Imaging device and imaging method and program

An imaging device includes a display on which a captured image of a subject is displayed, a first corrector to correct a first parameter related to shooting of the subject, a second corrector to correct a second parameter related to image processing to the captured image, and an automatic correction controller to determine a correction amount for the second parameter on the basis of a correction amount for the first parameter corrected by the first corrector, and control the second corrector to correct the second parameter by the determined correction amount.

CROSS REFERENCE TO RELATED APPLICATION

The present application is based on and claims priority from Japanese Patent Application No. 2011-20024, filed on Feb. 1, 2011, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an imaging device, an imaging method and an imaging program which can set exposure while a captured image is displayed on a display, and automatically correct a variation in the color of a captured image occurring from exposure correction, and correct the exposure and color of the image on the same display screen in accordance with a user's operation.

2. Description of the Prior Art

A known imaging device such as a digital camera can selectively set a photographic scene in order to easily set optimal photographic conditions in accordance with a subject. Another known imaging device can change exposure and white balance according to photographic situation or users' tastes. In these imaging devices the correctable exposure range and unit of setting are uniformly determined so that exposure correction cannot be performed in an optimal range or unit set depending on a photographic scene. In view of the problem, Japanese Patent Application Publication No. 2005-62370 discloses an imaging device which can change the range and unit of correction amount used in setting exposure in accordance with a photographic scene.

With an imaging device having a display, a user can shoot a subject or correct exposure while checking the image of the subject on the display.

In general, it is known that in correcting exposure to darken an image, the image on the display is changed to appear more bluish. Therefore, it may be necessary to correct the color of the image when brightness of the image is changed by exposure correction. This makes a user's operation complicated. That is, the user can correct the exposure of a captured image while viewing it on the display but needs to switch a setting screen to adjust the color of the image which varied due to the exposure correction. Furthermore, the user may need to re-adjust the exposure changed by the color adjustment and switch the setting screen again, which is complicated and troublesome.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an imaging device, an imaging method, and an imaging program which can automatically correct a variation in the color of a captured image occurring from exposure correction, and correct the exposure and color of an image on the same screen in accordance with a user's manipulation.

According to one aspect of the present invention, an imaging device includes a display on which a captured image of a subject is displayed, a first corrector to correct a first parameter related to shooting of the subject, a second corrector to correct a second parameter related to image processing to the captured image, and an automatic correction controller to determine a correction amount for the second parameter on the basis of a correction amount for the first parameter corrected by the first corrector, and control the second corrector to correct the second parameter by the determined correction amount.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

FIG. 1is a back view of a digital camera as an example of an imaging device according to one embodiment of the present invention. An imaging device1includes a camera body CB having, on the back face, an optical viewfinder4, an autofocus light emitting diode (LED)8, a stroboscopic LED9, a LCD10, a power switch SW13, a wide-angle zoom switch SW3, a telescopic zoom switch SW4, a self-timer set/reset switch SW5, a menu switch SW6, an upward/strobe switch SW7, a rightward switch SW8, a display switch SW9, a downward/macro switch SW10, a leftward/image check switch SW11, and an OK switch SW12. Further, the camera body CB includes a shutter button SW1and a mode dial SW2for setting a shooting mode on the top face.

Next, the function blocks of the imaging device1are described with reference toFIG. 2. The operations or processing of the imaging device1are controlled by an imaging program according to one embodiment of the present invention executed by a processor104as a digital signal processing integrated circuit (IC). The processor104includes a first charge coupled device (CCD1) signal processing block1041, a second CCD (CCD2) signal processing block1042, a CPU block1043, a local SRAM (static random access memory)1044, a USB (universal serial bus) block1045, a serial block1046, a JPEG CODEC block1047, a resize block1048, a TV signal display block1049and a memory card controller block10410. These blocks are connected with each other by bus lines.

Outside of the processor104an SDRAM103(synchronous random access memory), a RAM107, an internal memory120, a ROM108which stores a control program are provided and connected to the processor104via a bus line. The SDRAM103stores RAW-RGB image data, YUV image data and JPEG image data of a captured subject image.

A lens barrel unit7includes a zoom optical system71having a zoom lens71a, a focus optical system72having a focus lens72a, an aperture stop unit73having an aperture stop73aand a mechanical shutter unit74having a mechanical shutter74a. The optical zoom system71, optical focus system72, aperture stop unit73and mechanical shutter unit74are driven by a zoom motor71b, a focus motor72b, an aperture stop motor73band a mechanical shutter motor74b, respectively. These motors are driven by a motor driver75which is controlled by the CPU block1043of the processor104.

The zoom lens71aand the focus lens72aconstitute the imaging lens which focuses a subject image on the imaging plane of the CCD101. The CCD101is an image sensor to convert the subject image into an electric image signal and output the image signal to an F/E (front end)-IC102.

The F/E-IC102includes a correlated double sampling (CDS)1021, an automatic gain controller (AGC)1022and an analog-digital (A/D) converter1023to perform predetermined processings to the image signal and convert it to digital image data, respectively. The image data are input to the CCD1signal processing block1041of the processor104. The signal processing is controlled by a vertical drive (VD) signal and a horizontal drive (HD) signal from the CCD1signal processing block1041via a timing generator (TG)1024. The F/F-IC102processes image signals in synchronization with the VD/HD signals via the TG1024. The CCD1signal processing block1041performs signal processing such as white balance adjustment, γ adjustment to the digital image data and outputs the VD/HD signals.

The CPU block1043of the processor104is configured to control an audio recording of an audio recording circuit1151. Audio is converted into an audio recording signal by a microphone1153, amplified by a microphone amplifier1152and recorded on the internal memory120.

The CPU block1043also controls the operation of an audio reproducing circuit1161. The audio reproducing circuit1161is configured to read audio data from the internal memory120and amplifies it with an audio amplifier1162for outputs from a speaker1163. The CPU block1043also controls a stroboscopic circuit114to emit light from a strobe light unit3, and controls a ranging unit5.

The CPU block1043is connected to a sub-CPU109disposed outside the processor104and the sub CPU109controls display on a sub LCD1via an LCD driver111. The sub CPU109is connected with an autofocus LED8, a strobe LED9, a remote-control light receiver6, an operation key unit having the switches SW1to SW13, and a buzzer113.

The USB block1045is connected to a USB connector122, and the serial block1046is connected to a RS-232C connector1232through a serial driver circuit1231. The TV signal display block1049is connected to the LCD10via an LCD driver117and to a video jack119via a video amplifier118. The memory card controller block10410is connected to a contact point between a memory card throttle121and a memory card to electrically connect with the memory card when mounted in the throttle121and store image files on the memory card.

Now, the operation of the imaging device is described with reference toFIG. 3by way of example. First, upon power-on of the imaging device1with the power switch13, the image of a subject captured via the optical system is converted into an image signal by the CCD101, and the image signal is subjected to a predetermined image processing and displayed on the LCD10for preview in step S1.FIG. 4shows an image display on the LCD10after starting the preview display. During the preview display, a user presses down the menu switch SW6to display a not-shown operation menu on the LCD10, for example. Then, the user manipulates the switches SW7, SW8, SW10, SW11to select a desired operation and manipulates the OK switch SW12to store the settings of the selected operation. In the following, an image correction menu of the imaging device1to correct the color and exposure of an image displayed on the LCD10is described.

In step S2the image correction menu is selected and in step S3correction data is displayed on the LCD10.FIG. 5shows an example of a display of image correction data. The LCD10displays an indicator P1to indicate exposure correction amount as a first parameter at the right end and an indicator P2to indicate color correction amount as a second parameter at the bottom end. InFIG. 5the indicator P1is configured to change the exposure correction amount in 13 levels. A cursor C1of the indicator P1points at a current exposure amount. The exposure correction amount is ±0 [EV] when the cursor C1is at the center of the indicator P1, and the upper half of the indicator P1is for increasing the exposure and the lower half is for decreasing the exposure. For example, in a case where the exposure amount can be varied in unit of 0.5 [EV], the exposure amount when the cursor C1is at the topmost position of the indicator P1is +3.0V while that when the cursor C1is at the bottom position is −3.0 [EV]. Thus, while the cursor C1is above the center of the indicator P1, the image is brightened on the display and while it is below the center, the image is darkened.

Further, the indicator P2is configured to change the color correction amount in 13 levels. A cursor C2of the indicator P2points at a current color amount. The color correction amount is 1.0 when the cursor C2is at the center of the indicator P2, and the right half of the indicator P2is for correcting red color and the left half is for correcting blue color. For example, when the unit of color change is 0.2, the red color can be corrected by 1.0 to 2.2 and the blue color can be corrected by 1.0 to −2.2. Thus, while the cursor C2is on the right side of the indicator P2, the image on the display is changed to be more reddish and while it is on the left side, the image is changed to be more bluish.

Returning toFIG. 3, by operating the switches SW7, SW10to correct exposure while the indicators P1, P2as correction data are displayed, the cursor C1is moved on the indicator P1and an exposure amount corresponding to the position of the cursor1is selected in step S4. The brightness of the image on the LCD10is changed in line with the selected exposure amount and the color and brightness thereof are changed by a color amount (gain coefficient) corresponding to the selected exposure amount.

A table containing the exposure correction amount and the color amount inFIG. 6is stored in the ROM108, for example. In the table the gain coefficients of red (R) component and blue (B) component are defined in association with the values of exposure correction amount [EV]. At the exposure correction amount being 0 EV, the gain coefficients of the R and B components are both ×1.0. Thus, with no exposure correction, no color change occurs. At the exposure correction amount being −0.5 EV, the displayed image is darkened and becomes bluish as a whole. In order to correct this, only the gain coefficient of R component is increased to, for example, 1.2 and that of B component remains 1.0. The smaller the exposure correction amount, the larger the gain coefficient of R component.

At the exposure correction amount being +0.5 EV, the displayed image becomes slightly reddish. To correct this, the gain coefficient of B component is set to 1.2 and that of R component remains 1.0. The color change in an image can be thus adjusted in accordance with the exposure correction amount using the gain coefficients separately defined for R and B components. In line with the exposure correction amount set in step S4, the color gain coefficient is selected to automatically change the color of the image on the LCD10.

In step S5the display of the indicators P1, P2is automatically changed for the exposure and color correction of the displayed image.FIG. 7shows cursors C11, C21of the indicators P1, P2pointing at the levels before the correction operation in step S4. When the user manipulates the switch SW10to correct exposure and move the cursor to C1pointing at the exposure correction amount at −1.5 EV. As shown inFIG. 6, at the exposure correction amount being −1.5 EV, the gain coefficient of R component is 1.6. Then, the cursor of the indicator P2is shifted from the position C21to C2by 3 levels (corresponding to the gain coefficient of 1.6) rightward. Thus, the user can know that the color of the image has been automatically corrected. Note thatFIG. 7shows both the cursors C11, C21for the sake of convenience, however, the imaging device1according to the present embodiment is not configured to display the cursors C1and C11and C2and C21concurrently.

Upon press to the shutter button SW1(Yes in step S6), the exposure amount and gain coefficient currently selected are set in step S7and the image is processed using the set exposure amount and color amount in step S8. Upon press to the OK switch SW12inFIG. 1instead of the shutter button SW1(No in step S6), the exposure amount and gain coefficient currently selected are set as initial values for the next image correction. Moreover, the user can manipulate the switches SW8and SW11instead of the OK switch SW12to manually change the automatically set color amount (No in step S9and S4). For example, at the exposure correction amount being −1.5 EV, the image can be changed to be slightly bluish by moving the cursor C2leftward as shown inFIG. 8. Alternatively, with the color amount corrected, the image exposure can be automatically corrected referring to the table inFIG. 6.

Thus, the imaging device according to the present embodiment can automatically correct the color of an image simultaneously with the exposure correction. Further, it is made possible for the user to manually change the automatically set color amount without switching the screen display by manipulating the color amount indicator displayed together with the exposure amount indicator.

Further, the imaging device according to the present embodiment can automatically correct a change in the color of a captured image resulting from the exposure correction while allowing the user to visually check the corrected image on the display. Moreover, the user can manually change the automatically set color amount on the same screen without switching the exposure setting screen and easily and optimally set the parameters as the exposure amount related to shooting condition and the color amount related to image processing. In addition, the LCD10can be a touch panel so that the user can operate the indicators P1, P2with his/her finger.

The imaging device and imaging method according to the present embodiment are applicable to a camera function of a mobile phone and various cameras with a viewfinder function, in addition to a digital camera.

Although the present invention has been described in terms of exemplary embodiments, it is not limited thereto. It should be appreciated that variations or modifications may be made in the embodiments described by persons skilled in the art without departing from the scope of the present invention as defined by the following claims.