JP2007178708A - Imaging apparatus and photographing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of taking a composite image by one or two or more image compositing methods by performing photographing operation once, and a photographing method. <P>SOLUTION: The imaging apparatus 100 includes: a first CPU 128 which acquires the result of photometry of a subject and the focal distance information of a lens and decides the number of photographic images when performing the photographing operation once and exposure time per photographic image based on the result of photometry and the focal distance information which are acquired; and a CCD element 108 taking a plurality of images by performing photographing operation once based on the number of photographic images and the exposure time per photographic image which are decided by the first CPU 128. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging apparatus and an imaging method, and more particularly to an imaging apparatus and an imaging method for imaging a plurality of images by dividing an exposure time by a single imaging operation.

  Conventionally, a plurality of images are shot by one shooting operation (referred to as one shutter button operation) by combining a plurality of images shot by a plurality of shooting operations or by dividing an exposure time. As shown in FIG. 11, a method of correcting image blurring that occurs during shooting or increasing the resolution of the image is disclosed.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for taking a plurality of images and synthesizing the images so that the positions of the subjects coincide.

  Japanese Patent Application Laid-Open No. 2005-228561 discloses a technique that includes two division modes and synthesizes images that are divided and exposed in each division mode.

  Japanese Patent Application Laid-Open No. 2004-228688 discloses a technique for providing a shooting mode for performing divided exposure in addition to a shooting mode for performing normal shooting, and synthesizing images subjected to divided exposure.

JP 2002-0777725 A JP 2003-319252 A JP 2002-084444 A

  However, these conventional techniques have a problem that the number of shots is fixed, and the number of shots and the exposure time per sheet cannot be set flexibly according to the surrounding conditions at the time of shooting.

  Therefore, the present invention has been made in view of such a problem, and an object of the present invention is to automatically determine the number of shots and the exposure time per shot according to the surrounding conditions at the time of shooting. It is an object of the present invention to provide a new and improved imaging apparatus and imaging method that can be used.

  In order to solve the above problems, according to an aspect of the present invention, a photometry result acquisition unit that acquires a photometry result of a subject, a focal length acquisition unit that acquires focal length information of a lens, a photometry result acquisition unit, and a focus Based on the photometric result and focal length information acquired by the distance acquisition unit, a shooting condition determination unit that determines the number of shots and the exposure time per shot at the time of one shooting operation, and the number of shots determined by the shooting condition determination unit and An image pickup apparatus is provided that includes an image pickup unit that picks up a plurality of images by one shooting operation based on an exposure time per sheet.

  According to this configuration, when the photographer takes a picture, the photometry result acquisition unit acquires the photometry result of the subject, the focal length acquisition unit acquires the focal length information of the lens, and the shooting condition determination unit determines the photometry result and The focal length information is used to determine the number of shots and the exposure time per shot. Based on the number of shots determined by the shooting condition determination unit and the exposure time per frame, the imaging unit shoots the subject. As a result, an imaging apparatus according to an aspect of the present invention can obtain an appropriate image by automatically determining a suitable number of images and exposure time when shooting a plurality of images by a single shooting operation. it can.

  The exposure time per frame determined by the shooting condition determination unit may be set to be equal to or less than the exposure time due to the camera shake limit shutter speed, which is the longest shutter speed at which the subject can be shot without blurring. According to this configuration, the imaging unit captures a subject at a shutter speed that is equal to or lower than the camera shake limit shutter speed. As a result, the imaging apparatus according to an aspect of the present invention can capture a plurality of images without blurring of the subject.

  An image storage unit that stores a plurality of images captured by the imaging unit may be further included. With this configuration, a plurality of captured images can be read from the image storage unit and processed and combined.

  When the sum of the capacities of multiple images exceeds the storage capacity of the image storage unit, the number of shots is set to the upper limit of the number that can be stored in the storage capacity, and an insufficient exposure amount of the image indicates an increase in shutter time and / or gain May be supplemented. With this configuration, even when the total capacity of images captured under the imaging conditions determined by the imaging condition determination unit exceeds the storage capacity of the image storage unit, the image is stored without degrading the image quality. Can be memorized.

  If the exposure time per sheet does not match the shutter speed preset in the imaging apparatus, the exposure time per sheet is faster than the exposure time per sheet. It may be set to a shutter speed set in advance in the imaging apparatus that is close to the time, and an insufficient exposure amount of the image may be compensated by increasing the gain. With such a configuration, even an imaging device that cannot set the shutter speed to an arbitrary value can capture a plurality of images similar to the case where the shutter speed is set to an arbitrary value.

  Even if the exposure amount obtained from the photometric result of the subject is E and the number of shots is n (n is an integer of 1 or more), even if the exposure amount E / n is n + α (α is an integer of 1 or more). Good. With this configuration, it is possible to capture an image with a higher resolution as a whole than when capturing normally.

  The sum of the exposure amounts of a plurality of images may be equal to the exposure amount obtained from the photometric result of the subject. With this configuration, it is possible to take an image without reducing the overall exposure amount in a plurality of images.

  You may further include the image synthetic | combination part which synthesize | combines the several image memorize | stored in the image memory | storage part by the 1 or 2 or more image synthesis method. With this configuration, it is possible to easily take a photograph having a special effect as in the case of performing a normal shooting operation.

  One or more image composition methods include a method of composing a plurality of images as they are, a method of compositing a plurality of images so that the positions of subjects match, a method of compositing a plurality of images evenly, and a plurality of images Selected from the group consisting of a method of randomly shifting images, a method of combining multiple images by enlarging or reducing them, a method of combining multiple images by rotating, and a method of combining multiple images with varying brightness. Alternatively, one or more image synthesis methods may be used.

  The image synthesizing unit may further include a switch unit, and the image synthesizing unit may change the image synthesizing method depending on photographing conditions when the switch unit is activated. With this configuration, it is possible to synthesize a plurality of images by an appropriate image synthesis method based on the surrounding situation when the switch unit is operated.

  An imaging condition acquisition unit that acquires imaging conditions may be further included, and the image composition method may be changed according to the imaging conditions acquired by the imaging condition acquisition unit. With this configuration, a plurality of images can be synthesized by an appropriate image synthesis method based on the acquired shooting conditions.

  The camera shake amount detection unit may further detect an image shake amount of the image, the camera shake amount detection unit may select an image with a small amount of camera shake from a plurality of images, and the image composition unit may synthesize an image with a small amount of camera shake. . With this configuration, it is possible to obtain an image that is not affected by camera shake.

  You may further include the image recording part which records the image synthesize | combined by the image synthetic | combination part and / or the some image before a synthesis | combination. With this configuration, it is possible to freely process or combine a plurality of images before combining after shooting.

  A plurality of pre-combination images recorded in the image recording unit may be read and the plurality of images may be combined by the image combining unit. With this configuration, after photographing, a plurality of pre-combination images that have been recorded can be read out and processed or combined freely.

  It is also possible to read a plurality of pre-combination images recorded in the image recording unit, combine the plurality of images in the image combining unit, and then record the combined image in the image recording unit. With this configuration, a plurality of pre-combination images once recorded after shooting can be read and combined, and then the combined image can be recorded.

  The camera further includes a shift amount setting unit for setting the image shift amount in advance, and a shift amount acquiring unit for acquiring the image shift amount set by the shift amount setting unit. When selecting a method of combining a plurality of images by shifting from the above image combining methods, the shift amount acquisition unit may acquire the shift amount and combine the images based on the shift amount. With this configuration, a plurality of images can be synthesized by shifting the image by an arbitrary shift amount of the photographer.

  The shift amount setting unit may set the shift direction of the image, the shift amount acquisition unit may acquire the shift direction, and the image composition unit may combine the images based on the shift amount and the shift direction. With such a configuration, a plurality of images can be synthesized by shifting the images with any shift amount and shift direction of the photographer.

  A shift amount display unit that can display the shift amount on the screen may be further included. With this configuration, it is possible to confirm in advance the effect of shifting during the actual synthesis process.

  When the exposure time per sheet obtained from the photometric result of the subject is equal to or shorter than the exposure time due to the camera shake limit shutter speed, the exposure time may not be divided. With this configuration, even if a plurality of shooting modes are not prepared, normal shooting can be automatically performed when the exposure time does not reach the exposure time due to the camera shake limit shutter speed.

  In order to solve the above-described problems, according to another aspect of the present invention, there is provided a photographing method for photographing a plurality of images by dividing an exposure time by a single photographing operation, wherein a photometric result of a subject and a focal length of a lens are obtained. Based on the information, the number of shots and the exposure time per shot during a single shooting operation are determined. If the exposure time per shot is faster than the exposure time due to the camera shake limit shutter speed, A photographing method characterized in that a plurality of images are photographed by a photographing operation at a determined number of photographs and an exposure time per sheet, and the photographed images are synthesized by at least one or two or more image composition methods. Provided.

  According to this method, the photometry result of the subject and the focal length information of the lens are acquired at the time of shooting, and the exposure time per frame is faster than the camera shake limit shutter speed based on the photometry result of the subject and the focal length information of the lens. Take multiple images. The captured images are synthesized by at least one or more image synthesis methods. As a result, according to the photographing method according to another aspect of the present invention, it is possible to photograph images having various special effects and images corrected for camera shake by a single photographing operation.

  As described above, according to the present invention, a new and improved imaging apparatus and imaging device capable of automatically determining the number of images to be captured and the exposure time per image according to the surrounding conditions at the time of shooting. A method can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is an explanatory diagram showing an imaging apparatus according to the first embodiment of the present invention. As shown in FIG. 1, an imaging apparatus 100 according to an embodiment of the present invention includes a zoom lens 102, a diaphragm 104, a focus lens 106, a CCD (Charge Coupled Devices) element 108, and an amplifier integrated CDS. (Correlated Double Sampling) circuit 110, A / D converter 112, image input controller 114, image signal processing circuit 116, image coincidence detection circuit 118, image composition circuit 120, compression processing circuit 122, LCD (Liquid Crystal Display) driver 123, LCD 124, timing generator 126, first CPU (Central Processing Unit) 128, second CPU 130, operation unit 132, shutter button 1 3 includes a memory 134, a VRAM (Video Random Access Memory) 136, a media controller 138, a recording medium 140, a motor driver 142a, 142b, and 142c, a flash device 144, and a vertical and horizontal sensor 146.

  Hereinafter, the configuration of the imaging apparatus 100 according to the first embodiment of the present invention will be described with reference to FIG.

  The zoom lens 102, the diaphragm 104, the focus lens 106, and the CCD element 108 constitute an imaging unit. In the present embodiment, the imaging unit is configured by using the CCD element 108, but the present invention is not limited to such an example, and a CMOS (Complementary Metal Oxide Semiconductor) element may be used instead of the CCD element 108. Since the CMOS element can convert the image light of the subject into an electrical signal at a higher speed than the CCD element, it is possible to shorten the time from when the subject is photographed to when the image is combined.

  The zoom lens 102 is a lens whose focal length changes continuously by moving back and forth in the optical axis direction, and shoots while changing the size of the subject. The diaphragm 104 adjusts the amount of light entering the CCD element 108 when taking an image. The focus lens 106 adjusts the focus of the subject by moving back and forth in the optical axis direction.

  The timing generator 126 is for inputting a timing signal to the CCD element 108. The shutter speed is determined by the timing signal from the timing generator 126. In other words, the drive of the CCD element 108 is controlled by the timing signal from the timing generator 126, and the image signal from the subject is incident within the time that the CCD element 108 is driven, thereby generating an electrical signal that is the basis of the image data. The

  The CCD element 108 is an element for converting light incident from the zoom lens 102, the diaphragm 104, and the focus lens 106 into an electric signal. In this embodiment, the incident light is controlled by the electronic shutter to adjust the time for extracting the electric signal. However, the incident light may be controlled by using the mechanical shutter to adjust the time for extracting the electric signal.

  The CDS circuit 110 is a circuit in which a CDS circuit that is a kind of sampling circuit that removes noise from the electrical signal output from the CCD element 108 and an amplifier that amplifies the electrical signal after removing the noise are integrated. . In the present embodiment, the imaging apparatus 100 is configured using a circuit in which a CDS circuit and an amplifier are integrated. However, the CDS circuit and the amplifier may be configured as separate circuits.

  The A / D converter 112 converts the electrical signal generated by the CCD element 108 into a digital signal, and generates raw image data.

  The image signal processing circuit 116 is a circuit that performs light amount gain correction and white balance adjustment on the electrical signal output from the CCD element 108 and the image synthesized by the image synthesis circuit 120.

  The image coincidence detection circuit 118 includes a function of a camera shake amount detection unit, and is a circuit that detects the position of the same subject among a plurality of captured images.

  The image composition circuit 120 is an example of an image composition unit, and is a circuit that composes a plurality of captured images. The method for synthesizing the image may be automatically determined according to the surrounding situation when the image is taken, or may be determined according to the setting of the photographer. Further, the image coincidence detection circuit 118 may detect the position of the same subject in the plurality of images, and the image composition circuit 120 may synthesize the plurality of images so that the positions coincide.

  The compression processing circuit 122 performs compression processing for compressing the image combined by the image combining circuit 120 into image data of an appropriate format. The compression of the image may be a reversible format or an irreversible format. Examples of suitable formats include the JPEG (Joint Photographic Experts Group) and JPEG2000 formats. Further, before the compression processing circuit 122 performs compression processing, the image signal processing circuit 116 may perform light amount gain correction and white balance adjustment.

  The LCD 124 performs live view display before performing a shooting operation, displays various setting screens of the imaging apparatus 100, displays captured images, and the like.

  The first CPU 128 is a CPU for issuing a signal system command to the CCD element 108, the CDS circuit 110, etc., and the second CPU 130 is a CPU for performing an operation system command for operating the operation member. . The first CPU includes functions of a photometric result acquisition unit, a focal length acquisition unit, and an imaging condition determination unit, and the first CPU includes a function of a shift amount acquisition unit. In the present embodiment, the first CPU 128 and the second CPU 130 are separate components, but a signal-related command and an operation-related command may be executed by one CPU.

  The operation unit 132 is provided with members for operating the imaging apparatus 100. The operation unit 132 includes a function as a shift amount setting unit that sets a shift amount when combining a plurality of images. The members arranged on the operation unit 132 are arranged with a power button, a cross key and a selection button for selecting a shooting mode and setting a shift amount and a shift direction. The set shift amount is acquired by the second CPU 130 at the time of photographing, and a plurality of images are shifted and combined based on the shift amount and the shift direction acquired by the second CPU 130 at the time of combining images.

  The LCD 124 includes a function as a shift amount display unit, and can confirm a shift amount and a shift direction set by the operation unit 132. Display of image data and various information of the imaging apparatus 100 on the LCD 124 is performed via the LCD driver 123.

  In the operation unit 132, not only the shift amount and the shift direction, but also the rotation amount of the image when the image is rotated and combined, the enlargement amount or the reduction amount when the image is expanded or reduced and combined, and the brightness of the image are displayed. You may set the variation | change_quantity of the brightness at the time of combining by changing. With this configuration, it is possible to further reproduce the photographer's intention to shoot.

  The shutter button 133 is an example of a switch unit, and an image is taken by operating the shutter button 133 to be in an active state, for example, by pressing the shutter button 133.

  The memory 134 is an example of an image storage unit, and temporarily stores captured images and images synthesized by the image synthesis circuit 120. The memory 134 has a storage capacity sufficient to store a plurality of images. Reading and writing of images to and from the memory 134 is controlled by the image input controller 114.

  FIG. 2 is an explanatory diagram schematically showing a memory map of the memory 134. The number of images that can be stored depends on the capacity of the memory 134 and the size of the image. FIG. 2 shows that the storage capacity is sufficient to store four captured images and three composite images. As a form of the memory, DRAM (Dynamic Random Access Memory), SDRAM (Synchronous DRAM), DDR SDRAM (Double Data Rate SDRAM), or the like can be used.

  The VRAM 136 holds contents to be displayed on the LCD 124, and the resolution and maximum color number of the LCD 124 depend on the capacity of the VRAM 136.

  The recording medium 140 is an example of an image recording unit, and records captured images and synthesized images. Input / output to / from the recording medium 140 is controlled by the media controller 138. As the recording medium 140, a memory card, which is a card-type storage device that records data in a flash memory, can be used.

  Motor drivers 142a, 142b, and 142c control the motors that operate the zoom lens 102, the diaphragm 104, and the focus lens 106. By operating the zoom lens 102, the diaphragm 104, and the focus lens 106 by the motor drivers 142a, 142b, and 142c, the size of the subject, the amount of light, and the focus are adjusted.

  The flash device 144 is an example of a light source, and is used for brightly illuminating a subject when photographing outdoors at night or in a dark place. When flash photography is performed, a flash command is issued from the first CPU 128 to the flash device 144. The flash device 144 is caused to emit light according to the flash command from the first CPU 128, and the subject is brightened by the light emitted by the flash device 144. Illuminated. The vertical / horizontal sensor 146 detects the vertical and horizontal directions of shooting when the imaging apparatus 100 performs shooting.

  Subsequently, a flow of an image capturing method in the imaging apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 3.

  When shooting an image, the photographer first presses the shutter button 133. When the shutter button 133 is pressed, a signal from the shutter button 133 is supplied to the second CPU 130, and photographing processing is started.

  Receiving the signal from the shutter button 133, the second CPU 130 supplies a signal notifying the first CPU 128 that the shutter button 133 has been pressed. Upon receiving the signal, the first CPU 128 acquires focal length information of the focus lens 106 and information on the photometric result of the subject (S110). From the information of the photometric result of the subject, it is possible to derive the shutter speed necessary for photographing only one image by one photographing operation.

  When the first CPU 128 acquires the focal length information of the focus lens 106 and the information of the photometric result of the subject, the exposure time and the number of shots per image are determined from the acquired information (S120). It is determined whether the exposure time per image derived as a result of photometry of the subject is equal to or greater than the camera shake limit shutter speed (S130). If the exposure time per image of the image derived as a result of photometry of the subject is equal to or greater than the camera shake limit shutter speed, the camera exposure limit shutter is the longest shutter speed at which the subject can be photographed without camera shake. It is set below the speed. FIG. 4 is an explanatory diagram showing the relationship between the focal length of the lens and the camera shake limit shutter speed. As shown in FIG. 4, the camera shake limit shutter speed can be obtained in approximately 1 / f (seconds) when the focal length of the focus lens 106 is f (mm).

  A plurality of images are taken with the derived exposure time per sheet (S140). Here, taking the case where the focal length of the focus lens 106 is 50 mm as an example, the camera shake limit shutter speed is approximately 1/50 = 0.02 seconds. As a result of measuring the subject, if the shutter speed is 0.2 seconds, 10 images are taken at the shutter speed 0.02 seconds. In this case, 11 or more images may be taken at a shutter speed of 0.02 seconds. As a result, it is possible to shoot an image with a higher resolution as a whole than when shooting normally. In addition to obtaining the number of sheets from the shutter speed, the number of sheets may be set in advance, and the shutter speed per sheet may be obtained from the number of sheets. When the number of images taken is set to 20, the shutter speed per image is 0.01 seconds.

  If the exposure time per sheet does not match the shutter speed set in advance in the imaging apparatus 100, the shutter speed is higher than the exposure time per sheet and close to the exposure time per sheet, and the imaging apparatus in advance. The shutter speed is set to 100, and the shortage of image exposure is compensated for by increasing the gain. For example, when the shutter speed is 1/30 seconds as a result of photometry of the subject, and the number of images taken is set to 8, the shutter speed per image is 1/240 seconds. . However, depending on the imaging apparatus 100, the shutter speed may not be set to an arbitrary value. For example, when the shutter speed set for the imaging apparatus 100 is 1/125 seconds and 1/250 seconds, the shutter speed may not be set to 1/240 seconds. In such a case, the shutter speed is set to 1/250 seconds, which is a shutter speed higher than 1/240 seconds, and eight images are taken at the shutter speed 1/250 seconds. Since the exposure amount of the image is insufficient, the shortage of the exposure amount of the image is corrected by performing light amount gain correction by the image signal processing circuit 116.

  On the other hand, if the exposure time per image derived as a result of photometry of the subject is less than the camera shake limit shutter speed, only one image is taken without dividing the exposure time (S160). That is, in the above example, when the shutter speed derived as a result of photometry of the subject is 0.02 seconds or less, only one image is taken without dividing the exposure time.

  In accordance with the number of shots and the exposure time per frame determined by the second CPU 130, the image light of the subject is input to the CCD element 108. The image light of the subject passes through the zoom lens 102, the stop 104, and the focus lens 106 and is irradiated on the CCD element 108. The image light of the irradiated subject is converted into an electric signal by the CCD element 108.

  When the image light of the subject is converted into an electric signal by the CCD element 108, the CDS circuit 110 removes noise contained in the electric signal generated by the CCD element 108 and amplifies the electric signal. The amplified electrical signal is converted into a digital signal by the A / D converter 112, and image data is generated. The image data converted into the digital signal is stored in the memory 134 by the image input controller 114.

  The memory 134 stores all image data captured by one imaging operation. If the total image data capacity of a plurality of captured images exceeds the storable capacity of the memory 134, the memory 134 is stored. Save the number of images until the capacity reaches the upper limit. For example, if it is determined that the second CPU is to take 10 images, but the memory 134 can store only a capacity for nine image data, nine images are taken. Then, since the exposure amount as a whole becomes insufficient, the shortage of exposure amount may be compensated by extending the shutter speed, or may be compensated by correcting the light amount by the image signal processing circuit 116.

  When shooting is completed and the image is stored in the memory 134, the image is synthesized using the image (S160). For multiple images, a method of combining multiple images as they are, a method of combining multiple images so that the positions of the subjects coincide, a method of combining multiple images evenly shifted, and a method of shifting multiple images randomly Use at least one of the following methods: a method of combining, a method of combining multiple images by enlarging or reducing them, a method of combining multiple images by rotating, and a method of combining multiple images with varying brightness. .

  The method for synthesizing the image may be selected and determined in advance by the photographer, or may be automatically selected according to the surrounding conditions at the time of photographing. Further, the composition in one photographing may be performed only once, or the composition may be performed twice or more by different composition methods.

  When synthesizing a plurality of images by a method of synthesizing so that the positions of the subjects coincide with each other, before the images are synthesized by the image synthesizing circuit 120, the image matching detection circuit 118 uses the same subject in the plurality of images. The amount of deviation is detected, and based on the amount of deviation, the image composition circuit 120 synthesizes the vehicle, for example, so that the positions of the objects coincide, for example, as shown in FIG. As a result, when a method of combining a plurality of images so that the positions of the subjects coincide with each other as a combining method, a combined image in which the influence of camera shake is suppressed can be generated.

  When combining a plurality of images by randomly shifting and combining them, the second CPU 130 determines a shift amount and a shift direction at random, and combines them based on the shift amount and the shift direction.

  When combining the images by changing the brightness of a plurality of images, the second CPU 130 determines the amount of change in the brightness of the image, and based on the amount of change, shown in FIG. As described above, for example, the brightness of a car that is a subject is changed and combined. The amount of change in brightness may be set by the photographer operating the operation unit 132 or may be determined in advance.

  When combining a plurality of images by combining them in an enlarged or reduced manner, the second CPU 130 acquires the enlargement amount or reduction amount, and based on the enlargement amount or reduction amount, FIG. As shown, for example, the subject car is enlarged or reduced to be combined. The enlargement amount or reduction amount may be set by the photographer by operating the operation unit 132, or may be determined in advance.

  When combining a plurality of images by combining them by rotation, the second CPU 130 acquires the amount of rotation, and based on the amount of rotation, as shown in FIG. A certain car is rotated to compose. The rotation amount may be set by the photographer operating the operation unit 132, or may be determined in advance. Further, the center of rotation may be the center of the image, or the photographer may set it by operating the operation unit 132.

  When combining a plurality of images by equally shifting and combining them, based on the shift amount and shift direction acquired by the second CPU 130, for example, as shown in FIG. Synthesize evenly in the direction.

  When synthesizing a plurality of images as they are, the image synthesizing circuit 120 simply adds the plurality of images and synthesizes them so as to understand, for example, the operation of a golf pad as shown in FIG.

  A composite image obtained by combining a plurality of images is stored in the memory 134. When the memory 134 has a sufficient capacity, not only a synthesized image by one synthesis but also a synthesized image by a plurality of synthesis may be stored. With this configuration, it is possible to generate a composite image by a plurality of composition methods with a single photographing operation.

  The composite image stored in the memory 134 is compressed by the compression processing circuit 122 to be compressed into image data of an appropriate format. The compression of the image may be a reversible format or an irreversible format. As an example of an appropriate format, it may be converted into a JPEG or JPEG2000 format. Further, before the compression processing circuit 122 performs compression processing, the image signal processing circuit 116 may perform gain correction and white balance adjustment.

  The composite image that has been compressed by the compression processing circuit 122 is displayed on the LCD 124. The composite image is displayed on the LCD 124 and the composite image is recorded on the recording medium 140. When a composite image is generated by combining images by a plurality of methods, all the composite images may be recorded, the composite image may be switched by operating the operation unit 132, and the composite result may be confirmed on the LCD 124.

  As described above, according to the imaging apparatus and the imaging method according to the present embodiment, it is possible to capture a composite image by one or two or more image composition methods by a single imaging operation.

  The flow of image capturing in the imaging apparatus according to the first embodiment of the present invention has been described above with reference to FIGS. 1 and 3.

(Second Embodiment)
Next, an imaging apparatus and a photographing method according to the second embodiment of the present invention will be described with reference to FIGS.

  When taking a picture of a person or the like indoors or outdoors at night, even if the subject is properly exposed, the background is underexposed, and the subject such as a person appears bright but the background is dark There is a problem that is reflected.

  In addition, a slow sync method is known in which both the subject and the background are photographed brightly by slowing down the shutter speed when performing strobe photography. The slow sync has two functions: “first curtain sync” that emits a strobe immediately after the shutter is opened, and “second curtain sync” that emits a strobe immediately before the shutter is closed. Here, a description will be given of a photographing method that can obtain the same effect as slow sync by photographing a plurality of images by dividing the exposure time by one photographing operation.

  The components of the imaging apparatus according to the present embodiment are substantially the same as those of the imaging apparatus 100 according to the first embodiment. Only specific processes of the first CPU 128 and the second CPU 130 are different. The configuration of the imaging apparatus according to the present embodiment will be described with reference to FIG.

  The first embodiment is an imaging apparatus and a shooting method for shooting a plurality of images with a single shooting operation. The second embodiment is an application example of the first embodiment, in which a plurality of images are photographed by a single photographing operation, and the flash device is caused to emit light at the time of photographing, and the photographing is performed without causing the flash to emit light. An image pickup apparatus and a photographing method for obtaining both a photographed image and an image photographed by flash emission.

  When performing normal flash photography, first, the operation unit 132 is operated to set the photography mode to one capable of flash photography. Then, when the photographer operates the shutter button 133, the image photographing process is started. When the shutter button 133 is pressed, a signal from the shutter button 133 is supplied to the second CPU 130, and photographing processing is started. In normal strobe shooting, when the shutter button is pressed, a signal from the shutter button is supplied to the second CPU 130, and the second CPU 130 notifies the first CPU 128 that strobe shooting has been performed. .

  Upon receiving the notification, the first CPU 128 notifies the motor drivers 142a, 142b, 142c, the timing generator 126, and the flash device 144 that the flash photography has been performed. Upon receiving the notification, the motor drivers 142a, 142b, and 142c control the operations of the zoom lens 102, the diaphragm 104, and the focus lens 106 in order to set an appropriate focal length and diaphragm, and the first CPU 128 emits the flash device 144. Thus, the timing generator 126 determines the time for the image light from the subject to enter the CCD element 108, and the image is taken only once. The above is the operation of the imaging apparatus 100 when performing normal flash photography.

  The strobe shooting method according to the present embodiment shoots a plurality of images by dividing the exposure time by one shooting operation, and shoots by flashing the flash device 144 in accordance with the exposure time per sheet. .

  In the flash photography method according to the present embodiment, first, the operation unit 132 is operated to set the photography mode to be capable of flash photography. Then, the photographer presses the shutter button 133 to start the image photographing process. In addition to the method for setting the shooting mode by the photographer, the shooting mode for performing the flash shooting is automatically detected by the imaging apparatus 100 when detecting the surrounding situation (for example, in a dark room or outdoors at night). You may set to the mode which performs imaging | photography.

  When the shooting mode is set to be capable of flash photography by operating the operation unit 132, the operation unit 132 is operated to set at which timing the flash device 144 emits light. The light emission timing of the flash device 144 may be set not only when the first image is captured or when the last image is captured, but also when any image is captured in accordance with the exposure time per sheet. Further, the number of times of light emission may be one or two or more.

  Receiving the signal from the shutter button 133, the second CPU 130 supplies a signal notifying the first CPU 128 that the shutter button has been pressed. Upon receiving the signal, the first CPU 128 acquires the exposure time A in one shooting operation, the number of shots n (n is an integer of 1 or more), and information on the light emission timing of the flash unit 144 (S210). . The number of shots may be a predetermined fixed number, or the operation unit 132 may be operated to determine the number of shots.

  The first CPU 128 includes a function as an exposure time acquisition unit. When the exposure time A and the number of shots n in one shooting operation are acquired, the exposure time A is divided into n and the exposure time per sheet. Is set to A / n (S220). Then, the first CPU 128 determines whether or not the mode is for flash photography (S230). If the mode is for flash photography, n + 1 pictures are taken (S240). In order to capture n + 1 images, a signal for capturing n + 1 images with an exposure time A / n per image is sent to the timing generator 126, and image light from the subject is incident on the CCD element. The image light of the subject passes through the zoom lens 102, the stop 104, and the focus lens 106 and is irradiated on the CCD element 108. The image light of the irradiated subject is converted into an electric signal by the CCD element 108.

  Here, when shooting n + 1 images, the flash device 144 is caused to emit light when the first image or the last image is shot based on the light emission timing information of the flash device 144 acquired by the first CPU 128 (S250). . For example, when the flash unit 144 is set to emit light when the first image is taken by operating the operation unit 132, the flash unit 144 is caused to emit light at the same timing as the first image is taken. If the flash device 144 is set to emit light at the time of taking the last image, the flash device 144 is caused to emit light at the same timing as the taking of the (n + 1) th image.

  FIG. 9A is an explanatory diagram for a histogram showing the brightness of a subject, and FIG. 9B is an explanatory diagram showing a shooting timing when shooting n + 1 images. In normal shooting, the exposure time A is determined based on the photometric result of the subject. In the present embodiment, the exposure time A / n per sheet is determined by dividing the exposure time A determined based on the photometric result of the subject by n, and n + 1 images are taken at the exposure time A / n. As shown in FIG. 9B, photometry may be performed every time one image is taken, or only when the first image is taken.

  FIG. 9B illustrates a case where the flash device 144 emits light at the time of photographing the last (n + 1) th sheet. When the last (n + 1) th image is photographed, pre-light emission is performed at the time of subject photometry, and the flash device 144 is light-emitted at the time of exposure, whereby an image in which the subject is brightly illuminated can be photographed. Then, as shown in FIG. 9A, the histogram of the photometry result of the subject is almost the same as the result of adding the histograms of the images when the exposure time is divided and taken.

  FIG. 10 is an explanatory diagram for explaining a photographing method according to the second embodiment of the present invention. In FIG. 10, the first to n-th images are images taken without the flash device 144 being emitted, and the last n + 1-th image is the subject that has the flash device 144 emitted. This is an image taken by brightly illuminating a car.

  When the image light of the subject is converted into an electrical signal by the CCD element 108, the noise generated by the CCD element 108 is removed by the CDS circuit 110, the signal generated by the CCD element 108 is amplified, and an A / D converter 112 is obtained. Is converted into a digital signal. The image data converted into the digital signal is stored in the memory 134 by the image input controller 114.

  The memory 134 stores all the image data shot by one shooting operation. When the total amount of image data of a plurality of captured images exceeds the storable capacity of the memory 134, the number of images until the capacity of the memory 134 reaches the upper limit is stored. For example, if the number of shots acquired by the second CPU is 10, but the memory 134 can store only a capacity for nine pieces of image data, nine images are shot. Then, since the exposure amount as a whole becomes insufficient, the shortage of exposure amount may be compensated by extending the shutter speed, or may be compensated by correcting the light amount by the image signal processing circuit 116.

  When shooting is completed and a plurality of shot images are stored in the memory 134, the image combining circuit 120 combines the plurality of images. In the image synthesis, the first to nth images and the 2nd to n + 1th images are synthesized to generate two types of synthesized images (S260). When the images are combined, the image signal processing circuit 116 may perform light amount gain correction. The shortage of exposure that may occur by dividing the exposure time can be compensated by light amount gain correction in the image signal processing circuit 116.

  For example, when the flash device 144 is set to emit light when the first image is shot and n + 1 shots are taken, the first to nth images are combined with the second to n + 1th images. Then, two types of composite images may be generated. As a result, it is possible to obtain two types of images, that is, an image in which the flash device 144 emits light and the subject appears bright, and a normal image that is captured without the flash device 144 emitting light. In addition, an image captured by causing the flash device 144 to emit light at that time is an image having the same effect as that of the leading curtain sync.

  In addition, when n + 1 shots are performed with the flash device 144 set to emit light when the last image is shot, 1 is set as in the case where the flash device 144 is set to emit light when the first image is shot. Two types of synthesized images may be generated by synthesizing the nth image from the first image and the (n + 1) th image from the second image. As a result, it is possible to obtain two types of images, that is, an image in which the flash device 144 emits light and the subject appears bright, and a normal image that is captured without the flash device 144 emitting light. In addition, an image captured by causing the flash device 144 to emit light at that time is an image having an effect similar to that of the trailing curtain sync.

  In the present embodiment, when a plurality of images are combined by the image combining circuit 120, a plurality of images including images captured by the flash device 144 being emitted and an image excluding images emitted from the flash device 144 are combined. In this way, two types of composite images are generated, but only images captured by flashing the flash device 144 may be combined.

  If the first CPU 128 determines in S230 that the mode does not perform flash photography, n images are photographed with an exposure time A / n (S270). Then, the photographing operation as described above is performed, and n images are synthesized by the image synthesis circuit 120 (S280). Even in the case of shooting without performing flash shooting, the image signal processing circuit 116 may correct the gain of the light amount when combining the images. Although the exposure time may be insufficient due to the division of the exposure time, the shortage of the exposure amount can be compensated by the gain correction of the light amount in the image signal processing circuit 116.

  Before the image synthesis circuit 120 synthesizes the image, the image coincidence detection circuit 118 detects a common subject shift amount among a plurality of images, and based on the shift amount, the image synthesis circuit 120 detects the subject. The positions may be combined so that they match. As a result, it is possible to generate an image in which the influence of camera shake is suppressed.

  The two generated composite images are stored in the recording medium 140, subjected to image compression processing by the compression processing circuit 122, and converted into image data of an appropriate format. The compression of the image may be a reversible format or an irreversible format. In the case of the reversible format, the compressed image data can be completely restored. In the case of the irreversible format, the image data can be kept small. Examples of suitable formats include JPEG and JPEG2000 formats.

  Further, before the compression processing circuit 122 performs compression processing, the image signal processing circuit 116 may perform gain correction and white balance adjustment. With this configuration, it is possible to correct image quality degradation that may occur due to the division of the exposure time.

  The two composite images that have been subjected to compression processing by the compression processing circuit 122 are displayed on the LCD 124. By operating the operation unit 132, the composite image can be switched and displayed. The order of display on the screen may be a composite image including an image captured with the flash device 144 emitted first, or a composite image not including an image captured with the flash device 144 displayed first. Also good.

  The two composite images subjected to the compression processing by the compression processing circuit 122 can be recorded on the recording medium 140. Either one composite image may be recorded on the recording medium 140, or both may be recorded. When recording any one of the composite images, the composite image is displayed on the LCD 124, and then the composite image to be recorded is selected by operating the operation unit 132, and the selected composite image is recorded on the recording medium 140. May be.

  As described above, according to the imaging apparatus and the imaging method according to the second embodiment of the present invention, it is possible to capture both an image in which the strobe is emitted and an image in which the strobe is not emitted with a single photographing operation, and An image having the same effect as the slow sync can be taken.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, the photographed image and the generated composite image are compressed by the compression processing circuit 122 and then displayed on the LCD 124 or recorded on the recording medium 140, but the LCD 124 is not compressed by the compression processing circuit 122. Or may be recorded on the recording medium 140 without being compressed by the compression processing circuit 122.

  The present invention can be applied to an imaging apparatus and an imaging method capable of easily imaging an image having a special effect as in a normal imaging operation.

It is explanatory drawing which shows the structure of the imaging device which concerns on the 1st Embodiment of this invention. It is explanatory drawing for demonstrating the data structure memorize | stored in the memory which concerns on the 1st Embodiment of this invention. 3 is a flowchart showing a photographing method according to the first embodiment of the present invention. It is explanatory drawing which shows the relationship between the focal distance of the lens which concerns on the 1st Embodiment of this invention, and camera shake limit shutter speed. It is explanatory drawing for demonstrating the imaging | photography method which concerns on the 1st Embodiment of this invention. It is explanatory drawing for demonstrating the imaging | photography method which concerns on the 1st Embodiment of this invention. It is explanatory drawing for demonstrating the imaging | photography method which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the imaging | photography method which concerns on the 2nd Embodiment of this invention. It is explanatory drawing for demonstrating the imaging | photography method which concerns on the 2nd Embodiment of this invention. It is explanatory drawing for demonstrating the imaging | photography method which concerns on the 2nd Embodiment of this invention. It is explanatory drawing for demonstrating the conventional imaging | photography method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image pick-up device 108 CCD element 114 Image input controller 116 Image signal processing circuit 118 Image coincidence detection circuit 120 Image composition circuit 122 Compression processing circuit 123 LCD driver 124 LCD
126 Timing generator 128 First CPU
130 Second CPU
132 Operation Unit 133 Shutter Button 134 Memory 140 Recording Media 144 Flash Device

Claims (20)

A photometric result acquisition unit for acquiring the photometric result of the subject;
A focal length acquisition unit for acquiring focal length information of the lens;
A shooting condition determining unit that determines the number of shots and the exposure time per shot based on the photometric result and the focal length information acquired by the photometric result acquisition unit and the focal length acquisition unit;
An imaging unit that captures a plurality of images in one imaging operation based on the number of images to be captured and the exposure time per image determined by the imaging condition determination unit;
An imaging device comprising:   The exposure time per sheet determined by the shooting condition determination unit is set to be equal to or less than an exposure time due to a camera shake limit shutter speed, which is a longest shutter speed at which a subject can be shot without shaking. The imaging apparatus according to 1.   The imaging apparatus according to claim 1, further comprising an image storage unit that stores the plurality of images captured by the imaging unit.   When the sum of the capacities of the plurality of images exceeds the storage capacity of the image storage unit, the number of shots is set to the upper limit of the number that can be stored in the storage capacity, and the shortage of the exposure amount of the image is defined as the extension of the shutter time and / or The image pickup apparatus according to claim 1, wherein the image pickup apparatus compensates for the increase in gain.   If the exposure time per sheet does not match the shutter speed preset in the imaging device, the exposure time per sheet is faster than the exposure time per sheet. The imaging apparatus according to claim 1, wherein a shutter speed set in advance in the imaging apparatus that is close to time is set, and an insufficient exposure amount of the image is compensated by an increase in gain.   When the exposure amount obtained from the photometric result of the subject is E and the number of shots is n (n is an integer equal to or greater than 1), n + α (α is an integer equal to or greater than 1) is captured at the exposure amount E / n. The imaging device according to claim 1, wherein:   The imaging apparatus according to claim 1, wherein a sum of exposure amounts of the plurality of images is equal to an exposure amount obtained from a photometric result of the subject.   The imaging apparatus according to claim 1, further comprising an image synthesis unit that synthesizes the plurality of images stored in the image storage unit using one or more image synthesis methods.   The one or more image synthesis methods include a method of synthesizing the plurality of images as they are, a method of synthesizing the plurality of images so that the positions of subjects match, and a method of synthesizing the plurality of images by shifting them evenly , A method of combining the plurality of images at random, a method of combining the plurality of images by enlarging or reducing, a method of combining the plurality of images by rotating, and changing the brightness of the plurality of images 9. The image pickup apparatus according to claim 8, wherein the image synthesizing method is one or more image synthesizing methods selected from a group of synthesizing methods. A switch part,
The imaging apparatus according to claim 8 or 9, wherein the image composition unit changes the image composition method according to a photographing condition when the switch unit is activated. A shooting condition acquisition unit for acquiring the shooting conditions;
The imaging apparatus according to claim 8, wherein the image composition method is changed according to the imaging condition acquired by the imaging condition acquisition unit. A camera shake amount detecting unit for detecting a camera shake amount of the image;
12. The camera shake amount detection unit selects an image with a small amount of camera shake from the plurality of images, and the image composition unit synthesizes an image with a small amount of camera shake. The imaging device described in 1.   The imaging apparatus according to any one of claims 8 to 12, further comprising an image recording unit that records the image synthesized by the image synthesis unit and / or the plurality of images before synthesis.   14. The imaging apparatus according to claim 13, wherein the plurality of images before synthesis recorded in the image recording unit are read, and the plurality of images are synthesized by the image synthesis unit.   15. The imaging apparatus according to claim 14, wherein an image synthesized by the image synthesis unit is recorded in the image recording unit. A shift amount setting unit in which the photographer sets the shift amount of the image in advance;
A shift amount acquisition unit that acquires the shift amount of the image set by the shift amount setting unit;
Further including
When the image combining unit selects a method of combining a plurality of images from among the one or more image combining methods, the shift amount acquisition unit acquires the shift amount and sets the shift amount to the shift amount. The image pickup apparatus according to claim 8, wherein images are synthesized based on the image.   The shift amount setting unit sets an image shift direction, the shift amount acquisition unit acquires the shift direction, and the image composition unit synthesizes an image based on the shift amount and the shift direction. The imaging device according to claim 16.   The imaging apparatus according to claim 16 or 17, further comprising a shift amount display unit capable of displaying the shift amount on a screen.   The exposure time is not divided when the exposure time per sheet obtained from the photometric result of the subject is equal to or less than the exposure time due to the camera shake limit shutter speed, which is the longest shutter speed at which the subject can be photographed without blurring. The imaging apparatus according to claim 1. A shooting method that captures multiple images by dividing the exposure time in one shooting operation:
Obtain photometric results of the subject and focal length information of the lens;
Determining the number of shots and the exposure time per shot based on the photometric result of the subject and the focal length information of the lens;
When the exposure time per image is faster than the exposure time due to the camera shake limit shutter speed, which is the longest shutter speed at which the subject can be imaged without blurring, the number of images to be determined determined by one imaging operation. And taking a plurality of images with the exposure time per said sheet;
Combining the plurality of captured images with at least one or more image combining methods;
This is a photography method.

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