JP2004221992A - Imaging device and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a user-friendly miniaturized imaging device. <P>SOLUTION: The imaging device is capable of imaging: in a first imaging mode of obtaining an exposure-corrected synthesized image by combining a plurality of images obtained by successive imaging; or a second imaging mode of obtaining the image equivalent to the synthesized image by a single imaging. The imaging device is provided with a control means capable of setting one of the first imaging mode and the second imaging mode in accordance with imaging conditions. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image capturing apparatus that improves the accuracy of a captured image by correcting camera shake.
[0002]
[Prior art]
With the current camera, all the important operations for photographing such as exposure determination and focusing are automated, and even a person unskilled in camera operation is very unlikely to fail in photographing.
[0003]
In recent years, a system for preventing camera shake added to a camera has been studied, and a factor that causes a photographer to make a photographing error has almost disappeared.
[0004]
Here, an image stabilizing system for preventing camera shake will be briefly described.
[0005]
The camera shake at the time of shooting is typically a vibration of 1 Hz to 10 Hz as a frequency, but as a basic idea for enabling taking a photograph without image shake even if such a camera shake occurs at the time of exposure, A camera shake due to camera shake must be detected, and the correction lens must be displaced in a plane orthogonal to the optical axis in accordance with the detection result (optical anti-vibration system).
[0006]
That is, in order to take a picture in which image shake does not occur even when camera shake occurs, first, it is necessary to accurately detect the vibration of the camera and, second, to correct the optical axis change due to camera shake.
[0007]
In principle, the image blur is corrected by detecting acceleration, angular acceleration, angular velocity, angular displacement, and the like using a laser gyro or the like, and mounting a vibration detection unit in the camera that performs appropriate arithmetic processing on the detection result. be able to. Then, image shake correction is performed by driving a shake correction optical device (including a correction lens) that decenters the photographing optical axis based on the camera shake detection information from the vibration detection unit.
[0008]
On the other hand, photographing is repeated a plurality of times with an exposure time that does not cause camera shake, and the images obtained by the photographing are combined while correcting the image deviation to obtain a photographed image (synthesized image) with a long exposure time. There is a method (for example, Patent Document 1).
[0009]
[Patent Document 1]
Patent No. 3110797
[0010]
[Problems to be solved by the invention]
Recent digital cameras have become smaller than silver halide compact cameras, and in particular, cameras having a VGA class image sensor have become smaller as they are built into portable electronic devices (for example, cellular phones).
[0011]
Under these circumstances, if the above-described optical image stabilizing system is mounted on a camera, it is necessary to further reduce the size of the shake correction optical device or the size of the vibration detection unit.
[0012]
However, since the shake correction optical device needs to support the correction lens and drive it with high precision, there is a limit to miniaturization. In addition, most of the vibration detection units currently used use inertial force. Therefore, when the vibration detection unit is miniaturized, the detection sensitivity is reduced, and there is a problem that accurate vibration correction cannot be performed.
[0013]
Further, as the shake applied to the camera, there are an angular shake about a predetermined axis and a shift shake that shakes the camera in parallel, and the angular shake can be corrected by the optical image stabilization system, but it is difficult to take measures against the shift shake. . In particular, as the camera becomes smaller, the shift shake tends to increase.
[0014]
On the other hand, as another image stabilization system, an image sensor detects a motion vector of a screen and changes a readout position of an image in accordance with the motion vector as in the case of using a video camera to shoot a moving image. There is also a way to get a video without any.
[0015]
In the case of such a method, there is no need for a dedicated vibration detection unit or a correction lens as in the above-described optical image stabilization system, and thus there is an advantage that the entire product can be reduced in size.
[0016]
However, this video camera image stabilization system cannot be easily applied to a digital camera. The reason will be described below.
[0017]
The extraction of a motion vector in a video camera is performed every time an image is read out. For example, if 15 frames of images are extracted per second, the extracted images are compared to detect a motion vector.
[0018]
However, when photographing a still image with a digital camera, only one exposure is performed on the photographed subject, so that it is impossible to detect a motion vector by comparing images as in a video camera.
[0019]
For this reason, the image stabilizing system of the video camera cannot be simply adapted to the digital camera.
[0020]
On the other hand, in the image stabilization method as disclosed in Japanese Patent Application Laid-Open No. H11-157300, photographing is repeated a plurality of times, so that the photographing time is long. For this reason, if this method is used indiscriminately, the number of failed pictures such as blurring of the subject may be increased.
[0021]
The user must always consider the conditions for using the image stabilization method, and the system becomes more difficult to handle than a normal imaging method in which imaging is performed with one exposure. This will be specifically described below.
[0022]
Unlike a silver halide camera, a digital camera can freely change the sensitivity (imaging sensitivity) of an image sensor. For this reason, a certain amount of camera shake can be prevented by increasing the imaging sensitivity even for a dark subject.
[0023]
The imaging sensitivity can be set by the camera (automatic setting) or can be set by the user himself.
[0024]
In this way, digital cameras have more parameters to determine the necessity of using image stabilization than silver halide cameras, so it is difficult for the user to judge whether anti-vibration measures are really necessary. This makes the system difficult to handle.
[0025]
Further, in the above-described image stabilization method, since a plurality of exposures are performed at one time of photographing, the user may feel uncomfortable.
[0026]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a small image stabilization system for photographing a still image of a digital camera different from an optical image stabilization system of a silver halide camera or a video camera. A method of repeating photographing a plurality of times with an exposure time that does not cause camera shake, and synthesizing the images obtained by the plurality of photographing while correcting the deviation to obtain a photographed image (synthesized image) having a long exposure time It is an object of the present invention to provide a photographing device in which even when the camera is mounted on a digital camera, the operation is automatically set by the camera to prevent a failure in photographing, and the user does not feel uncomfortable with the handling.
[0027]
[Means for Solving the Problems]
The first invention of the present application provides a first imaging mode in which a plurality of images obtained by sequentially capturing images are combined to obtain a composite image subjected to exposure correction, and an image corresponding to a combined image obtained by one shot. A photographing apparatus capable of photographing in a second photographing mode to be obtained, comprising a control means capable of setting one of the first photographing mode and the second photographing mode according to photographing conditions at the time of photographing. It is characterized by having.
[0028]
The second invention of the present application is a first photographing mode in which a plurality of images obtained by sequentially photographing are combined to obtain a combined image with exposure correction, and an image corresponding to a combined image by one photographing is formed. A program that enables shooting in a second shooting mode to be obtained, the control step being capable of setting one of the first shooting mode and the second shooting mode according to shooting conditions at the time of shooting. It is characterized by having.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
FIG. 1 is a diagram showing a configuration of a camera (photographing apparatus) according to a first embodiment of the present invention. A light beam (photographing light) incident from the photographing lens 11 passes through the shutter 12a and is imaged by the image pickup unit 19 after the light amount is restricted by the aperture 13a. The imaging unit 19 includes a semiconductor imaging device such as a MOS or a CCD.
[0030]
The taking lens 11 is composed of a plurality of optical lens groups, and some or all of these lens groups move on the optical axis 10 by receiving a driving force from the AF drive motor 14a and stop at a predetermined focusing position. Focus adjustment. The AF drive motor 14a is driven by receiving a drive signal from the focus drive unit 14b.
[0031]
Further, some optical lens groups of the photographing lens 11 receive the driving force from the zoom drive motor 15a, move on the optical axis 10, and stop at a predetermined zoom position to change the photographing angle of view. The zoom drive motor 15a is driven by receiving a drive signal from the zoom drive unit 15b.
[0032]
The aperture 13a has a plurality of aperture blades, and these aperture blades operate by receiving a driving force from an aperture drive unit 13b to change an opening area (aperture aperture) serving as a light passage port. The shutter 12a has a plurality of shutter blades, and these shutter blades open and close an opening serving as a light passage opening by receiving a driving force from the shutter driving unit 12a. Thereby, the light beam incident on the imaging unit 19 is controlled.
[0033]
In addition, the strobe 16a is driven (emitted) by receiving a drive signal from the flash drive unit 16b in accordance with conditions at the time of shooting (such as subject brightness).
[0034]
Further, the speaker 17a is driven (sounds) in response to a driving signal from the sounding drive unit 17b in order to notify the photographer of the shooting operation.
[0035]
The driving of the focus drive unit 14b, the zoom drive unit 15b, the aperture drive unit 13b, the shutter drive unit 12b, the flash drive unit 16b, and the sound drive unit 17b is controlled by a shooting control unit (control means) 18.
[0036]
Operation signals from a release operation unit 12c, an aperture operation unit 13c, a zoom operation unit 15c, a flash operation unit 16c, and an image stabilization operation unit 120 to be described later are input to the imaging control unit 18. The operation signals are given to the focus driving unit 14b, the zoom driving unit 15b, the aperture driving unit 13b, the shutter driving unit 12b, and the flash driving unit 16b in accordance with the photographing state, and the photographing conditions are set to perform photographing. .
[0037]
The aperture diameter of the aperture 13a and the light emission of the strobe 16a are normally set automatically by the camera at the time of photographing. Therefore, the aperture operation section 13c and the flash drive section 16b are unnecessary, but the photographer can arbitrarily take the It is provided for setting conditions.
[0038]
The photographing control unit 18 measures the subject brightness (photometry) based on an image signal captured by a signal processing unit 111 described later, and based on the photometric result, the aperture diameter of the aperture 13a and the closing timing (exposure) of the shutter 12a. Time). Further, the imaging control unit 18 obtains the in-focus position of the imaging lens 11 based on the output from the signal processing unit 111 while driving the focus driving unit 14b.
[0039]
The video signal output from the imaging unit 19 is converted into a digital signal by the A / D conversion unit 110 and input to the signal processing unit 111. The signal processing unit 111 performs signal processing such as forming a luminance signal and a color signal on the input signal to form a color video signal.
[0040]
Then, the video signal processed by the signal processing unit 111 is input to the image correction unit 117 via the signal switching unit 112.
[0041]
The image correction unit 117 performs gamma correction and compression processing on the input signal.
[0042]
An output signal of the image correction unit 117 is input to a display unit (display unit) 118 and a recording unit 119, and a captured image is displayed on the display unit 118 and recorded in the recording unit 119.
[0043]
In the operation described above, if the subject to be photographed is dark and the exposure time is long, there is a risk of camera shake, so the photographer operates the image stabilization operation unit 120 to turn on the image stabilization system, and performs the following operation. Switch.
[0044]
First, when the photographer half-presses the release button of the release operation unit 12c, a photographing preparation operation (focus adjustment operation, photometric operation, etc.) is started. Then, the closing timing (exposure time) of the shutter 12a and the aperture diameter of the aperture 13a are set based on the photometric value obtained by the photometric operation, but the subject is generally dark under shooting conditions such as using an anti-vibration system. Therefore, the aperture is fully open and the exposure time is long exposure.
[0045]
Therefore, this exposure time is divided into a plurality of short exposure times, and photographing is repeated by the number of divisions. When the exposure time is divided into such short exposure times, each image obtained by exposure becomes underexposed, but these images are less affected by camera shake.
[0046]
Then, the exposure is improved by combining a plurality of images after photographing and combining them into one image.
[0047]
However, when capturing a plurality of images, the composition between the images may be slightly shifted due to camera shake during continuous shooting even if the effect of camera shake does not occur in each image obtained by the plurality of shootings. is there. Here, if these images are combined as they are, the combined image will be an image in which the composition of each image is deviated by the deviation.
[0048]
In the present embodiment, an image signal output from the imaging unit 19 for each shooting in accordance with continuous shooting is converted into a digital signal by the A / D conversion unit 110 and then subjected to signal processing by the signal processing unit 111. You.
[0049]
On the other hand, when the imaging control unit 18 is instructed to operate the image stabilization operation unit 120 to turn on the image stabilization system, the image data from the signal processing unit 111 is transmitted to the image storage unit via the signal switching unit 112. 113 is input. That is, the input to the image correction unit 117 is cut off.
[0050]
The image storage unit 113 stores all of the plurality of captured images.
[0051]
The displacement detection unit (displacement amount detection means) 114 extracts a feature point (specific point) in the image stored in the image storage unit 113, and calculates the position coordinates of this feature point in the shooting screen.
[0052]
For example, as shown in FIG. 2, consider a case where a photograph is taken in which a person 122a stands with a building 123a as a background in a frame 121a. At this time, if a plurality of images are taken, an image whose composition is deviated from the frame 121a due to camera shake, such as the frame 121b, may be taken.
[0053]
The displacement detection unit 114 extracts an edge 125a of the window 124a, which is a point of high luminance, from the building 123a located around the screen as a feature point by edge detection, and compares the feature point 125a with the feature point 125b in the frame 121b. Then, the difference is corrected (coordinate conversion).
[0054]
In FIG. 2, the coordinates of the frame 121b are transformed such that the characteristic points 125b of the frame 121b overlap the characteristic points 125a of the frame 121a as indicated by arrows 126.
[0055]
Here, the reason why the periphery of the shooting screen is selected as a feature point will be described below.
[0056]
In many shootings, the main subject is located near the center of the screen, and the main subject is often a person. In such a case, if the main subject is selected as a feature point, inconvenience due to subject shake appears.
[0057]
In other words, not only the camera shake of the photographer but also the shake of the subject are superimposed when a plurality of images are taken, so that the coordinates of the image are converted based on the shake of the subject.
[0058]
In this case, it seems that a preferable image can be obtained because the coordinate transformation is performed so that the composition of the main subject is appropriate.However, in general, the movement of the person is complicated, and the deviation detection accuracy is large depending on where to select the feature points. It depends.
[0059]
For example, if the eye of the main subject (person) is selected as a feature point, there is an effect of blinking. If the tip of the hand is selected as a feature point, the hand moves easily, which is different from the actual shake of the entire subject. Would.
[0060]
Even if the coordinates of an image are converted using one point of a person as a feature point in this manner, not all of the persons are properly converted in coordinates. Each time, the position of the coordinates varies, and a preferable image cannot be obtained.
[0061]
Therefore, as in the present embodiment, it is preferable to select a still subject such as a background as a feature point and to perform coordinate transformation of the image to obtain an image. In this case, the above-described influence of the subject shake appears.
[0062]
Therefore, in the present embodiment, the subject is irradiated with the light of the strobe 16a only for one of the plurality of shot frames.
[0063]
Here, an image captured using the flash 16a is referred to as a first image, and a plurality of images captured without using the flash 16a is referred to as a second image group.
[0064]
At this time, there are the following differences between the first image group and the second image group in addition to the above-described composition deviation.
[0065]
That is, the brightness of the subject area to which the flash reaches in the first image is different from the brightness of the same area in each image in the second image group.
[0066]
Then, in the first image, a sufficient exposure is obtained for the subject to which the flash has reached, and the background which does not reach will have insufficient exposure. This is because the main subject, such as a person, is generally located near the camera and receives a flash, and the background is far from the camera and does not reach the flash.
[0067]
The background with insufficient exposure is compensated by synthesizing the second image group while correcting the composition deviation.
[0068]
FIG. 3 shows a method of selecting a feature point extraction region by the displacement detection unit 114. One image 128 of the second image group is shown in a first image 127 using the strobe 16a (FIG. 3A) and a second image group not using the strobe 16a (FIG. 3B). ), The strobe light arrives in the first image 127 for the person 122a, and the person is dark in the second image 128 because the person is not irradiated with the strobe light.
[0069]
On the other hand, in the background where the strobe light does not reach, the change in the brightness of the feature points 125a (125b) of the building 123a (123b) does not change between the first image 127 and the second image 128.
[0070]
In this way, the background area where there is no change in brightness does not reach the strobe light and the exposure is insufficient. (Coordinate conversion).
[0071]
In FIG. 3, as described above, in the building 123 a (123 b) around the screen where the brightness does not change in the first image 127 and the second image 128, the edge 125 a of the window, which is a point of high luminance, is set. It is extracted as a feature point by edge detection.
[0072]
Then, as described with reference to FIG. 2, the feature point 125a in the first image 127 is compared with the feature point 125b in the second image 128, and the difference is corrected (coordinate conversion). That is, the coordinate conversion unit (coordinate conversion means) 115 performs coordinate conversion on the second image 128 so that the feature point 125b of the second image 128 overlaps with the feature point 125a of the first image 127.
[0073]
The coordinates of the feature point 125b are also obtained for the second and subsequent images in the second image group, and the coordinate conversion unit is configured to overlap the coordinates of the feature point 125a defined in the first image 127. Reference numeral 115 converts the coordinates of each image (second image group).
[0074]
Here, the feature point coordinates for each image are obtained for the sake of explanation. However, in practice, the first image 127 and the first image 128 of the second image group are correlated, and the corresponding pixels are respectively calculated. Is determined as a motion vector by the shift detecting unit 114, and is set as a change in a feature point.
[0075]
Then, for the second image of the second image group, the change of the feature point is obtained by the correlation operation with the first image 127, and thereafter, the change of the feature point of each image is obtained in the same manner.
[0076]
Instead of selecting only one feature point, a plurality of points may be selected, and the average value of the motion vectors of these points or the minimum value of the scalar may be used as the change of the feature point.
[0077]
Here, the reason why the minimum value is used as the change of the feature point is to select a feature point which does not move most since the feature point selected around the screen itself may move.
[0078]
Each image subjected to coordinate conversion by the coordinate conversion unit 115 is output to an image synthesis unit (synthesis unit) 116, and each image is synthesized into one image.
[0079]
As described above, in the present embodiment, the first image 127 using the strobe 16a is used as a reference (center), and each image of the second image group 128 is coordinate-transformed so as to overlap the image.
[0080]
Here, the reason based on the first image 127 will be described.
[0081]
When combining two photos having different compositions as shown in FIG. 2, an area 129 where the two images do not overlap occurs as shown in FIG. Therefore, the image synthesizing unit 116 cuts the region 129, performs diffusion complementation processing only on the region where the two images overlap, and returns to the original frame size.
[0082]
For this reason, the periphery of the screen of each image of the second image group is cut off according to the direction and size of the composition shift.
[0083]
Among the first image 127 and the second image group 128, the image with the best image information is the first image 127 using the strobe 16a.
[0084]
Therefore, in order not to cut off the periphery of the first image 127, it is preferable to superimpose each image of the second image group 128 on the basis of the first image 127.
[0085]
In the case of a digital image, exposure can be corrected by increasing the gain of a single underexposed photograph, but increasing the gain increases noise and results in an unsightly image.
[0086]
However, when the gain of the entire image is increased by combining many images as in the present embodiment, an image having a large S / N ratio can be obtained because the noise of each image is averaged. As a result, noise can be suppressed and exposure can be optimized.
[0087]
According to another concept, it can be said that, for example, random images included in an image are reduced by allowing a noise and photographing a plurality of images with high sensitivity of the imaging unit 19 and averaging these images.
[0088]
The synthesized image data is input to the image correction unit 117 and subjected to gamma correction and compression processing. Thereafter, the image data is displayed on the display unit 118 as a captured image and recorded in the recording unit 119.
[0089]
FIG. 5 is a flowchart summarizing the shooting operation of the camera according to the present embodiment. This flow starts when the power of the camera is turned on.
[0090]
In step S1001, the photographer waits until sw1 is turned on by half-pressing the release button, and when sw1 is turned on, the process proceeds to step S1002.
[0091]
In step S1002, imaging is performed by the imaging unit 19. The photographing control unit 18 drives the AF drive motor 14a to move the photographing lens 11 in the optical axis direction while detecting the contrast of the image based on the output from the signal processing unit 111.
[0092]
Then, when the contrast is highest, the driving of the photographing lens 11 is stopped to bring the photographing optical system into a focused state (AF by the hill-climbing method). Note that focus adjustment can also be performed by detecting a phase difference.
[0093]
Further, the imaging control unit 18 simultaneously obtains the brightness of the subject based on the output of the imaging unit 19.
[0094]
In step S1003, it is determined whether or not the photographer has turned on the image stabilization operation unit 120. When the image stabilization operation unit 120 has been turned on, the process proceeds to step S1004, and when it has been turned off, the process proceeds to step S1019.
[0095]
First, a flow that flows when the image stabilizing operation unit 120 is turned on will be described.
[0096]
In step S1004, the number of images to be photographed and the respective exposure times are obtained from the photographing conditions such as the brightness of the subject obtained in step S1002.
[0097]
The shooting conditions mentioned here are
・ Brightness of subject
・ Focal length of shooting optical system
・ Brightness of shooting optical system (aperture value)
・ Sensitivity of imaging unit 19
4 points.
[0098]
For example, assume that the sensitivity of the imaging unit 19 is set to ISO200.
[0099]
In order to measure the brightness of the subject (photometry) and properly perform exposure based on the photometry result, the aperture 13a is fully opened (for example, f2.8) and the closing timing of the shutter 12a, that is, the exposure time is reduced by 1 /. Assume that it needs to be 8 seconds.
[0100]
Here, when the focal length of the photographing optical system is 30 mm in terms of a 35 mm film, there is a possibility that image blurring may occur due to camera shake in photographing with an exposure time of 1/8 second. The time is set to 1/32 second and the shooting is set to be performed four times.
[0101]
On the other hand, when the photographing focal length is 300 mm, the exposure time is set to 1/320 second and the photographing is performed 40 times so that image blur does not occur.
[0102]
In this way, the exposure time for performing multiple image capturing is determined according to the image capturing conditions, and the number of images to be captured is also set according to the image capturing conditions.
[0103]
Even when the same subject is divided into a plurality of images and photographed, accurate information can be obtained in the imaging by the imaging unit 19 when the exposure condition of each imaging is as close to the proper exposure as possible.
[0104]
For this reason, in the case of a dark subject, in the case where the aperture 13a is narrowed down and the image is dark, and in the case where the sensitivity of the imaging unit 19 is set to be low, the exposure time of each shooting is set to be as long as possible, even for multiple shootings. Set to exposure conditions.
[0105]
However, if the exposure time is too long, the effect of image deterioration due to camera shake appears on the image plane. Therefore, when the focal length of the photographic optical system is 30 mm in 35 mm film conversion as described above, it is necessary to prevent image shake from occurring. The exposure time is set to 1/32 second, which is equal to one part of the focal length.
[0106]
The shortage of the exposure time is complemented by the number of shots.
[0107]
If the focal length is long, image deterioration due to camera shake occurs unless the exposure time is further shortened. Therefore, the exposure time is further shortened, and the number of shots is increased to compensate for the exposure.
[0108]
As described above, the exposure time in the multiple-image shooting becomes longer as the shooting subject is darker and the shooting lens is darker, becomes longer as the sensitivity of the imaging unit 19 is lower, and becomes shorter as the focal length of the lens is longer.
[0109]
The number of images to be photographed in a plurality of images is increased as the imaging subject is darker and the imaging lens is darker. The number is increased as the sensitivity of the imaging unit 19 is lowered, and is increased as the focal length of the lens is increased.
[0110]
After the calculation of the exposure time and the number of shots according to the shooting conditions has been completed as described above, the display unit provided in the viewfinder of the camera or the liquid crystal display unit provided on the exterior of the camera displays the image stabilization mode (multiple At the same time, the set number of shots is displayed, and at the same time, the obtained number of shots is displayed to notify the photographer.
[0111]
In step S1005, the process waits by circulating from step S1001 to step S1005 until sw2 is turned on by full-pressing the release button.
[0112]
In step S1006, shooting of the first image is started.
[0113]
Simultaneously at this time, the sound generation at the start of photographing is performed by driving a speaker (sound generating means) 17a via a sound generating drive section (sound generating means) 17b.
[0114]
This sound may be, for example, an electronic sound such as "beep", a shutter opening sound in a film camera or the like, or a mirror-up sound.
[0115]
Steps S1006 to S1014, which will be described later, are operations in a composite shooting mode in which shooting with a short exposure time is repeated a plurality of times, and images obtained by the plurality of shootings are synthesized to make apparent exposure appropriate.
[0116]
Here, as described in this step, the first photographing is performed by emitting light from the strobe 16a in order to obtain the above-described first image 127 (FIG. 3A).
[0117]
In step S1007, the captured image is temporarily stored in the image storage unit 113.
[0118]
In step S1008, steps S1006 and # 1007 are circulated and wait until all shooting is completed. At this time, the second and subsequent images are shot without using the strobe 16a in order to obtain the second image group.
[0119]
When the shooting is completed, the process proceeds to step S1009.
[0120]
In step S1009, the sound generation completion is performed by driving the speaker 17a via the sound drive unit 17b.
[0121]
This sound may be, for example, an electronic sound such as "beep", a shutter closing sound in a film camera, a mirror down sound, or a film winding sound.
[0122]
In the case of taking a plurality of images in this way, the sound representing the operation is one set (one time at the start of the exposure of the first image and once at the completion of the exposure of the last image). Absent.
[0123]
In other words, the number of times of sounding is the same between the case where normal shooting (one exposure) is performed and the case where a plurality of images are shot, and it is possible to prevent the photographer from feeling uncomfortable when shooting.
[0124]
In step S1010, the displacement detection unit 114 extracts a characteristic image (feature point) from the peripheral area of the image (for example, the buildings 123a and 123b in FIG. 3) and obtains the coordinates of the image.
[0125]
This is because, as described above, the first image 127 and the images 128 of the second image group are compared with each other, and regions other than regions having different brightness (that is, regions where the flash of the strobe 16a sufficiently illuminates the subject) ( That is, a feature point is extracted from the area where the flash of the strobe 16a does not sufficiently illuminate the subject, and its coordinates are obtained.
[0126]
In step S1011, the coordinate conversion unit 115 performs coordinate conversion of each image. Here, the coordinate conversion is not performed for only the first image (the first image 127 using the strobe 16a). That is, the first image 127 is used as a reference for coordinate conversion.
[0127]
In step S1012, the process circulates through steps S1010 and 1011 and waits until the coordinate conversion is completed for all the images of the second image 128. When the coordinate conversion of all the images is completed, the process proceeds to step S1013.
[0128]
In step S1013, the first image 127 and the images 128 of the second image group subjected to coordinate conversion are combined.
[0129]
Here, the synthesis of the images is performed by averaging the signals at the corresponding coordinates of each image, and the random noise in the images is reduced by averaging. Then, the gain of the image with reduced noise is increased to optimize the exposure.
[0130]
In step S1014, an area (area 129 in FIG. 4) in which the images do not overlap due to composition blur in the synthesized image is cut, and the image is complemented by diffusion so as to have the size of the original frame.
[0131]
In step S1015, gamma correction and compression processing are performed on the composite image signal.
[0132]
In step S1016, the image obtained in step S1015 is displayed on a liquid crystal display unit (display unit 118) disposed on the back of the camera or the like.
[0133]
In step S1017, the image data obtained in step S1015 is recorded on a recording medium (recording unit 119) constituted by, for example, a semiconductor memory and detachable from the camera.
[0134]
In step S1018, the process returns to the start.
[0135]
If the release button is still half-pressed and sw1 is on at step S1018, the flow proceeds to steps S1001, # 1002, # 1003, and # 1004 again.
[0136]
If the release button is fully pressed and sw2 is on at step S1018, the process returns to the start and waits in step S1018.
[0137]
Next, a flow that flows when the image stabilization operation unit 120 is off in step S1003 will be described.
[0138]
If it is determined in step S1003 that the image stabilization operation unit 120 is off, the process advances to step S1019.
[0139]
In step S1019, it is determined whether or not shooting conditions are such that image deterioration due to camera shake occurs when the image stabilization system is not used.
[0140]
As described above, the shooting conditions are the brightness of the subject, the brightness of the lens, the imaging sensitivity, and the shooting focal length, and the exposure time is obtained based on the brightness of the subject, the brightness of the lens, and the imaging sensitivity. It is determined in step S1019 whether there is a possibility of image deterioration due to camera shake at the current shooting focal length.
[0141]
When there is a possibility of image deterioration, the process proceeds to step S1020, and otherwise, the process proceeds to step S1021.
[0142]
In step S1020, a display that recommends that the image stabilization mode be set is displayed on a display unit provided in the viewfinder of the camera or a liquid crystal display unit (display unit 118) provided on the exterior of the camera.
[0143]
In step S1021, the release button is fully pressed, and the process waits by circulating from step S1001 to step S1021 until sw2 is turned on.
[0144]
In step S1022, the process waits until normal shooting (normal shooting mode for forming an effective exposure condition by one exposure, second shooting mode) is completed, and the process proceeds to step S1015 upon completion of exposure.
[0145]
Although omitted here, even in the shooting in the normal shooting mode, the shooting operation sound is emitted from the speaker 17a in accordance with the operation from the start to the end of the shooting.
[0146]
In other words, the same style of shooting operation sound is emitted in both the composite shooting mode (synthesis of a plurality of shots, the first shooting mode) and the normal shooting mode. In this case, the photographer can recognize whether or not the long-time exposure has been performed depending on the difference in the operation sound length of the speaker 17a (the length from the shooting start sound to the shooting completion sound). The photographer does not know whether or not the photographing is being performed.
[0147]
For this reason, even in the composite photographing mode, the photographer does not recognize that special photographing is being performed, and the camera is easy to use.
[0148]
In step S1015, gamma correction and compression processing are performed on the composite image signal.
[0149]
In step S1016, the image obtained in step S1015 is displayed on a liquid crystal display unit (display unit 118) arranged on the back of the camera or the like.
[0150]
In step S1017, the image data obtained in step S1015 is recorded on a recording medium (recording unit 119) constituted by, for example, a semiconductor memory and detachable from the camera.
[0151]
In step S1018, the process returns to the start.
[0152]
As can be seen from this flow, even when the image stabilization operation unit 120 is turned off, in a shooting condition in which image deterioration due to camera shake occurs, a display urging the photographer to utilize the image stabilization system (synthesis shooting mode) is displayed. Degradation is prevented beforehand.
[0153]
Also, in the composite photographing mode, by changing each exposure time according to the focal length of the photographing optical system, desired photographing can be performed at any focal length.
[0154]
(2nd Embodiment)
This embodiment is a modification of the first embodiment. The configuration of the camera of this embodiment is substantially the same as that of the first embodiment (FIG. 1), and the same members will be described with the same reference numerals.
[0155]
In the first embodiment, the feature point extraction area by the shift detection unit 114 is set by setting the area where the flash 16a of the strobe 16a is insufficiently illuminated as the feature point extraction area by comparing the brightness of each captured image. I have.
[0156]
However, the feature point extraction region is not limited to this example. A region outside the focus area in the shooting screen at the time of shooting is set as a feature point extraction region, or a region other than the currently focused region is extracted as a feature point extraction region. Or an area.
[0157]
This is because the main subject (person) is superimposed on the focus area (focus detection area) at the time of photographing. Therefore, in order to set a feature point other than the main subject, an area other than the focus area may be set as a feature point extraction area. It is.
[0158]
FIG. 6 is a diagram showing a feature point extraction region in the photographing screen, where a main subject is captured in focus areas 131a, 131b, 131c, 131d, and 131e provided on the photographing screen (within frame 121a). When focusing is performed in the focus area 130c, the screen peripheral area 130 excluding the main subject area 132 centered on the focus area 130c is set as a feature point extraction area.
[0159]
That is, the main subject area 132 and the feature point extraction area are changed according to whether the main subject is located in any one of the focus areas 131a, 131b, 131c, 131d, and 131e.
[0160]
If an image suitable for the feature point extraction region is set as a feature point and the image is synthesized by correcting the deviation of each image based on the coordinates of the feature point, preferable image synthesis can be performed.
[0161]
Also, as shown in the flow of FIG. 5, the coordinate transformation of all the images is completed, and the images are not synthesized after the saving of these images is completed. May go.
[0162]
FIG. 7 is a timing chart for explaining such an operation. For the exposure f1 (where f1 is exposure using the strobe 16a), a signal that has been photoelectrically converted and accumulated in the imaging unit 19 is read out as an imaging signal F1. Similarly, for the exposure f2 (f2 does not use the strobe 16a), a signal that has been photoelectrically converted and accumulated in the imaging unit 19 is read out as an imaging signal F2. At the same time as the reading of the imaging signal F2, a correlation operation between the previous imaging signal F1 and the current imaging signal F2 is performed. As a result, a change in a feature point between the two images is obtained, and the two imaging signals F1 and F2 are synthesized to obtain a synthesized signal C2.
[0163]
Next, at the same time as the readout of the image pickup signal F3, a correlation operation is performed between the previous composite signal C2 and the current image pickup signal F3 to obtain a change in a feature point, and the composite signal C2 and the image pickup signal F3 are combined to obtain a composite signal. Obtain C3.
[0164]
Next, a change in a feature point is obtained by performing a correlation operation between the previous composite signal C3 and the current image signal F4 simultaneously with the reading of the image signal F4, and the composite signal C3 and the image signal F4 are combined to obtain the composite signal. Obtain C4.
[0165]
Then, the obtained synthesized signal C4 (synthesized image) is displayed on a liquid crystal display unit provided on the back of the camera or the like, and is also recorded on a recording medium.
[0166]
FIG. 8 is a flowchart illustrating the above operation. Compared to the flowchart of FIG. 5, the image storage in step S1007 is not performed, and the order of step S1012 and step S1013 is reversed.
[0167]
The reason why the image storage in step S1007 is abolished is that, in the present embodiment, each captured image is combined with the previous captured image at the same time as capturing, so only one composite image is stored in the image combining step S1013. This is because other captured images are unnecessary.
[0168]
That is, since the composite image is updated for each photographing, there is no need to store each photographed image. Therefore, the camera of the present embodiment does not include the image storage unit 113 shown in FIG.
[0169]
In the flow of FIG. 8, it seems that the next photographing is not performed until all the image processing in step S1012 is completed. However, in actuality, photographing, imaging signal output, correlation calculation, and image synthesis are performed as shown in the timing chart of FIG. 7. It is performed simultaneously.
[0170]
(Third embodiment)
In the first embodiment, when a photographing condition necessary for the image stabilizing system is used, a message to that effect is displayed to notify the photographer, thereby preventing photographing failure.
[0171]
However, the anti-vibration system according to this embodiment requires a longer exposure time because of the nature of obtaining a proper exposure by combining a plurality of images.
[0172]
As described above, when the exposure time is 1/8 second and the focal length is 30 mm, shooting with an exposure time of 1/32 second is performed in four times, and these are combined to obtain an appropriate exposure.
[0173]
However, since a processing time (for example, a transfer time of image data and a data storage time) between these photographing operations is also required, 1/8 second is required until photographing with an exposure time of 1/32 second is completed four times. The above time (for example, 1/4) is required.
[0174]
The subject shake, which is a problem in long-time shooting (shooting when the subject is dark), can be solved by using the strobe 16a as described above. However, when the subject is bright to some extent, the strobe 16a does not flash. The subject is also captured in the shot frame (second image group), and the subject blur suppression effect of the strobe 16a is weakened in the combined image.
[0175]
In other words, when the composite photographing mode is used under a relatively bright photographing condition, the subject shake may be more conspicuous than in the normal photographing mode.
[0176]
In an optical anti-vibration system using a vibrating gyroscope or correction optical device, these elements must be mounted on the camera (enlargement of the camera), and the shift component of camera shake and the roll component around the optical axis are corrected. There are disadvantages that can not be done. However, under the photographing condition where the optical image stabilization system is unnecessary, the image shake obtained by the image stabilization system using the image synthesis is less noticeable than the image in the image stabilization OFF state.
[0177]
On the other hand, an image stabilization system based on image synthesis has the advantages that it is not necessary to mount a special element on the camera, and that a shift component of camera shake and a roll component around the optical axis can be corrected.
[0178]
On the other hand, in a shooting condition in which the image stabilization system using the image stabilization is unnecessary, an image obtained by turning on the image stabilization system may have a more noticeable subject shake than an image obtained by turning off the image stabilization system.
[0179]
Therefore, in the present embodiment, under the photographing condition that does not require the image stabilization system by the image synthesis, the photographing with the image stabilization system turned on is not permitted. The system allows shooting).
[0180]
In recent digital cameras, noise is less likely to appear even when the sensitivity of the imaging unit 19 is increased, and the processing of generated noise is becoming better.
[0181]
Therefore, until the subject is darkened to some extent (or until the focal length becomes longer or the photographing optical system is stopped down), by increasing the sensitivity of the imaging unit 19, appropriate exposure can be obtained without increasing the exposure time. The image stabilizing system based on image synthesis is used only when the exposure becomes insufficient unless the exposure time is lengthened.
[0182]
Specifically, even if the photographer turns on the image stabilization operation unit 120 to perform shooting, if the subject is bright or the like, the image stabilization unnecessary is displayed and shooting is performed in the normal shooting mode.
[0183]
FIG. 9 is a flowchart of the present embodiment, which is different from the flowchart of FIG. 5 in that even if the image stabilization operation unit 120 is on, it is determined whether or not the image is in the image stabilization shooting condition. In the case where the shake shooting condition is not satisfied, shooting is performed in the normal shooting mode even when the shake preventing operation unit 120 is turned on (displaying a stabilization unnecessary display at this time). Note that the configuration of the camera of the present embodiment is the same as the configuration of the camera of the first embodiment (FIG. 1).
[0184]
FIG. 9 is a flowchart summarizing the photographing operation of the camera according to the present embodiment. This flow starts when the power of the camera is turned on.
[0185]
In step S1001, the photographer half-presses the release button to wait until sw1 is turned on. When sw1 is turned on, the process proceeds to step S1002.
[0186]
In step S1002, the imaging unit 19 images the subject. The photographing control unit 18 drives the AF drive motor 14a to move the photographing lens 11 in the direction of the optical axis 10 while detecting the contrast of the image based on the output from the signal processing unit 111.
[0187]
Then, when the contrast is highest, the driving of the photographing lens 11 is stopped to bring the photographing optical system into a focused state.
[0188]
Further, the imaging control unit 18 simultaneously obtains the brightness of the subject based on the output of the imaging unit 19.
[0189]
In step S1003, it is determined whether or not the photographer has turned on the image stabilizing operation unit 120. When the image stabilizing operation unit 120 has been turned on, the process proceeds to step S1019, and when it has been turned off, the process proceeds to step S1021.
[0190]
First, a case where the image stabilizing operation unit 120 is turned on will be described.
[0191]
In step S1019, it is determined whether or not shooting conditions are such that image deterioration due to camera shake occurs unless the image stabilization system (synthetic shooting mode) is used.
[0192]
The shooting conditions are, as described above, the brightness of the subject, the brightness of the lens, the imaging sensitivity, and the shooting focal length. The exposure time is calculated based on the brightness of the subject, the brightness of the lens, and the imaging sensitivity. In step S1019, it is determined whether there is a possibility of image degradation due to camera shake at the current shooting focal length.
[0193]
Here, the imaging sensitivity is the sensitivity state of the imaging unit 19, and in the case of a digital camera, the sensitivity of the imaging unit 19 is automatically changed according to imaging conditions, and the imaging sensitivity is fixedly set according to the photographer's preference. There is a fixed sensitivity mode.
[0194]
In the case of the auto mode, the exposure time is set according to the brightness of the subject and the brightness of the lens, and it is determined whether or not image blur occurs at the exposure time obtained for the currently set photographing focal length. judge.
[0195]
If image blur is likely to occur, the exposure time is shortened by increasing the imaging sensitivity. If the exposure time still causes image blur, image stabilization (shooting in the composite shooting mode) is required. Is determined.
[0196]
In the case of the fixed sensitivity mode, the exposure time is set in accordance with the brightness of the subject, the brightness of the lens, and the set imaging sensitivity, and is obtained with respect to the currently set focal length of the imaging optical system. It is determined whether or not image blur occurs during the exposure time. Here, if there is a possibility that image blurring occurs, it is determined that image stabilization is necessary.
[0197]
A semi-auto mode that allows a change in the imaging sensitivity to a certain extent is also considered as a shooting scene selection mode (for example, a portrait mode) between the auto mode and the fixed sensitivity mode.
[0198]
Even in such a case, if there is a possibility that an image shake occurs during the exposure time at the allowable imaging sensitivity, it is determined that the image stabilization is necessary.
[0199]
If it is determined that the image stabilization is necessary, the process proceeds to step S1004, and if not, the process proceeds to step S2001.
[0200]
First, a flow in which it is determined that image stabilization is necessary and the process proceeds to step S1004 will be described.
[0201]
In step S1004, the number of images to be photographed and each exposure time are obtained from the photographing conditions for normal photographing obtained in step S1019.
[0202]
What are the shooting conditions mentioned here?
・ Brightness of subject
・ Focal length of shooting optical system
・ Brightness of shooting optical system (aperture value)
・ Sensitivity of imaging unit 19
4 points.
[0203]
For example, it is assumed that an exposure time of 1/8 second is required in step S1019.
[0204]
At this time, when the focal length of the photographing optical system is 30 mm in terms of 35 mm film, there is a possibility that image blurring due to camera shake may occur in photographing in which the exposure time is 1/8 second. / 32 seconds and set to shoot four times.
[0205]
In addition, when the shooting focal length is 300 mm, the exposure time is set to 1/320 second and shooting is performed 40 times so that image blur does not occur.
[0206]
In this way, the exposure time for performing multiple image capturing is determined according to the image capturing conditions, and the number of images to be captured is also set according to the image capturing conditions.
[0207]
Even when the same subject is divided into a plurality of images and photographed, accurate information can be obtained in the imaging by the imaging unit 19 when the exposure condition of each imaging is as close to the proper exposure as possible.
[0208]
For this reason, in the case of a dark subject, in the case where the aperture 13a is narrowed down and the image is dark, and in the case where the sensitivity of the imaging unit 19 is set to be low, the exposure time of each shooting is set to be as long as possible, even for multiple shootings. Set to exposure conditions.
[0209]
However, if the exposure time is too long, the influence of image deterioration due to camera shake appears on the image plane. Therefore, when the photographing focal length is 30 mm in 35 mm film conversion as described above, the focal length is about the focal length where there is no risk of image shake. The exposure time is set to 1/32 second, which is equal to one.
[0210]
The shortage of the exposure time is complemented by the number of shots.
[0211]
If the focal length is long, image deterioration due to camera shake will occur unless the exposure time is further shortened. Therefore, the exposure time is further shortened, and the number of shots is increased to compensate for the exposure.
[0212]
As described above, the exposure time in multiple-image shooting becomes longer as the shooting subject is darker and the shooting lens is darker. In the fixed sensitivity mode, the exposure time becomes longer as the sensitivity of the imaging unit 19 becomes lower, and becomes shorter as the focal length of the lens becomes longer. .
[0213]
The number of shots in multiple shooting is such that the darker the shooting subject,
The darker the lens, the larger the number, the lower the sensitivity of the imaging unit 19 in the fixed sensitivity mode, and the larger the focal length of the lens.
[0214]
After the calculation of the exposure time and the number of shots according to the shooting conditions has been completed as described above, the display unit provided in the viewfinder of the camera or the liquid crystal display unit provided on the exterior of the camera displays the image stabilization mode (multiple At the same time, the set number of shots is displayed, and at the same time, the obtained number of shots is displayed to notify the photographer.
[0215]
In step S1005, the process waits by circulating from step S1001 to step S1005 until sw2 is turned on by full-pressing the release button.
[0216]
In step S1006, shooting of the first image is started.
[0219]
Simultaneously at this time, the sound generation at the start of photographing is performed by driving the speaker 17a via the sound generation drive unit 17b.
[0218]
The shooting operation sound may be, for example, an electronic sound such as “beep”, a shutter opening sound in a film camera or the like, or a mirror-up sound.
[0219]
Steps S1006 to S1014, which will be described later, are operations in a composite shooting mode in which shooting with a short exposure time is repeated a plurality of times, and images obtained by the plurality of shootings are synthesized to make apparent exposure appropriate.
[0220]
Here, as described in this step, the first photographing is performed by flashing the strobe 16a in order to obtain the first image 127 described above.
[0221]
In step S1007, the captured image is temporarily stored in the image storage unit 113.
[0222]
In step S1008, steps S1006 and # 1007 are circulated and wait until all shooting is completed.
[0223]
At this time, the second and subsequent images are shot without using the strobe 16a to obtain the second image group.
[0224]
When the shooting is completed, the process proceeds to step S1009.
[0225]
In step S1009, the sound generation completion is performed by driving the speaker 17a via the sound drive unit 17b.
[0226]
The shooting operation sound may be, for example, an electronic sound such as "beep", a shutter closing sound in a film camera, a mirror down sound, or a film winding sound.
[0227]
As described above, even when a plurality of images are taken, the sound representing the operation is one set (one time at the start of the exposure of the first image and at the completion of the exposure of the last image). There is no discomfort.
[0228]
In step S1010, the displacement detection unit 114 extracts a characteristic image (feature point) from the peripheral area of the image (for example, the buildings 123a and 123b in FIG. 3) and obtains the coordinates of the image.
[0229]
This is because, as described above, the first image 127 and the images 128 of the second image group are compared with each other, and regions other than regions having different brightness (that is, regions where the flash of the strobe 16a sufficiently illuminates the subject) ( That is, a feature point is extracted from the area where the flash of the strobe 16a does not sufficiently illuminate the subject, and its coordinates are obtained.
[0230]
In step S1011, the coordinate conversion unit 115 performs coordinate conversion on each image, but does not perform coordinate conversion on only the first image (first image 127 using the strobe 16a). That is, the first image 127 is used as a reference for coordinate conversion.
[0231]
In step S1012, steps S1010 and 1011 are circulated and wait until all the images have been subjected to the coordinate conversion. When the coordinate conversion of all the images is completed, the process proceeds to step S1013.
[0232]
In step S1013, images are combined.
[0233]
Here, the synthesis of the images is performed by averaging the signals at the corresponding coordinates of each image, and the random noise in the images is reduced by averaging. Then, the gain of the image with reduced noise is increased to optimize the exposure.
[0234]
In step S1014, an area (area 129 in FIG. 4) in which the images do not overlap due to composition blur in the synthesized image is cut, and the image is complemented by diffusion so as to have the size of the original frame.
[0235]
In step S1015, gamma correction and compression processing are performed on the composite image signal.
[0236]
In step S1016, the image obtained in step S1015 is displayed on a liquid crystal display unit (display unit 118) arranged on the back of the camera or the like.
[0237]
In step S1017, the image data obtained in step S1015 is recorded on a recording medium (recording unit 119) constituted by, for example, a semiconductor memory and detachable from the camera.
[0238]
In step S1018, the process returns to the start.
[0239]
If the release button is still half-pressed and sw1 is on at step S1018, the flow proceeds to steps S1001, # 1002, and # 1003 again.
[0240]
If the release button is fully pressed at step S1018 to turn on sw2, the process returns to the start and waits at step S1018.
[0241]
Next, a case where the image stabilization operation unit 120 is off in step S1003 will be described. At this time, a flow flows from step S1003 to step S1021.
[0242]
In step S1021, the process waits by circulating from step S1001 to step S1021 until the release button is fully pressed and sw2 is turned on.
[0243]
In step S1022, the process waits until normal shooting (normal shooting mode in which an effective exposure condition is formed by one exposure) is completed, and the process proceeds to step S1015 upon completion of exposure.
[0244]
Although omitted here, even in the shooting in the normal shooting mode, the shooting operation sound is emitted from the speaker 17a in accordance with the operation from the start to the end of the shooting.
[0245]
That is, in both the composite photographing mode (composite of a plurality of images) and the normal photographing mode, the photographing operation sound of the same style is generated, and the length of the operation sound (the length from the photographing start sound to the photographing completion sound) The difference is that the photographer can recognize whether or not the long exposure time has elapsed, and the photographer cannot know whether or not a plurality of images have been photographed.
[0246]
For this reason, as described above, the camera is easy to use without giving the photographer recognition that special photographing is being performed even in the composite photographing mode, and without giving the photographer a sense of incongruity.
[0247]
In step S1015, gamma correction and compression processing are performed on the composite image signal.
[0248]
In step S1016, the image obtained in step S1015 is displayed on a liquid crystal display unit (display unit 118) disposed on the back of the camera or the like.
[0249]
In step S1017, the image data obtained in step S1015 is recorded on a recording medium (recording unit 119) constituted by, for example, a semiconductor memory and detachable from the camera.
In step S1018, the process returns to the start.
[0250]
Next, a flow in which it is determined in step S1019 that image stabilization is unnecessary and the flow proceeds to step S2001 will be described.
[0251]
In step S2001, the display unit provided in the viewfinder of the camera or the display unit 118 on the back of the camera indicates that image stabilization (imaging in the composite imaging mode) is unnecessary.
[0252]
Then, the process proceeds from step S2001 to step S1021.
[0253]
In step S1021, the process waits by circulating from step S1001 to step S1021 until the release button is fully pressed and sw2 is turned on.
[0254]
In step S1022, the process waits until normal shooting (normal shooting mode in which an effective exposure condition is formed by one exposure) is completed, and the process proceeds to step S1015 upon completion of exposure.
[0255]
Although omitted here, even in the shooting in the normal shooting mode, the shooting operation sound is emitted from the speaker 17a in accordance with the operation from the start to the end of the shooting.
[0256]
In other words, in the composite photographing mode (combining a plurality of images) and in the normal photographing mode, the same type of photographing operation sound is generated.
[0257]
In this case, the photographer can recognize whether or not a long-time exposure has been performed depending on the difference in the operation sound interval (the length from the shooting start sound to the shooting completion sound), and whether or not a plurality of shots has been taken. Is hidden from the photographer.
[0258]
For this reason, as described above, the camera is easy to use without giving the photographer the recognition that special photographing is being performed even in the composite photographing mode.
[0259]
In step S1015, gamma correction and compression processing are performed on the composite image signal.
[0260]
In step S1016, the image obtained in step S1015 is displayed on a liquid crystal display unit (display unit 118) arranged on the back of the camera or the like.
[0261]
In step S1017, the image obtained in step S1015 is recorded on a recording medium (recording unit 119) that is configured by, for example, a semiconductor memory and is detachable from the camera.
In step S1018, the process returns to the start.
[0262]
As can be seen from this flow, even if the image stabilization operation unit 120 is operated to turn on the image stabilization system, depending on the shooting conditions, the image stabilization system is not operated (the shooting in the composite shooting mode is not performed), and By performing the display, deterioration of the image under certain shooting conditions is prevented.
[0263]
(Fourth embodiment)
FIG. 10 is a block diagram of a camera according to a fourth embodiment of the present invention. The difference from FIG. 1 is that the anti-vibration operation unit 120 is eliminated. The same members as those described with reference to FIG. 1 are denoted by the same reference numerals and description thereof will be omitted.
[0264]
In the present embodiment, when a shooting condition (stabilization shooting condition) requiring image stabilization is reached, the mode automatically shifts to the composite shooting mode, and when it is not a stabilization shooting condition, the shooting mode is fixed to the normal shooting mode. I have.
[0265]
For this reason, the photographer does not need to consider the necessity of image stabilization according to the shooting scene, and can shoot a good image stably.
[0266]
FIG. 11 is a flowchart summarizing the photographing operation of the camera in the present embodiment. This flow starts when the power of the camera is turned on.
[0267]
In step S1001, the photographer performs a half-pressing operation (sw1 on) of the release button and waits by circulating through this step until the photographing preparation operation (focus adjustment operation, photometric operation) starts. When it reaches, the process proceeds to step S1002.
[0268]
In step S1002, the imaging unit 19 images the subject. The photographing control unit 18 drives the AF drive motor 14a to move the photographing lens 11 in the optical axis direction while detecting the contrast of the image based on the output from the signal processing unit 111. Then, when the contrast is the highest, the driving of the photographing lens 11 is stopped. As a result, the imaging optical system is brought into a focused state.
[0269]
Further, the imaging control unit 18 simultaneously obtains the brightness of the subject based on the output of the imaging unit 19.
[0270]
In step S1019, it is determined whether or not the shooting condition is such that image deterioration due to camera shake occurs unless the image stabilization system is used (synthesis shooting mode is set).
[0271]
The shooting conditions are the brightness of the subject, the brightness of the lens, the imaging sensitivity, and the shooting focal length, as described above. The exposure time is obtained based on the brightness of the subject, the brightness of the lens, and the imaging sensitivity. In step S1019, it is determined whether or not there is a possibility of image deterioration due to camera shake at the current (at the time of shooting) focal length.
[0272]
Here, the imaging sensitivity is the sensitivity state of the imaging unit 19, and in the case of a digital camera, the sensitivity of the imaging unit 19 is automatically changed according to imaging conditions, and the imaging sensitivity is fixedly set according to the photographer's preference. There is a fixed sensitivity mode.
[0273]
In the auto mode, the exposure time is set according to the brightness of the subject and the brightness of the lens, and it is determined whether or not image shake occurs with the exposure time obtained for the currently set shooting focal length. I do.
[0274]
If there is a possibility of image blurring, the exposure time is shortened by increasing the imaging sensitivity. If the exposure time still causes image blurring, image stabilization (shooting in the composite shooting mode) is performed. Determine that it is necessary.
[0275]
In the case of the fixed sensitivity mode, the exposure time is set according to the brightness of the subject, the brightness of the lens, and the set imaging sensitivity, and the exposure time obtained for the currently set photographing focal length is set. Then, it is determined whether or not image blur occurs.
[0276]
Then, when there is a possibility that image blurring occurs, it is determined that image stabilization is necessary.
[0277]
A semi-auto mode that allows a change in the imaging sensitivity to a certain extent is also considered as a shooting scene selection mode (for example, a portrait mode) between the auto mode and the fixed sensitivity mode.
[0278]
Even in such a case, if there is a possibility that an image shake occurs during the exposure time at the allowable imaging sensitivity, it is determined that the image stabilization is necessary.
[0279]
If it is determined that the image stabilization is necessary, the process proceeds to step S1004, and if not, the process proceeds to step S1021.
[0280]
First, a flow in which it is determined that image stabilization is necessary and the process proceeds to step S1004 will be described.
[0281]
In step S1004, the number of images to be photographed and each exposure time are obtained from the photographing conditions for normal photographing obtained in step S1019.
[0282]
What are the shooting conditions mentioned here?
・ Brightness of subject
・ Focal length of shooting optical system
・ Brightness of shooting optical system (aperture value)
・ Sensitivity of imaging unit 19
4 points.
[0283]
For example, assume that the exposure time needs to be reduced to 1/8 second in step S1019.
[0284]
Here, when the photographing focal length is 30 mm in 35 mm film conversion, there is a risk of image deterioration due to camera shake in photographing with an exposure time of 1/8 second, so that the exposure time is reduced by 1/32 to prevent image deterioration. Seconds are set so that shooting is performed four times.
[0285]
When the photographing focal length is 300 mm, the exposure time is set to 1/320 second and photographing is performed 40 times so that image deterioration due to camera shake does not occur.
[0286]
In this way, the exposure time for performing multiple image capturing is determined according to the image capturing conditions, and the number of images to be captured is also set according to the image capturing conditions.
[0287]
Even if the same subject is divided into a plurality of images and photographed, if the exposure condition for each photographing is as close as possible to the proper exposure, accurate information of the object can be obtained by the imaging by the imaging unit 19.
[0288]
For this reason, in the case of a dark subject, in the case where the aperture 13a is narrowed down and the image is dark, and in the case where the sensitivity of the imaging unit 19 is set to be low, the exposure time of each shooting is set to be as long as possible, even for multiple shootings. Set to exposure conditions.
[0289]
However, if the exposure time is too long, the effect of image deterioration due to camera shake will appear on the image plane. Therefore, when the shooting focal length is 30 mm in 35 mm film conversion as described above, one-fourth of the focal length where there is no risk of image shake Is set to 1/32 second, which is the exposure time equal to.
[0290]
The shortage of the exposure time is complemented by the number of shots.
[0291]
If the focal length is long, image deterioration due to camera shake will occur unless the exposure time is further shortened. Therefore, the exposure time is further shortened, and the number of shots is increased to compensate for the exposure.
[0292]
As described above, the exposure time in shooting a plurality of images is longer as the shooting subject is darker and the shooting lens is darker. In the fixed sensitivity mode, the exposure time is longer as the sensitivity of the image sensor is lower, and is shorter as the focal length of the lens is longer.
[0293]
The number of images to be photographed in a plurality of images is increased as the imaging object is dark and the imaging lens is dark. In the fixed sensitivity mode, the number is increased as the sensitivity of the imaging unit 19 is lowered and as the focal length of the lens is increased.
[0294]
After the calculation of the exposure time and the number of shots according to the shooting conditions is completed as described above, the display unit provided in the viewfinder of the camera or the liquid crystal display unit provided on the exterior of the camera displays the image stabilization mode (composite image). At the same time, the photographing mode is set and the number of photographed images is displayed to notify the photographer.
[0295]
In step S1005, the process waits by cycling from step S1001 to step S1005 until there is an instruction to start shooting by fully pressing the release button.
[0296]
In step S1006, shooting of the first image is started. Simultaneously at this time, the sound generation at the start of photographing is performed by driving the speaker 17a via the sound generation drive unit 17b.
[0297]
The shooting operation sound may be, for example, an electronic sound such as “beep”, a shutter opening sound in a film camera or the like, or a mirror-up sound.
[0298]
Steps S1006 to S1014, which will be described later, are operations in a combined shooting mode in which shooting with a short exposure time is repeated a plurality of times, and images obtained by the plurality of shootings are combined to make an apparent exposure appropriate.
[0299]
Here, as described in this step, the first photographing is performed by flashing the flash 16a to obtain the first image 127 described above.
[0300]
In step S1007, the captured image is temporarily stored in the image storage unit 113.
[0301]
In step S1008, steps S1006 and # 1007 are circulated and wait until all shooting is completed. At this time, the second and subsequent images are shot without using the strobe 16a in order to obtain the second image group.
[0302]
When the shooting is completed, the process proceeds to step S1009.
[0303]
In step S1009, the sound generation completion is performed by driving the speaker 17a via the sound drive unit 17b.
[0304]
The shooting operation sound may be, for example, an electronic sound such as "beep", a shutter closing sound in a film camera, a mirror down sound, or a film winding sound.
[0305]
As described above, even when a plurality of images are taken, the sound representing the operation is one set (one time at the start of the exposure of the first image and at the completion of the exposure of the last image). There is no discomfort.
[0306]
In step S1010, the displacement detection unit 114 extracts a characteristic image (feature point) from the peripheral area of the image (for example, the buildings 123a and 123b in FIG. 3) and obtains the coordinates of the image.
[0307]
This is because, as described above, the first image 127 and the images 128 of the second image group are compared with each other, and regions other than regions having different brightness (that is, regions where the flash light of the strobe 16a sufficiently illuminates the subject) (i.e., regions) This is to extract a feature point from the area where the flash of the strobe 16a does not sufficiently illuminate the subject and obtain its coordinates.
[0308]
In step S1011, the coordinate conversion unit 115 performs coordinate conversion of each image, but does not perform coordinate conversion of only the first one image (the first image 127 using the strobe 16a). That is, the first image 127 is used as a reference for coordinate conversion.
[0309]
In step S1012, steps S1010 and 1011 are circulated and wait until coordinate conversion is completed for all images. When coordinate conversion of all images is completed, the process proceeds to step S1013.
[0310]
In step S1013, images are combined.
[0311]
Here, the synthesis of the images is performed by averaging the signals at the corresponding coordinates of each image, and the random noise in the images is reduced by averaging. Then, the gain of the image with reduced noise is increased to optimize the exposure.
[0312]
In step S1014, an area (area 129 in FIG. 4) in which the images do not overlap due to composition blur in the synthesized image is cut, and the image is complemented by diffusion so as to have the size of the original frame.
[0313]
In step S1015, gamma correction and compression processing are performed on the composite image signal.
[0314]
In step S1016, the image obtained in step S1015 is displayed on a liquid crystal display unit (display unit 118) arranged on the back of the camera or the like.
[0315]
In step S1017, the image data obtained in step S1015 is recorded on a recording medium (recording unit 119) constituted by, for example, a semiconductor memory and detachable from the camera.
[0316]
In step S1018, the process returns to the start.
[0317]
If the half-press (sw1 on) of the release button is still being performed at step S1018, the flow proceeds to steps S1001 and # 1002 again.
[0318]
If the full-press operation (sw2 on) of the release button is continuously operated in step S1018, the process waits in step S1018 without returning to the start.
[0319]
Next, a flow in which it is determined in step S1019 that image stabilization is unnecessary and the flow proceeds to step S1021 will be described.
[0320]
In step S1021, the process waits by circulating from step S1001 to step S1021 until there is an instruction to start shooting by a full-press operation of the release button.
[0321]
In step S1022, the process waits until normal shooting (normal shooting mode in which an effective exposure condition is formed by one exposure) is completed, and the process proceeds to step S1015 upon completion of exposure.
[0322]
Although omitted here, even in the shooting in the normal shooting mode, the shooting operation sound is emitted from the speaker 17a in accordance with the operation from the start to the end of the shooting.
[0323]
In other words, in the composite photographing mode (combining a plurality of images) and in the normal photographing mode, the same type of photographing operation sound is generated.
[0324]
In this case, the photographer can recognize whether or not the exposure is long-time exposure due to the difference in the operation sound interval of the speaker 17a (the length from the photographing start sound to the photographing completion sound). The photographer does not know whether or not there is.
[0325]
For this reason, as described above, the camera is easy to use without giving the photographer the recognition that special photographing is being performed even in the composite photographing mode.
[0326]
In step S1015, gamma correction and compression processing are performed on the composite image signal.
[0327]
In step S1016, the image obtained in step S1015 is displayed on a liquid crystal display unit (display unit 118) arranged on the back of the camera or the like.
[0328]
In step S1017, the image data obtained in step S1015 is recorded on a recording medium (recording unit 119) constituted by, for example, a semiconductor memory and detachable from the camera. In step S1018, the process returns to the start.
[0329]
As can be seen from this flow, the user automatically activates the image stabilizing system (synthetic image capturing mode) or deactivates (the normal image capturing mode) depending on the photographing conditions without performing the image stabilizing (composite image capturing mode) setting. In addition, by displaying the image at the time of the image stabilization operation, stable imaging without deterioration of the image can be performed each time a still image is captured.
[0330]
(Fifth embodiment)
FIG. 12 is a configuration diagram of a camera according to a fifth embodiment of the present invention. The same members as those described with reference to FIG. 1 or FIG.
[0331]
The difference from FIG. 1 is that a vibration detecting unit (vibration detecting means) 31 is provided instead of eliminating the anti-vibration operation unit 120.
[0332]
Ideally, the vibration detection unit 31 uses a high-precision sensor such as a vibration gyro used in an optical vibration isolation system, but what is detected is not a waveform of the camera shake but whether or not a large camera shake has occurred. Since the frequency characteristic is also limited, a less expensive sensor such as an acceleration sensor or an optical sensor (AF sensor) may be used.
[0333]
In the present embodiment, the composite photographing mode and the normal photographing mode are not automatically selected before photographing according to photographing conditions.
[0334]
Instead, when the camera shake detected by the vibration detection unit 31 during exposure becomes large during exposure in the normal imaging mode, the mode shifts to the composite imaging mode.
[0335]
That is, if the camera shake becomes large during the shooting, the shooting is interrupted and the shooting is performed again. If the camera shake during the second shooting becomes large, the shooting is also interrupted and the process proceeds to the third shooting until the composite image is properly exposed. This operation is repeated.
[0336]
For this reason, as long as the camera shake is small, shooting in the normal shooting mode can be performed even with long exposure time, so that the influence of subject shake, which is poor in the composite shooting mode, can be reduced.
[0337]
FIG. 13 is a flowchart summarizing the photographing operation of the camera in the present embodiment. This flow starts when the power of the camera is turned on.
[0338]
In step S1001, the photographer performs a half-pressing operation (sw1 on) of the release button and waits by circulating through this step until a photographing preparation operation (focus adjustment operation, photometric operation) is started, and when sw1 is turned on. Proceed to step S1002.
[0339]
In step S1002, the imaging unit 19 images the subject. The photographing control unit 18 drives the AF drive motor 14a to move the photographing lens 11 in the optical axis direction while detecting the contrast of the image based on the output from the signal processing unit 111. Then, the drive of the photographing lens 11 is stopped at the time when the contrast is highest. Thereby, the photographing optical system is brought into a focused state.
[0340]
Further, the photographing control unit 18 simultaneously obtains the brightness of the subject based on the output of the imaging unit 19 and sets photographing conditions.
[0341]
As described above, the shooting conditions are the brightness of the subject, the brightness of the lens, the imaging sensitivity, and the shooting focal length. The exposure time is obtained based on the brightness of the subject, the brightness of the lens, and the imaging sensitivity.
[0342]
Here, the imaging sensitivity is a sensitivity state of the imaging unit 19, and in the case of a digital camera, the sensitivity of the imaging unit 19 is fixedly set according to an auto mode automatically changed according to imaging conditions and a photographer's preference. There is a fixed sensitivity mode.
[0343]
In the case of the auto mode, the exposure time is set according to the brightness of the subject and the brightness of the lens, and the value of the aperture 13b (aperture aperture) and the closing timing of the shutter 12a (exposure time) are obtained.
[0344]
Then, it is determined whether or not image blur due to camera shake occurs in the exposure time obtained with respect to the currently set focal length of the photographing optical system. If image blur may occur, the imaging sensitivity is increased. Thus, the exposure time is shortened, and the value of the aperture 13b and the closing timing (exposure time) of the shutter 12a are calculated again.
[0345]
In the mode in which the flash 16a is automatically fired in accordance with the shooting conditions, the flash 16a is fired when the subject is dark, and when the user sets the forced flash or the flash prohibition of the flash 16a, the flash 16a is fired. The light emission control of 16a is performed.
[0346]
In the case of the fixed sensitivity mode, the exposure time is set according to the brightness of the subject, the brightness of the lens, and the set imaging sensitivity.
[0347]
A semi-auto mode that allows a change in the imaging sensitivity to a certain extent is also considered as a shooting scene selection mode (for example, a portrait mode) between the auto mode and the fixed sensitivity mode. In such a case as well, the exposure time is set by increasing the imaging sensitivity so that the image blur is reduced within the set allowable sensitivity range as described above.
[0348]
In step S1005, the process circulates from step S1001 to step S1005 and waits until sw2 is turned on by fully pressing the release button.
[0349]
In step S3001, it is determined whether or not shooting is the first image. In the case of the first shooting, the process proceeds to step S3003. In the case of the second or subsequent shooting, the process proceeds to step S3002.
[0350]
When the first shooting is performed, a flow flows from step S3001 to step S3003.
[0351]
In step S3003, exposure is started. That is, the electric charge stored in each photodiode of the imaging unit 19 is reset and re-accumulation is started.
[0352]
When the flash 16a is to be emitted according to the result obtained in step S1002, the flash 16a is emitted in this step.
[0353]
At the same time, sound generation at the start of photographing is performed by driving the speaker 17a via the sound drive unit 17b. The shooting operation sound may be, for example, an electronic sound such as “beep”, a shutter opening sound in a film camera or the like, or a mirror-up sound.
[0354]
In step S3004, it is determined whether the exposure time has passed the time set in step S1002. If the exposure time has passed, the process proceeds to step S1015, and if not, the process proceeds to step S3006.
[0355]
In step S3006, the camera shake applied to the camera during the exposure is detected by the vibration detection unit 31. If the camera shake affects the image, the process proceeds to step S3007; otherwise, the process proceeds to steps S3001, # 3003, and # 3004. , # 3006 to continue exposure.
[0356]
Here, whether or not the camera shake affects the image is determined based on the camera shake amount and the shooting focal length at that time. Even if the camera shake amount is smaller than the predetermined amount, the image deteriorates when the shooting focal length is longer than the predetermined distance. It is determined that the image is not deteriorated when the photographing focal length is shorter than the predetermined distance even if the camera shake amount is larger than the predetermined amount.
[0357]
If the exposure time set in step S1002 has been reached without significant camera shake while circulating from step S3001 to step S3006, the process proceeds to step S1015 as described above.
[0358]
If it is determined that a large camera shake occurs during the circulation from step S3001 to step S3006 and the image deteriorates, the circulation is cut off and the process proceeds to step S3007.
[0359]
Steps S3007 to S1014 are steps to be performed when it is determined that the image is deteriorated during the exposure as described above, and the subsequent steps are the composite photographing mode.
[0360]
In step S3007, the exposure is interrupted by closing the shutter 12a. This can prevent image deterioration due to camera shake.
[0361]
At this time, since the set appropriate exposure time has not elapsed, the exposure of the image obtained by shooting is insufficient.
[0362]
In step S1010, the displacement detection unit 114 extracts a characteristic image (feature point) from the peripheral area of the image (for example, the buildings 123a and 123b in FIG. 3) and obtains the coordinates of the image.
[0363]
This is because, as described above, the first image 127 and the images 128 of the second image group are compared with each other, and regions other than regions having different brightness (that is, regions where the flash of the strobe 16a sufficiently illuminates the subject) (i.e., regions). This is to extract a feature point from the area where the flash of the strobe 16a does not sufficiently illuminate the subject and obtain its coordinates.
[0364]
However, since the first image has no image to be compared, the coordinate conversion value is zero. That is, in step S1011, the coordinate conversion unit 115 performs coordinate conversion of each image, but does not perform coordinate conversion of only the first image (the first image 127 using the strobe 16a). This first image 127 serves as a reference for coordinate conversion.
[0365]
In step S1013, images are combined.
[0366]
Here, the synthesis of the images is performed by averaging the signals at the corresponding coordinates of each image, and the random noise in the images is reduced by averaging. Then, the gain of the image with reduced noise is increased to optimize the exposure. Note that, in the case of the first captured image, there is no image to be synthesized, so no synthesis is performed.
[0367]
In step S3008, it is determined whether or not the total exposure time of the combined photographed image has reached the exposure time (set exposure time) set in step S1002. In this case, the process proceeds to step S1009. If the exposure is still insufficient, the process returns to step S3001 to capture the next image for combination.
[0368]
Hereinafter, a case will be described in which the exposure is insufficient in step S3008 and the process returns to step S3001 for composite shooting.
[0369]
When the process returns to step S3001, the flow proceeds to step S3002 because the shooting is the second time.
[0370]
In step S3002, exposure is started. First, the charge stored in each photodiode of the imaging unit 19 is reset and re-accumulation is started.
[0371]
In step S3003, since the flash 16a is emitting light and the photographing operation sound (sound for starting exposure) is also sounding, the flash 16a is not emitted or sounded in this step.
[0372]
In step S3005, it is determined whether or not the remaining exposure time (time for complementing the underexposure) of the exposure time in the photographing in step S3003 has elapsed with respect to the exposure time set in step S1002. If the remaining time has elapsed, the process proceeds to step S3007; otherwise, the process proceeds to step S3006.
[0373]
In step S3006, camera shake applied to the camera during exposure is detected by the vibration detection unit 31, and if the camera shake affects the image, the process proceeds to step S3007. Exposure is continued by circulating 3006.
[0374]
Here, whether or not the camera shake affects the image is determined based on the camera shake amount and the shooting focal length at that time. As described above, it is determined that the image is deteriorated when the shooting focal length is long even if the camera shake is small, and the camera shake is determined. Even if it is large, it is determined that the image does not deteriorate when the shooting focal length is short.
[0375]
If the remaining exposure time has been reached without significant camera shake while circulating from step S3001 to step S3006, the process proceeds to step S3007 as described above.
[0376]
If it is determined that a large camera shake occurs during the circulation from step S3001 to step S3006 and the image deteriorates, the circulation is cut off and the process proceeds to step S3007.
[0377]
In step S3007, the exposure is interrupted by closing the shutter 12a. If the flow has flowed from step S3006, image deterioration due to camera shake can be prevented.
[0378]
When the flow has flowed from step S3005 to step S3007, the exposure is thereby completed.
[0379]
At this time (when the process proceeds from step S3006 to step S3007), since the set proper exposure time has not yet elapsed for the entire photographed image, each image obtained by this photographing has insufficient exposure.
[0380]
In step S1010, the displacement detection unit 114 extracts a characteristic image (feature point) from the peripheral area of the image (for example, the buildings 123a and 123b in FIG. 3) and obtains the coordinates of the image.
[0381]
This is because, as described above, the first image 127 and the images 128 of the second image group are compared with each other, and an area other than an area having a different brightness (that is, an area where the flash of the strobe 16a sufficiently illuminates the subject) ( That is, a feature point is extracted from the area where the flash of the strobe 16a does not sufficiently illuminate the subject, and its coordinates are obtained.
[0382]
In step S1011, the coordinate conversion unit 115 performs coordinate conversion of each image.
[0383]
This is because the coordinate conversion of the second image (the image passed through step S3002) is performed so that the first image (the first image 127 using the strobe 16a) overlaps with the first image. It is.
[0384]
In step S1013, images are combined.
[0385]
Here, the synthesis of the images is performed by averaging the signals at the corresponding coordinates of each image, and the random noise in the images is reduced by averaging. Then, the gain of the image with reduced noise is increased to optimize the exposure.
[0386]
In step S3008, it is determined whether or not the total exposure time of the combined photographed image has reached the exposure time set in step S1002. The process advances to step S1009, and if the exposure is still insufficient, the process returns to step S3001 to capture the next image for synthesis.
[0387]
That is, in step S3005, it is determined whether or not photographing has been performed after the remaining exposure time has elapsed. When photographing has been successfully completed, the image after composition has been properly exposed, so the photographing operation is terminated and step S1009 is performed. Proceed to. On the other hand, if the exposure is still insufficient (the shooting is interrupted due to camera shake even in the second shooting), the process returns to step S3001 and the shooting operation is repeated again.
[0388]
Thus, the photographing operation is repeated by repeating steps S3001 to # 3008 until the photographing with the set exposure time elapses, and the images are synthesized.
[0389]
For this reason, when the image deterioration due to the camera shake is large (the camera shake is large and the focal length is long), the number of shots increases.
[0390]
When the shooting is completed, the process proceeds to step S1009.
[0391]
In step S1009, the sound generation completion is performed by driving the speaker 17a via the sound drive unit 17b. The shooting operation sound may be, for example, an electronic sound such as "beep", a shutter closing sound in a film camera, a mirror down sound, or a film winding sound.
[0392]
In this way, even when a plurality of images are taken, the sound representing the operation is one set (one time at the start of the exposure of the first photographing and once at the completion of the exposure of the last photographing). There is no discomfort.
[0393]
In step S1014, an area (area 129 in FIG. 4) in which the images do not overlap due to composition blur in the synthesized image is cut, and the image is complemented by diffusion so as to have the size of the original frame.
[0394]
In step S1015, gamma correction and compression processing are performed on the composite image signal.
[0395]
In step S1016, the image obtained in step S1015 is displayed on a liquid crystal display unit (display unit 118) arranged on the back of the camera or the like.
[0396]
In step S1017, the image obtained in step S1015 is recorded on a recording medium (recording unit 119) that is configured by, for example, a semiconductor memory and is detachable from the camera.
[0397]
In step S1018, the process returns to the start.
[0398]
If the release button is still half-pressed (sw1 on) at step S1018, the flow proceeds to steps S1001 and # 1002 again.
[0399]
If the release button has been fully pressed (sw2 on) in step S1018, the process does not return to the start but waits in step S1018.
[0400]
Each embodiment described above is also an example of the case where each of the following inventions is implemented, and each of the following inventions is implemented by adding various changes and improvements to each of the above embodiments.
[0401]
[Invention 1] A first photographing mode in which a plurality of images obtained by sequentially photographing are combined to obtain a combined image with exposure correction, and a first photographing mode in which an image corresponding to the combined image is obtained by one photographing operation A photographing device capable of photographing in the photographing mode of 2,
An imaging apparatus, comprising: a control unit that can set one of the first imaging mode and the second imaging mode according to imaging conditions at the time of imaging.
[0402]
Depending on the shooting conditions at the time of shooting, there are cases where it is better to shoot in the first shooting mode and cases where it is better to shoot in the second shooting mode. Therefore, in the present invention, by setting one of the first shooting mode and the second shooting mode according to the shooting conditions, a better shot image can be obtained.
[0403]
By automatically switching between the two photographing modes, the photographer can easily use the image stabilizing function (image composition by exposure correction). For example, when the focal length of the photographing optical system provided in the photographing device is longer than a predetermined focal length, or when the sensitivity of the image pickup device provided in the photographing device is lower than the predetermined sensitivity, the second Can be switched from the shooting mode to the first shooting mode.
[0404]
When the photographing optical system is dark (when the aperture is smaller than a predetermined aperture) or when the subject is dark (subject brightness is equal to or lower than a predetermined level), the mode is switched from the second shooting mode to the first shooting mode. Can be.
[0405]
[Invention 2] A first photographing mode in which a plurality of images obtained by sequentially photographing are combined to obtain a combined image with exposure correction, and a second photographing mode in which an image corresponding to the combined image is acquired by one photographing operation A photographing device capable of photographing in the photographing mode of 2,
Display means for displaying information about shooting;
Control means for controlling the driving of the display means,
The control means selects one of the first shooting mode and the second shooting mode according to shooting conditions at the time of shooting, and displays information on the selected shooting mode on the display means. A photographing device characterized by causing the photographing device to perform a photographing.
[0406]
According to the present invention, it is possible to confirm on the display unit which of the first shooting mode and the second shooting mode should be used for shooting, so that an image without failure (image blur) can be displayed. Obtainable.
[0407]
For example, when the focal length of the photographing optical system provided in the photographing device is longer than a predetermined focal length, or when the sensitivity of the image pickup device provided in the photographing device is lower than the predetermined sensitivity, the first Can be displayed on the display means.
[0408]
Further, when the photographing optical system is dark (when the aperture diameter is smaller than a predetermined diameter) or when the subject is dark (subject brightness is equal to or lower than a predetermined level), information regarding the first shooting mode is displayed on the display means. Can be.
[0409]
[Invention 3] An image capturing apparatus that obtains an exposure-corrected composite image by combining a plurality of images obtained by sequentially capturing,
A photographing apparatus comprising: a control unit that changes a photographing time of each image according to photographing conditions at the time of photographing.
[0410]
According to the present invention, each photographing is performed at a photographing time suitable for photographing conditions at the time of photographing, so that a composite image without failure can be obtained even when images obtained by each photographing are combined. .
[0411]
For example, when the focal length of the photographing optical system in the photographing device is longer than a predetermined focal length, the photographing time (exposure time) can be shorter than when the focal length is shorter than the predetermined focal length. When the sensitivity of the image sensor is higher than the predetermined sensitivity, the photographing time can be shortened as compared with the case where the sensitivity is lower than the predetermined sensitivity.
[0412]
When the imaging optical system is bright (when the aperture is larger than a predetermined aperture), the exposure time can be shorter than when the imaging optical system is dark (when the aperture is smaller than the predetermined aperture). In addition, when the subject brightness is higher than the predetermined brightness, the shooting time can be shorter than when the subject brightness is lower than the predetermined brightness.
[0413]
[Invention 4] An image capturing apparatus that obtains an exposure-corrected composite image by combining a plurality of images obtained by sequentially capturing,
An image capturing apparatus, comprising: a control unit that changes the number of images to be captured according to image capturing conditions at the time of image capturing.
[0414]
For example, when the focal length of the photographing optical system in the photographing device is longer than a predetermined focal length, the number of photographings can be increased as compared with the case where the focal length is shorter than the predetermined focal length. Further, when the sensitivity of the image sensor provided in the imaging device is higher than a predetermined sensitivity, the number of images can be reduced as compared with the case where the sensitivity is lower than the predetermined sensitivity.
[0415]
When the imaging optical system is bright (when the aperture is larger than a predetermined aperture), the number of images can be reduced as compared with when the imaging optical system is dark (when the aperture is smaller than the predetermined aperture). Further, when the subject brightness is higher (bright) than the predetermined brightness, the number of shots can be reduced as compared with the case where the subject brightness is lower (dark).
[0416]
[Invention 5] The imaging apparatus according to any one of Inventions 1 to 4, wherein the imaging conditions are a focal length of an imaging optical system, sensitivity of an imaging element, aperture, or subject brightness.
[0417]
[Invention 6] Displacement amount detecting means for extracting a specific point in each image among the plurality of images, and detecting a displacement amount of a specific point on another image with respect to the specific point on the reference image,
Coordinate conversion means for performing coordinate conversion of the other image based on a detection result of the displacement amount detection means,
The image capturing apparatus according to any one of the first to fifth aspects, further comprising a combining unit that combines the reference image and another image that has been subjected to coordinate conversion by the coordinate converting unit.
[0418]
[Invention 7] A first imaging mode in which a plurality of images obtained by sequentially capturing images are combined to obtain a composite image subjected to exposure correction, and a first image capturing mode in which an image corresponding to the composite image is obtained by one image capturing operation. A photographing device capable of photographing in the photographing mode of 2,
It has sound generating means for emitting sound,
The sounding means emits a sound at the time of the first shooting and the last shooting in the shooting in the first shooting mode, and emits a sound when the shooting is started and the shooting is completed in the shooting in the second shooting mode. An imaging device characterized by the above-mentioned.
[0419]
Even when the same still image is shot, the number of times of shooting is different between the first shooting mode and the second shooting mode, so that the user may feel uncomfortable. Therefore, as in the present invention, by making the sounds (number of times) emitted at the time of shooting in the first shooting mode and the second shooting mode the same, it is possible to prevent the photographer from feeling uncomfortable. .
[0420]
[Invention 8] An image capturing apparatus that obtains an exposure-corrected composite image by combining a plurality of images obtained by sequentially capturing,
Displacement amount detecting means for extracting a specific point in each image among the plurality of images, and detecting a displacement amount of a specific point on another image with respect to the specific point on the reference image,
Coordinate conversion means for performing coordinate conversion of the other image based on a detection result of the displacement amount detection means,
Synthesizing means for synthesizing the reference image and another image subjected to coordinate conversion by the coordinate converting means,
Vibration detection means for detecting vibration applied to the device body,
Control means for controlling the operation of the device,
The photographing apparatus according to claim 1, wherein the control means stops photographing once and resumes photographing according to a detection result of the vibration detecting means and a photographing condition at the time of photographing.
[0421]
[Invention 9] The imaging apparatus according to Invention 8, wherein the imaging condition is a focal length of an imaging optical system.
[0422]
[Invention 10] A first imaging mode in which a plurality of images obtained by sequentially capturing images are combined to obtain a composite image subjected to exposure correction, and a first image capturing mode in which an image corresponding to the composite image is obtained by one shooting. 2 is a program that enables shooting in the shooting mode 2,
A program comprising a control step capable of setting one of the first shooting mode and the second shooting mode according to shooting conditions at the time of shooting.
[0423]
[Invention 11] A first imaging mode in which a plurality of images obtained by sequentially capturing images are combined to obtain a composite image subjected to exposure correction, and a first image capturing mode in which an image corresponding to the composite image is obtained by one image capturing operation. 2 is a program that enables shooting in the shooting mode 2,
A display step for displaying information about shooting;
Control step of controlling the driving of the display means,
In the control step, one of the first shooting mode and the second shooting mode is selected according to shooting conditions at the time of shooting, and information on the selected shooting mode is displayed. And the program.
[0424]
[Invention 12] A program for obtaining an exposure-corrected synthesized image by synthesizing a plurality of images obtained by sequentially photographing,
A program comprising a control step of changing a photographing time of each image according to photographing conditions at the time of photographing.
[0425]
[Invention 13] A program for obtaining an exposure-corrected composite image by combining a plurality of images obtained by sequentially photographing,
A program having a control step of changing the number of shots according to shooting conditions at the time of shooting.
[0426]
[Invention 14] A displacement detection step of extracting a specific point in each image of the plurality of images and detecting a displacement of a specific point on another image with respect to the specific point on the reference image,
A coordinate conversion step of performing a coordinate conversion of the other image based on a detection result of the displacement amount detection step;
A combining step of combining the reference image and another image subjected to the coordinate transformation in the coordinate transformation step.
[0427]
[Invention 15] A first photographing mode in which a plurality of images obtained by sequentially photographing are combined to obtain a combined image with exposure correction, and a first photographing mode in which an image corresponding to the combined image is obtained by one photographing operation 2 is a program that enables shooting in the shooting mode 2,
Having a sounding step of emitting a sound,
In the sounding step, a sound is emitted at the time of the first shooting and the last shooting in the shooting in the first shooting mode, and a sound is emitted at the time of shooting start and shooting completion in the shooting in the second shooting mode. A program characterized by the following.
[0428]
[Invention 16] A program for obtaining an exposure-corrected synthesized image by synthesizing a plurality of images obtained by sequentially photographing,
Extracting a specific point in each image of the plurality of images, a displacement amount detecting step of detecting a displacement amount of a specific point on another image with respect to the specific point on the reference image,
A coordinate conversion step of performing a coordinate conversion of the other image based on a detection result of the displacement amount detection step;
A synthesizing step of synthesizing the reference image and another image subjected to the coordinate conversion in the coordinate conversion step,
A vibration detection step of detecting vibration applied to the device body,
Controlling the operation of the device,
In the control step, according to a detection result of the vibration detecting step and a photographing condition at the time of photographing, the photographing is once terminated and then resumed.
[0429]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the imaging | photography apparatus provided with the image stabilization function can reduce imaging | photography failure, and becomes user-friendly.
[Brief description of the drawings]
FIG. 1 is a block diagram of a camera according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram of coordinate conversion according to the first embodiment of the present invention.
FIG. 3 is an explanatory diagram (a, b) of a feature point extraction region according to the first embodiment of the present invention.
FIG. 4 is an explanatory diagram of image synthesis according to the first embodiment of the present invention.
FIG. 5 is a flowchart illustrating a shooting operation according to the first embodiment of the present invention.
FIG. 6 is an explanatory diagram of a feature point extraction area according to a second embodiment of the present invention.
FIG. 7 is a timing chart showing a shooting processing operation according to the second embodiment of the present invention.
FIG. 8 is a flowchart illustrating a shooting operation according to the second embodiment of the present invention.
FIG. 9 is a flowchart illustrating a shooting operation according to a third embodiment of the present invention.
FIG. 10 is a block diagram of a camera according to a fourth embodiment of the present invention.
FIG. 11 is a flowchart illustrating a shooting operation according to a fourth embodiment of the present invention.
FIG. 12 is a block diagram of a camera according to a fifth embodiment of the present invention.
FIG. 13 is a flowchart illustrating a shooting operation according to a fifth embodiment of the present invention.
[Explanation of symbols]
10: Optical axis
11: Shooting lens
12a: Shutter
12b: shutter drive unit
13a: Aperture
13b: diaphragm drive unit
14a: AF drive motor
14b: focus driver
15a: Zoom drive motor
15b: zoom drive unit
16a: Strobe
16b: Flash drive unit
17a: Speaker
17b: sound drive unit
18: Shooting control unit
19: Imaging unit
110: A / D converter
111: signal processing unit
112: Signal switching unit
113: Image storage unit
114: shift detection unit
115: coordinate conversion unit
116: Image synthesis unit
117: Image correction unit
118: Display unit
119: recording unit
120: anti-vibration operation unit
121a: Frame
122a: person
123a: Building
124a: window
125a: feature point (edge)
126: coordinate transformation direction (quantity)
127: First image
128: second image group
129: Area where two images do not overlap
130: Image peripheral area
131a: Focus area
131b: Focus area
131c: Focus area
131d: focus area
131e: Focus area
132: Main subject area
31: Vibration detector

Claims (2)

A first shooting mode in which a plurality of images obtained by sequentially shooting are combined to obtain a combined image with exposure correction, and a second shooting mode in which an image equivalent to the combined image is obtained by one shooting. A photographing apparatus capable of performing photographing in the first photographing mode, the photographing apparatus having a control unit capable of setting one of the first photographing mode and the second photographing mode according to photographing conditions at the time of photographing. Imaging device. A first shooting mode in which a plurality of images obtained by sequentially shooting are combined to obtain a combined image subjected to exposure correction, and a second shooting mode in which an image corresponding to the combined image is obtained by one shooting. Is a program that enables shooting in
A program comprising a control step capable of setting one of the first shooting mode and the second shooting mode according to shooting conditions at the time of shooting.

Images