JP2001197345A - Digital camera, its picture display method and computer- readable recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a photographic fault by confirming the composition of a multi-exposed photographing in advance. SOLUTION: A base picture obtaining part 210 obtains a base picture, which can be obtained by the reproducing processing of a recorded picture. An un- photographed picture obtaining part 212 obtains an un-photographed picture from a photographing part. An adding part 230 as a superposing part superposes the base picture and the un-photographed picture to generate a transmitting superposed picture where both of the pictures are seen through. The transmitting superposed picture is displayed on a display unit 100. In response to shutter operation by a user who confirms the transmitting superposed picture, a photographic picture obtaining part 214 obtains a photographic picture. A multi- exposed photographic picture is finally obtained from the photographic picture and the base picture.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera, and more particularly, to a digital camera having a multiple exposure photographing function.

2. Description of the Related Art One of the additional functions of a digital camera is a multiple exposure photographing function. JP-A-10-9
No. 3851 discloses a digital camera having such a multiple exposure shooting function. A plurality of images taken before and after in time are stored in a memory. Then, the plurality of images are combined by digital processing. Thus, multiple exposure shooting similar to that of a general silver halide camera is realized.

However, in the prior art, when photographing a later image, the composition of the previously photographed image cannot be confirmed. For this reason, the positional relationship between the images may not be as intended by the user, and the photographing may fail. The user has to repeat the same operation, such as pressing the shutter and checking the composite image, until a satisfactory result is obtained.

Originally, in a conventional general digital camera, a signal processing mode of a reproducing system and a signal processing mode of a photographing system are separated and independent. Therefore, in the photographing mode, it is impossible to reproduce and confirm the photographed image.

[0002] The present invention has been made in view of the above problems, and a main object thereof is to improve functions related to multiple exposure photographing. This object is achieved by a combination of features described in the independent claims. And the dependent
It defines specific and useful aspects of the present invention.

The above object can be attained by providing a digital camera technique having a function not available in conventional silver halide cameras and digital cameras, that is, a function of confirming the composition of multiple exposures before photographing. Is done.

One embodiment of the present invention is a digital camera having a multiple exposure photographing function. This digital camera is
A superposition unit that superimposes a base image obtained by a reproduction process of a recorded image and an unphotographed image obtained from the imaging unit, and generates a transmission superimposed image that allows both images to be seen through,
A display unit for displaying the transmission superimposed image for confirming a subject.

[0004] A "base image" is an image read out from a memory card or the like by a reproduction process, for example. The last image on the main memory may be used. An image obtained from outside the camera may be used. "Unphotographed image"
This is an image obtained from the imaging unit before a captured image is captured by the shutter operation, and shows a composition of an image to be captured. A substantial moving image called a so-called through movie image corresponds to an unphotographed image.
The “transmission superimposed image” is an image in which the base image and the unphotographed image can be seen through each other as described above. A transmission superimposed image is not a composite image in which one image is placed before the other. Such a non-transparent composite image is not suitable for a display for confirming multiple exposure shooting.

[0005] The superimposing section may add the base image and the unphotographed image. The superimposing unit may include an adding unit that adds a signal to the data of the base image and the data of the unphotographed image in pixel units. The weight may be different between the images. Further, the weight may be adjustable. The superimposing unit may generate the transmission superimposed image by arranging data selected from the base image and the unphotographed image. The ratio of data selected from the base image and the unphotographed image may be different. Further, the ratio of the data may be adjustable.

[0006] The digital camera of the present invention may further include a color changing section for performing a color changing process of at least one of the base image and the unphotographed image. A base image search unit may be provided. The base image search unit is
The base image is searched from a plurality of recorded images.
The base image is, for example, a similar image obtained by photographing a subject similar to the unphotographed image in the past.

Further, a size adjustment unit may be provided, and the size adjustment unit enlarges or reduces at least one of the base image and the unphotographed image,
The size relationship of the subject in the base image and the unphotographed image is adjusted.

Another embodiment of the present invention is a digital camera image display method. This image display method includes a step of obtaining a base image obtained by a reproduction process of a recorded image, a step of obtaining an unphotographed image to be photographed from the imaging unit, and a step of obtaining the base image and the unphotographed image. Are superimposed to generate a transmission superimposed image that allows both images to be seen through, and a step of displaying the transmission superimposed image for subject confirmation.

Another embodiment of the present invention is a recording medium recording a program. The program includes a step of acquiring a base image obtained by a reproduction process of a recorded image, a step of acquiring an unphotographed image to be photographed from the imaging unit, and superimposing the base image and the unphotographed image. In addition, the digital camera computer is caused to execute a step of generating a transmission superimposed image that allows both images to be seen through, and a step of displaying the transmission superimposed image for object confirmation.

The above summary of the invention does not list all the features necessary for the present invention.
Sub-combinations of these features can also be inventions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following embodiments do not limit the invention described in the claims, and all combinations of features described in the embodiments are solutions of the invention. It is not always necessary for the means.

FIG. 1 shows the configuration of a digital camera 10 having a multiple exposure shooting function and a preview function according to an embodiment. The configuration characteristic of the embodiment is mainly realized mainly by the processing unit 60 in FIG. 1, particularly, the main CPU 62, which will be described in detail with reference to FIG.

The digital camera 10 shown in FIG. 1 mainly includes an imaging unit 20, an imaging control unit 40, and a processing unit 6.
0, a display unit 100, and an operation unit 110.

The imaging unit 20 includes a mechanism member and an electric member related to photographing and image formation. Imaging unit 20
First, a photographing lens 22 for capturing and processing images,
An aperture 24, a shutter 26, an optical LPF (low-pass filter) 28, a CCD 30, and an image signal processing unit 32 are included. The taking lens 22 includes a focus lens, a zoom lens, and the like. With this configuration, the subject image is
Image on the light receiving surface of. Charges are accumulated in each sensor element (not shown) of the CCD 30 according to the amount of light of the formed subject image (hereinafter, the charges are referred to as “accumulated charges”). The accumulated charge is read out to a shift register (not shown) by a read gate pulse, and is sequentially read out as a voltage signal by a register transfer pulse.

Since the digital camera 10 generally has an electronic shutter function, a mechanical shutter such as the shutter 26 is not essential. In order to realize the electronic shutter function, the CCD 30 is provided with a shutter drain via a shutter gate. When the shutter gate is driven, accumulated charges are swept out to the shutter drain. By controlling the shutter gate, the time for accumulating the electric charges in each sensor element, that is, the shutter speed can be controlled.

A voltage signal output from the CCD 30, that is, an analog signal is color-separated into R, G, and B components by an image signal processing unit 32, and a white balance is adjusted first.
Subsequently, the imaging signal processing unit 32 performs gamma correction, sequentially A / D converts the R, G, and B signals at necessary timing, and obtains digital image data (hereinafter, simply referred to as “digital image data”) obtained as a result. ) Is output to the processing unit 60.

The image pickup unit 20 further includes a finder 3
4 and a strobe 36. The finder 34 may be equipped with an LCD (not shown). In this case, various information from the main CPU 62 and the like described later can be displayed in the finder 34. The strobe 36 functions by emitting light when energy stored in a capacitor (not shown) is supplied to the discharge tube 36a.

The imaging control unit 40 includes a zoom drive unit 4
2. It has a focus drive unit 44, an aperture drive unit 46, a shutter drive unit 48, an imaging system CPU 50 that controls them, a distance measurement sensor 52, and a photometry sensor 54. The driving units such as the zoom driving unit 42 each have a driving unit such as a stepping motor. When a release switch 114 described later is pressed, the distance measurement sensor 52 measures the distance to the subject, and the photometry sensor 54 measures the brightness of the subject. The measured distance data (hereinafter simply referred to as “distance measurement data”) and the subject luminance data (hereinafter simply referred to as “photometry data”) are sent to the imaging system CPU 50. Imaging system CPU 50
Controls the zoom drive unit 42 and the focus drive unit 44 to adjust the zoom magnification and focus of the photographing lens 22 based on the photographing information such as the zoom magnification designated by the user.

The image pickup system CPU 50 controls the R of one image frame.
The aperture value and the shutter speed are determined based on the integrated value of the digital signal of GB, that is, the AE information. According to the determined values, the aperture driving unit 46 and the shutter driving unit 48 adjust the aperture amount and open and close the shutter 26, respectively.

The imaging system CPU 50 controls the emission of the strobe light 36 based on the photometric data, and simultaneously adjusts the aperture of the aperture 24. When the user instructs the capture of an image, the CCD 30 starts to accumulate electric charges, and the accumulated electric charges are output to the imaging signal processing unit 32 after a lapse of a shutter time calculated from the photometric data.

The processing unit 60 includes the digital camera 10
The main C that controls the whole, especially the processing unit 60 itself
PU 62 and memory control unit 6 controlled by PU 62
4, a YC processing unit 70, an optional device control unit 74, a compression / decompression processing unit 78, and a communication I / F unit 80. Main C
The PU 62 is connected to the imaging CPU 5 by serial communication or the like.
Necessary information is exchanged with 0. Main CPU6
The second operation clock is provided from a clock generator 88. The clock generator 88 also provides clocks having different frequencies to the imaging system CPU 50 and the display unit 100, respectively.

The main CPU 62 is provided with a character generator 84 and a timer 86. The timer 86 is backed up by a battery and always counts the date and time.
From this count value, information about the shooting date and time and other time information are given to the main CPU 62. The character generation unit 84 generates character information such as a shooting date and time and a title, and the character information is appropriately combined with the captured image.

The memory control unit 64 includes a nonvolatile memory 66
And the main memory 68. Non-volatile memory 66
Is constituted by an EEPROM (electrically erasable and programmable ROM) or a flash memory, and stores data to be retained even when the power of the digital camera 10 is off, such as setting information by a user and adjustment values at the time of shipment. ing. The non-volatile memory 66 may have a main CP
A boot program or a system program of U62 may be stored. On the other hand, the main memory 68 generally has a D
It is composed of a relatively inexpensive and large-capacity memory such as a RAM. The main memory 68 has a function as a frame memory for storing data output from the imaging unit 20, a function as a system memory for loading various programs, and a function as a work area. The non-volatile memory 66 and the main memory 68
Data is exchanged with each unit inside and outside the unit 0 via the main bus 82.

The YC processing section 70 performs YC conversion on the digital image data, and outputs a luminance signal Y and a color difference (chroma) signal B-
Generate Y, RY. The luminance signal and the color difference signal are temporarily stored in the main memory 68 by the memory control unit 64.
The compression / decompression processing unit 78 sequentially reads out the luminance signal and the color difference signal from the main memory 68 and compresses them. The data thus compressed (hereinafter simply referred to as “compressed data”) is written to a memory card, which is a type of the optional device 76, via the optional device control section 74.

The processing unit 60 further includes an encoder 72
With. The encoder 72 receives a luminance signal and a color difference signal, converts them into a video signal (NTSC or PAL signal), and outputs the video signal from a video output terminal 90. When a video signal is generated from data recorded in the optional device 76, the data is first supplied to the compression / decompression processing unit 78 via the optional device control unit 74. Subsequently, the data subjected to the necessary expansion processing by the compression / expansion processing unit 78 is converted into a video signal by the encoder 72.

The optional device control section 74 generates necessary signals between the main bus 82 and the optional device 76, performs logical conversion, or converts voltage according to the signal specifications recognized by the optional device 76 and the bus specifications of the main bus 82. And so on. The digital camera 10 may include, for example, a PCM as an optional device 76 in addition to the above-described memory card.
A standard CIA-compliant standard I / O card may be supported. In that case, the optional device control unit 74
It may be constituted by an IA bus control LSI or the like.

The communication I / F section 80 is provided for the digital camera 10
Performs control such as protocol conversion according to the communication specifications supported by, for example, USB, RS-image reduction unit 232C, Ethernet, and the like. The communication I / F unit 80 includes a driver IC as necessary, and communicates with an external device including a network via a connector 92. In addition to such standard specifications, data may be exchanged with an external device such as a printer, a karaoke machine, a game machine, or the like by a unique I / F.

The display unit 100 includes an LCD monitor 10
2 and an LCD panel 104. These are the LCD driver monitor driver 106, panel driver 10
8 respectively. LCD monitor 102
Is provided on the back of the camera with a size of, for example, about 2 inches, and displays a current shooting and playback mode, a zoom ratio for shooting and playback, a remaining battery level, a date and time, a screen for mode setting, a subject image, and the like. . The LCD panel 104 is, for example, a small black-and-white LCD provided on the upper surface of the camera and has an image quality (FINE).
/ NORMAL / BASIC etc.), information such as strobe light emission / non-light emission, standard number of recordable images, number of pixels, battery capacity, etc. are simply displayed.

The operation unit 110 includes mechanisms and electrical members necessary for the user to set or instruct the operation and the mode of the digital camera 10. The power switch 112 determines whether the power of the digital camera 10 is turned on or off. The release switch 114 has a two-stage pressing structure of half pressing and full pressing. As an example, AF and AE are locked by a half-press, captured images are captured by a full-press, and are recorded in the main memory 68, the optional device 76, etc. after necessary signal processing, data compression, and the like. The operation unit 110 may receive a setting using a rotary mode dial, a cross key, or the like in addition to these switches, and these are collectively referred to as a function setting unit 116 in FIG. Examples of operations or functions that can be specified by the operation unit 110 include “file format”, “special effects”, “printing”, “determine / save”, and “display switching”. The “multiple exposure shooting mode” according to the present embodiment is also set using the operation unit 110. Zoom switch 1
Reference numeral 18 determines the zoom magnification.

The main operation of the above configuration is as follows. First, the power switch 11 of the digital camera 10
2 is turned on, and power is supplied to each part of the camera. The main CPU 62 determines whether the digital camera 10 is in the shooting mode or the playback mode by reading the state of the function setting unit 116.

When the camera is in the shooting mode, the main C
The PU 62 monitors the half-pressed state of the release switch 114. When the half-pressed state is detected, the main CPU 62
Obtains photometry data and distance measurement data from the photometry sensor 54 and the distance measurement sensor 52, respectively. The imaging control unit 40 operates based on the obtained data, and the focus, aperture, and the like of the photographing lens 22 are adjusted. Once the adjustment is complete,
Characters such as "standby" are displayed on the LCD monitor 102 to inform the user of the fact, and then the state of the release switch 114 being fully pressed is monitored. Release switch 1
When the shutter 14 is fully pressed, the shutter 26 is closed after a predetermined shutter time, and the accumulated charges in the CCD 30 are swept out to the imaging signal processing unit 32. The digital image data generated as a result of the processing by the imaging signal processing unit 32 is output to the main bus 82. The digital image data is temporarily stored in the main memory 68, and then processed by the YC processing unit 70 and the compression / decompression processing unit 78.
Is recorded in the option device 76 via the. The recorded image is displayed on the LCD monitor 102 for a while in a frozen state, so that the user can know the captured image. Thus, a series of photographing operations is completed.

On the other hand, when the digital camera 10 is in the reproduction mode, the main CPU 62 reads out the last photographed image from the main memory 68 via the memory control unit 64,
This is displayed on the LCD monitor 102 of the display unit 100.

In this state, when the user instructs "forward" or "reverse" in the function setting section 116, images taken before and after the currently displayed image are read out, and the
It is displayed on the monitor 102.

The overall configuration and operation of the digital camera 10 have been described above. Next, the multiple exposure shooting function according to the present embodiment will be described.

FIG. 2 is a schematic functional block diagram showing a configuration relating to the multiple exposure photographing function provided in the digital camera. 2 is mainly realized by the processing unit 60 of FIG. The main CPU 62 and the programs stored or loaded in the main memory 68 or the non-volatile memory 66 suitably function. Although FIG. 2 describes the functions related to the multiple exposure shooting as a unitary configuration, the actual functions are not always physically unitary and need not be included. Digital camera 10
The degree of freedom of design for implementing the function of the configuration shown in FIG. 2 will be understood by those skilled in the art.

FIG. 2 shows three image acquisition units, that is, a base image acquisition unit 210, an unphotographed image acquisition unit 212, and a photographed image acquisition unit 214. Image acquisition unit 21
Reference numerals 0, 212, and 214 respectively acquire a base image, an unphotographed image, and a photographed image. Using these images,
The “multiple exposure shooting function” and the “multiple exposure preview function” characteristic of the present embodiment are realized.

Schematically, the "multiple exposure preview function"
Is a function for confirming the composition of the multiple exposure shooting in advance.
By superimposing the base image and the unphotographed image, a transmission superimposed image that allows both images to be seen through is generated, and the transmission superimposed image is displayed on the display unit 100. After confirming the display of the preview, the user presses the release switch. In response to this operation, the “multiple exposure shooting function” superimposes the base image and the shot image, and obtains a multiple exposure shot image. Hereinafter, each configuration of FIG. 2 will be described for both functions.

[Multiple Exposure Preview Function] The base image acquiring section 210 acquires a base image from the optional device 76. The option device 76 is, for example, a memory card. The base image is an image serving as a basis for multiple exposure shooting, and is obtained by a reproduction process of a recorded image. In the present embodiment, as an example, the base image is RGB data. The image data is read from the memory card and expanded /
A decoding process is performed, whereby a base image in RGB format is obtained. In addition, the base image is the optional device 7
Configurations other than 6 may be obtained, for example, from outside the digital camera 10.

The unphotographed image obtaining section 212 obtains an unphotographed image from the imaging unit 20. The unphotographed image is an image before the captured image is captured by the shutter operation, and is an image indicating the composition of an image to be captured. As described above, when the user performs a shutter operation on the release switch, a photograph is taken by the imaging unit 20. The unphotographed image is taken by the imaging unit 20 before the shutter.
It is supplied continuously from.

An unphotographed image is typically an image called a so-called through movie image, and is supplied from the imaging unit 20 in the form of a substantial moving image. The number of pixels of the unphotographed image may be smaller than that of the captured image or the base image. For example, data may be thinned out so that the number of pixels becomes about 1/4. In the present embodiment, the unphotographed image is also RGB data like the base image. The RGB data of the through movie is obtained by software by the CPU.

The above-described base image acquisition section 210 includes a base image search section 211. The base image search unit 211 searches for an appropriate base image from a plurality of images stored in the memory card. For example, an image similar to an unphotographed image is searched for as a base image. The similar image is, for example, an image including a common subject.

The search for the base image may be manually performed by the user. In this case, the user operates the operation unit 11
Operate 0. Preferably, "forward" in playback mode
The search operation means (the operation unit 110 and related devices (the processing unit 60, the display unit, and the like)) are configured such that the base image is searched for by the same operation as “backward”. The operation is easy for the user, and the operability can be improved. Further, a base image similar to an unphotographed image may be automatically searched for by the base image search unit 211.

The base image and the unphotographed image obtained by the base image obtaining unit 210 and the unphotographed image obtaining unit 212 undergo the following processing. The base image and the unphotographed image are stored in the base image storage unit 216 and the unphotographed image storage unit 218, respectively, as display data. These storage units 216 and 218 are provided in the main memory.

The base image and the unphotographed image are subjected to color change processing by the color change unit 222 and the color change unit 224, respectively. Here, the colors of the base image and the unphotographed image are changed according to the user's instruction input from the operation unit 110. The user can specify a desired color for the base image and the unphotographed image so that the preview image with multiple exposures can be easily viewed.

The color changing process of the color changing unit 222 and the color changing unit 224 may be automatically performed. For example, the colors of the base image and the unphotographed image are converted to the default colors. As an example, a base image is converted to a grayscale image. As a modification, only one of the color changing unit 222 and the color changing unit 224 may be provided. The color change described above may be reflected in actual multiple exposure shooting described later.

With the above-described color change processing, the preview display of the multiple exposure becomes easy to see. In addition, by reflecting the color change on the multiple exposure photographed image, an effect that cannot be obtained with the silver halide camera can be given to the image.

Further, the base image and the unphotographed image are subjected to size adjustment processing by the size adjustment unit 226 and the size adjustment unit 228. The size adjustment unit 226 and the size adjustment unit 228 enlarge and expand the base image and the unphotographed image, respectively.
By reducing the size, the size relationship of the subject in the base image and the unphotographed image is adjusted (size alignment).

The size of both images may be manually adjusted by the user. The size adjustment unit 226 and the size adjustment unit 228 change the size of the base image and the size of the unphotographed image according to a user instruction input from the operation unit 110. In response to the instruction to adjust the size of the unphotographed image,
The zoom adjustment is performed by the imaging unit 20. The user can freely adjust the sizes of the base image and the unphotographed image.

The size of both images may be adjusted automatically or semi-automatically. For example, the user specifies a certain area in the base image and a certain area in the unphotographed image.
The image size is adjusted so that the two regions have the same size. The size of one image may be fixed and the size of the other image may be changed. The size of both images may be adjusted so that the two designated areas are converted to a size between them.

For example, in the automatic adjustment, 2
Two points are specified to the user. The size of at least one of the images is adjusted so that the distance between the two points is equal in both images. As a modified example, only one of the size adjustment unit 226 and the size adjustment unit 228 may be provided. Through the size adjustment processing described above, the size relationship between a plurality of images superimposed by multiple exposure can be appropriately set.

The size-adjusted base image and unphotographed image are sent to an adder 230 (signal adder, signal processing block having a data addition function). The adding unit 230 is one form of the superimposing unit. The adding unit 230 adds the base image and the unphotographed image. Base image data and unphotographed image data (both RGB data) are added in pixel units. If the number of pixels in the unphotographed image is thinned out and the number is small, the number of pixels in one or both images may be adjusted appropriately. It is possible to obtain a more natural image. Through the addition processing, a transmission superimposed image that allows the base image and the unphotographed image to be seen through each other is generated.

The transmission superimposed image is an image in which the base image and the unphotographed image can be seen through each other as described above. A transmission superimposed image is not a composite image in which one image is placed before the other. Such a composite image is not suitable for use as a preview image for multiple exposure shooting since the rear image cannot be seen through.

The transmission superimposed image is preferably an image obtained by superimposing images of the same size. If one of the images is a partial image (for example, a frame image occupying a peripheral region), a transmission superimposed image suitable for multiple exposure photographing whose main purpose is to multiplex images photographed one after another in time is I can't get it.

The weight setting section 232 sets weights for the addition processing in the addition section 230. The weight is set manually by the user. The user operates the operation unit 110
Can be operated to designate a desired weight. Alternatively, the weights may be set automatically. For example, a default value of the weight is set. Alternatively, weighting is determined according to the type of image. Also, weighting may be set so that some parameter of the two images, for example, the overall brightness is made uniform.

The adding section 230 adds the base image and the unphotographed image according to the weight set by the weight setting section 232. The data of the base image and the data of the unphotographed image are signal-added in pixel units. This makes it easier to see the multiple-exposure preview image. The weight set by the weight setting unit 232 may be reflected in actual multiple exposure shooting described later. An effect that cannot be obtained with a silver halide camera is given to an image.

The selector 234 is provided after the adder 230.
(Selector). The transmission superimposed image is subjected to appropriate filtering from the adder 230 and then to the selector 234.
Sent to The base image and the unphotographed image are also sent to the selector 234 from the size adjustment unit 226 and the size adjustment unit 228. The selector 234 sends one of a base image, an unphotographed image, and a transparent superimposed image to the display unit 100 according to a user instruction input from the operation unit 110. The selected image is sent to the display unit 100 via the main bus 82. In the display unit 100, an image is displayed on an LCD monitor via a monitor driver. Further, the selected image may be appropriately displayed on the finder of the imaging unit 20.

FIG. 3 shows these three types of images, that is, a base image (a), an unphotographed image (b), and a transmission superimposed image (c). The user can easily grasp the relationship between the base image and the unphotographed image by looking at the transmission superimposed image. In addition, since three types of images can be selectively displayed, the user can further examine whether or not the shooting conditions of the multiple exposure shooting are appropriate by switching the images, which is convenient.

In the foregoing, each configuration relating to the preview function of the multiple exposure shooting has been described. According to the above configuration, the base image obtained by the reproduction processing of the recorded image and the unphotographed image obtained from the imaging unit are superimposed, and a transparent superimposed image that can see through both images is generated. Then, a transmission superimposed image is displayed for subject confirmation.

By the way, in the conventional digital camera, it was not possible to view the transmission superimposed image before photographing. originally,
In a conventional general digital camera, a signal processing mode of a reproducing system and a signal processing mode of a photographing system are independent and separated modes. It is not possible to play back a captured image and check the image while checking the image, and thus it is not possible to display images in both modes in an overlapping manner.

On the other hand, in the configuration shown in FIG. 2, there is provided a configuration in which the signal of the reproduction system and the signal of the imaging system are integrally processed, so that it is possible to obtain a transmission superimposed image before imaging. Has become. Therefore, the user can check the transmission superimposed image to check the base image, and can check the relationship between the base image and the image to be shot. The user can predict the image after multiple exposure, and can easily set the composition. It is possible to avoid a shooting failure due to the lack of such a function. In other words, the probability of successful multi-exposure shooting increases, and the user can easily perform multiple-exposure shooting. Therefore, operability can be improved.

When the user sees the transmission superimposed image and satisfies the shooting conditions, the user pushes down the release switch of the operation unit 110. In response to this shutter operation, the following multiple exposure shooting is performed.

"Multiple exposure shooting function" As shown in FIG.
The configuration related to the multiple exposure shooting function is described in
0, captured image acquisition unit 214, base image storage unit 216,
Captured image storage section 220 and multiple exposure image generation section 236
including. The base image acquisition unit 210 and the base image storage unit 216 are as described above.

The photographed image acquisition section 214
The captured image is acquired from 0. The captured image is an image captured by the shutter operation of the imaging unit 20.
As described above, the user depresses the release switch in two steps. In response to this depression, the imaging unit 20 generates digital image data of the captured image under the control of the imaging control unit. This photographed image is acquired by the photographed image acquisition unit 214 via the main bus 82 and stored in the photographed image storage unit 220 provided in the main memory.

Unlike an unphotographed image which is, for example, thinned data for display, a photographed image is a detailed image for recording. The captured image and the base image are combined into a multiple exposure image
6. The multiple exposure image generator 236 adds the captured image and the base image. Thereby, a multiple exposure photographed image similar to that obtained by a general silver halide camera can be obtained.

The multiple exposure photographed image undergoes the same processing as a normal photographed image. The multiple-exposure photographed image is once stored in the main memory, recorded in the optional device 76, and further displayed on the display unit 100. The option device 76 is, for example, a memory card. Prior to recording on the memory card, the multiple exposure photographed image undergoes YC conversion and compression processing.

[Multi-Exposure Preview and Photographing Operation] FIG. 4 is a flowchart showing an example of the multiple-exposure preview and photographing operation by the digital camera 10. When the user operates the operation unit 110 to instruct the setting of the “multiple exposure shooting mode”, the processing in FIG. 4 starts.

First, a base image is obtained (S10),
Further, an unphotographed image is obtained (S12). It is determined whether to change one or both colors of the base image and the unphotographed image (S14). Color change processing is performed according to the determination result (S16). Further, it is determined whether to adjust the size of one or both of the base image and the unphotographed image (S18). A size adjustment process is performed according to the determination result (S20). When adjusting the size of an unphotographed image, a zoom adjustment instruction is sent to the imaging control unit.

Further, the weight setting value is read (S22). The base image and the unphotographed image are added according to the weight setting value, and a transmission superimposed image is generated (S2).
4). The display image selection instruction by the user is referred to (S26). In accordance with the user's instruction, the base image, the transmission superimposed image or the unphotographed image is displayed (S28, S3).
0, S32).

Next, it is determined whether or not the base image should be changed (S34). The user can give an instruction to change the base image. To change the base image,
Returning to 10, another base image is acquired. If the base image is not changed, the process proceeds to S36, and it is determined whether or not a shooting operation (shutter operation) has been performed (S36). S3
If 6 is NO, the process returns to S12.

If S36 is YES, a photographed image is obtained by the shutter operation (S38). The captured image and the base image are added to finally generate a multiple exposure captured image (S40). Then, the multiple exposure photographed image is recorded and displayed (S42). The user can check the photographing result. Since the transmission superimposed image is confirmed before photographing, a desired photographing result can be obtained with a high probability.

FIG. 5 is a functional block diagram showing a modification of the configuration of FIG. A selection data arrangement unit 240 and an arrangement ratio setting unit 242 are provided instead of the addition unit 230 and the weight setting unit 232 in FIG. The selection data array section 240 is also one form of the overlapping section, like the adding section 230. The selection data arraying unit 240 generates transmission superimposed images by arranging data selected from the base image and the unphotographed images.

FIG. 6 shows an example of data array processing. FIG.
In the example, data is selected in pixel units from both images. Pixel data of both images are alternately arranged. When such sequence data is displayed, for the user,
Both images can be seen through each other. Therefore, the transmission superimposed image of the present embodiment can be obtained.

The format of the array is not limited to the example shown in FIG. Various arrangements such as a staggered arrangement are conceivable. Further, data of both images may not be arranged in pixel units. For example, blocks formed by a plurality of pixels may be alternately arranged. Also, as in the description of FIG. 2, when the number of pixels of the unphotographed image is thinned out and small, the number of pixels of both images may be appropriately adjusted.

The arrangement ratio setting section 242 is a ratio (array ratio) of data selected from the base image and the unphotographed image.
Set. The arrangement ratio is manually set by the user. The user can operate the operation unit 110 to specify a desired arrangement ratio. Alternatively, the arrangement ratio may be set automatically. For example, a default value of the array ratio is set. Alternatively, the arrangement ratio is determined according to the type of the image. In addition, the arrangement ratio may be set so that some parameter of the two images, for example, the overall brightness is made uniform.

The selection data arrangement section 240 arranges data selected from the base image and the unphotographed image according to the arrangement ratio set by the arrangement ratio setting section 242. For example, in the example of FIG. 6, the arrangement ratio is 1: 1. If the arrangement ratio is 1: 2, twice as many pixels as the pixels selected from the base image are selected from the unphotographed image.

By adjusting the arrangement ratio, the same effect as the weight adjustment in the configuration of FIG. 2 can be obtained. That is, the arrangement ratio setting unit 242 can change the weighting state of the transmission superimposed image by changing the arrangement ratio. Then, by adjusting the ratio, the preview image with multiple exposures can be more easily viewed. Also, the result of the ratio adjustment may be reflected in actual multiple exposure shooting similarly to the weighting.

Further, in the configuration shown in FIG. 5, the multiple-exposure image generating section 236 may generate a multiple-exposure image according to the arrangement of the selection data. Alternatively, as in FIG. 2, the base image and the captured image may be added. Conversely, in the configuration of FIG. 2, the multiple exposure image generation unit 236 may arrange data selected from the base image and the captured image.

FIG. 7 shows the operation of the multiple exposure preview and the multiple exposure shooting with the configuration of FIG. Compared to the flowchart of FIG. 4, the weighted reading step S
An arrangement ratio reading step S23 is provided in place of 22. A selection data arrangement step S25 is provided instead of the addition processing step S24. The processing in S23 and S25 is performed by the arrangement ratio setting unit 2 in FIG.
42 and the selection data arrangement unit 240.
Other processes are the same as those in FIG.

The characteristic configuration and operation of the embodiment have been described. According to the present embodiment, since the transmission superimposed image is displayed, failures in multiple exposure shooting are reduced, and the operability of the camera is improved.

The weighting state of the transmission superimposed image can be adjusted through the weighting and the arrangement ratio, and the transmission superimposed image can be easily viewed. If the weighted state is reflected in the multiple exposure photographed image, an effect that cannot be obtained by the silver halide camera can be given to the image.

The color change processing makes the transmission superimposed image easy to see. If the color change is reflected in the multiple exposure photographed image, an effect that cannot be obtained with a silver halide camera can be given to the image.

Further, by the size adjustment processing, it is possible to appropriately set the size relationship between a plurality of images superimposed by multiple exposure.

Since the base image search section is provided, a desired base image can be found. As a result, an image captured a plurality of times before can be used as a base image. This is a convenient function that has not been available in the past.

Although the embodiments have been described, the technical scope of the present invention is not limited to these descriptions. It is understood by those skilled in the art that various changes or improvements can be made to these embodiments.

As a first modification, in the present embodiment,
A transmission superimposed image was generated from the RGB data. RGB
The data is advantageous in that it is technically easy to handle. However, a transmission superimposed image may be generated using other types of data. For example, in the configuration shown in FIG. 2, image data of any format that can be added can be used.

As a second modification, in the present embodiment, the transmission superimposed image is formed by adding or arranging the base image and the non-photographed image. However, the base image and the non-photographed image are superimposed by other processing. Is also good. Any superimposition process can be applied such that the two images can be seen through each other when the display is viewed by a human.

As a third modified example, the order of various processes may be appropriately changed. For example, the order of the color change and the size change may be reversed or simultaneous, and one or both of these processes may be performed at another stage.

As a fourth modification, it is needless to say that the number of images to be superimposed may be three or more. In this case, there are two or more base images. The base image acquisition unit 210 acquires two or more base images. Subsequent processing is also performed on a plurality of base images.

As a fifth modification, an electronic device having the function of a digital camera (for example, a computer equipped with a CCD camera) may be provided with the configuration of the present invention. include.

It is easily understood by those skilled in the art that other various modifications and changes can be made, and these can be included in the concept of the present invention.

As described above, the composition of the multiple exposure shooting can be confirmed in advance, and a digital camera technology capable of reducing shooting failure can be provided.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a digital camera according to an embodiment.

FIG. 2 is a functional block diagram schematically showing a configuration related to a multiple exposure shooting function in the digital camera of FIG. 1;

FIG. 3 is a diagram showing a transmission superimposed image obtained by a multiple exposure preview function having the configuration of FIG. 2;

FIG. 4 is a flowchart illustrating an example of a processing procedure of multiple exposure preview and multiple exposure shooting with the configuration of FIG. 2;

FIG. 5 is a functional block diagram showing a modification of the configuration of FIG. 2;

FIG. 6 is a diagram showing a process of arranging selection data according to the configuration of FIG. 5;

FIG. 7 is a flowchart illustrating a modification of the processing procedure of FIG. 4;

[Explanation of symbols]

10 digital camera, 20 imaging unit, 40 imaging control unit, 60 processing unit, 62 main CP
U, 64 Memory control unit, 76 Optional device, 10
0 display unit, 110 operation unit, 210 base image acquisition unit, 211 base image search unit, 212
Unphotographed image acquisition unit, 214 photographed image acquisition unit, 216
Base image storage unit, 218 unphotographed image storage unit, 220
Captured image storage unit, 222, 224 Color change unit, 22
6,228 size adjustment unit, 230 addition unit, 232
Weight setting section, 234 selector, 236 multiple exposure image generation section, 240 selection data array section, 242 array ratio setting section

Claims (9)

[Claims] 1. A digital camera having a multiple exposure photographing function, wherein a base image obtained by a reproduction process of a recorded image and an unphotographed image obtained from an image pickup section are superimposed, and a transparent superimposed image capable of seeing both images is provided. A digital camera, comprising: a superimposing unit that generates the image; and a display unit that displays the transmission superimposed image for subject confirmation. 2. The digital camera according to claim 1, wherein the superimposing unit includes an adding unit that adds signals of the base image data and the unphotographed image data in pixel units. 3. The digital camera according to claim 1, wherein the superimposing unit generates the transmission superimposed image by arranging data selected from the base image and the unphotographed image. 4. The digital camera according to claim 3, wherein the superposing unit changes a ratio of data selected from the base image and the unphotographed image. 5. The apparatus according to claim 3, further comprising a ratio setting unit configured to change a weighting state of the base image and the unphotographed image in the transmission superimposed image by changing a ratio of the data. Or the digital camera according to 4. 6. The digital camera according to claim 1, further comprising a color changing unit that performs a color changing process on at least one of the base image and the unphotographed image. 7. A size adjustment unit for enlarging or reducing at least one of the base image and the unphotographed image to adjust a size relationship of a subject in the base image and the unphotographed image. The digital camera according to claim 1. 8. A step of obtaining a base image obtained by a reproduction process of a recorded image, a step of obtaining an unphotographed image to be photographed from the image pickup unit, and a step of obtaining the base image and the unphotographed image. A superimposed image to generate a transparent superimposed image that allows both images to be seen through, and a step of displaying the transparent superimposed image for subject confirmation. 9. A recording medium storing a program executable by a computer of a digital camera, wherein the program is obtained from a step of obtaining a base image obtained by a reproduction process of a recorded image; Obtaining an unphotographed image to be photographed from now on; superimposing the base image and the unphotographed image to generate a transmission superimposed image that allows both images to be seen through; and And causing the computer to execute the step of displaying.