JP2002135724A - Methods for shooting and reproducing images and their device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide methods for shooting and reproducing images and their devices which enables to avoid capacity oppression of a recording medium by devising photographing of interval images, and to reduce the labor at reproduction of the interval images. SOLUTION: An image shooting part 2 periodically generates and outputs image signals. A control part 4 functions as a control means, provided with a means for capturing images from the shooting part 2 at prescribed internals, a means for evaluating correlation between the adjacently captured images on the time axis, and a control means for storing only low correlation images evaluated by the evaluation means in a storage means (storage part 6).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image capturing method, an image reproducing method, an image capturing apparatus, and an image reproducing apparatus.
The present invention relates to an imaging method, an image reproducing method, an imaging device, and an image reproducing device applicable to a digital camera and the like.

[0002]

2. Description of the Related Art Recently, a CCD (Charge Coupled Device) has been developed.
2. Description of the Related Art Imaging devices such as digital cameras that electronically record image signals captured by an image sensor such as e) in a storage medium such as a semiconductor memory have become widespread. Such an imaging device is
It has excellent features not found in traditional silver halide cameras, such as the ability to instantly delete unwanted images by checking the image playback and providing various special shooting modes using its digital processing function.

Here, one of the special photographing modes is called "interval photographing". In this mode, an image signal captured by an image sensor is fetched and recorded electronically on a storage medium at a fixed value or at fixed time intervals that can be set by a user. Now, assuming that the above-mentioned fixed time is t minutes and the number of shots is n for convenience, the camera is fixed with a tripod, the camera is pointed at the subject, the composition is adjusted, and then the camera is set to the interval shooting mode and the shutter is released. When is depressed, n images finally taken at intervals of t minutes are recorded in the storage medium inside the camera. Therefore, for example, photographing that requires patience, such as flowering photographing of a flower, can be easily performed.

[0004]

However, in the above-described conventional imaging apparatus having the interval photographing mode, all the n images photographed at every t time are recorded. However, when photographing the flowering of a flower, a plurality of similar images are recorded, so that there is a problem that the capacity of the recording medium is pressed. Further, at the time of reproducing the image, it is necessary to search for an image showing a specific change (for example, the moment of flowering) from similar images, which is troublesome.

Accordingly, the present invention avoids pressure on the recording medium by devising shooting of an interval image,
An object of the present invention is to reduce time and effort in reproducing an interval image.

[0006]

According to one aspect of the present invention, an image from an image generating means for periodically generating and outputting an image signal is captured at predetermined intervals, and each captured image is stored as an interval image in a storage means. When letting
It is characterized in that the correlation between adjacent images on the time axis is evaluated, and only images having low correlation are stored in the storage means. According to one aspect of the invention, the similarity between adjacent images on the time axis is determined, and only images having low similarity are stored as interval images. The second invention captures an image from an image generating unit that periodically generates and outputs an image signal at predetermined intervals, and stores each captured image in a storage unit as an interval image. Evaluating the correlation of matching images and storing an identifier with low correlation in the storage means, and storing an image with low correlation in the storage means without adding an identifier, or a time axis While evaluating the correlation of the adjacent images above and assigning an identifier to an image having a low correlation and storing the image in the storage unit, an image having a low correlation is stored in the storage unit without an identifier. It is characterized by having done. In the second invention, the similarity of the images adjacent on the time axis is determined, and images with low similarity are assigned and stored, while images with low similarity are not assigned with identifiers. Images are stored, or images with high similarity are identified and stored, while images with low similarity are stored without identification. According to a third aspect of the present invention, when reading out the interval images stored in the storage means and displaying the interval images on the display means, it is determined whether or not each read-out image has an identifier, and the display image is selected according to the presence or absence of the identifier. It is characterized by doing. According to the third aspect, only one of the interval image stored in the storage means and the image to which the identifier has been added is displayed. In a preferred aspect of each of the above inventions, the threshold value for the correlation determination is selected or designated by a user. In this aspect, the similarity determination condition is selected or designated by the user.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below by taking a digital camera as an example with reference to the drawings. First, the configuration will be described. FIG. 1 is a conceptual block diagram of a digital camera. In this block diagram, for example, an image pickup unit 2 (image generation unit), an operation unit 3, and a control unit 4 (capture unit, evaluation unit) classified according to functions ,
Control unit, reading unit), display unit 5 (display unit), storage unit 6 (storage unit), and external I / O unit 7.

The imaging section 2 includes an image sensor (not shown) such as a CCD that captures an image of the subject 1 and generates an image signal of several tens of frames per second. The image signal is generally a color image signal, but may be a monochrome image signal in the spirit of the present invention. Hereinafter, assuming that the image signal is a color image signal, the imaging unit 2 includes an auxiliary circuit (a timing circuit, a sampling and holding circuit, an analog-to-digital conversion circuit, and the like) of the image sensor, and also includes a color difference signal generation circuit. The color difference signal generation circuit separates a luminance component (Y) and color components (Cr, Cb) from the analog-digital converted color image signal, and outputs the YCrCb signal to the control unit 4.

The operation unit 3 includes various operation keys provided at arbitrary positions on the body of the digital camera. These keys are at least a power switch and a shutter key operated at the time of shooting, and further, for example, a mode switching key for switching between a shooting mode and a playback mode,
Menu keys for performing system settings, cursor operation keys for menu selection, and the like.

The control unit 4 includes a CPU 4a as shown in a conceptual block diagram of FIG.
4a, a program memory 4c, a work memory 4d, an input unit 4e, an output unit 4f, and the like are connected via a bus 4b. CPU 4a is a program memory 4
c is stored in the work memory 4
By loading the data into d and executing it, the entire operation of the digital camera is controlled while fetching data from the input unit 4e and writing data to the output unit 4f.

The display unit 5 has a display for visualizing and displaying various data output from the control unit 4. This display is generally a high-resolution color liquid crystal display, which displays a through image at the time of shooting and a captured image at the time of reproduction, and also displays various setting screens. The storage unit 6 is a recording medium for recording a captured image in a non-volatile manner (that is, information is not lost even when the power is turned off). For example, a semiconductor storage device such as a flash memory or a magnetic memory device is used. . The storage unit 6 may be mounted on the digital camera in a detachable state. The external I / O 7 is required, for example, when exchanging image information with an external personal computer.

Next, the operation will be described. FIG. 3 is a schematic flowchart showing a part of the control program stored in the program memory 4c, and particularly shows a part executed when performing “interval shooting”. The execution of this interval shooting program is started by turning on the power switch of the digital camera and switching the shooting mode to “interval shooting”. In addition, as explained at the beginning,
"Each time a fixed value or a user-settable time interval, an image signal captured by the image sensor is fetched and electronically recorded on a storage medium."

When the illustrated interval photographing program is executed, first, a screen for prompting the user to select a mode of the interval photographing (hereinafter, referred to as a "photographing mode selection screen") is displayed (steps S11 and S1).
2). FIG. 4A is a diagram showing a display example of a photographing mode selection screen. The display of the display unit 5 displays an operation guide character string (“Please select a photographing mode for interval photographing” in the figure). A shooting mode selection screen 10 including a display area 10a and a display area 10b of a selection menu (in the figure, two menus of “motion detection off mode” and “motion detection on mode”) is displayed.

When the user desires the same interval photographing as that of the prior art, he operates the cursor keys to select the "motion detection off mode". If it is desired to eliminate the difficulty of searching for the middle image of interest), the user similarly operates the cursor keys to select the "motion detection on mode".

When the mode selection of the interval shooting is detected ("YES" determination in step S12), a screen for prompting the user to specify the interval (hereinafter, referred to as "interval interval designation screen") is displayed (step S12). Step S13, Step S14). FIG. 4B is a diagram showing a display example of the interval interval designation screen, and the display unit 5
The display area 11 of the operation guide character string (“Please specify the interval interval” in the figure) is displayed on the display.
a and one of the selection menus (“1 minute” to “10 minutes” in the figure)
An interval specification screen 11 including a display area 11b of “0 menus” is displayed. The user operates the cursor key to select and specify a time corresponding to or close to the desired interval from the menu.

When the designation of the interval is detected ("YES" determination in step S14), the image signal (YCrCb signal, hereinafter simply referred to as "image signal") for one frame from the image pickup section 2 is fetched. (Step S1
5) The operation of sending the image signal to the display unit 5 and displaying the image signal on the display (step S16) is performed by pressing down the shutter key (“YE” in step S17).
The processing is repeatedly executed until S ”determination).

Accordingly, in the above steps, an image signal periodically updated at several tens of frames per second is displayed as a through image on the display of the display unit 5 until the shutter key is pressed down. The user can adjust the composition of the subject 1 while watching the through image.

If the shutter key detects a depression operation ("YES" determination in step S17), the latter half of the interval photographing program shown in FIG. 5 is executed for convenience of illustration. In the latter half, first, the loop variable i is set to 0 and initialized (step S18), and then the mode determination of the interval shooting is performed (step S19). FIG. 4A shows the interval shooting mode.
Is a mode selected by the user using the interval shooting mode selection screen 10 shown in FIG. 1 and is either the “motion detection off mode” or the “motion detection on mode”.

<Motion Detection Off Mode> The motion detection off mode is a mode corresponding to the related art at the beginning, in other words, a mode inherent in the disadvantages of the related art. In this mode, first, an image signal (hereinafter, referred to as a “current image”) taken into the control unit 4 from the imaging unit 2 at that time is stored in the storage unit 6 as an i-th interval image (Gi) (step S1). After S20), the loop variable i is incremented by 1 (step S21), then, the expression “i> imax” is evaluated (step S22), and the evaluation result is True (a true value; “YES” determination in the flow). ) Until the interval interval elapses (“YE” in step S23).
The image signal is fetched for each S ”determination (step S2)
4) is performed, and the above steps S20 to S24 are repeatedly executed. Here, imax is the maximum number of recorded interval images.

According to this, when the evaluation result of the expression "i>imax" becomes True and the interval photographing is completed, the interval image array 12 as shown in FIG. Become. Here, the illustrated interval image array 12 includes a 0th interval image (G0), a first interval image (G1),
The third interval image (G3), the fourth interval image (G3)
4), ‥‥. For example, the interval specified by the user is “1 minute”, and the time when the shutter key is pressed down is “7: 0” for convenience.
When "0" is set, the shooting time of G0 is 7:00, the shooting time of G1 is 7:01, the shooting time of G2 is 7:02, the shooting time of G3 is 7:03, and the shooting time of G4 is 7:04. .

By the way, as described in the related art at the beginning, in such interval photographing at regular intervals, for example, when photographing the flowering of a flower, the moment of flowering is photographed at each interval. However, in many cases, similar images are arranged. For example, FIG. 7 is an example of an image arrangement of a flower blooming photographed in the “motion detection off mode” (in other words, the interval photographing mode of the related art at the beginning). There are only two images, and if the image before flowering (G0) is also included, only three images are useful.
It is only a sheet (G0, G3, G5). For this reason, in the “motion detection off mode” (the first prior art interval photographing mode), useless images are also stored in the storage unit 6, so that there is a problem that the storage capacity is compressed,
Further, there is a problem in that many images must be previewed to find a meaningful image (for example, the moment of flowering) when reproducing the interval image, which is troublesome.

On the other hand, in a mode (motion detection ON mode) specific to the present embodiment described below, the correlation between image signals before and after adjacent on the time axis is compared, and the correlation is high. Since the similar images are not stored in the storage unit 6, the above problem can be solved.

<Motion Detection On Mode> That is, in the motion detection on mode, first, an image signal (hereinafter, referred to as a “current image”) taken into the control unit 4 from the imaging unit 2 at that time is used as a current image variable. Set to Gc (step S25). Next, the loop variable i is checked and if it is the initial value (0) ("YES" in step S26)
Determination), the image set in Gc is stored in the storage unit 6 as the i-th interval image (Gi) (step S2).
7) On the other hand, if the loop variable i exceeds the initial value (0) ("NO" determination in step S26), Gc and Gi-
1 is calculated (step S28), and the correlation value is compared with a predetermined value (step S29). If the correlation value is smaller than the predetermined value, the image set to Gc is replaced with the i-th interval image ( Gi) is stored in the storage unit 6 (step S
30).

Then, similarly to the motion detection off mode, the loop variable i is incremented by 1 (step S31).
> Imax ”(step S32), and image signals are fetched (step S34) every time the interval interval elapses (“ YES ”determination in step S33) until the evaluation result becomes True.
Step S34 is repeatedly executed.

Here, Gi-1 is the previously stored G
i, and the correlation value between Gc and Gi-1 is, for example,
A correlation value obtained by using an evaluation method such as a frame correlation. The correlation value indicates a large value when the similarity between the two images (Gc and Gi-1) is high, and indicates a small value when the similarity is low. The “predetermined value” in step S29 is a “threshold value” for similarity determination, and in the motion detection on mode, an image (G) having a correlation value less than this threshold value
Only c) is stored in the storage unit 6 as the i-th interval image (Gi).

Therefore, according to the motion detection ON mode, two images (Gc and Gi-
By comparing 1), an image having a large correlation value exceeding a predetermined value (an image having a high similarity) can be prevented from being included in the interval image (Gi). Eliminating the drawback of (Equivalent) can be avoided, and it is possible to avoid pressure on the storage capacity and to reduce the time and effort required for reproduction.

For example, FIG. 8 shows an example of an image arrangement of a flowering flower photographed in the "motion detection on mode". The image arrangement includes an image before flowering (G0) and an image at the moment of flowering (G1, G2), an image having a large correlation value exceeding a predetermined value (an image having a high similarity: FIG. 7) when compared with the image arrangement example in the motion detection off mode (see FIG. 7). G1, G2, G4, G6, G at
7, G8) is eliminated, so that the storage capacity is not squeezed, and many images are used to find a meaningful image (for example, the moment of flowering) when reproducing the interval image. The special effect that there is no need to preview is obtained.

The present invention is not limited to the above embodiment, but includes various modifications within the scope of the present invention. For example, in the above embodiment, only those having low similarity between the images (Gc and Gi-1) adjacent on the time axis are stored in the storage unit 6, but all the images are stored and reproduced. At the stage, only those having low similarity may be selectively extracted. At least, the time and effort required for reproduction can be reduced.

FIG. 9 is a flowchart showing a modification of the embodiment, and corresponds to steps 25 to S34 in FIG. Note that the same steps as those in FIG. 5 are denoted by the same step numbers.

In FIG. 9, the difference from FIG. 5 is that the current image (Gc) is unconditionally changed between the step S25 and the step S26.
i) storing in the storage unit 6 (step S5)
In the case where the correlation value <predetermined value is determined in step S29, in other words, when the similarity between Gc and Gi-1 is low, a predetermined identifier (hereinafter referred to as Gc) is added to Gc (= Gi). (Hereinafter, referred to as “mark”) is added (step S52). A mark (identifier) is a flag added to image data to determine an image.

According to this, all of the interval images photographed at regular intervals are stored in the storage unit 6, and a predetermined mark is given to an image having low similarity among the images adjacent on the time axis. Therefore, by extracting a reproduced image with reference to the mark, it is possible to obtain an effect that at least labor required for image reproduction can be reduced. Of course, contrary to the above description, a predetermined mark is applied to an image having a high similarity among the images adjacent on the time axis, and an image other than the marked image is extracted as a reproduced image. Has the same effect.

FIG. 10 is a flowchart of an interval image reproducing program for performing mark reference. When this program is executed, first, an image selection screen prompting the user to select which of the interval images stored in the storage unit 6 is to be reproduced is displayed on the display unit 5 (step S61).
When the reproduction interval image is selected, the loop variable i is initialized to 0 (step S62), and it is determined whether or not the i-th interval image (Gi) is marked (step S63). ), If marked, the image (Gi) is read from the storage unit 6 (step S64) and displayed on the display unit 5 (step S64).
65), and waits for the next image display update operation (NEXT operation) by the user (step S66), and NEXT
When an operation is detected, the loop variable i is incremented by 1 (step S
67), evaluate the expression “i> imax” (step S68)
Steps S63 to S68 are repeated until the evaluation result becomes True.

According to this, even if all of the interval images photographed at regular intervals are stored in the storage unit 6, when the interval images are reproduced,
Only images having low similarity can be selected and extracted from the images adjacent on the time axis and displayed on the display unit 5.
At least, it is not necessary to search for an image showing a specific change from similar images, so that it is possible to reduce labor.

In the above description, a fixed value set in advance as the "threshold" for determining the similarity of the images arranged on the time axis (see the predetermined value in step S29 in FIG. 5 or FIG. 9) However, the present invention is not limited to this. A threshold value that can be manually selected (or designated) by the user may be used.

For example, at an appropriate stage immediately after the start of the interval photographing mode (before step S11 in FIG. 3, between steps S12 and S13 or in step S13).
14), the threshold selection screen 1 as shown in FIG.
3 may be displayed to allow the user to select a desired threshold condition.

In FIG. 11, on the display of the display unit 5, a display area 1 of an operation guide character string ("Please specify a motion detection level for interval photographing.").
3a and a selection menu ("Detect large motion" in the figure)
"Detects medium or higher motion" and "Detects small motion"
A threshold selection screen 13 including a display area 13b of a three-stage menu) is displayed. The user operates the cursor keys to select and specify a desired threshold condition from the menu.

According to this, when "detect a large motion" is designated, a large value is set to the predetermined value in step S29 of FIG. 5 or FIG. 9, or "detect a medium or higher motion". If specified, set the medium value to the predetermined value, or set "small motion detection" to a small value to the predetermined value to set each threshold condition. Accordingly, the interval image can be selectively recorded (or selectively marked) in three cases of large, medium and small similarities of images adjacent on the time axis, and the optimal interval adapted to the movement of the subject Shooting can be performed.

[0038]

According to one aspect of the present invention, similarities between images adjacent on the time axis are determined, and only images having low similarity are stored as interval images, so that images with little motion can be excluded from recording. , You can avoid pressure on storage capacity,
There is no need to search for a specific image at the time of reproduction, and it is possible to reduce labor. According to the second aspect, the similarity between the images adjacent on the time axis is determined, and the images having low similarity are identified and stored, while the images having low similarity are identified. Since it is stored without being stored, it is possible to at least reduce the labor at the time of reproduction by selectively reproducing only the image with the identifier. Alternatively, this effect can also be obtained by storing an image with a high similarity by assigning an identifier to the image and by storing an image with a low similarity without assigning an identifier. This is because it is only necessary to selectively reproduce only images for which no identifier has been assigned. According to the third aspect, of the interval images stored in the storage means, only the image with the identifier (or only the image without the identifier)
Is displayed. Therefore, by combining with the second invention, it is possible to realize an image recording / reproducing apparatus which achieves a reduction in labor during reproduction. According to the preferred aspect of each of the above inventions, the similarity determination condition is selected or designated by the user, so that the determination condition suitable for the movement of the subject can be applied, and it is possible to flexibly cope with various shooting environments.

[Brief description of the drawings]

FIG. 1 is a conceptual block diagram of a digital camera.

FIG. 2 is a conceptual block diagram of a control unit 4.

FIG. 3 is a diagram showing a flowchart of an interval shooting program.

FIG. 4 is a diagram showing a display example of a shooting mode selection screen and an interval interval designation screen.

FIG. 5 is a diagram showing a flowchart of the latter half of the interval shooting program.

FIG. 6 is a diagram illustrating an example of an interval image array shot in a motion detection off mode.

FIG. 7 is a diagram illustrating an example of an image arrangement of flowering of flowers photographed in the motion detection off mode.

FIG. 8 is a diagram illustrating an image arrangement example of flowering of a flower taken in the motion detection on mode.

FIG. 9 is a diagram showing a modification of the motion detection on mode processing program.

FIG. 10 is a flowchart of an interval image reproducing program for performing mark reference.

FIG. 11 is a diagram showing a display example of a threshold value selection screen.

[Explanation of symbols]

2 imaging unit (image generation unit) 4 control unit (capture unit, evaluation unit, control unit, reading unit) 5 display unit (display unit) 6 storage unit (storage unit)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H04N 5/225 H04N 5/225 F 5/232 Z 5/232 101: 00 5/765 5/92 H 5 / 781 5/781 520A 5/915 5/91 K // H04N 101: 00

Claims (8)

[Claims] An image from an image generating means for periodically generating and outputting an image signal is captured at predetermined intervals, and when each captured image is stored as an interval image in a storage means, the adjacent image is stored on a time axis. An imaging method, wherein the correlation between matching images is evaluated, and only images having low correlation are stored in the storage unit. 2. An image from an image generating means for periodically generating and outputting an image signal is taken in at predetermined intervals, and each of the taken images is stored as an interval image in a storage means. While evaluating the correlation of the matching image and assigning an identifier to the image with low correlation and storing the identifier in the storage means,
Images that are not low in correlation are stored in the storage unit without attaching an identifier, or images that are not low in correlation are evaluated by evaluating the correlation between adjacent images on the time axis, and the storage unit is assigned an identifier. An imaging method, wherein an image having low correlation is stored in the storage unit without an identifier. 3. The imaging method according to claim 1, wherein a threshold value for the correlation determination is selected or designated by a user. 4. When reading an interval image stored in a storage means and displaying the interval image on a display means, it is determined whether or not each read image is assigned an identifier. An image reproducing method, characterized in that only one of the unexecuted images is to be displayed. 5. An image generating means for periodically generating and outputting an image signal, capturing means for capturing an image from the image generating means at predetermined intervals, and a correlation between the captured images adjacent on a time axis. An image pickup apparatus comprising: an evaluation unit that evaluates the following; and a control unit that stores only an image with low correlation evaluated by the evaluation unit in the storage unit. 6. An image generating means for periodically generating and outputting an image signal, capturing means for capturing an image from the image generating means at predetermined intervals, and correlation between the captured images adjacent on a time axis. An evaluation means for evaluating the image, and storing the image having a low correlation evaluated by the evaluation means with an identifier and storing the image in the storage means. The control means or the image having a low correlation evaluated by the evaluation means is assigned an identifier and stored in the storage means, while the image with low correlation is stored in the storage means without the identifier. An imaging apparatus, comprising: any one of control means. 7. The imaging apparatus according to claim 5, wherein a threshold value for the correlation determination is selected or designated by a user. 8. A storage means for storing an interval image, a reading means for reading each of the interval images from the storage means, an image for determining whether or not each read image is assigned an identifier, and identifying the image. Or a control means for outputting only one of the images to which no identifier is assigned to the display means and displaying the image on the display means.