JPH0255480A - Picture freeze device - Google Patents

Abstract

PURPOSE:To record or store a still picture with less deterioration in a picture caused by the movement of an object with simple constitution by detecting the movement of the object to control the write or recording of an input picture signal. CONSTITUTION:A picture signal inputted to a picture memory 1 is subject to write/readout control by a memory R/W controller 7 and displayed as a moving picture by an external display device (not shown). In the case of storing a still picture, a picture freeze command is given from a freeze command means 3 and sent to a threshold level circuit 5, then an output of the threshold level circuit 5 is enabled. Then a reference signal and an output of a movement detection means 2 are compared to discriminate the quantity of the movement of the object and the result is sent to a write inhibit gate 6. When the movement of the object is large, the write is not inhibited by the gate 6 and the moving picture display is continued as it is. When the movement of the object is small, the write to the picture memory 1 is inhibited and the picture is frozen.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device for storing or recording still images.
More specifically, the present invention relates to an image freezing device that stores or records a still image without blurring an input image signal.

[Problems that conventional technology and inventions attempt to solve] Conventionally,
Recording image signals on magnetic tape or magnetic disk,
2. Description of the Related Art Devices are known that display images stored in storage elements such as OD memory, MOS memory, magnetic bubble memory, or IC memory. In particular, as a device for recording still images, a device equipped with a magnetic disk device such as a recording/reproducing device inside the camera is disclosed in Japanese Patent Laid-Open No. 49-52912.
This method is disclosed in Japanese Patent Application Laid-open No. 5T-140510. In addition, an electronic photographic camera of the same kind that could be played back immediately after shooting and could be retaken was developed in Japanese Patent Application Laid-open No. 5
It has been proposed in Publication No. 7-44.374.

However, these devices record or temporarily store information related to the pressing operation of the release button, so when the subject's movement is faster than the shutter speed, There are many cases where the captured image becomes blurred due to so-called camera shake, in which the imaging device moves during the ivy operation, and it is necessary to retake the image.

Also, for example, when an interlaced scanning type image sensor is used as an image sensor to photograph a fast-moving subject, different images are stored between fields, which causes flickering, making the image extremely difficult to see. have.

Related to this drawback, in order to prevent flickering between fields when storing still images, the movement of the subject is detected and the frame is frozen if there is no movement, and the field is frozen if there is movement. A device constructed is proposed by US Pat. No. 4,272,787. However, this device automatically freezes the field when there is movement in the imaged object, so it has the disadvantage that the resolution in the vertical direction deteriorates for moving objects.

In addition, in recent years, advances in manufacturing technology for solid-state imaging devices have led to higher pixel density and ultra-miniaturization of chips, and endoscopes with solid-state imaging devices mounted at their tips, so-called electronic endoscope devices, have become more popular. being developed. These devices have the function of inserting into a body cavity to observe the area to be examined and to record the observed images of the same area.In addition to their observation ability, the quality of the recorded images is also extremely high. This is important and greatly affects the diagnosis of the area being examined. Therefore, when recording, the endoscope operator holds the patient still, freezes and displays the image of the area to be examined several times, selects the most desirable image as the recorded image, and selects the most desirable image to be recorded, for example, using a monitor image photographing device. Still images were recorded on cameras, video printers, or Sujiru video floppy devices.

However, even if the patient is held still, as long as VA is detected inside the body, there will be some movement in the area to be examined, and in order to eliminate blurring of the image due to this movement, it may be necessary to refreeze the image many times. There is a problem that there is.

The manner in which such deterioration of recorded images due to the movement of the subject occurs differs depending on the type of image sensor and the imaging method. For example, if a frame 1 to frame 7 type COD is used as an image sensor, the movement of the subject during the exposure period will cause image blur, and if an interline type COD is used to perform interlaced scanning. In this case, in addition to image blur caused by the movement of the subject during the exposure time, flicker occurs due to image differences between fields. In addition, for the purpose of reducing the diameter of the endoscope, a monochrome COD is mounted on the tip of the endoscope, and the illumination light is converted into RGB, for example.
In the so-called color plane sequential method, which uses sequential light, R, G, and B primary color images taken sequentially in chronological order are displayed simultaneously, so the movement of the subject is displayed as a shift in color. So-called color misregistration is a problem.

[Object of the Invention] The present invention has been made in view of the above circumstances, and provides an image freezing device that has a simple configuration and is capable of storing or recording still images with little image deterioration caused by subject movement. is intended to provide.

[Means for Solving the Problems] As shown in the conceptual diagram of FIG.
a recording means 101; a motion detection means 102 for detecting the movement of a subject from the image signal; an image freeze instruction means 103 for instructing the image storage/recording means 101 to store or record a still image; write/record control means 104 that is activated by an instruction signal from the motion detection means 102 and controls the write operation or recording operation of the input image signal to the image storage/record means 101 according to the output of the motion detection means 102. It is something.

[Operation] In the present invention, when an instruction to store or record a still image is issued by the image freeze instruction means 103, the writing/recording control means 104 is activated by an instruction signal from the instruction means 103, and the writing/recording is started. Control means 1
04 controls the writing operation or recording operation of the input image signal to the image storage/recording means 101 according to the output of the motion detection means 102. Then, a still image is stored or recorded in the image storage/recording means 101.

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

Figures 2 to 4 relate to the first embodiment of the present invention;
FIG. 3 is a block diagram showing the configuration of the image freezing device of this embodiment, FIG. 3 is a block diagram showing an example of a motion detecting means, and FIG. 4 is a circuit diagram showing an example of a threshold circuit.

As shown in FIG. 2, the image freezing device of this embodiment is
An image memory 1 that stores a digital input image signal, and a motion detection means 2 that detects the movement of a subject from the image signal.
and a freeze instruction means 3 for instructing the image memory 1 to store a still image. writing/recording control means 4 for controlling the writing operation of input image signals to 1;
It is equipped with

The writing/recording control means 4 is activated by an image freeze instruction signal from the freeze instruction means 3, and compares a preset reference value with the motion detection amount from the motion detection means 2 to detect the movement of the subject. The threshold for determining the size of the
a threshold) value circuit 5; a write inhibit gate 6 that controls whether or not writing to the image memory 1 is prohibited in accordance with a determination signal from the threshold circuit 5; It is equipped with a memory R/W controller 7 that controls writing (W) and reading (R). Note that the memory write control signal from the memory R/W controller 7 is transmitted to the write inhibit gate 6.
A memory read control signal is directly applied to the image memory 1 through the image memory 1.

Next, the operation of the image freezing device of this embodiment will be explained.

The input image signal is guided to an image memory 1 and a motion detection detection means 2. The motion detection means 2 calculates a motion detection amount corresponding to the movement of the subject from the input image signal, and outputs it to a threshold circuit 5 installed in the writing/recording control means 4. The image signal input to memory 1 is
Memory R/W provided in the write/record control means 4
Writing/reading is controlled by the controller 7,
Normally, images that are sequentially input are sequentially output as they are, and displayed as a moving image on an external display device (not shown).

In this case, the threshold circuit 5 is not activated, and the write inhibit gate 6 does not inhibit writing.

On the other hand, if a still image is to be stored, the freeze instruction means 3 is instructed to do so with J:. When an image freeze instruction signal is generated from the freeze instruction means 3 and transmitted to the threshold value circuit 5, the output of the threshold value circuit 5 is enabled, and the motion is set to a preset reference value. The magnitude of the movement of the subject is determined by comparing the output of the detection means 2, and the determination signal is sent to the write-protect gate 6.
tell to. In this write-protection gate 6, when the movement of the subject is large, writing is not prohibited and the video display continues as it is, and when it is determined that the movement of the subject is small, old data is not written to the image memory. It will be banned and the image will be frozen.

An example of the motion detecting means 2 is shown in FIG.

In this example, the input image signal is guided by the frame memory 21 and the subtraction circuit 22.

The image signal read out from the frame memory 21 one frame period ago is guided by the power of the subtraction circuit 22, and is subtracted from the input image signal asked for the input. The output signal of the circuit 22 is converted into an absolute value by an absolute value circuit 23, and outputted as a motion detection amount via a low pass filter (IPF) 2/I. In this example, the greater the movement of the subject, the greater the motion detection amount. Although the frame memory 21 is used to compare images frame by frame to detect motion, it may be constructed using a field memory or a line memory instead.

Further, an example of the threshold circuit 5 is shown in FIG.

The threshold circuit 5 can be configured using a comparator 51 with an enable terminal EN, and in this example, the amount of motion detected from the motion detecting means 2 is converted into the power of the comparator 51.
The reference value Es preset by the reference value setting means 52
are applied individually, and an image freeze instruction signal from the freeze instruction means 3 is applied to the enable terminal of the comparator 51. In this example, the motion detection amount and the reference value Es are compared only when an image freeze instruction signal is being issued, and based on the magnitude thereof, it is determined whether or not there is movement of the subject, and the result is output to a subsequent stage. Furthermore, when the motion detecting means 2 is configured as shown in FIG. 3, when the amount of motion detected is less than the reference value Es, the subsequent locking prohibition gate is activated to freeze the image. generates a control signal. Here, the comparator 51 may be one that directly compares the digital data, and the reference value setting means 52 for setting the reference value Es may also be of a digital type.

Furthermore, if the operation of the write inhibit gate 6 is controlled in synchronization with a frame signal indicating the division of input images, it becomes possible to freeze one screen at a time.

As described above, according to this embodiment, the movement of the subject is detected by the motion detection means 2, and when there is little movement of the subject, writing to the image memory 1 is prohibited and the image is frozen. Therefore, with a simple configuration, it is possible to store still images with less image deterioration caused by subject movement.

5 and 6 relate to a second embodiment of the present invention, FIG. 5 is a block diagram showing the configuration of an image freezing device of this embodiment, and FIG. 6 is a block diagram showing an example of motion detection means. be.

This embodiment is an example in which the input image signal is an analog signal, and this analog input image signal is sent to the A/D converter 1.
1 is converted into a digital signal and written into the image memory 1. Further, the image memory 1
The image signal read out is converted into an analog signal by the D/A converter 12 and output to the subsequent stage.

Further, the analog input image signal is input to the motion detection means 2. In this example,
The motion detecting means 2 is composed of an analog circuit, as shown in FIG. 6, for example. As shown in this figure, the input analog image signal is transmitted to a CCD controlled by a controller 251.
After being delayed for one horizontal period by the delay line 25 and having the clock component removed by the LPF 26, it is guided by the power of the subtraction circuit 27. Further, the input image signal is guided by the one-man power of the subtraction circuit 27, and the input image signal led by the ten-man power is subtracted by the image signal after this -horizontal period, and this subtraction circuit 27 The output signal of the absolute value circuit 28
, and is output as a motion detection amount via the LPF 29.

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

FIG. 7 is a block diagram showing the configuration of an image freezing device according to a third embodiment of the present invention.

In this embodiment, as in the first embodiment, the input image signal is a digital signal, but the image signal read out from the image memory 1 is converted into an analog signal by the D/A converter 13, and then It is now output to . Also,
Analog image signals from the D/A converter 13 are input to the motion detection means 2, which is constructed of an analog circuit as in the second embodiment.

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

8 and 9 relate to a fourth embodiment of the present invention, FIG. 8 is a block diagram showing the configuration of the image freezing device of this embodiment, and FIG. 9 is a block diagram showing an example of motion detection means. It is.

This embodiment is an example in which the present invention is applied to a sequential R, G, B color plane system. In this embodiment, an image captured by a color plane sequential imaging device (not shown) is converted into an A/D converter (not shown) as a color plane sequential signal generated corresponding to the readout period of each primary color image. Converted to Marzibrek→
J-(MUX) 13, the simultaneous memories 14R, 14, G, 14B (
It is represented by the reference numeral 14. ).

When reading from the simultaneous memory 171, each primary color image is read simultaneously and sequentially written to the freeze memories 31R, 31G, and 31B (represented by reference numeral 31) as color surface simultaneous signals. . The RGB image signals written in the freeze memory 31 are sequentially read out and output in synchronization with a synchronizing signal from a display device or processing device (not shown) connected at a subsequent stage.

Also, each of the simultaneous memories 14R, 17! IG, 14B
At the same time, the color surface simultaneous signal read out from the chrominance plane simultaneous signal is also guided to the motion detection means 2, and the detected amount of movement of the subject outputted from the motion detection means 2 is outputted to the threshold circuit 5. .

Now, when an image freeze instruction signal is issued from the freeze setting means 3, the output of the threshold circuit 5 is enabled, and if the detected amount of movement of the subject is smaller than a preset value, the freeze memory 31 is Writing is prohibited by the write inhibit gate 6, and the image at this time is frozen.

An example of the motion detection means 2 according to this embodiment is shown in FIG.

RGB primary color images captured using the RGB color plane sequential imaging method Due to that method, for example, R, G, and B are generated in the order of time, so the movement of the subject is caused by R and G, G and B, and B. R
appears as a difference between each image. Therefore, the difference between the images can be determined for at least one of R and G, G and B, and B and R, and using this, the motion detection amount can be calculated.

In the example shown in FIG. 9, for both R, G, G and B,
I'm looking for the difference between images. That is, the chromatic simultaneous signal R is applied to the subtracting circuit 221, the chromatic simultaneous signal B is applied to the subtracting circuit 222, and the chromatic simultaneous signal G is applied to the subtracting circuits 221 and 222. applied to each ten inputs. Then, the subtraction circuits 221 and 222 calculate the difference between the R and G image signals and the difference between the G and B image signals, and convert them into absolute values in the absolute value circuits 231 and 232. 25 and outputs the detected amount of motion of the subject via the IPF 24.

Furthermore, as an example of an imaging device using the color plane sequential method, a monochrome COD is mounted at the tip, and the illumination light is converted into, for example, RGB.
There are electronic endoscopes with sequential light, and television cameras that are detachably attached to the eyepiece of fiberscopes and use a field-sequential system.

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

FIG. 10 is a block diagram showing the configuration of an image freezing device according to a fifth embodiment of the present invention.

In the first to fourth embodiments described above, the motion of the subject is detected from the sequentially inputted image signals, and freeze control is performed based on the detected value, but the motion detection means 2 includes a delay means. If images are input consecutively,
When determining whether or not to freeze by detecting the amount of movement,
There may be a situation where a new image input has already started and the image at the time following the image in which motion was detected is frozen. The movement of the subject is not that steep [
If this is the case, the above configuration is sufficient to achieve the object of the present invention, but if not, an image with image blur or color shift may be frozen even though the motion detection means is operating correctly. There is a problem with this.

This embodiment is an example in which the above-mentioned problems are solved.

As shown in FIG. 10, in the image freezing device according to the first embodiment, an image signal delaying means 8 is added to the input stage of the image memory 1, and the amount of delay of the motion detecting means 2 is controlled by the image signal delaying means 8. It is characterized in that the image for which the amount of movement of the subject is determined to be less than or equal to a predetermined value is corrected so that the image to be frozen matches the image.

The other functions and effects of Structure 2 are the same as those of the first embodiment.

FIG. 11 is a block diagram showing the configuration of an image freezing device according to a sixth embodiment of the present invention.

This embodiment is an example in which the present invention is applied to an apparatus that images a subject and records the still image on a recording medium.

As shown in FIG. 11, the optical image of the subject formed by the imaging optical system 70 on the imaging surface of the imaging device 790 is photoelectrically converted by the imaging device 790 and scanned under the control of a scanning circuit 791. As an image signal, the scanning circuit 791
The signal is input to a signal processing circuit 78 controlled by.

The image signal subjected to various processing in this signal processing circuit 78 is transmitted to a header 710 to be recorded on a recording medium 711. A drive circuit 712 that drives the header 710 and the recording medium 711 is connected to a control circuit 7.
It is controlled by 7.

The image signal from the signal processing circuit 78 is also input to the motion detection circuit 72 at the same time.
2, the amount of movement of the subject is detected. The output of the motion detection circuit 72 is transmitted to the recording instruction means 7.
3 (freeze instruction means 3 in the first to fifth embodiments)
corresponds to ) is entered into the threshold circuit 75 which is activated by >). A control signal from this threshold value circuit 75 is input to the control circuit 77.

Now, when a recording instruction signal is issued from the recording instruction means 73, the threshold circuit 75 detects the motion detection circuit 72.
The output is compared with a preset reference value, a determination is made as to whether or not the image at that time is to be stored, and the result is communicated to the control circuit 77.

If the motion of the subject is less than a predetermined value, the control circuit 77 controls the header 710 . The drive circuit 712 is controlled to record the image signal at that time on the recording medium 711.

Note that the recording medium 711 is a magnetic tape.

Various types are possible, such as magnetic disks, optical disks, methyl video disks, etc.

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

FIG. 12 is a block diagram showing the configuration of an image freezing device according to a seventh embodiment of the present invention.

This embodiment is an example in which a part of the image freezing device is configured outside the main device and used as an accessory device.

As shown in FIG. 12, the image freezing device of this embodiment includes a main unit 800 and an accessory device 801 provided outside the main unit 80.

The main body device 800 is configured as follows. That is, the optical image of the subject formed by the imaging optical system 80 on the imaging surface of the imaging device 890 is
0, and is scanned under the control of a scanning circuit 891 and input as an image signal to a signal processing circuit 88 controlled by the scanning circuit 891.

The image signal that has undergone various processing in the signal processing circuit 88 is A/D converted by an A/D converter 811 and then written into an image memory 810.

The image signal read out from the image memory 810 is D
After being subjected to D/A conversion by a /A converter 812, the signal is processed by a signal processing circuit 813, and is input to a monitor 814 provided outside the main device 800. still,
The image memory 810 is written/written by a memory R/W controller 87 provided in the main device 800.
Reading is now controlled. The memory R/W controller 1 to roller 87 also include the scanning circuit 89.
A synchronization signal from 1 is input, and the image sensor 890 and the signal processing circuit 88 are synchronized.

On the other hand, the accessory @801 includes the signal processing circuit 813
a motion detecting means 82 for detecting the motion of the subject from an output image signal from the freeze instructing means 83;
A threshold value circuit 85 is provided for determining whether or not freezing is possible based on the detected amount of motion of the subject detected in . Then, the discrimination signal from the threshold circuit 85 is transmitted to the main body device 8.
The data is sent to the memory R/W controller 87 in 00.

In this embodiment, when the freeze instruction signal is issued from the freeze instruction means 83, the signal processing circuit 8 of the main device 800
Based on the detected amount of motion of the subject detected by the motion detection means 82 from the output image signal of 13, the threshold circuit 85 determines whether freezing is possible and sends the determination signal to the memory R/W controller in the main device 800. Send to 0-ra87. When the threshold circuit 85 determines that the amount of movement of the subject is less than a predetermined value, the image is frozen.

In this way, according to this embodiment, freeze control can be performed by controlling the remote control 1. The signal transmission method between the threshold circuit 85 and the memory R/W controller and the roller 87 can be wired, wireless, optical, or the like.

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

FIG. 13 is a block diagram showing the configuration of an image freezing device according to an eighth embodiment of the present invention.

This embodiment is an example in which the present invention is applied to a color simultaneous imaging system using a mosaic filter type element as an imaging element.

In this embodiment, the image sensor 990 is
The optical image of the subject formed on the image carrier plane is photoelectrically converted by the image sensor 990 and scanned under the control of the scanning circuit 991 as an image signal, which is sent to the signal processing circuit controlled by the scanning circuit 991. 98. The sensor element 990 is provided with a color mosaic filter for color separation on the front surface of the imaging surface. The analog luminance signal AY and color line sequential signal AC obtained by signal processing in the signal processing circuit 98 are sent to an A/D converter 911.
After the signal is converted into a digital luminance signal DY and a color line sequential signal DC, it is written into an image recorder 910. The digital luminance signal DY and color line sequential signal DC read out from the image memory 910 are converted into analog luminance signal AY and color line sequential signal AC by a D/A converter 912, and then sent to an NTSC encoder 913'. cNTSC
The signal is converted into a signal and input to an external monitor 914, and the subject image is displayed on this monitor 914.

Note that writing/reading of the image memory 910 is controlled by a memory R/W controller 97. In addition, this memory R/W controller 9
A synchronizing signal from the scanning circuit 991 is input to 7, and synchronization is established with the image pickup device 990 and the signal processing circuit 98.

Further, the digital luminance signal DY from the A/D converter 911 is also input to a motion detecting means 92, and the motion detecting circuit 92 detects the amount of movement of the subject. The output of the motion detection amount 92 is input to a threshold value circuit 95 activated by the freeze instruction means 93. A determination signal from this threshold circuit 95 is sent to the memory R/W controller 97. When a freeze instruction signal is issued from the freeze instruction means 93, the threshold circuit 95 determines whether freezing is possible based on the detected amount of movement of the subject detected by the motion detection means 92, and the determination signal is stored in the memory. It is sent to the R/W controller 97. When the threshold circuit 95 determines that the amount of movement of the subject is less than a predetermined value, the image is frozen.

In this way, in this embodiment, the motion of the subject is detected from the digital luminance signal DY, and freeze control is performed based on the detected amount, but this is done in consideration of the visibility of the human eye. It is configured to detect movement from the luminance signal DY, and if it is desired to detect movement by paying particular attention to the color of the subject, movement may be detected using a digital color signal DC.

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

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be applied to, for example, a photographing device for monitoring images.

[Effects of the Invention] As explained above, according to the present invention, the writing operation or recording operation of the input image signal to the storage or recording means is controlled in accordance with the output of the motion detection means for detecting the movement of the subject. As a result, it is possible to memorize or record still images with little image deterioration caused by subject movement with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of the present invention, FIGS. 2 to 4 relate to the first embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the image freezing device of this embodiment, and FIG. 4 is a block diagram showing an example of a motion detection means, FIG. 4 is a circuit diagram showing an example of a threshold circuit, FIGS. 5 and 6 relate to the second embodiment of the present invention, and FIG. 5 shows the present embodiment. FIG. 6 is a block diagram showing an example of a motion detection means; FIG. 7 is a block diagram showing the structure of an image freezing device according to a third embodiment of the present invention; FIG. and FIG. 9 relate to a fourth embodiment of the present invention, FIG. 8 is a block diagram showing the configuration of the image freezing device of this embodiment, FIG. 9 is a block diagram showing an example of motion detection means, and FIG. 10 11 is a block diagram showing the configuration of an image freezing device according to the fifth embodiment of the present invention, FIG. 11 is a block diagram showing the configuration of the image freezing device according to the sixth embodiment of the present invention, and FIG. FIG. 13 is a block diagram showing the structure of an image freezing device according to an eighth embodiment of the present invention. 101... Image recording fB/recording means 102... Movement detection means 103... Image freeze instruction means 104... Writing/recording control means

Claims (1)

[Scope of Claims] Means for storing or recording an input image signal; motion detecting means for detecting movement of a subject from the image signal; and an image for instructing the storing or recording means to store or record a still image. Freeze instruction means; and control means that is activated by an instruction signal from the instruction means and controls the writing or recording operation of the input image signal to the storage or recording means in accordance with the output of the motion detection means. An image freezing device characterized by comprising: