JPH0834577B2 - Image freeze signal processor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a signal processing device for storing or recording an image signal in order to obtain a still image.

[Problems to be Solved by Conventional Techniques and Inventions] Conventionally, image signals are recorded on a magnetic tape or a magnetic disk, or are stored in a storage element such as a CCD memory, a MOS memory, a magnetic valve memory, or an IC memory. , A device for displaying the image is known. In particular, as a device for recording a still image, a device provided with a magnetic disk device as a recording / reproducing device inside a camera is disclosed in JP-A-49-52912 and JP-A-54-140510. Further, Japanese Patent Application Laid-Open No. 57-44374 proposes an electrophotographic camera which can be reproduced immediately after shooting with the same type of device.

However, these devices are recorded or temporarily stored in association with the pressing operation of the release button. Therefore, when the movement of the subject is faster than the shutter speed, or when the image pickup device moves during shutter operation, so-called camera shake occurs. As a result, there are many cases in which the imaged image is blurred and the image is taken again. Further, for example, when a fast-moving subject is photographed using an interlaced scanning type element as an image pickup element, different images are stored between fields,
It has a drawback that it causes flicker and makes the image very difficult to see.

In relation to this drawback, in order to prevent flicker between fields when storing still images, it is configured to detect the movement of the subject and perform frame freeze when there is no movement and field freeze when there is movement. Such a device is proposed by US Pat. No. 4,272,787. But,
This device has a drawback in that the vertical resolution of a moving subject is degraded because the device automatically freezes the field when the subject is moving.

In addition, due to the recent progress in the manufacturing technology of solid-state imaging devices,
With the progress of higher density of pixels and ultra-miniaturization of chips, an endoscope in which a solid-state image sensor is mounted on a tip portion, that is, an electronic endoscope apparatus has been developed. These devices have a function of inserting the device into a body cavity and observing a region to be inspected, and recording an observation image of the region. The quality of the recorded image is very high in addition to its observation ability. It is important and greatly affects the diagnosis of the inspected part. Therefore, at the time of recording, the operator of the endoscope makes the patient stand still, freeze-displays the image of the site to be inspected several times, selects the most desirable image as the recorded image, and selects, for example, a monitor image photographing device. Still images were recorded on a video printer, a still video floppy device, or the like. However, even if the patient is stationary, as long as they are observing the inside of the living body, there are many movements of the inspected part, and it may be necessary to freeze again and again to eliminate the blurring of the image due to this movement. Have a defect.

The deterioration of the recorded image due to the movement of the subject is
The mode of occurrence differs depending on the type of imaging device and the imaging method. For example, when a frame transfer type CCD is used as an image sensor, the movement of the subject during the exposure period causes image blurring, and when interline type CCD is used for interlaced scanning. In addition to the blurring of the image due to the movement of the subject during the exposure time, flicker due to the difference in the image between the fields occurs. In addition, in order to reduce the diameter of the endoscope, a monochrome CCD is mounted on the tip of the endoscope, and the illumination light is, for example, RGB sequential light. Since G, B, and B primary color images are displayed simultaneously, there is a problem of so-called color misregistration, in which the movement of the subject is displayed as a color misregistration.

In order to deal with such a problem, the present applicant detects a shift between primary color signals sent in time series of a color plane sequential system and a shift between fields by a simultaneous system, and moves the shift. An image freeze device has been proposed in which the amount of movement is determined to be small when the amount of movement is below a certain value and the image signal is frozen. According to this device, it is possible to store or record a still image with little deterioration of the image due to the movement of the subject.

An example of the operation of the image freeze device will be described with reference to FIG. FIG. 13 shows the relationship between the time and the motion detection amount. In the figure, a, b, and c indicate the motion amounts at the times ta, tb, and tc, respectively. Here, consider a case where the set value of the threshold value for whether or not to freeze the image is Mth. in this case,
The motion amount of the subject is detected from the sequentially input image signals, this motion detection amount is compared with the set value Mth, and when the motion detection amount is below the set value Mth, the image is frozen. In the example of FIG. 13, the motion detection amount b at time t _b
However, it falls below the set value Mth, and the image at this time is frozen. However, in this device, when an image signal with less deviation is input as at time t _c in FIG. 13 after it is determined that the deviation is small, that is, the amount of movement is small, Since the freeze is completed at time t _b , the image with the smallest amount of motion cannot always be frozen.

[Object of the Invention] The present invention has been made in view of the above circumstances, and it is possible to freeze an image in the vicinity of a time point when the movement of a subject is the smallest and to store a still image in which the image is less deteriorated due to the movement of the subject. It is an object of the present invention to provide an image freeze signal processing device capable of recording.

[Means for Solving the Problem] As shown in the conceptual diagram of FIG. 1, a signal processing device for image freeze of the present invention includes a motion detection means 1 for detecting a motion of an object from an input image signal, and an image freeze instruction. Minimum value detecting means 4 which is activated by means 2 and detects the minimum value of the amount of movement of the subject within at least the predetermined time set by the set time detecting means 3 from the output of the motion detecting means 1, and the minimum value. The control means 6 controls the writing operation or the recording operation of the input image signal to the means 5 for storing or recording the image signal according to the output of the detecting means 4.

[Operation] In the present invention, the motion detecting means 1 detects the motion of the subject as the amount of motion from the sequentially input image signals,
Each motion amount is input to the minimum value detecting means 4 activated by the image freeze instructing means 2. As shown in FIG. 2, the activated minimum value detecting means 4 compares the motion amounts sequentially input within the time (t ₂ −t ₁ ) set by the set time detecting means 3, and, for example, When the value with the smallest amount of motion is detected, the detection signal is sent to the control means 6 for controlling the writing operation or the recording operation of the image signal.
When the control means 6 receives the detection signal from the minimum value detection means 4, the control means 6 controls the writing operation or recording operation of the input image signal to the means 5 for storing or recording the image signal to perform the freeze operation. With the above operation, as shown in FIG. 2, the freeze operation is performed on the image signal having the smallest movement among the image signals input within the set time.

In FIG. 2, the black circles indicate the frozen image, the white circles indicate the unfrozen image, and the double circle with the inner black circle is judged to have the least movement within the period (t ₂ −t ₁ ). And shows a frozen image. In the example of this figure, the image of the motion amount a at time t ₁ is frozen, and thereafter, the motion amount is gradually reduced, so that the image having the minimum motion amount b is also frozen. After that, between the images before the image having the motion amount c, the motion amount exceeds b, so that the image is not frozen. The image with the motion amount c again freezes because the motion amount falls below b, and finally the image with the smallest motion amount d within the (t ₂ −t ₁ ) period becomes the frozen image.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

3 to 6 relate to the first embodiment of the present invention, FIG. 3 is a block diagram showing the configuration of an image freeze signal processing apparatus, and FIG. 4 is a graph for explaining the operation of this embodiment. 5 is a block diagram showing an example of a digital minimum value detection circuit, and FIG. 6 is a circuit diagram showing an example of an analog minimum value detection circuit.

 The present embodiment is an example in the case of the color plane sequential method.

As shown in FIG. 3, the signal processing apparatus of the present embodiment includes a digital color plane sequential signal, that is, a synchronization memory 21 for synchronizing primary color signals of images input in time series, and a synchronization memory 21. The output image signal of the memory 21 is provided with a signal processing circuit 22 for enlarging or interpolating an image, a freeze memory 23 capable of freezing the output image signal of the signal processing circuit 22, and the output of the freeze memory 23. The image signal is output to a display device, a processing device or the like in the subsequent stage.

The synchronization memory 21 is configured as follows.
That is, the color plane sequential signal is applied to the input end of the 1-input / 3-output changeover switch 31. Of the three output terminals a, b, c of the changeover switch 31, the first frame memory 32 is connected to the output terminal a and the second frame memory 32 is connected to the output terminal c.
The frame memory 33 of is connected. The output of the first frame memory 32 is a three-input one-output selector switch 34.
Applied to the input end a of the three input ends a, b, and c of the output of the second frame memory 33.
It is adapted to be applied to the input terminal c of 34. The output terminal of the changeover switch 34 is connected to the signal processing circuit 22.

The freeze memory 23 is configured as follows. That is, the output image signal of the signal processing circuit 22 is applied to the input end of the 1-input / 3-output changeover switch 35. Of the three output ends a, b, c of the changeover switch 35, the output end a has a first field memory 3
6 is connected to the second field memory 37 at the output terminal c.
Is connected. The output of the first field memory 36 is the three input terminals a of the three-input one-output changeover switch 38,
It is applied to the input end a of b and c, and the output of the second field memory 37 is applied to the input end c of the changeover switch 38. A digital image signal is output from the output end of the changeover switch 38.

The synchronization memory 21 and the freeze memory 23 are the memory R /
W controller (hereinafter referred to as memory controller) 2
Writing and reading are controlled by 7. A write control signal from the memory controller 27 to the freeze memory 23 is sent to the freeze memory 23 via the write inhibit gate circuit 26.

Further, the signal processing apparatus of the present embodiment further includes a motion detection circuit 24 that detects the motion of the subject from the output signal of the signal processing circuit 22, and the amount of motion within a predetermined time from the output of this motion detection circuit 24. Value detection circuit to detect the minimum value of
25, a freeze instruction circuit 28 for activating the minimum value detection circuit 25, and a set time detection circuit 29 for setting a time for the minimum value detection circuit 25 to detect the minimum value. The write inhibit gate circuit 26 is controlled by the minimum value detection circuit 25.

The synchronized primary color signals from the signal processing circuit 22 are
It is also sent to the motion detection circuit 24, and in this motion detection circuit 24,
The amount of movement of the subject is detected from the cross-correlation of the primary color signals. The amount of motion is detected, for example, by calculating the difference between corresponding pixels of arbitrary two primary color signals in one frame, or multiplying each primary color signal by a coefficient, calculating the difference between the corresponding pixels, and calculating the absolute value of each difference. The cumulative value of is detected as the amount of movement.

Further, when the freeze instruction circuit 28 inputs the image freeze instruction signal to the minimum value detection circuit 25, the minimum value detection circuit 25 sequentially receives the motion amount for each one frame from the motion detection circuit 24, Within the time set by the set time detection circuit 29, the movement amounts sequentially input are compared, and according to the result, a control signal is sent to the memory controller 27 through the write inhibit gate circuit 26. .

Next, the operation of this embodiment will be described with reference to FIG.

First, in the normal time when the image freeze is not performed, the primary color signals of the image input in time series are alternately alternated for each frame in the first frame memory 32 and the second frame memory 33.
Are sequentially written to one of the two. For example, in a certain state, as shown in FIG. 3, the output terminal a of the switch 31 is made conductive by the control signal from the memory controller 27, the input terminal c of the switch 34 is made conductive, and the switches 34 are chronologically arranged. The input primary color signals of the image are sequentially written in the first frame memory 32. At this time, the already written primary color signals are simultaneously read out from the second frame memory 33. This image signal is sent to the freeze memory 23 after being subjected to processing such as image enlargement and interpolation in the signal processing circuit 22.

In the freeze memory 23, the output signal a of the switch 35 is rendered conductive by the control signal from the memory controller 27, and the input terminal c of the switch 38 is rendered conductive by the control signal from the signal processing circuit 22. The image signal of one field is written in the first field momeri 36. At this time, the second field memory 37 reads the already written image signal of the second field of the previous frame.

Next, in the freeze memory 23, the switch 35 switches the output terminal c to the conductive state and the switch 38 switches the input terminal a to the conductive state by the control signal from the memory controller 27. The second field image signal sent from the second field image signal 37
Write to At this time, in the first field memory 36, the image signal of the first field written by the above operation is read.

As described above, in the color plane sequential method, the primary color signals of the images that are sequentially transmitted are synchronized in the synchronization memory 21 and output as an output image signal through the freeze memory 23.

 Next, a case where the image is frozen will be described.

The synchronized primary color signals sent to the freeze memory 23 are
It is also sent to the motion detection circuit 24, and the motion detection circuit 24 detects the amount of motion of the subject from the cross-correlation of the primary color signals.

When the image freeze instruction signal is input to the minimum value detection circuit 25 by the freeze instruction circuit 28, the minimum value detection circuit 25 sequentially receives the motion amount for each one frame from the motion detection circuit 24.

The amount of motion sent to the minimum value detection circuit 25 and the image signal written in the freeze memory 23 will be described below.

As shown in FIG. 4, the time when the minimum value detection circuit 25 is activated by the image freeze instruction signal is t _1, and the end time of the set time set by the set time detection circuit 29 is t n (t ₁ <
tn). Further, the image signals for each frame read from the synchronization memory 21 after the image freeze instruction signal is output are F ₁ , F ₂ , ..., Fn, and the corresponding motion amounts are M ₁ , M ₂ ,. , Mn.

Now, at time t ₁ , the image signal written to the first frame memory 32 of the synchronization memory 21 is F ₂ , and the image signal read from the second frame memory 33 is F ₁ . When the image freeze instruction signal is output at this time t ₁ , the output terminal b of the switch 35 is rendered conductive by the write inhibit gate circuit 26, and writing to the freeze memory 23 is inhibited. Further, the motion detection circuit 24 detects the motion amount M ₁ of the image signal F ₁ read from the synchronization memory 21.

Further, the minimum value detection circuit 25 sets the motion amount M ₁ sent from the motion detection circuit 24 as an initial value of the minimum value, and the image signal written in the second frame memory 33 of the synchronization memory 21. F ₁ is read again, freeze memory
A control signal is sent to the memory controller 27 through the write inhibit gate 26 so as to write into the respective field memories 36 and 37 of 23. At this time, since the first frame memory 32 of the synchronization memory 21 is in the writing state, the image signal F ₃ that follows the image signal F ₂ is written.

Next, the memory controller 27 switches the switches 31 and 34 of the synchronization memory 21 to put the first frame memory 32 into the read state, and sets the second frame memory 33 to the image signal F ₄
Write state. Also, the switch 35 of the freeze memory 23 sets the output end b to the conductive state to prohibit writing to the field memories 36 and 37 of the freeze memory 23.

Further, based on the image signal F ₃ read from the synchronization memory 21, the motion amount M ₃ is obtained by the motion detection circuit 24,
In the minimum value detection circuit 25, it is compared with the set value M ₁ . Here, as shown in FIG. 4, if M ₃ <M ₁ , the image signal F ₃
The memory controller 27 is controlled so as to write in the freeze memory 23. Further, in the minimum value detection circuit 25,
Instead of M ₁ , the motion amount M ₃ is set as the minimum value.

In this way, when the motion amount is updated to the minimum value, the above operation is repeated.

Next, the case where the amount of movement is larger than the minimum value will be described by taking the case of the image signal F ₉ as an example. The image signal F ₇ is written to the freeze memory 23, the image signal F ₈ is written to the frame memory of the synchronization memory 21, the image signal F ₉ is written to the synchronization memory 21 by the memory controller 27.
When the image signal F ₉ written in is read out, the motion amount M ₉ is obtained by the motion detecting circuit 24, and is compared with the set value M ₇ by the minimum value detecting circuit 25. In this case, as shown in FIG. 4, since M ₇ <M ₉ , the minimum value detection circuit 25 prohibits writing to the freeze memory 23, and the image signal F already written to the synchronization memory 21. _A control signal is sent to the memory controller 27 through the write inhibit gate circuit 26 so that the movement amount of ₁₀ can be obtained.

To summarize the operation when performing image freeze as described above, the motion amount Ml detected by the motion detection circuit 24 is
When the value falls below the set value of the minimum value detection circuit 25, the image signal Fl corresponding to the detected motion amount is read again from the synchronization memory 21 and written into the field memories 36 and 37 of the freeze memory 23. Further, in this case, the next image signal Fl ₊₁ is canceled, and the motion amount is obtained for the next image signal. On the other hand, if the motion amount Ml detected by the motion detection circuit 24 exceeds the set value of the minimum value detection circuit 25, writing to the freeze memory 23 is prohibited, and unlike the previous case, the next image signal Fl _{+ The} amount of movement is required for 1.

By such an operation, the image signal Fm corresponding to the smallest value Mm of the motion amount detected within the set time tn−t ₁ ) is written in the freeze memory 23.

In FIG. 4, black circles represent frozen images and white circles represent unfrozen images.

As described above, according to the present embodiment, it is possible to freeze the image at the time when the movement of the subject is the smallest, and it is possible to store the still image in which the image deterioration such as the color shift or the image blur caused by the movement of the subject is small. .

By the way, the minimum value detection circuit 25 is configured, for example, as shown in FIG. 5 or FIG.

FIG. 5 shows a digital minimum value detection circuit. This minimum value detection circuit is preset by a preset signal, and an up counter 113 and a down counter 115 that count a counter clock by a motion amount, a latch 114 that holds the output of the up counter 113, and the latch 114.
Write inhibit gate circuit while sending update clock to
26, and a gate circuit 111 that outputs a control signal for freezing an image. The gate circuit 111
Is generated from the down counter 115 (borro
When w) is input, the update clock is not output.

When the image freeze instruction signal is output from the freeze instruction circuit 28, the counters 113 and 115 of the minimum value detection circuit are
Up counter 113 is all low by the preset signal
At (0), the down counters 115 are all set to Hi (1) and counted by the number of movements.

It is assumed that each of the counters 113 and 115 can count a larger number than the maximum value of the movement amount, and therefore, even if the counting ends, the carry or borrow from the counters 113 and 115 does not occur. Further, since the borrow does not occur from the down counter 115, the gate circuit 111 sends the update clock to the latch 114 and latches the output of the up counter 113. Further, the gate circuit 111 sends a control signal to the write inhibit gate circuit 26 so as to freeze the initial value image.

When the next motion amount is detected, the preset signal
The up counter 113 is Low (0) and the down counter 115
Receives the output value of the up counter 113 from the latch 114 and sets it as a preset value. And each counter 11
If 3,115 is counted by the number of movements and the movement is larger than the previous movement, the down counter 115
Generates a borrow, and the gate circuit 111 does not output the update clock.
The preset value is 5.

On the other hand, if the movement amount is smaller than the previous movement amount, the down counter 115 does not generate a borrow, the update clock is output by the gate circuit 111, and the value of the up counter 113 is held in the latch 114. It becomes the next preset value of the down counter 115.

With the above operation, the value of the smallest motion amount is held at the output of the latch 114.

FIG. 6 shows an analog minimum value detection circuit. In this minimum value detection circuit, the input end of the buffer 123 is connected to the input end of the movement amount via the switch 121.
The input end of 23 is grounded via a capacitor 122. The output terminal of the buffer 123 is connected to the inverting input terminal of the TTL output comparator 126 and also connected to the input terminal of the buffer 128 via the switch 127. The input terminal of the buffer 128 is grounded via a capacitor 129. The output terminal of the buffer 128 is connected to the non-inverting input terminal of the comparator 126. The output terminal of the comparator 126 is connected to a control input terminal for inputting a signal for controlling opening / closing of the switch 127. Further, a control signal from the freeze instruction circuit 28 is applied to each control input terminal of both the switches 121 and 127.

When the image freeze instructing signal is output from the freeze instructing circuit 28, the capacitor 129 of the minimum value detecting circuit is fully charged, and the value obtained by converting the motion amount into the voltage is switched to the switch 121.
By turning on, the capacitor 122 holds it as a motion amount voltage. At this time, the switch 127 is turned off.
Is. Then, with the buffers 123 and 128, the capacitor 1
The voltage held at 22,129 is compared by the TTL output comparator 126. At this time, since the output voltage of the buffer 128 is higher than the voltage of the buffer 123, the comparator 1
The switch 127 is turned on by the output of 26, and the voltage of the buffer 123 is held in the capacitor 129.

When the next movement amount is input by the switch 121, the movement amount is held in the capacitor 122, and is compared by the comparator 126 with the previous movement amount held in the capacitor 129. At this time, if the amount of movement held in the capacitor 122 is smaller than the amount of movement held in the capacitor 129, the comparator 126 outputs, for example, +5 V, turns on the switch 127, and turns on the capacitor 1
The voltage of 21 is held in the capacitor 129, and the image signal of the input motion amount is written in the freeze memory. On the other hand, the amount of movement held in the condenser 122 is
If it is larger than the amount of movement held in the capacitor 129, the comparator 126 outputs 0V and the switch 127 is turned off.
And hold the voltage of the capacitor 129.

With the above operation, the minimum value of the movement amount is held in the condenser 129.

As described above, according to the present embodiment, it is possible to freeze the image at the time when the movement of the subject is the smallest, and it is possible to store a still image with little deterioration of the image due to the movement of the subject.

Incidentally, as an example of an image pickup apparatus using a color plane sequential method for generating a color plane sequential signal input to the signal processing apparatus of the present embodiment, a monochrome CCD is mounted at the tip end, and the illumination light is, for example, R
There are GB-sequential electronic endoscopes and field-sequential external TV cameras that are detachably attached to the eyepiece of the fiberscope.

7 and 8 relate to a second embodiment of the present invention,
FIG. 8 is a block diagram showing the configuration of the image freeze signal processing device, and FIG. 8 is a graph for explaining the operation of this embodiment.

As shown in FIG. 7, the signal processing apparatus of the present embodiment includes a digital color plane sequential signal, that is, a synchronization memory 41 for synchronizing primary color signals of an image input in a time series, and a synchronization memory 41. The output image signal of the memory 41 is provided with a signal processing circuit 42 for enlarging or interpolating an image, and a freeze memory 43 capable of freezing the output image signal of the signal processing circuit 42. The image signal is output to the display device and the processing device in the subsequent stage.

The synchronization memory 41 is a changeover switch similar to the changeover switches 31 and 34 and the frame memories 52 and 33 in the first embodiment.
51, 54, a first frame memory 52 and a second frame memory 53 are provided.

On the other hand, the freeze memory 43 has change-over switches 55 and 58 similar to the change-over switches 35 and 38 in the first embodiment, and instead of the field memories 36 and 37, a first frame memory 56 and a second frame memory. A memory 57 is provided.

Further, the motion detecting circuit 44, the minimum value detecting circuit 45, the write inhibit gate circuit 46, the memory R / W controller 47, the freeze indicating circuit 48 and the set time detecting circuit 49 which are the same as those in the first embodiment.
It has.

 Next, the operation of this embodiment will be described.

Image signals input in time series are
The data is alternately written to one of the first frame memory 52 and the second frame memory 55. For example, in a certain state, the input image signal is written in the first frame memory 52 of the synchronization memory 41, and the second frame memory 53 reads the already written image signal. The image signal read by the synchronization memory 41 is sent to one frame memory of the freeze memory 43, for example, the first frame memory 56 through the signal processing circuit 42. Also,
In the second frame memory 57, the image signal already written is read and used as an output image signal.

Further, the image signal sent to the freeze memory 43,
It is also sent to the motion detection circuit 44, and the amount of motion is obtained.

 Next, a case where the image is frozen will be described.

As shown in FIG. 8, the image signals for each frame read from the synchronization memory 41 from time t ₁ are represented by F ₁ , F ₂ , ..., Fn.
Then, correspondingly, the motion amounts obtained by the motion detection circuit 44 are M ₁ , M ₂ , ..., Mn. In addition, the set time detection circuit 49
The end time of the set time set by is tn (t ₁ <tn).

When the image freeze signal is output from the freeze instruction circuit 48 at time t ₃ , the image signal F ₁ read from the synchronization memory 41 is written in one frame memory of the freeze memory 43, and at the same time, the motion amount M ₁ is detected. Then, the minimum value detection circuit 45 is set as an initial value.

Next, when the image signal F ₂ is read from the synchronization memory 41, the image signal F ₂ is the other frame memory of the freeze memory 43 (a frame memory different from the frame memory in which the image signal F ₁ is written). Written to the motion detection circuit
The movement amount M ₂ is detected by 44.

The motion amount M ₂ is compared with the set value M ₁ of the minimum value detection circuit 45, and if M ₂ <M ₁ as shown in FIG. 8, the freeze memory 43 is used so that the image signal F ₂ becomes the output image signal. Each switch 5
The minimum value detection circuit 45 sends a control signal to the memory controller 47 through the write inhibit gate circuit 46 so as to switch 5, 58. Therefore, the image signal next input to the freeze memory 43 is stored in the frame memory other than the frame memory in which the image signal with the minimum amount of motion is stored.

On the other hand, when the motion amount is larger than the minimum value like the image signal F _{7 in} FIG. 8, the switches 55 and 58 of the freeze memory 43 are set so that the image signal with the minimum motion amount becomes the output image signal. The minimum value detection circuit 45 switches the memory controller 47 through the write inhibit gate circuit 46 so that
Send a control signal to. Therefore, the image signal next input to the freeze memory 43 is also stored in the frame memory other than the frame memory in which the image signal with the minimum amount of motion is stored.

In FIG. 8, black circles represent frozen images and white circles represent unfrozen images.

With the above-described operation, in the present embodiment, the motion amount is detected for all the image signals taken in the synchronization memory 41 and once written in the freeze memory 43, the detected motion amount is set to the minimum value detection circuit. As compared with 45, an image with a small amount of motion can be read from the freeze memory 43, and an image signal with the least amount of motion within the set time can be frozen.

FIG. 9 is a block diagram showing the arrangement of an image freeze signal processing apparatus according to the third embodiment of the present invention.

 The present embodiment is an example in which the present invention is applied to the simultaneous system.

In this embodiment, the input image signal is sent to the delay circuit 61 and the motion detection circuit 65, respectively. The image signal 63 delayed by one frame by the delay circuit 61 is sent to the freeze memory 62 and the motion detection circuit 65. The motion detection circuit 65 detects the amount of motion based on the cross-correlation between the image signal 64 of the current frame and the image signal 63 of the previous frame delayed by one frame. This motion amount detection method is such that the difference between corresponding pixels in the current frame and the previous frame is obtained, and the cumulative value of the absolute values of the respective differences is used as the motion amount.

The freeze memory 62 is a memory R / W controller 68.
The writing and reading are controlled by. A write control signal from the memory controller 68 to the freeze memory 62 is sent to the freeze memory 62 via the write inhibit gate circuit 67.

Further, the signal processing device of the present embodiment is provided with the motion detection circuit.
From the output of 65, a minimum value detection circuit 66 that detects the minimum value of the movement amount within a predetermined time, a freeze instruction circuit 69 that activates this minimum value detection circuit 66, and the minimum value detection circuit 66 detects the minimum value. And a set time detection circuit 70 for setting the set time. Then, the write inhibit gate circuit 67
Are controlled by the minimum value detection circuit 66.

When the image freeze instruction signal is output from the freeze instruction circuit 69, the amount of movement of each image signal is detected by the minimum value detection circuit.
A control signal is sent to the write inhibit gate circuit 67 so that the image signal having a small amount of motion, which is input to the 66 and is sequentially sent by the minimum value detection circuit 66, is written in the freeze memory 62.

As described above, according to the present embodiment, while the motion amount is calculated and compared with the minimum value (about one frame), the image signal is delayed by one frame by the delay circuit 61 and sent to the freeze memory 62. Therefore, with respect to the image signal output by the image freeze instruction signal and input by the time set by the set time detection circuit 70, the image signal having the least movement is written in the freeze memory 62.

Next, a fourth embodiment of the present invention will be described with reference to FIG.

The configuration of this embodiment is as shown in FIG. 3 similarly to the first embodiment, but the operation is different from that of the first embodiment.

 The operation of this embodiment will be described below.

In this embodiment, even when the primary color signals sent in time series are written in the synchronization memory 21 and the freeze instruction circuit 28 outputs the image freeze instruction signal, the synchronization memory 21
The image signals are sequentially read out. When the motion amount of each image signal is detected, the motion amount of the image signal read from the synchronization memory 21 is detected until the time set by the set time detection circuit 29 comes after the image freeze instruction signal is output. Then, the motion amount sequentially detected by the minimum value detection circuit 25 is compared, and a value having a small motion amount is set as a new setting.
When the detected motion amount is below the set value, the minimum value detection circuit 25 sends a control signal to the memory controller 27 through the write inhibit gate circuit 26 so as to write the image signal to the freeze memory 23. On the other hand, if the detected amount of movement exceeds the set value, a control signal is sent so that the image signal is not written to the freeze memory 23.

As described above, in this embodiment, the motion amounts of all the image signals sent to the synchronization memory 21 are detected, the minimum value of the motion amount is detected, and the image signals are written to the freeze memory 23.
The image signal written in the freeze memory 23 is the image signal immediately after the image signal whose movement amount is determined to be the minimum value.

FIG. 10 and FIG. 11 relate to the fifth embodiment of the present invention,
FIG. 11 is a block diagram showing the configuration of the image processing device for image freeze, and FIG. 11 is a graph for explaining the operation of this embodiment.

This embodiment is an example in which the set time detection circuit is not used in the simultaneous system.

Similar to the third embodiment, in this embodiment, the input image signal is sent to the delay circuit 81 and the motion detection circuit 85, respectively. The image signal 83 delayed by one frame by the delay circuit 81 is sent to the freeze memory 82 and the motion detection circuit 85. The motion detection circuit 85 detects the amount of motion based on the image signal 84 of the current frame and the image signal 83 of the previous frame delayed by one frame. Writing and reading of the freeze memory 82 are restricted by the memory R / W controller 89. A write control signal from the memory controller 89 to the freeze memory 82 is sent to the freeze memory 82 via the write inhibit gate circuit 87. Further, the signal processing apparatus of this embodiment includes a minimum value detection circuit 86 that detects the minimum value of the motion amount from the output of the motion detection circuit 85, and a freeze instruction circuit 88 that activates this minimum value detection circuit 86. ing. The write inhibit gate circuit 87 is controlled by the minimum value detection circuit 86.

As shown in FIG. 11, at time t ₁ , the freeze instruction circuit 88
When the image freeze instruction signal is output, the motion amount M ₁ detected by the motion detection circuit 85 is set as the initial value of the minimum value detection circuit 86, and the image signal F ₁ delayed by one frame by the delay circuit 81 is set. Write to freeze memory 82.

Next, the motion amount M ₂ is detected by the motion detection circuit 85 to which the image signal F ₂ is input, and the set value is detected by the minimum value detection circuit 86.
Is compared with M _1, the M ₂ <M _1, so that the image signal F ₂ sent to the freeze memory 82 is written, controls the write inhibit gate circuit 87. In this way, the minimum value detection circuit
The control unit 86 controls the write inhibit gate circuit 87 so that the image signals, which are sequentially transmitted with a small amount of movement, are written in the freeze memory 82.

In FIG. 11, black circles represent frozen images and white circles represent unfrozen images.

As described above, according to the present embodiment, the minimum value detection circuit 86 compares motion amounts, and the image signal with the smallest motion amount is always written in the freeze memory 82.

FIG. 12 is a block diagram showing the arrangement of an image freeze signal processing apparatus according to the sixth embodiment of the present invention.

In the above-mentioned first to fifth embodiments, the frozen image signal is once written into the freeze memory, but this embodiment does not use a storage medium such as the freeze memory but a VTR magnetic tape. In this example, a recording medium such as a magnetic disk or an optical disk is used.

As shown in FIG. 12, the input image signal is subjected to various processing in the signal processing circuit 101 and then sent to the header 102 to be recorded on the recording medium 103. The header 102 and the drive circuit 104 for driving the recording medium 103 are controlled by the control circuit 108. The timing of the signal processing circuit 101 and the control circuit 108 is controlled by the timing generation circuit 106.

The image signal from the signal processing color 101 is also input to the motion detection circuit 105, and the amount of motion sent from the motion detection circuit 105 is compared by the minimum value detection circuit 107 activated by the freeze instruction circuit 109. It is like this. Then, the control circuit 108 uses the minimum value detection circuit 1
It is controlled by the detection signal from 07.

In this embodiment, the motion detection circuit 105 determines the motion amount of the input image signal, the minimum value detection circuit 107 compares the motion amounts of the respective image signals, and an image with a small motion amount is recorded on the recording medium 10.
The minimum value detection circuit 107 sends a detection signal to the control circuit 108 so as to be written in 3.

The control circuit 108 controls writing of the image signal to the recording medium 103 while timing of the image signal sent to the header 102 is controlled by the signal of the timing generation circuit 106.

Thus, according to the present embodiment, the image signal with the smallest amount of movement is always recorded on the recording medium 103.

As the recording medium 103, various types such as a magnetic tape, a magnetic disk, an optical disk, a still video floppy, etc. can be used.

Further, as in the first to fourth embodiments, the time for obtaining the minimum value of the movement amount may be set.

Needless to say, the minimum value detection circuit shown in FIGS. 5 and 6 described in the first embodiment can be applied to other embodiments.

The present invention is not limited to the above-mentioned embodiments, and for example,
In the case of detecting the movement, it is not limited to the unit of one frame and may be performed in the unit of one line.

The present invention can also be applied to, for example, a monitor image photographic imaging device.

[Effect of the Invention] As described above, according to the present invention, the input image signal is written to the means for storing or recording the image signal in accordance with the output of the minimum value detecting means for detecting the minimum value of the amount of movement of the subject. Since the operation or recording operation is controlled, it is possible to freeze the image near the time when the subject moves the least and to store or record the still image with little deterioration of the image due to the subject motion. is there.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of the present invention, FIG. 2 is an explanatory diagram for explaining the operation of the present invention, and FIGS. 3 to 6 are first diagrams of the present invention.
FIG. 3 is a block diagram showing the configuration of an image freeze signal processing device according to the embodiment, FIG. 4 is a graph for explaining the operation of the present embodiment, and FIG. 5 is an example of a digital minimum value detection circuit. FIG. 6 is a circuit diagram showing an example of an analog minimum value detection circuit, FIGS. 7 and 8 are related to a second embodiment of the present invention, and FIG. 7 is a signal processing device for image freeze. FIG. 8 is a block diagram showing the configuration of FIG. 8, FIG. 8 is a graph for explaining the operation of the present embodiment, and FIG. 9 is a block diagram showing the configuration of an image freeze signal processing device of the third embodiment of the present invention. FIG. 11 and FIG. 11 relate to the fifth embodiment of the present invention,
FIG. 10 is a block diagram showing the configuration of an image freeze signal processing apparatus, FIG. 11 is a graph for explaining the operation of this embodiment, and FIG. 12 is an image freeze signal processing apparatus of the sixth embodiment of the present invention. FIG. 13 is a block diagram showing the configuration of FIG. 13, and FIG. 13 is a graph for explaining the operation of the image freeze device of the related art. DESCRIPTION OF SYMBOLS 1 ... Motion detection means, 2 ... Freeze instruction means 3, ... Set time detection means, 4 ... Minimum value detection means 5 ... Image signal storage / recording means 6 ... Writing / recording control means

 ─────────────────────────────────────────────────── ─── Continued front page (72) Masahide Sugano 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Katsuyuki Saito 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Akinobu Uchikubo 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Katsuyoshi Sasakawa 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Co., Ltd. (72) Inventor Shinji Yamashita 2-34-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Yudai Nakagawa 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Co., Ltd. (56) Reference JP-A-1-303124 (JP, A) JP-A-1-279689 (J , A) JP flat 2-131686 (JP, A)

Claims (1)

[Claims] 1. A motion detecting means for detecting a motion of an object from an input image signal and an image freeze instructing means, which is activated to detect a minimum value of the motion amount of the object within at least a predetermined time from the output of the motion detecting means. And a control means for controlling the writing operation or the recording operation of the input image signal to the means for storing or recording the image signal according to the output of the minimum value detecting means. Image freeze signal processing device.