Patent Publication Number: US-2009219430-A1

Title: Digital camera having a bracketing capability

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 11/210,680, filed Aug. 25, 2005, which claims priority to Japanese Application No. 2004-250438, filed Aug. 30, 2004, the contents of which are expressly incorporated by reference herein in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a digital camera, more particularly, it relates to a digital camera capable of taking bracket images. 
     2. Description of the Related Art 
     Conventionally, it is known that a digital camera takes bracket images while setting gradual steps for a parameter of photograph condition e.g. exposure value, as shown in Japanese Unexamined Patent Publication (KOKAI) No. 2003-87608. In this case, when a release button is pushed, an object is photographed continuously so as to obtain a plurality of photograph images, of which the compositions are substantially same, but which are taken under different photograph conditions from one another. 
     Sometimes it is difficult to judge the appropriate exposure value when the object is photographed. In this case, if the bracket images are taken, it is possible to choose the best image which is photographed under the appropriate exposure values among the plurality of photograph images after photographing. Namely, taking bracket images counteracts failure to set the correct photograph conditions e.g. exposure value. 
     Further, when an object moves fast, it is impossible for more than one photograph image having the same composition to be taken because the opportunity for photographing it is very short. However, if the bracket images are photographed, it is possible to obtain a plurality of images which are photographed under various photograph conditions and having the same composition. Namely, even if the object moves fast, a plurality of images having various characteristics can be obtained by taking bracket images. 
     In order to obtain the image having the characteristics the photographer desires, it is necessary to set the parameters for the photograph conditions precisely. However, if there are too many steps for setting only one parameter e.g. exposure value, it often happens that the image which the photographer desires is not obtained. 
     Accordingly, it is thought that bracket images should be photographed while setting several steps for one parameter and this photographing operation should be repeated after setting several steps for another parameter. In this method, another parameter has to be set manually by operating an operation device, and this operation takes a long time. Therefore, a good opportunity for photographing is sometimes lost, if the object moves fast. Further, the plurality of images, which are photographed as described above method, are not displayed on the camera monitor at the same time. In addition to this, the plurality of images are not associated with each other automatically. Therefore, it is difficult for users to select the most desirable image from the plurality of photograph images. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the present invention is to provide a digital camera, which can obtain bracket images based on a plurality of parameters for which several steps are set. 
     According to the present invention, there is provided a digital camera which generates a plurality of photograph images as bracket images of an object. The digital camera comprises a setting processor, a first bracket processor, and a second bracket processor. The setting processor sets a plurality of steps for first and second parameters. The first bracket processor obtains a plurality of intermediate images of the object based on each step of the first parameter. And the second bracket processor obtains a plurality of photograph images from each image of the intermediate images based on each step of the second parameter. 
     The digital camera preferably further comprises a monitor and a first display processor. The first display processor displays a display image on the monitor. The display image contains two or more than two of the photograph images. 
     The first display processor preferably displays the display image containing all the plurality of photograph images which are obtained by the second bracket processor. 
     The first display processor preferably divides a display field of the display image into vertical columns based on the number of steps of one parameter of the first and second parameters and horizontal rows based on the number of steps of one of the first and second parameters so as to generate a plurality of divided unit fields. Each photograph image is displayed in each divided unit field. 
     The first display processor preferably arranges the photograph images which are generated based on a single step of one parameter of the first and second parameters, in a vertical direction. Further, the first display processor arranges the photograph images which are converted based on a single step of another parameter of the first and second parameters, in a horizontal direction. The number of steps of the first parameter is preferably the same as the number of steps of the second parameter. 
     The first display processor rearranges the photograph images which are generated based on a single step of one parameter in a horizontal direction, and the photograph images which are generated based on a single step of another parameter, in a vertical direction. 
     The first display processor rearranges the photograph images according to a switch input for example. 
     The digital camera preferably comprises a distinction processor and deletion processor. The distinction processor distinguishes at least one of the photograph images from other photograph images. The deletion processor deletes the images which are distinguished by the distinction processor. 
     The digital camera can comprise a third bracket processor. In this case, the setting processor sets a plurality of step for a third parameter. The first bracket processor obtains a plurality of first intermediate images of the object based on each step of the first parameter. The second bracket processor obtains a plurality of second intermediate images from each first intermediate image based on each step of the second parameter. The third bracket processor obtains a plurality of photograph images from each of the second intermediate images based on each step of the second parameter. 
     The digital camera preferably comprises a monitor, and a second display processor that displays the display image on the monitor. In this case, the display image contains photograph images which are generated based on one step of a specific of the first, second, and third parameters. The specific parameter is changed according to a switch operation for example. 
     The first and second parameters are preferably selected from a plurality of selectable parameters, which include exposure value, a white balance value, a sharpness value, a saturation value, and a contrast value. 
     The first bracket processor is a photograph processor, and the second bracket processor is an image processor for example. The photograph processor continuously generates a plurality of frames of original image signals of a substantially the same object image, according to each step of the one parameter. The image processor converts the frames of the original image signals to a plurality of photograph images according to each step of another parameter. 
     The digital camera preferably comprises a photograph processor and an image processor, and both the first and second bracket processors are image processor for example. The photograph processor generates a frame of original image signals from an object. The image processor converts a frame of the original image signals to the intermediate images based on each step of first parameter, and further converts each of the intermediate images to a plurality of photograph images based on each step of the second parameter. 
     Another object of the present invention is to provide a digital camera that generates a plurality of photograph images as bracket images of an object. The digital camera comprises a setting processor that sets a plurality of steps for first and second parameters, and a bracketing processor that generates the plurality of photograph images of the object, based on each first multi-parameter of a plurality of the first multi-parameters. The first multi-parameter is a combination of each step of the first parameter and each step of the second parameter. 
     The setting processor can set a plurality of steps for a third parameter, and the bracketing processor converts the object image to a plurality of photograph images as bracket images, based on each second multi-parameter of a plurality of second multi-parameters. Each second multi-parameter is a combination of each the first multi-parameter and each step of the third parameter. 
     Another object of the present invention is to provide a bracket-image generating device which obtains a plurality of photograph images of an object. The device has first and second bracket processors, a monitor, and a display processor. The first bracket processor obtains a plurality of intermediate images of the object based on a first parameter. The first parameter has a plurality of steps, and each intermediate image is obtained based on each step of the plurality of steps of the first parameter. The second bracket processor obtains a plurality of photograph images from each the intermediate image, based on a second parameter. The second parameter has a plurality of steps, and the each photograph image is obtained based on each step of the plurality of steps of the second parameter. The display processor displays a display image on the monitor. The display image is divided into vertical columns and horizontal rows so as to generate a plurality of divided unit fields. The display processor displays each image of the photograph images in each the divided unit field. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which: 
         FIG. 1  shows a perspective view of a digital camera in a first embodiment; 
         FIG. 2  shows a monitor which displays a setting image for selecting parameters; 
         FIG. 3  shows a list for first and second parameters which are set up to three steps; 
         FIG. 4  is a block diagram of the digital camera in a first embodiment of this invention; 
         FIG. 5  shows a display image which is displayed on a monitor in the initial situation in the first embodiment; 
         FIG. 6  shows a display image which is displayed on a monitor after rearranging the unit display images in the first embodiment; 
         FIG. 7  is a flowchart showing a routine for the photograph mode; 
         FIG. 8  is a flowchart showing routine for displaying the photograph images in the first embodiment; 
         FIG. 9  shows a display image if the first and second parameters are set to five steps; 
         FIG. 10  shows display images in a second embodiment; 
         FIG. 11  shows display images after the ranking of parameters has been changed; and 
         FIG. 12  is a flowchart showing a routine for displaying the photograph images in the second embodiment. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will be described below with reference to the embodiments shown in the drawings. 
       FIG. 1  shows a perspective view of a digital camera in a first embodiment. The digital camera  10  is provided with a camera body  11  having an upper surface  11 U, a back surface  11 B, and a front surface  11 F. The camera body  11  is provided with a photograph lens system  12  at the center of the front surface  11 F. The camera body  11  is provided with a LCD monitor  14  at the left side of the back surface  11 B. 
     Reflected light from an object, which is received at the photograph lens system  12 , is converted to image signals, and then the image signals are converted to photograph image, which are displayed on the LCD monitor  14  as a still picture image. 
     A 4-way controller switch  15  is provided at the right side of the LCD monitor  14 , and an OK switch  16  is provided at the center of the 4-way controller switch  15 . A replay switch  18 , a menu switch  19 , and a bracket switch  20  are provided on the back surface  11 B around the LCD monitor  14 , a zoom switch  22  is provided on the back surface  11 B above the 4-way controller switch  15 . 
     A release button  24  is provided at the right side on the upper surface  11 U, when the digital camera  10  is viewed from behind. A power switch  25  is provided at the center of the upper surface  11 U. A card slot  26  is formed at one side surface of the camera body  11  in order to insert a PC card (a recording media, not shown in  FIG. 1 ) in the camera body  11 . Inside the card slot  26 , a card connector (not shown in  FIG. 1 ) for connecting the PC card is provided. 
     If the power switch  25  is pushed, the power supply to the digital camera  10  is switched on and then a mode of the digital camera  11  is set to an ordinary photograph mode. In the ordinary photograph mode, an ordinary photograph is carried out if the release button  24  is pushed. Further, in the ordinary photograph mode, if the bracket switch  20  is operated the mode of the digital camera  11  is changed to a bracket mode from the ordinary photograph mode. 
     In the ordinary photograph mode, when the object is photographed, the photographed image is captured and displayed as a single photograph image based on a plurality of parameters. On the other hand, in the bracket mode, when the object is photographed, a plurality of photograph images is obtained being substantially the same photograph image, where each photograph image has a different combination of step values for the plurality of parameters. 
       FIG. 2  shows a monitor which displays a setting image in a condition setting mode. If the mode is changed to the bracket mode, first a condition setting mode is started. In the condition setting mode, a setting image SI is displayed on the monitor  14 , and then first and second parameter X 1  and X 2  are selected from the plurality of selectable parameters according to the 4-way controller switch  15  input. The selectable parameters include selectable photograph parameters and selectable image process parameters. The selectable photograph parameters are for determining the conditions when the original image signals of the object image are generated, for example one could be the exposure value. The selectable image process parameters are for determining the conditions when the original image signals undergo image processes so as to obtain photograph images, for example they might be a white balance value, a sharpness value, a saturation value, and a contrast value. 
     Regarding selected first and second parameter X 1  and X 2  these values are set to three steps in this embodiment, and the differences between each step (the step levels) X 3  and X 4  are set up in the condition setting mode. If the OK switch  16  is pushed, the bracket mode is started in the state where the selected parameters X 1  and X 2  and set-up step levels X 3  and X 4  are set. 
     As shown in  FIG. 2 , when the image indicates that the step level X 3  is ±0.3 EV, this means that each step for the first parameter X 1  (exposure value) is set to −0.3, ±0, and +0.3 EV. The step level X 3  (the difference between each step) is altered for example among (0.3-2.0) EV according to the 4-way controller switch  15  input. Similarly, when the image indicates that the step level X 4  is ±1, it means that the each step for the second parameter X 2  is −1, ±0, +1. The step level (difference between each step) is altered for example between (1-5) according to the 4-way controller switch  15  input. If the OK switch  16  is operated, the conditions in the bracket mode are set as the setting image SI is indicated. Namely, the exposure value and the white balance value are set as the first and second parameters and 0.3 and 1 are set as the step levels of the first and second parameters, if the setting image SI as shown in  FIG. 2  is displayed. 
       FIG. 3  shows a list of first and second parameters which are set up. As described above, the first and second parameters which are set up to have three steps in the bracket mode. And then each step of the first parameter is combined with each step of the second parameter so as to form these combinations as a plurality of first multi-parameters ( 1 )-( 9 ). And then the photograph images are generated as bracket images of the object, based on each first multi-parameter of a plurality of first multi-parameters ( 1 )-( 9 ). Namely, a plurality of intermediate images is generated from the object based on each step of the first parameter. And the plurality of photograph images is generated from each of the intermediate images, based on each step of the second parameter. 
     As shown in  FIG. 3 , when the first and second parameters are determined as the exposure value and the white balance value, and each step is set to −0.3, ±0, +0.3 EV, and −1, ±0, +1, respectively, the nine multi-parameters ( 1 )-( 9 ) are formed by combining each step of the exposure value and each step of the white balance value. Namely, first the three intermediate images are formed based on exposure values −0.3, ±0, and +0.3 EV. Next, each image of the three intermediate images is converted to three photograph images based on the white balance values −1, ±0, and +1. In other words, nine photograph images in total are obtained. 
     Further, the exposure value means the degree of exposure, and the minus, the zero, and the plus mean “under-exposure”, “standard exposure”, and “over-exposure” respectively for the exposure value. Similarly the white balance value means the degree of correction for the white balance. The larger the absolute value thereof, the larger the corrected strength. And the plus, the zero, and minus mean “plus correction”, “no correction”, and “minus correction” respectively. Of course, the step values regarding the other parameters have the same meaning as those for the white balance. 
     The working of the digital camera  10  in the bracket mode will be explained using  FIG. 4 . Hereinafter the case when the first and second parameters are the exposure value and the white balance respectively will be explained. The working of digital camera  10  is controlled by a system control circuit  31 . 
     In the digital camera  10 , the photographic optical system  12  includes the lens group. The position thereof for focusing is controlled by a lens drive circuit  36 . A diaphragm  33  is disposed backward of the lens group, and is controlled by a diaphragm drive circuit  35  so that the aperture thereof can be adjusted. 
     A CCD (an imaging device)  40  is disposed on the optical axis of the optical system  12  and backward thereof, and is driven by the CCD drive circuit  37 . At the imaging device  40 , original image signals corresponding to the object image which is obtained by the optical system  12 , are generated and are input to an image process circuit  43  as the digital signals through a correlated-double-sampling and auto-gain-control (CDS/AGC) circuit  41  and an A/D converter  42 . The original image signals undergo many kinds of image processes at the image process circuit  43  so that the original image signals are converted to image data of the photograph image. The circuits  35 ,  36 ,  37 , and  43  are connected to the system control circuit  31  and are controlled thereby. The system control circuit  31  further connects the switches so as to control the working of the digital camera  10  according to the signals input from the switches. 
     In the bracket mode, when the release button  24  is half-pushed, a photometry switch  50  is activated and the photometric value of the object is detected by a photometry circuit  60 . After detecting, the photometric value is input to the system control circuit  31 . As described above one of the first parameters is the exposure value. Therefore, the aperture value of the diaphragm  33  and the shutter speed of the CCD  40  are calculated based on the detected photometric value and the three steps of the exposure value which were set (for example −0.3, ±0, and +0.3 EV). 
     When the release button  24  is fully-pushed, a release switch  51  is activated and first, second, and third original image signals regarding first, second, and third frames respectively, are generated successively based on the three steps of the exposure value. Namely, when the release switch  51  is activated, the aperture of the diaphragm  33  is adjusted based on the first step exposure value (−0.3 EV) and the CCD  40  is exposed to the received light from the object through the photographic optical system  12  and the diaphragm  33  for the charge storing period (namely, the calculated shutter speed based on the first step exposure value (−0.3 EV)). Due to this exposure, the first image frame of the first original image signals are generated according to the received light. The first original image signals are output and input to the image process circuit  43  as digital signals through the CDS/AGC circuit  41  and the A/D converter  42 . After the first image signals are output from the CCD  40 , the CCD  40  is exposed again and the second frame of the second original image signals are generated from the received light based on the second step exposure value (0 EV), similar to the first original image signals. After, the second original image signals are output from the CCD  40 , the third frame of the third image signals are generated at the CCD  40  based on the third step exposure value (+0.3 EV), similar to the first and second original image signals. 
     Further, as described above, the first, second, and third original image signals based on the under exposure (−0.3 EV), the standard exposure (0 EV), and the over exposure (+0.3 EV) are generated successively in this sequence. However, this sequence can be changed according to the switch input by the user for example. 
     At the image process circuit  43 , the first, second, and third original image signals undergo many kinds of image processes including a white balance adjustment, a sharpness adjustment, a saturation adjustment, and a contrast adjustment. As described above, one of the first and second parameters is the white balance value, and the white balance value has three steps on levels (plus correction (+1), no correction (±0), and minus correction (−1)). Accordingly, the first original image signals undergo a white balance adjustment regarding each step level (+1, 0, −1) so that the first original image signals are converted to image data regarding three photograph images based on each step of the second parameter. On the other hand, the parameters regarding the sharpness value, the saturation value, and the contrast value are set at a single step or level. Therefore, while the first original image signals are converted to image data regarding all of the photograph images, the original image signals undergo the sharpness adjustment, the saturation adjustment, and the contrast adjustment under the same conditions. Similarly, the second and third original image signals are converted to image data. Due to this, the image data of the nine photograph images are generated. 
     In the case as described above, the first parameter is a photograph parameter and the second parameter is an image process parameter. Therefore, the control conditions for controlling the photograph processor including the photographic optical system  12 , the diaphragm  33 , and CCD  40  are changed according to steps on levels of the photograph parameters. Similarly, the conditions for controlling the image process circuit  43  (image processor) which carries out many kinds of image processes, are changed according to steps or levels of the photograph parameter. 
     However, both the first and second parameters can be image process parameters. The case when both the first and second parameters are the image process parameters (the white balance and the sharpness for example) is explained below. In this case, the control conditions for the photograph processor are the same. Therefore, when the release switch  51  is activated, only a single frame of original signals is generated at the CCD  40 . Namely, when the release button  24  is half-pushed, the aperture value of the diaphragm  33  and shutter speed of the CCD  40  are calculated based on the photometric value which is detected by the photometry circuit  60  and the exposure value (for example 0 EV) which is set to a single step value. When the release button  24  is fully-pushed, the single frame of the original image signals is generated based on the aperture value and shutter speed which are calculated when the release button  24  is half-pushed. And then the original image signals are input to the image process circuit  43 . 
     Three steps or levels are set for the first and second parameters (the white balance value and the sharpness value). Therefore, a single frame of the original image signals undergoes the white balance adjustment based on each step of the first parameter (the white balance value) so as to generate the image signals regarding the three intermediate images. The image signals regarding the three intermediate images further undergo the sharpness adjustment based on each step of the second parameter (the sharpness value) respectively so as to generate the image signals regarding nine photograph images. Further, while the original image signals are converted to the image signals regarding the nine photograph images, the image signals undergo the saturation adjustment, and the contrast adjustment and so on, of which parameters are set to single step or value. 
     The image signals regarding nine photograph images are sent to an SDRAM  44  and are temporarily stored therein as nine stored images without reducing the number of image pixels of the stored images. The image data of the stored images which are determined as the image to be recorded as described below are recorded in the recording media  47 . 
     On the other hand, the number of image pixels that are in the nine photograph images are reduced and then they are stored in the SDRAM  44  as nine unit display images. The image data regarding the nine unit display images is read from the SDRAM  44  and then the nine unit display images are synthesized at the image process circuit  43  so as to generate a single display image  70  which is displayed on the monitor  14  as shown in  FIG. 5 . A selected frame  75  and character  76  (as shown in  FIG. 5 ) are read from a character image memory  48 , and then are synthesized on the display image  70  at the image process circuit  43 . 
       FIG. 5  shows a schematic view of the display image. The display image  70  has a substantially rectangular shape, and is displayed on the entire display field of the monitor  14 . The nine unit display images ( 1 )-( 9 ) form a 3×3 matrix in the display image  70 . Namely, the display field of the display image  70  is divided into three horizontal rows and three vertical columns which are the number of steps of the first and second parameters, so as to generate a plurality of divided unit fields. And then each unit display image ( 1 )-( 9 ) is displayed in each divided unit field. Further the unit display images ( 1 )-( 9 ) are generated based on the multi-parameters ( 1 )-( 9 ) respectively as shown in  FIG. 3 . 
     The unit display images are arranged from the left side to the right side of the display image  70  in the step sequence of the first parameter (from low exposure value to the high exposure value, −0.3 EV, 0 EV, and 0.3 EV). And the unit display images which are generated based on the same step of the first parameter are arranged in the same column (in the same vertical direction). Therefore, the unit display images ( 1 ), ( 4 ), and ( 7 ) which are generated based on the under exposure are arranged in a left column  1 A. Similarly, the images ( 2 ), ( 5 ), and ( 8 ) are arranged in a center column  2 A, and the images ( 3 ), ( 6 ), and ( 9 ) are arranged in a right column  3 A. 
     Similarly, the unit display images are arranged from the top side to the bottom side of the display image  70  in the step sequence of the second parameter (from a high white balance value to the low value, +1, 0, and −1). And the unit display images which are generated based on the same step of the second parameter are arranged in the same row (in the same horizontal direction). Therefore, the unit display images ( 1 ), ( 2 ), and ( 3 ) which are generated based on the plus correction (+1) are arranged in a top row  1 B. Similarly, the images ( 4 ), ( 5 ), and ( 6 ) are arranged in a center row  2 B, and the images ( 7 ), ( 8 ), and ( 9 ) are arranged in a bottom row  3 B. 
     If the display image  70  is displayed on the monitor  14 , when the menu switch  19  is operated, the direction in which the unit display images (generated based on the same step of first and second parameters) are arranged, is changed. Namely, if the each unit display image is arranged as shown in  FIG. 5 , the each unit display image is rearranged as shown in  FIG. 6 , when the menu switch  19  is operated. Due to this, the unit display images generated based on the same step of the first parameter, are rearranged in a horizontal direction. Further the unit display images are arranged from the bottom side to the top side of the display image  70  in the step sequence of the first parameter. The unit display images generated based on the same step of the second parameter, are rearranged in a vertical direction. Further, the unit display images are arranged from the right side to the left side of the display image  70  in the step sequence of the second parameter. Furthermore, if each unit display image is arranged as shown in  FIG. 6 , the each unit display image is rearranged as shown in  FIG. 5 , when the menu switch  19  is input. 
     In this embodiment, the unit display image ( 5 ), which is generated based on the center steps of the first and second parameters, is always disposed at the center position of the display image  70 . Due to this, the user always sees the unit display image which is generated based on the standard step values (for example 0 EV, and 0) for the first and second parameters, in the center of the display image  70 . 
     The photograph images are deleted or recorded as described below. In the initial situation, all unit display images are set as the images to be recorded. As shown in  FIG. 5 , the selected frame  75  which surrounds one of the unit display images is displayed on the display image  70 . The unit display image which the selected frame  75  surrounds is altered by operation of the 4-way controller switch  15 . And when the OK switch  16  is operated, the unit display image, which the selected frame  75  surrounds, is determined as the image to be deleted. A check mark  76  in the form of a character, is applied to the unit image determined as the image to be deleted so as to distinguish the unit image determined as the image to be deleted from other displayed unit images. Further, the unit display image, which is surrounded by the selected frame  75  and which is set as the image to be deleted, is determined as the image to be recorded when the OK switch  16  is operated again. 
     More than one unit display image can be determined as an image to be deleted by operating the 4-way controller switch  15  and the OK switch  16 . If the unit display images ( 1 ), ( 4 ), and ( 5 ) are determined as the images to be deleted, the check marks  76  are applied to these images ( 1 ), ( 4 ), and ( 5 ) as shown in  FIG. 5 . On the other hand, the unit display images which do not have the check mark  76  applied, are determined as the images to be recorded. When the bracket switch  20  is operated, the image data of the stored images corresponding to the unit display images ( 1 ), ( 4 ), and ( 5 ) which are determined as the images to be deleted are deleted from the SDRAM  44 . At the same time, the image data of the stored images corresponding to the unit display images ( 2 ), ( 3 ), and ( 6 )-( 9 ) determined as the image to be recorded is recorded in the recording media  47 . After this procedure, the bracket mode is finished. 
     Further, the photograph image can be recorded in the recording media  47  by other processes. For example, the digital camera  10  has a delete switch, and if the delete switch is operated, the stored image in the SDRAM  44  corresponding to the unit display image which the selected frame  75  surrounds, is deleted immediately. Further, a unit display image to which the check mark  76  is not applied, can be determined as the delete image, on the other hand, the unit display image to which the check mark  76  is applied, can be determined as the recoded image. Furthermore, whether the check mark  76  is applied to the image to be deleted or the image to be recorded can be set-up according to the switch operation. 
     As described above, it is easy for a user to obtain several photograph images which are generated from substantially the same object image while setting a plurality steps for several parameters. Further, these several photograph images can be displayed on the same display field of the monitor, therefore it is easy for the user to judge whether the photograph images are necessary or unnecessary. And the unnecessary images are deleted and the necessary images are recorded by simple is operations in this embodiment. 
       FIG. 7  shows the routine for taking photographs. In the routine for taking a photograph, first whether the bracket switch  20  is operated is determined at step S 100 . If the bracket switch is operated, the digital camera  10  enters the bracket mode. If the bracket switch is not operated, the digital camera  10  enters the ordinary photograph mode in step S 102 . 
     If the digital camera  10  enters the bracket mode, first the condition setting mode as shown in  FIG. 2  is started at step S 104 . In this mode, the first and second parameters are selected from a plurality of selectable parameters according to the switch inputs. And the steps of the first and second parameters are set according to the switch inputs. After this setting, whether the release button  24  is half-pushed is determined at step S 108 . If the release button  24  is not half-pushed, the routine waits at step S 108 . If the release button  24  is half-pushed, the photometric value of the object is detected at step S 110 . Next, whether the exposure value is selected as the first or second parameter at step S 104  is determined at step S 112 . If the exposure value is selected as the first or second parameter, the routine goes to step S 114 . 
     If the first or second parameter is the exposure value, three frames of the original image signals are generated by the CCD  40  based on the three steps of the exposure value for substantially the same object image. Therefore, at step S 114  the three steps of the aperture values and the shutter speeds are calculated based on the three steps of the exposure values and on the detected photometric value at step S 110 , in order to generate the three frames of original image signals by the CCD  40 . Next, whether the release button is fully-pushed, half-pushed, or not pushed is determined at step S 116  and S 118 . If the release button is not fully-pushed but the release button is continually half-pushed, the routine waits at step S 116  and step  118 . If the release button is neither fully-pushed nor half-pushed, the routine goes back to step S 108  from step S 118 . 
     If the release button is fully-pushed, the object is photographed at step S 120 . Namely, the CCD  40  is exposed three times successively so as to generate the three frames of original image signals (three intermediate images) of substantially the same object image, based on the three aperture-values steps and the three shutter-speed steps which are calculated at step S 114 . The original image signals regarding each frame of three frames undergo many kinds of image processes. Specially, the original image signals regarding each frame undergo a specific image process which corresponds to the selected first or second parameter based on the three steps of the parameter set at step S 104 . Due to these image processes, the original image signals are converted to image data regarding nine photograph images. 
     On the other hand, if it is determined that the exposure value is not set to the first and second parameters the routine goes to step S 130 . A single frame of the original image signals is generated by the CCD  40  based on the value of the single exposure step. Therefore, at step S 130  one aperture value and one shutter speed are calculated based on the value of the single exposure step and the detected photometric value. Next, whether the release button is fully-pushed, half-pushed, or not pushed is determined at step S 132  and S 134 , similar to step S 116  and step S 118 . 
     If the release button is fully-pushed, the object is photographed at steps S 140  and S 142 . Namely, at step S 140  the CCD  40  is exposed once so as to generate one frame of original image signals based on a single aperture value and a single shutter speed calculated at step S 130 . One frame of the original image signals undergoes many kinds of image processes at step S 142 . Specially, the original image signals undergo a specific image process corresponding to the first parameter, more precisely based on the three steps of the first parameter set at step S 104 , so that original image signals are converted to the image data regarding three intermediate images. In addition to this, the image data regarding three intermediate images undergoes a specific image process corresponding to the second parameter based on three steps of the second parameter. Due to these image processes, the original image signals are converted to image data regarding nine photograph images at step S 142 . The image data regarding nine photograph images which are generated at step S 120  or S 142  are temporarily stored in SDRAM  44 . 
       FIG. 8  shows the routine for displaying the photograph image. At step S 150 , the image data regarding nine photograph images is read from the SDRAM  44 , and then the display image  70  which includes the nine photograph images as the unit display images ( 1 )-( 9 ) is displayed on the monitor  14  as shown in FIG.  5 . At step S 151 , the selected frame  75  is displayed on the displayed image  70  which surrounds the unit display image ( 5 ) which is disposed at the center of the display image  70  and the photograph image corresponding thereto is set to the selected image. 
     At step S 152 , whether the menu switch  19  is operated is determined. If it is determined that the switch  19  is operated, the display sequence of the unit display image ( 1 )-( 9 ) is changed at step S 154 . Namely, if the switch  19  is operated, the display sequence of the display image  70  is changed from that shown in  FIG. 5  to that shown in  FIG. 6 , or from that shown in  FIG. 6  to that shown in  FIG. 5 . At step S 156 , whether the 4-way controller switch  15  is operated is determined. If it is determined that the switch  15  is operated, the selected frame  75  is moved in a direction according to the operated part of the switch  15 , and the selected image is changed to the photograph image corresponding to the unit display image which is surrounded by the selected frame  75 . 
     At step S 160 , whether the OK switch  15  is operated is determined. If it is determined that the switch  16  is operated, the selected image is set as an image to be deleted or an image to be recorded at step S 162 . And a check mark  75  is applied to the unit display image which is set as an image to be deleted as shown in  FIG. 5 . 
     At step S 164 , whether the bracket switch  20  is operated is determined. If it is determined that the switch  20  is not operated, the routine repeats from step S 152  to step S 164 . If it is determined that the switch  20  is operated, the routine goes to step S 170 . At step S 170 , the image data regarding a photograph image (stored in SDRAM  44  as the stored image) which is set as the image to be recorded is recorded in the recording media  47 . On the other hand, the data regarding a photograph image which is set as the image to be deleted is deleted at step S 170 . When finishing step S 170 , the routine for taking a bracket photograph is finished and the digital camera enters the ordinary photograph mode. 
     In this embodiment, three steps for first and second parameters are set as described above. However, “n” steps for first and second parameters can be set (“n” is a natural number and is two or more than two). In this case, n 2  photograph images are generated as the bracket images, and the display image  70  (referring to  FIG. 5 ) is divided into “n” horizontal rows and “n” vertical columns so as to generate the n 2  divided unit fields. Each unit display image corresponding to each photograph image is displayed in each of the divided unit fields. Similar to the embodiment as described above, the unit display images are arranged from the left side to the right side of the display image  70  in the step sequence of the first parameter, and the unit display images are arranged from the top side to the bottom side of the display image  70  in the step sequence of the second parameter in the initial situation. 
     For example, if the steps for the first and second parameters are set to five steps, then twenty-five photograph images are generated of the object. And all of these photograph images are displayed on the display image  70  as the unit display images, as shown in  FIG. 9 . 
     In this embodiment, the number of steps of the first parameter is the same as the number of the steps of the second parameter. However, the number of the steps of the first parameter can be different from the number of the steps of the second parameter. In this case, if the display field of the monitor  14  is longer from side to side than an ordinary display field, the unit display images are arranged in the horizontal direction according to step sequence having the larger number of steps, so that each unit display image has a suitable size for a user to easily see. 
     Further, the number of steps of the first and second parameters is preferably an odd number. If it is an odd number, the photograph images which are generated based on the standard step of the first or second parameter are always displayed in the center row or column. In addition to this, the photograph image which is generated based on the standard step of both the first and second parameters is always displayed in the center of the display image  70 . Due to this, the user can compare each photograph image easily. 
     Furthermore, in this embodiment, there is only one selectable photograph parameter, namely only the exposure value, however there can be two or more than two selectable photograph parameters, namely they might be the shutter speed and the aperture value of the diaphragm  33  for example instead of the exposure value. In this case, if both the shutter speed and the aperture value are set as the first and second parameters, the CCD  40  is exposed nine times so as to generate the nine frame images of original image signals when the release button is fully-pushed once. 
     In this embodiment, all photograph images are set as the images to be recorded in the initial situation. However, all photograph images can be set as images to be deleted in the initial situation. Of course, whether all photograph images are set as the images to be recorded or set as the images to be deleted in the initial situation is selected by a user. 
     Next, the second embodiment will be explained using  FIGS. 10 ,  11 , and  12 . In the first embodiment, the first and second parameters are selected from the selectable parameters. However, in this embodiment, the first, second, and third parameters are selected from the selectable parameters. Hereinafter the case in which the first, second, and third parameters are the exposure value, the white balance value, and sharpness value respectively will be explained. In this case, the number of steps for the first, second, and third parameters is set to three, similar to the first embodiment for example. Each step of the first parameter is combined with each the step of the second parameter so as to form nine combinations as nine first multi-parameters. And each of the nine first multi-parameters is combined with each the step of the third parameter so as to form twenty-seven combinations as twenty-seven second multi-parameters. And then the photograph images are generated as bracket images of substantially the same object based on each multi-parameter of the twenty-seven second multi-parameters. Namely, the CCD  40  is exposed three times based on each step of the first parameter (the exposure value) so as to generate three first intermediate images from substantially the same object image, similar to the first embodiment. Next, the nine second intermediate images are generated from three first intermediate images based on each step of the second parameter (the white balance value) in the image process circuit  43 . In addition to this, twenty-seven photograph images as bracket images are generated from the second intermediate images based on each the step of the third parameter (the sharpness value). The image signals regarding twenty-seven photograph images are temporarily stored in the SDRAM  44  as the stored images and as the unit display images, similar to the first embodiment. 
     It is difficult to display the twenty-seven unit display images in the display field of the monitor  14  at the same time. Therefore, in this embodiment, the twenty-seven unit display images are grouped into three groups, each group having nine unit display images. The nine unit display images in one group are synthesized at the image process circuit  43  into one display image. Due to these processes, the first, second, and, third display images  81 ,  82 , and  83  which contain the nine unit display images are generated as shown in  FIGS. 10 and 11 . 
     The first, second, and third parameters are ranked. For each image of the display images  81 ,  82 , and  83 , the unit display images are generated based on each step of the first and second ranked parameters, and a single step of the third ranked parameter. And then the unit display images are arranged from the left side to the right side of the display image  81  in the step sequence of the first ranked parameter. And the unit display images are arranged from the top side to the bottom side of the display image  81  in the step sequence of the second ranked parameter. 
     The first, second, and third parameters are ranked into first, second, and third ranked parameters respectively in the initial situation. Therefore, in the initial situation, the unit display images which are generated based on the −0.3 EV, 0 EV, and +0.3 EV of the exposure value (the first parameter) are arranged in the columns  1 A,  2 A, and  3 A respectively in each image of the display images  81 ,  82 , and  83 . Similarly, the unit display images which are generated based on the −1, 0, and +1 of the white balance value (the second prior) are arranged in the rows  1 B,  2 B, and  3 B respectively in each image of the display images  81 ,  82 , and  83 . However, the unit display images are generated based on the same step of the sharpness value (the third parameter) in each display image  81 ,  82 , and  83 . 
     The first, second, and third parameters are ranked to first, second, and third ranked parameters respectively in the initial situation. However, the ranking of the parameters can be changed by operating the menu switch  19 . 
     In the initial situation, the unit display image ( 5 ) which is generated based on the standard steps regarding all of the first, second, and third parameters is displayed on the monitor  14 . Therefore, in the initial situation the second displayed image  82  is displayed on the monitor  14 . 
     Furthermore, the selected frame  75  surrounds the unit display image ( 5 ) which is disposed in the center of the second image  82  and which is generated based the standard steps regarding the first, second, and third parameters in the initial situation. 
     Of course, which display image  81 ,  82 , or  83  is displayed on the monitor  14  can be changed according to the input replay switch  18 . 
     The  FIG. 12  shows the routine for displaying the photograph image in the second embodiment. As described above, the twenty-seven photograph images are generated when the release button is pushed once in the bracket mode, and these twenty-seven photograph images are composed of one of the first, second, and third display images  81 ,  82 , and  83 . 
     In this routine, the second display image  82  is displayed at step S 240  at first, and then the center unit display image ( 5 ) is surrounded by the selected frame  75  at step S 241  as shown in  FIG. 10 . At step S 242 , whether the replay switch  18  is operated is determined. If it is determined that the switch  18  is operated, the display image which is displayed on the monitor  14  is changed at step S 244 . Namely, if the display image which is displayed on the monitor  14  is the first display image  81  the display image is changed to the second display image  82 . Similarly, it is changed from the second or third image  82  or  83  to the third or first image  83  or  81  if the second or third image  82  or  83  is displayed. 
     At step S 250 , whether the menu switch  19  is operated is determined. If it is determined that the switch  19  is operated, the ranking of the parameters is changed at step S 252 , namely the parameters which are ranked first, second, and third are changed to the third, first, and second ranked parameters respectively. After this step the twenty-seven unit display images are rearranged according to the ranks of the parameters at step S 254 . Namely, each image of the three display images  81 ,  82 , and  83  contains the unit display images which are generated based on each step of the new first and second ranked parameters and single step of the new third ranked parameter. Next, the routine goes back to the step S 240 , and then the new second display image  82  is displayed on the monitor  14 . 
     Namely, in the initial situation, each image of the three display images  81 ,  82 , and  83  contains the nine unit display images which are generated based on each step of the first and second parameters, and a single step of the third parameter. And if the menu switch  19  is pushed once, the first, second, and third parameters are set to the third, first, and second ranked parameters respectively as shown in  FIG. 11 , therefore each image of the new three display images  81 ,  82 , and  83  contains the nine unit display images which are generated based on each step of the second and third parameters, and a single step of the first parameter as shown in  FIG. 11 . 
     The routine from step S 256  to step S 266  is similar to that of the first embodiment, therefore these explanations are omitted. 
     As described above, the bracket images can be obtained of substantially the same object image based on each combination of steps of three parameters by a simple operation. Further, the bracket images are displayed on the monitor according to predetermined rules therefore the user can confirm each of the bracket images easily. 
     Of course, the number of parameters which are selected from the selectable parameters is changed according to the switch operation for example. 
     Although the embodiments of the present invention have been described herein with reference to the accompanying drawings, obviously many modifications and changes may be made by those skilled in this art without departing from the scope of the invention. 
     The present disclosure relates to subject matter contained in Japanese Patent Application No. 2004-250438 (filed on Aug. 30, 2004) which is expressly incorporated herein, by reference, in its entirety.