JPH10150637A - Device and method for reproducing image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve picture quality and to prevent an image jump by selecting image information according to movement detection output based upon a field of image information which is inputted at the variable-speed reproduction, and performing field output of image information on a movement part and frame output image information on a stationary part. SOLUTION: A memory control part 62 freezes an image signal of one frame right after a freeze from a mode control part in a storage part 61 to control the write and read of an image signal to and from the storage part 61. A movement detection part 63, on the other hand, performs movement detection by field correlation on the basis of the final field of the image signal inputted to the storage part 61 as to the frozen image signal of one frame. Then an output selection part 64 selectively outputs the image signal read out of the storage part 61 to perform the field output of the image information on the movement part and the frame output of the image information on the stationary part at the variable-speed reproduction according to the detection output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an image reproducing apparatus and an image reproducing method for reproducing image information recorded on a recording medium at a speed lower than a standard reproducing speed.

[0002]

2. Description of the Related Art Conventionally, when obtaining a still image as a reproduction output of a video signal recorded by a video tape recorder, an image of two fields constituting one frame is repeatedly output. In the still image obtained in this manner, since there is a time difference corresponding to the field period between the images of the two fields constituting one frame, the image of the moving part is blurred. Therefore,
A still image whose image quality has been improved by capturing a video signal containing a moving image portion and a still image portion into the memory, freezing it, performing motion detection based on the frame difference of the video signal, and outputting the image of the moving portion as a field output. I'm trying to get

[0003]

By the way, a conventional image reproducing method in which a motion detection is performed based on a frame difference of a video signal, and a moving image is output as a field to obtain a still image with improved image quality. In the device, for example, as shown in FIG.
When an image whose scene changes between fields is recorded on a recording medium, the reproduction is paused, and when the reproduced image stops between the fifth field and the sixth field, the motion detection based on the frame difference method is performed. Since the difference between the third field and the fifth field is usually calculated, it is determined that most of the movement is motion.
As shown in the image on the monitor screen in FIG. 8B, the paused image after the sixth field becomes a field still image in which the image of the fifth field is repeatedly output, and only the field image quality is obtained. There is a problem that there is no.

In a conventional image reproducing apparatus, for example, an image in which a car is moving from left to right is recorded on a recording medium as shown in FIG. When the reproduced image is stopped between the third field and the fifth field, and the third field is used as a reference for the time axis, as shown in the image on the monitor screen in FIG. There is a problem that an image is skipped between the vehicles and the car returns.

An object of the present invention is to provide an image reproducing apparatus and an image reproducing method which can improve image quality in variable speed reproduction such as reproduction pause and low-speed reproduction, and which does not cause image skipping. It is in.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an image reproducing apparatus having a variable-speed reproducing function for reproducing image information recorded on a recording medium at a speed lower than a standard reproducing speed. A storage unit having a storage capacity for storing image information for one frame; a motion detection unit for performing motion detection based on field correlation with respect to image information reproduced from a recording medium; And output selection means for selectively outputting the image information from the storage means so that the image information of the moving part is output as a field and the image information of the still part is output as a frame.

In the image reproducing apparatus according to the present invention, at the time of variable-speed reproduction, for example, based on the motion detection output by the motion detection means for the frame image based on the last field of the image fetched into the storage means, The image information from the storage unit is selected by the selection unit, and the image information of the moving part is output as a field, and the image information of the still part is output as a frame.

In the image reproducing apparatus according to the present invention, for example, when reproduction is temporarily stopped, the image information from the storage means is selected by the output selecting means based on the detection output by the motion detecting means, and Is output as a field, and the image information of the still part is output as a frame.

Further, in the image reproducing apparatus according to the present invention,
For example, at the time of low-speed reproduction, the image information from the storage means is selected by the output selection means based on the detection output by the motion detection means, the image information of the moving part is output as a field, and the image information of the stationary part is a frame. Output.

According to the image reproducing method of the present invention, at the time of variable speed reproduction in which image information recorded on a recording medium is reproduced at a speed lower than the standard reproduction speed, at least one frame of image information reproduced from the recording medium is stored. Then, motion detection based on field correlation is performed on the image information reproduced from the recording medium, and based on the result of the motion detection, the image information of the moving part is output as a field, and the image information of the stationary part is output as a frame.

In the image reproducing method according to the present invention, for example,
Based on the motion detection output for the frame image based on the last field of the captured image, the image information of the moving part is output as a field, and the image information of the still part is output as a frame.

In the image reproducing method according to the present invention, for example, when the reproduction is temporarily stopped, the image information of the moving part is output as a field and the image information of the still part is output as a frame based on the motion detection output.

Further, in the image reproducing method according to the present invention,
For example, at the time of low-speed reproduction, based on the motion detection output, image information of a moving part is output as a field, and image information of a still part is output as a frame.

[0014]

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

The present invention is applied to, for example, a reproduction system of a video tape recorder having a configuration as shown in FIG.

The reproduction system of the video tape recorder shown in FIG. 1 includes an A / D converter 4 to which an image signal reproduced from a video tape 1 by a video head 2 is supplied via a reproduction amplifier 3. The image signal converted into a digital signal by the A / D converter 4 is output to an image signal processing unit 5.
Are subjected to various signal processing such as FM demodulation and de-emphasis, and are supplied to the image signal output processing unit 6. The operation of the image signal output processing unit 6 is switched in accordance with the operation mode of the reproduction system. At the time of variable-speed reproduction, motion detection based on field correlation is performed on the image signal supplied from the image signal processing unit 5 to obtain a high-quality still image. A signal processing for generating an image is performed to obtain a reproduced image signal, and at the time of normal reproduction, the image signal supplied from the image signal processing unit 5 is directly output as a reproduced image signal via the D / A converter 7. It has become.

The playback system of this video tape recorder has a variable speed playback function for playing back an image signal recorded on a recording medium, that is, a video tape 1 at a speed lower than a standard playback speed, as shown in FIG. And operation panel 1
When the pause (PAUSE) button 10A provided at 0 is pressed, the mode control unit 11 receives an operation input by the pressing operation of the pause button 10A and sends a playback pause flag to the mechanism control unit 12 and The freeze flag is sent to the image signal output processing unit 6 at a timing so as to capture the image signal immediately before the video tape 1 stops.

Thus, the mechanism control unit 12 controls the servo control unit 13 in accordance with the reproduction pause flag, and feeds a tape running system supply reel 14 for running the video tape 1 wound on the rotating drum 9. The take-up reel 15 and the capstan 16 are stopped to pause the reproduction.

On the other hand, immediately after receiving the freeze flag, the image signal output processing section 6 takes in the image signal for one frame into the frame memory, freezes, detects a motion, and outputs a high quality still image signal.

As a result, a high-quality reproduction-paused image signal without blurring of one frame immediately before the video tape 1 is stopped is obtained for image output.

When a low-speed (SLOW) button 10B provided on the operation panel 10 is pressed, the mode control unit 11 receives an operation input by pressing the low-speed button 10B, and A low-speed playback flag is sent to the control unit 12 to control the servo control unit 13 so as to intermittently perform the above-described playback pause control operation, and to stop the video tape 1 due to the intermittent playback pause. By sending a freeze flag to the image signal output processing unit 6 at the same time as capturing the immediately preceding image,
It is possible to output a high-quality low-speed reproduction image signal without blurring through the image signal output processing unit 6.

Here, as shown in FIG. 3, the image signal output processing section 6 has a storage section 61 for storing the image signal supplied from the image signal processing section 5, and an image signal for the storage section 61. A memory control unit 62 for controlling the writing / reading of the image, a motion detection unit 63 for detecting the motion of the image signal taken into the storage unit 61, and image information of the motion part based on the detection output by the motion detection means. Is provided with an output selection unit 64 for selectively outputting an image signal read out from the storage unit 61 so as to output a field and output image information of a still part as a frame.

The storage section 61 has a storage capacity for storing image signals for one frame, and here is constituted by two field memories 61A and 61B. The memory control unit 62 controls to sequentially write and read the image signals supplied from the image signal processing unit 5 to the storage unit 61, and receives a freeze flag from the mode control unit 11. The writing is stopped in a state where the image signal for one frame immediately after that is taken into the storage unit 61, so that the image signal for one frame is frozen in the storage unit 61 and repeated from the storage unit 61. The writing / reading of the image signal to / from the storage unit 61 is controlled so as to be read.

The motion detecting section 63 detects the motion of the image signal for one frame frozen in the storage section 61 by the field correlation based on the last field of the image signal fetched into the storage section 61. Is performed, and the output selection unit 64 is controlled by the detection output. Accordingly, the output selection unit 64 selectively outputs the image signal read from the storage unit 61 so that the image information of the moving part is output as a field and the image information of the still part is output as a frame during variable-speed reproduction. Output.

Here, FIG. 4 shows an example of a mode transition diagram when the reproduction is temporarily stopped in the reproduction system of the video tape recorder.

That is, in the playback system of this video tape recorder, the mode control section 11 which has received the operation input of the pause button 10A in the O1 field sets the timing of writing to the storage section 61 of the image signal output processing section 6 above. To wait for two fields, a playback pause flag (PAUSE) is sent to the mechanism controller 12 in the O2 field. Upon receiving this, the mechanism control unit 12 issues a stop instruction (STOP) to the servo control unit 13 within the same field. As a result, the reproduced image is reproduced up to the O2 field, and the field still image of the last O2 field is output.

On the other hand, by sending a freeze flag (FREEZE) in the O1 field and the E2 field to the image signal output processing section 6, the image signal for one frame of the E2 field and the O2 field is frozen in the storage section 61. . As a result, the image signal for one frame immediately before the pause of the reproduction can be stored in the storage unit 61.

Further, the mode control section 11 sends a memory signal (MEM) to the image signal output processing section 6 in the O2 field after the freeze in order to switch the monitor image. Thus, the image signal output processing unit 6 switches from a through image signal to a memory image signal. Therefore, as the monitor image, the reproduced image is output as it is up to the O2 field, and thereafter, the memory image stored in the storage unit 61 is output.

Here, in the image signal output processing section 6,
The motion detection unit 6 detects the image signal for one frame of the E2 field and the O2 field stored in the storage unit 61.
By performing motion detection by field correlation in step 3,
Generate high-quality still images.

At this time, by setting the reference of the time axis to the O2 field, smooth switching can be performed without image skipping when switching from the reproduced image to the memory image.

FIG. 5 shows an example of a mode transition diagram at the time of 1/2 low-speed reproduction in the reproduction system of the video tape recorder.

That is, in the playback system of this video tape recorder, the low speed button 10B
The mode control unit 11, which has received the operation input of / 2 low-speed reproduction (1 / 2-SLOW), waits for two fields to take the timing of writing to the storage unit 61 of the image signal output processing unit 6 and waits for O2. A playback pause flag (PAUSE) is sent to the mechanism control unit 12 in the field. Mechanism control unit 12 receiving this
Sends a stop instruction (STOP) to the servo control unit 13 in the same field. As a result, the reproduced image is reproduced up to the O2 field, and the field still image of the last O2 field is output.

On the other hand, by sending a freeze flag (FREEZE) in the O1 field and the E2 field to the image signal output processing section 6, the image signal for one frame of the E2 field and the O2 field is frozen in the storage section 61. . As a result, the image signal for one frame immediately before the pause of the reproduction can be stored in the storage unit 61.

The mode control section 11 sends a memory signal (MEM) to the image signal output processing section 6 in the O2 field after the freeze in order to switch the monitor image. Thus, the image signal output processing unit 6 switches from a through image signal to a memory image signal. Therefore, as the monitor image, the reproduced image is output as it is up to the O2 field, and the E3 field and the O3 field are the memory still images composed of the image signals for one frame of the E2 field and the O2 field stored in the storage unit 61. Is done.

Here, in the image signal output processing section 6,
The motion detection unit 6 detects the image signal for one frame of the E2 field and the O2 field stored in the storage unit 61.
By performing motion detection by field correlation in step 3,
Generate high-quality still images.

At this time, by setting the reference of the time axis to the O2 field, smooth switching can be performed without image skipping when switching from the reproduced image to the memory image.

Then, the mode control unit 11 sends a release flag to the mechanism control unit 12 in the O3 field where the output of one frame of the memory still image ends. Upon receiving this, the mechanism control unit 12 sets the servo control unit 13 in the same field.
To the playback instruction (PB). As a result, the reproduced image up to the E4 field and the O4 field is output for one frame. In the meantime, a freeze flag (FREEZE) is sent to the image signal output processing unit 6, and the image signals of the E4 field and the O4 field are fetched into the storage unit 61 and frozen, and the output of the reproduced image is completed in the O4 field. A playback pause flag (PAUSE) is sent to the mechanism control unit 12. As a result, in the next E5 field and O5 field, a memory still image including one frame of image signals of the E4 field and the O4 field stored in the storage unit 61 is output.

Hereinafter, the same operation is repeated, and a memory still image is output every other frame, whereby a 1/2 low-speed reproduction operation can be performed.

As described above, in the image reproducing apparatus according to the present invention, the motion detection is performed based on the frame difference of the image signal, and the image of the moving part is output as a field to obtain a still image with improved image quality. For example, when an image whose scene is changed between the third field and the fourth field is recorded on the recording medium as shown in FIG. And the sixth
When the reproduced image stops between the fields, the motion detection based on the field correlation calculates the difference between the fourth field and the fifth field, so that the correct motion detection can be performed.
As shown in the image on the monitor screen in (B) of FIG.
A frame still image composed of the image of the field and the image of the fifth field is obtained, and the frame image quality can be obtained.

In this image reproducing apparatus, for example, FIG.
(A), an image in which the car is moving from left to right is recorded on the recording medium, and when the reproduction is paused and the reproduced image stops between the fourth field and the fifth field, Since the last field of the image signal fetched into the storage section 61, that is, the fourth field, is used as a reference on the time axis, the fourth field and the fifth field are displayed as shown in FIG. There is no skipping between fields.

[0041]

According to the image reproducing apparatus of the present invention, at least one frame of image information reproduced from the recording medium is stored by the storage means, and the motion detecting means detects the motion by the field correlation. Based on the detection output by the motion detection means, the image information from the storage means is selected by the output selection means, and the image information of the moving part is output as a field, and the image information of the still part is output as a frame. At a variable speed reproduction image output.

Further, in the image reproducing apparatus according to the present invention, at the time of variable-speed reproduction, for example, based on the motion detection output by the motion detection means for the frame image based on the last field of the image fetched into the storage means, The image information from the storage unit is selected by the output selection unit, and the image information of the moving part is output as a field, and the image information of the still part is output as a frame. When entering, it is possible to obtain a high-quality variable-speed reproduction image output without image skipping.

In the image reproducing method according to the present invention, at the time of variable speed reproduction in which image information recorded on the recording medium is reproduced at a speed lower than the standard reproduction speed, the image information for at least one frame reproduced from the recording medium is stored. Then, motion detection based on field correlation is performed on the image information reproduced from the recording medium, and based on the result of the motion detection, the image information of the moving part is output as a field, and the image information of the stationary part is output as a frame. It is possible to obtain a variable-speed reproduction image output of image quality.

In the image reproducing method according to the present invention, for example, based on a motion detection output for a frame image based on the last field of a captured image, image information of a moving portion is output as a field, and a still portion is output. Since the image information is output as a frame, a high-quality variable-speed reproduced image output can be obtained without causing image skipping when performing variable-speed reproduction such as reproduction pause or low-speed reproduction.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a playback system of a video tape recorder to which the present invention has been applied.

FIG. 2 is a block diagram showing a configuration for variable speed playback in a playback system of the video tape recorder.

FIG. 3 is a block diagram showing a configuration of an image signal output processing unit in a reproduction system of the video tape recorder.

FIG. 4 is a mode transition diagram in the playback system of the video tape recorder when playback is temporarily stopped.

FIG. 5 shows 1 in the reproduction system of the video tape recorder.
It is a mode transition diagram at the time of / 2 low-speed reproduction.

FIG. 6 is a diagram for explaining a monitor image on which motion detection based on field correlation has been performed in the reproduction system of the video tape recorder.

FIG. 7 is a diagram for explaining image skipping in a reproduction system of the video tape recorder.

FIG. 8 is a diagram for explaining a monitor image on which motion is detected by a frame difference method in a conventional image reproducing apparatus.

FIG. 9 is a diagram for explaining image skipping in a conventional image reproducing apparatus.

[Explanation of symbols]

1 video tape, 2 heads, 6 video signal processor,
7 video signal output processing unit, 10 operation panel, 11
Mode control unit, 12 mechanism control unit, 13 servo control unit, 61 storage unit, 62 memory control unit, 63 motion detection unit, 64 output selection unit

Claims (8)

[Claims] An image reproducing apparatus having a variable speed reproduction function for reproducing image information recorded on a recording medium at a speed lower than a standard reproduction speed, wherein the image information for at least one frame reproduced from the recording medium is stored. Storage means having a storage capacity for performing the motion detection; and motion detection means for performing motion detection based on field correlation for image information reproduced from the recording medium. At the time of variable-speed reproduction, the image information of the motion part is determined based on the detection output by the motion detection means. An image reproducing apparatus, comprising: output selection means for selectively outputting image information from the storage means so as to output a field and output image information of a still part as a frame. 2. The image processing apparatus according to claim 1, wherein the output selecting unit is configured to perform an image of a moving part during variable speed reproduction based on a motion detection output of the motion detecting unit with respect to a frame image based on a last field of the image captured in the storage unit. 2. The image reproducing apparatus according to claim 1, wherein the image information from the storage unit is selectively output so that the information is output as a field and the image information of the still part is output as a frame. 3. The image processing apparatus according to claim 1, wherein the output selection unit outputs image information of a moving part as a field output and image information of a still part as a frame output based on a detection output by the motion detection unit when the reproduction is paused. 2. The image processing apparatus according to claim 1, wherein the image information from the storage unit is selectively output.
The image reproducing apparatus according to any one of the preceding claims. 4. The image processing apparatus according to claim 1, wherein the output selecting means outputs the field information of the moving part and outputs the frame information of the stationary part based on the detection output by the motion detecting means at the time of low-speed reproduction. 2. The image reproducing apparatus according to claim 1, wherein the image information from the storage means is selectively output. 5. At the time of variable speed reproduction in which image information recorded on a recording medium is reproduced at a speed lower than a standard reproduction speed, at least one frame of image information reproduced from the recording medium is stored and reproduced from the recording medium. An image reproducing method, comprising: performing motion detection on image information by field correlation; and outputting image information of a moving part as a field output and image information of a still part as a frame output based on the result of the motion detection. 6. The image information of a moving part is output as a field, and the image information of a still part is output as a frame, based on a motion detection output for a frame image based on the last field of the captured image. The image reproducing method according to claim 5, wherein 7. The image reproducing method according to claim 5, wherein, when the reproduction is paused, the image information of the moving part is output as a field and the image information of the stationary part is output as a frame based on the motion detection output. . 8. The image reproducing method according to claim 5, wherein at the time of low-speed reproduction, based on the motion detection output, the image information of the moving part is output as a field, and the image information of the stationary part is output as a frame.