FIG.

When the freeze instruction signal FD is output by operating the freeze / freeze release button 32 as shown in FIG. 5 (a), the freeze & freeze release circuit 63 synchronizes with the reset pulse RP and returns to FIG. The freeze command signal FC of "H" shown is output. By this signal FC, the memories 36R, 36G, 36B enter the still image mode as shown in FIG. The period of the still image mode lasts at least when a color misregistration is detected for the still image and the result of the determination is performed.

The freeze command signal FC is input to the timer circuit 74, and when the judgment by the comparison circuit 62 judges that the amount of color misregistration is large ("L" level in FIG. 5E), the timer circuit 74 turns on the circuit shown in FIG. As shown in (c), the freeze command signal FC is delayed by a predetermined time T and output to the freeze & freeze cancel circuit 63. For this reason, the freeze & freeze release circuit 63 outputs the freeze command signal FC at regular time intervals T.

The period during which the freeze command signal FC is not output is a freeze release period, and the memories 36R, 36G, and 36B are in the moving image mode.

In this manner, the still image mode and the moving image mode are repeated at regular time intervals T.

Thus, in each still image mode, the amount of color misregistration with respect to the still image is detected. For example, when the comparison circuit 62 determines that the amount of color misregistration is equal to or less than the reference value, the output becomes “H” level, The delay operation of the timer circuit 74 is stopped by the “H” level, and the freeze command signal FC is continuously output from the freeze & freeze release circuit 63 as shown in FIG. 5 (b), and the memories 36R, 36G, 36B The freeze mode is maintained.

When a freeze release instruction is given, the freeze mode is released and the mode returns to the normal moving image mode.

The second embodiment has the same effect as the first embodiment, and also calculates the ratio of the G and B image signals to detect the amount of color misregistration. Variation of the shift amount detection level can be prevented, and the color shift detection capability is improved.

In each of the above embodiments, the amount of color misregistration is detected for signals read from the memories 36R, 36G, and 36B. However, the present invention is not limited to this, and the memories 36R, 36G, 36
A signal written to B may be fetched to directly detect the amount of color misregistration.

Further, a memory means may be provided to detect a color shift, and a color shift amount may be detected by detecting a level difference between the same colors one field or one frame before. Further, a memory means may be provided to detect the amount of color misregistration by detecting the level difference between different colors.

When the color shift amount is detected, a portion where the image signal is saturated may not be used for color shift detection. Further, the color shift amount detection may be standardized using an image signal portion (period) in which the color shift amount is not detected or an image signal portion in which the color shift amount is detected.

When a memory unit is provided for detecting a color shift amount, the color shift amount may be detected within one field / frame period. In this case, when a freeze instruction is given, the color shift amount is detected. If is greater than or equal to the reference value, it can be made almost the same as a moving image.

The present invention can also be applied to a television camera external type device in which a television camera having a built-in CCD or the like is mounted on the eyepiece of the fiberscope.

Effect of the Invention] As described above, according to the present invention, the freeze instructing unit determines whether the image signal stored in the image storing unit determines whether the color shift amount of the image signal is within the set value or not. If the image signal has a color shift within the set value, it is stored as a still image. Since the image signal is stored in the storage unit, an image signal with a small color shift amount can be reliably stored as a still image.

[Brief description of the drawings]

1 to 3 relate to a first embodiment of the present invention.
FIG. 1 is a block diagram showing the configuration of an endoscope apparatus having the first embodiment, FIG. 2 is a block diagram showing the configuration of the first embodiment, FIG. 3 is an overall view of the endoscope apparatus, and FIG. FIG. 5 is a block diagram showing the configuration of a second embodiment of the present invention, and FIG. 5 is an operation explanatory diagram of the second embodiment. DESCRIPTION OF SYMBOLS 1 ... Endoscope apparatus, 2 ... Electronic endoscope 3 ... Light source device, 4 ... Signal processing circuit 5 ... Video processor, 6 ... Color monitor 7 ... Color shift prevention unit 32 ... Freeze / Freeze release button 36R, 36G, 36B… Memory 40… Memory controller 60… Integration circuit 61… Detection control circuit 62… Comparison circuit 64… Reference value setting circuit 63… Freeze & freeze release circuit

Claims (1)

(57) [Claims] 1. An endoscope imaging apparatus comprising: imaging means for imaging a subject sequentially illuminated with illumination light of different wavelength ranges; and image storage means for temporarily storing a captured image signal. A freeze command means for outputting a freeze command signal for temporarily freezing the image to the image storage means, a color shift detecting means for detecting a color shift amount with respect to the frozen still image, and the color shift detection Means for judging whether the amount of color misregistration detected by the means is within a set value, and holding the freeze command signal when the judgment means judges that the amount is within the set value, and judges that the value is equal to or more than the set value. In this case, a re-freezing control unit for releasing the freeze command signal once and freezing a new image in the image storage unit is provided.