JP2007312169A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of easily controlling white balance to be close to user's intention. <P>SOLUTION: The imaging apparatus comprises an imaging means which images a subject to generate image data; a process means which acquires control amount of white balance based on the image data, and corrects the white balance of the generated image data based on the acquired white balance control amount; a display means which displays the image data that has been processed; and an input means for accepting designation of an arbitrary region in the image data displayed on the display means. The process means corrects the white balance of the image data generated by the imaging means, based on the image data in the designated region accepted by the input means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging device that captures and records an image.

As a method for a user to select fine adjustment of white balance of an imaging apparatus typified by a digital camera, there is a technique described in Patent Document 1. A portion that is a candidate for the white balance control amount is extracted from the image and displayed. The user selects one of them.
JP 2004-221737 A

  However, the displayed candidate may not be able to achieve proper white balance. In addition, since the candidate is an average value in a certain range in the image, a correct control amount may not be obtained.

  Therefore, the present invention interpolates and displays the white balance control amount selected by the user from several white balance control amount candidates while continuously changing the interpolation amount. The balance control amount can be selected. In addition, it is possible to use the effective pixel in the range in the image instead of the average value of the certain range in the image as the candidate for the white balance control amount. Thus, an object is to obtain a white balance control amount as intended by the user.

  In order to achieve the above object, an imaging apparatus according to the present invention obtains a white balance control amount based on an imaging unit that shoots a subject and generates image data, and based on the image data. Based on the processing means for correcting the white balance of the generated image data, a display means for displaying the processed image data, and an input for accepting designation of an arbitrary area of the image data displayed on the display means And the processing means corrects the white balance of the image data generated by the imaging means based on the image data in the designated area received by the input means.

  With this configuration, the white balance control amount is obtained from a plurality of white balance control amount candidates, and the user can select an arbitrary white balance control amount. In addition, the candidate is not an average value in a certain range in the image, but a powerful pixel in the range in the image can be used.

  As described above, according to the imaging apparatus of the present invention, the white balance can be easily controlled close to the user's intention.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
1 Outline of Digital Still Camera According to Embodiment of Present Invention A digital camera according to an embodiment of the present invention divides one screen of a captured image (for example, the image shown in FIG. 1A) into a plurality of regions. (For example, the image shown in FIG. 1B), a white balance control amount for controlling the white balance is calculated for each region. Also, a white balance control amount for a known light source is obtained in advance.

  Two candidates are selected from the divided image data area or a plurality of known light sources. The user selects an appropriate white balance control amount by interpolating the white balance control amounts for the two selected candidates. The white balance control of the image is performed according to the selected white balance control amount.

Images controlled by the selected white balance control amount can be stored.
2. Configuration of Digital Still Camera According to Embodiment of the Present Invention FIG. 2 shows a configuration of a digital still camera according to an embodiment of the present invention. The light condensed by the lens 1 enters the CCD 2 driven by the CCD drive circuit 4 and is converted into image data which is an electric signal. The image data converted into an electrical signal by the CCD 2 is converted into a digital signal by the A / D conversion circuit 3. The image data converted into the digital signal is stored in the SDRAM 5.

  Image data stored in the SDRAM 5 is converted into a display image by the CPU 6 and an image processing circuit that handles image processing including white balance control, and is displayed on the LCD 10. When shooting, the CPU 6 receives an instruction from the operation key 8 and the CPU 6 drives the CCD drive circuit 4. It is displayed on the LCD 10 and recorded on the memory card 9 as well.

  The lens 1, the CCD 2, the A / D conversion circuit 3, and the CCD driving circuit 4 are the imaging device of the present invention. The CPU 6 and the image processing circuit 7 are processing means of the present invention. Although a case where a CCD is used as the image sensor will be described here, a CMOS or other image sensor may be used.

  Further, although a case where an SDRAM is used as a storage device will be described, an SRAM, a DDR SDRAM, or other storage element may be used.

  Although the case where an LCD is used as the display device will be described, an organic EL or CRT (display or other display may be used).

Although a case where a memory card is used as a storage device will be described, a magnetic recording medium such as a floppy (registered trademark) disk, an MO, and a hard disk, or another storage device may be used.
3. Operation of Digital Still Camera According to Embodiment of Present Invention Based on FIGS. 3 to 11, the operation of the digital still camera according to the embodiment of the present invention will be described. More specifically, after the digital still camera captures the subject shown in FIG. 1 (a) and is stored in the SDRAM 5, the user determines an appropriate white balance control amount and displays it on the LCD 10 (FIG. 4). Will be explained.

In the state where FIG. 1A is stored in the SDRAM 5 as a digital signal, white balance control is not performed. The control until the white balance control amount is determined is shown using the flowchart of FIG.
3.1 Preprocessing The image data stored in the SDRAM 5 is divided into a plurality of areas as shown in FIG. 1B (S1). The number of divisions is 42, but it may be more or less.
3.2 Derivation of White Balance Control Amount for Each Region A white balance control amount is obtained for each divided region (S2). The method of obtaining the white balance control amount for each region is a method of obtaining from the average value of all the pixels in the region (the flowchart in FIG. 5), obtaining the white balance control amount for all the pixels in the region, and calculating the control amount for each constant value. A method of obtaining the white balance control amount of the category having the highest frequency (FIG. 6) divided into categories (FIG. 6), obtaining the white balance control amount for all pixels in the region, There is a method of obtaining a pixel white balance control amount within the effective range of the obtained white balance control amount (FIG. 8) based on the shutter speed, the F value of the lens, the presence or absence of flicker, and the like (the flowchart of FIG. 9). The user decides in which method the white balance control amount for each divided region is derived.
3.2.1 Method of Obtaining from Average Value of All Pixels in Region Add RGB of each pixel of image data (S211), perform for all pixels in the relevant region (S212), and obtain the average value for each channel of RGB (S213), from the obtained average value,
A white balance control amount is obtained (S214).

Here, the image data is configured as three channels of RGB, but the image data may be RGB, YCC, or the like. The white balance control amount is a value obtained by dividing the G channel value by the R channel value and a value obtained by dividing the G channel value by the B channel value.
It may be a value based on the color temperature or a value standardized in order to cope with variations in the spectral sensitivity of the CCD. The white balance control amount to be obtained does not need to be a correction amount for making the target RGB achromatic. For example, when it is preferable that the color remains with a light source having a low color temperature, the control for leaving the original color is left. It may be an amount.
3.2.2 Method of Obtaining from Frequency of White Balance Control Amount in Region The white balance control amount is obtained from each RGB channel of the pixel (S221). The obtained white balance control amounts are divided into categories by R gain and B gain as shown in FIG. 6 (S222).

  The values of the RGB channels are added for each category (S223). This is performed for all the pixels in the corresponding region (S224). A category in which the most pixels are classified is obtained (S225). An average value is obtained for each RGB channel of the obtained category, and a white balance control amount is obtained from the obtained average value (S226).

In FIG. 6, the white balance control amount is handled in two dimensions of R gain and B gain, but may be three dimensions of R gain, G gain, and B gain. Further, it may be a value that conforms to the color temperature or a value that is standardized in order to cope with variations in the spectral sensitivity of the CCD.
3.2.3 Method of Finding Average Value of Pixels with Effective White Balance Gain A range of white balance gain that is a white balance control amount in the achromatic region is obtained (FIG. 8). The required range changes depending on the shutter speed of the camera, the F value of the lens, the presence or absence of flicker, and the like (S231). A white balance control amount is obtained from each of the RGB channels of the pixel (S232). As shown in FIG. 8, the obtained white balance control amount is divided into a white balance control amount range 20 that is an achromatic region and a non-a white balance control amount, and (S233) adds the values of RGB channels ( S234). This is performed for all the pixels in the corresponding area (S235). An average value is obtained for each of the RGB channels in the obtained effective range, and a white balance control amount is obtained from the obtained average value (S226).
3.3 Determination of White Balance Control Amount Two candidates for interpolation of the white balance control amount are selected, the white balance control amount is interpolated from them, and an appropriate white balance control amount is obtained by the user and displayed on the LCD 10 ( S3). This will be described with reference to the flowchart of FIG.

  From the large window 13 on the LCD 11 and the candidate area (S31) displayed on the known light source 18, the user selects the first candidate, candidate 1 (S32). For selection of a candidate, a cross key 16, an enter button 17, and a cancel button 18 are used. The cross key 16 is used for vertical and horizontal movement. When the cross key 16 is moved, the selected area 15 is moved. The selected area 15 is displayed with a thick frame so that the user can see it. The large window 13 in the LCD 11 is controlled and displayed with the selected area white balance control amount (S33).

  The LCD 11 in FIG. 4 has five light sources as the known light sources 18, but the number need not be five, and may be five or more or five or less.

When the user presses the enter button 17, the small window A12 in the LCD 11 is controlled and displayed with the white balance control amount of the selected area, and is determined as candidate 1 (S34).
The user moves the selected area 15 using the cross key 16 to select the second candidate, candidate 2 (S35). It is controlled by the white balance control amount of the selected area 15 and displayed on the large window 13 in the LCD 13 (S36). When the user presses the enter button 17, the small window B14 in the LCD 11 is controlled and displayed with the white balance control amount of the selected area 15, and is determined as candidate 2 (S37).

  The image data controlled by the white balance control amount obtained by continuously interpolating the white balance control amount from the candidates 1 and 2 is displayed on the large window 13, and the user selects an arbitrary control amount (S38). FIG. 11 shows a flowchart. The amount of change per unit time is calculated by interpolating the white balance control amounts of candidate 1 and candidate 2 (S381). First, the white balance control amount of the image displayed on the large window 13 is displayed as the candidate 1 white balance control amount (S382), and the time is set to zero. A white balance control amount obtained by multiplying the change amount per unit time by the unit time is obtained (S383). The image controlled with the obtained white balance control amount is displayed on the large window 13 (S384). When the user presses the enter button 17, the white balance control amount is determined (S385). When the user does not press the enter button 17 and the white balance control amount displayed in the large window 13 is not equal to the white balance control amount of the candidate 2, the time is advanced by one and the change per unit time A white balance control amount obtained by multiplying the amount by unit time is obtained. When the white balance control amount displayed on the large window 13 is equal to the white balance control amount of the candidate 2, the time is initialized and the white balance control amount of the image displayed on the large window 13 is set to the white of the candidate 1. The balance control amount is displayed (S386).

  An image controlled by the white balance control amount determined by the user is displayed on the large window 13. When the user presses the determination button 17, the white balance control amount is fixed, and when the cancel button 18 is pressed, the small window A 12 is displayed. The display of the small window B14 disappears, and the white balance control amount of candidate 1 is displayed on the large window 13 (S33).

  The white balance control amounts for candidate 1 and candidate 2 do not necessarily have to be determined by the user. For example, a region having a white balance control amount close to that of candidate 1 can be determined as a candidate 2 on the digital still camera side, or both candidate 1 and candidate 2 can be determined on the digital still camera side. . In addition, two candidates are used here, but two or more candidates may be used.

  The present invention can be applied to an apparatus for correcting white balance. For example, the present invention can be applied to digital still cameras, movies, mobile phone terminals with camera functions, and the like.

Schematic diagram showing the subject 1 is a block diagram showing a configuration of a digital still camera according to an embodiment. The flowchart for demonstrating operation | movement of the digital still camera concerning this embodiment. Rear view of the digital still camera according to this embodiment Flow chart showing calculation operation of white balance control value based on average value Schematic diagram showing white balance control value categories Flow chart showing white balance control value calculation operation based on white balance control value category Schematic diagram showing the range of R gain and B gain that are achromatic regions Flowchart showing the calculation operation of the white balance control value by the range of R gain and B gain that become an achromatic region Flow chart showing interpolation candidate selection operation Flow chart showing white balance gain calculation operation by interpolation

Explanation of symbols

1 Lens 2 CCD
3 CCD control circuit 4 A / D conversion circuit 5 SDRAM
6 Image processing circuit 7 CPU
8 LCD
9 Operation keys 10 Memory card 11 LCD
12 Small window A
13 Large window 14 Small window B
15 Four-way controller 16 Enter button 17 Cancel button 18 Known light source 19 White balance gain range to be an achromatic region

Claims (2)

An imaging means for capturing a subject and generating image data;
Processing means for obtaining a white balance control amount based on the image data and correcting the white balance of the generated image data based on the obtained white balance control amount;
Display means for displaying the processed image data;
Input means for accepting designation of an arbitrary area of the image data displayed on the display means,
The processing means corrects the white balance of the image data generated by the imaging means based on the image data in the designated area received by the input means.
Imaging device. The processing means obtains a white balance control amount for each area for the image data in the designated area received by the input means, and performs white balance correction by interpolating the white balance control quantity for each obtained area. Do,
The imaging device according to claim 1.

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