JP2000013675A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital camera capable of obtaining an appropriate image even in panoramic photographing, digital zoom photographing, etc. SOLUTION: This digital camera which records prescribed image data on a recording medium after performing photoelectric conversion of image pickup light that is made incident on an image pickup device through an optical system is provided with an exposure controlling means 11 which measures light quantity from the image pickup light and performs appropriate exposure control and an attentional part extracting means 14 which selects image data of a prescribed attentional part among the image pickup light, expands it whenever necessary and makes it the prescribed image data in a prescribed photographic mode. The means 11 performs the exposure control based on the light quantity of image pickup light that corresponds to at least a main part of the attentional part and a peripheral part of the attentional part as occasion demands when the means 14 selects the image data of the prescribed attentional part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a digital camera having an automatic exposure control function, and more particularly to a digital camera that performs exposure control based on a focused portion when performing panoramic photography and / or digital zoom photography.

[0002]

2. Description of the Related Art In recent years, digital cameras (electronic still cameras) have been developed / sold and are becoming popular. A digital camera is configured to obtain image data by photoelectrically converting imaging light, record the image data on a recording medium, and output the image data to an external image processing device such as a personal computer (hereinafter, a personal computer). Image data creation processing is performed, the created print image data is output to a printer, and the photographed image is printed / reproduced on paper. Many digital cameras are provided with a liquid crystal display for displaying an imaging result, and image data obtained by photoelectric conversion is compressed and recorded on a recording medium. The compression process is usually JP
Compression according to the EG standard (hereinafter, JPEG compression) is performed.

In such a digital camera, automatic exposure control is performed in order to obtain an image having an appropriate brightness as in a normal film camera. Such automatic exposure control
The brightness of the imaging screen is obtained by averaging the light amounts of the imaging light input to the imaging device, and comparing this brightness with a reference value to maintain proper exposure.

[0004] Similarly, some image processing apparatuses have white balance control means for appropriately controlling the white balance by comparing the luminance of the color components of the imaging light input to the image sensor.

[0005]

On the other hand, a recent digital camera may have a panorama mode or a digital zoom mode.
Since the above-described exposure control and white balance control are performed on the entire normal-sized image, an appropriate image may not be obtained. This is because panorama and zoom only cut out the screen.For example, in the panorama mode that removes the upper and lower parts of the shooting screen, if there is a sky at the top or snow at the bottom, etc. However, there is a problem in that if exposure calculation is performed using the entire original screen, the exposure will be underexposed on a panoramic screen in which these portions are cut. In general, when performing zooming of a person's face, etc., exposure control should be performed only on the face.However, underexposure or overexposure is affected by the landscape or clothes behind the cut face. It tends to be.

[0006] In view of such circumstances, an object of the present invention is to provide a digital camera capable of obtaining an image with proper exposure and white balance even in panoramic photography or digital zoom photography.

[0007]

According to a first aspect of the present invention for solving the above-mentioned problems, a predetermined image data is recorded on a recording medium after photoelectrically converting imaging light incident on an imaging device via an optical system. A digital camera that measures the amount of light from the image pickup light to perform appropriate exposure control, and selects and selects image data of a predetermined target portion from the image pickup light in a predetermined photographing mode. And an exposure control unit that enlarges the image data according to the predetermined image data and sets the predetermined image data as the predetermined image data. Wherein the exposure control is performed based on the amount of imaging light corresponding to at least the main part and, if necessary, the peripheral part of the target part.

In the first aspect, since exposure control is performed by focusing only on a target portion of interest in a predetermined photographing mode,
An appropriate image can be obtained.

According to a second aspect of the present invention, there is provided the digital camera according to the first aspect, wherein the attention portion extracting means forms a panoramic image.

In the second aspect, an appropriate panoramic image can be obtained.

According to a third aspect of the present invention, there is provided the digital camera according to the first or second aspect, wherein the attention portion extracting means forms a digitally zoomed image.

In the third aspect, a proper zoom image can be obtained.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the exposure control means divides the image pickup device into a plurality of blocks and assigns them to at least one or more pixels in each block. In the digital camera, the exposure control is performed from corresponding imaging light.

In the fourth aspect, since the exposure is controlled by focusing only on the representative pixels in the block, the exposure control can be performed quickly and easily.

According to a fifth aspect of the present invention, in the fourth aspect, the exposure control means performs the exposure control by adding a weighting coefficient to the plurality of blocks and performing weighting. In the camera.

In the fifth aspect, more appropriate exposure control can be performed by weighting the blocks that divide the screen.

According to a sixth aspect of the present invention, in the fourth or fifth aspect, the exposure control means, when the attention portion extraction means extracts the attention portion, from the plurality of blocks. And at least one target block corresponding to the target is selected, and the exposure control is performed by the imaging light from the target.

In the sixth aspect, appropriate exposure control can be performed by focusing only on the block corresponding to the target portion.

According to a seventh aspect of the present invention, in the sixth aspect, the exposure control means performs the exposure control by selecting the block of interest by changing the weighting coefficient. In digital cameras.

In the seventh aspect, the block of interest can be selected only by changing the weight coefficient corresponding to each block that partitions the screen.

According to an eighth aspect of the present invention, in the digital camera according to the seventh aspect, the exposure control means performs weighting in the target block.

In the eighth aspect, weighting is performed even in the target portion, and more appropriate exposure control can be realized.

According to a ninth aspect of the present invention, in any one of the first to eighth aspects, a white balance control means for comparing the luminance of color components from the imaging light and performing appropriate white balance control is further provided. A digital camera characterized by comprising:

In the ninth aspect, a more appropriate image can be obtained with an appropriate white balance.

According to a tenth aspect of the present invention, in the ninth aspect, the white balance control means, when the attention portion extraction means selects image data of a predetermined attention portion, includes at least the main data of the attention portion. A digital camera that performs the white balance control based on luminance from imaging light corresponding to a part and, if necessary, a peripheral part of the target part.

In the tenth aspect, in a predetermined photographing mode, the white balance is adjusted by focusing on the target portion, and a more appropriate image can be obtained.

According to an eleventh aspect of the present invention, in the tenth aspect, the white balance control means divides the image pickup device into a plurality of blocks and picks up an image pickup light corresponding to at least one pixel in each block. The digital camera performs the white balance control.

In the eleventh aspect, the exposure is controlled by focusing only on the representative pixels in the block, so that white balance control can be performed quickly and easily.

According to a twelfth aspect of the present invention, in the eleventh aspect, the white balance control means performs the white balance control by adding a weighting coefficient to the plurality of blocks and performing weighting. Digital camera.

In the twelfth aspect, more appropriate white balance control can be performed by weighting the blocks that divide the screen.

A thirteenth aspect of the present invention is directed to the eleventh or first aspect.
In the second aspect, the white balance control means includes:
In the case where the attention portion extraction means extracts the attention portion,
A digital camera is characterized in that at least one target block corresponding to the target part is selected from the plurality of blocks, and the white balance control is performed using image pickup light from the target part.

In the thirteenth aspect, appropriate white balance control can be performed by focusing only on the block corresponding to the target portion.

According to a fourteenth aspect of the present invention, in the thirteenth aspect, the white balance control means performs the white balance control by selecting the target block by changing the weighting coefficient. It is in a digital camera.

In the fourteenth aspect, the block of interest can be selected only by changing the weight coefficient corresponding to each block dividing the screen.

A fifteenth aspect of the present invention is the digital camera according to the fourteenth aspect, characterized in that the white balance control means performs weighting in the block of interest.

In the fifteenth aspect, weighting is performed even on the target portion, and more appropriate white balance control can be realized.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration example of a digital camera according to an embodiment of the present invention.

As shown in FIG. 1, the digital camera 100
Has an optical system including a lens 1, an aperture mechanism 2, a shutter 3, and the like, and has a CCD 4 that receives imaging light from an image to be captured through this optical system and converts it into an electric signal. The digital camera 100 processes the signal from the CCD 4 and outputs multi-valued (R, G, B) raster data (image data). The image data created by the image data creation unit 5 And the image data output unit 7 that outputs image data by converting R, G, and B raster data on the frame memory 6 into a luminance component Y and color difference components U and V, for example. The image data and the like created by the image data output unit 7 are stored in a recording medium 9 via a recording medium control unit 8 and output to the outside via an interface 10 as needed. Further, the digital camera 100 includes an optical system control unit 11 for controlling an optical system, a moving image display control unit 12 for displaying a moving image.
And a liquid crystal display (LCD) 13, an attention portion extraction unit 14 for performing special shooting, and a control unit 15.

Here, the image data output unit 7 converts the R, G, and B raster data in the frame memory 6 into the luminance components Y and Convert to color difference components U and V and JPE
G compression is performed, and a reduction process for creating a thumbnail image is performed.

The recording medium control unit 8 includes an image data output unit 7
To write JPEG-compressed image data (hereinafter simply referred to as image data) and reduced image data to a predetermined position on the built-in recording medium 9 and read out each recorded JPEG image data And the like. The recording medium 9 is for storing image data.
Interface 10 such as serial or parallel
Is for exchanging data with an external device,
The image data stored in the built-in recording medium 9 is output to an external device, for example, a computer device such as a personal computer, a modem, a printer, or the like via the interface 10.

The recording medium 9 is an extended recording medium such as a flash memory fixed inside the camera 100 and / or a removable memory card.

The optical system control means 11 controls the aperture mechanism 2 and the shutter 3 based on the data stored in the frame memory 6 to appropriately control the exposure and white balance.

The moving image display control unit 12 includes the frame memory 6
Is output to the LCD 13 to display a moving image. Normally, the image data is written into the frame memory 6 by the image data creating unit 5 a predetermined number of times, for example, 30 times or 60 times a second. Are performed in the same phase in synchronization with the writing of data.

The attention portion extracting means 14 controls the display of moving images and the creation of image data when performing special photographing such as panoramic photographing and digital zoom photographing. That is,
When a special photographing mode is selected by a selection means (not shown), an image corresponding to the selection is displayed on the LCD 13, and when a specific button or the like is pressed during this display and photographing is performed. Creates corresponding image data.

The control unit 15 includes a CPU 16 and a ROM
17 and a RAM 18 and the like, and operation control and image processing of the image data creation unit 5, image data output unit 7, recording medium control unit 8, optical system control unit 11, moving image display control unit 12, and attention unit extraction unit 14. And controls the execution of image compression / decompression processing and the like. The ROM 17 stores a group of programs necessary for data processing inside the digital camera, such as operation control of the digital camera 100 and data compression / decompression processing. Further, an instruction from an input unit including buttons, switches, and the like (not shown) is converted into a digital signal and input to the control unit 15.

In the present embodiment, the optical system control means 11
Automatic exposure control and automatic white balance control in the image data output unit 7 are performed.

More specifically, the automatic exposure control (AE) reads out the image data stored in the frame memory 6, calculates the brightness of the entire frame, compares the brightness with a predetermined value, and compares the brightness with a predetermined value. , The CCD 4 to properly control the accumulation time, shutter speed, and the like.

Further, the automatic white balance compares the luminance of each of RGB and determines an appropriate R based on a predetermined standard.
RG in the image data creation unit 5 so as to achieve GB balance
B is for adjusting and controlling the amplification factor for each data.

Here, the calculation of the brightness for the AE is C
The average value of all the pixels of the CD4 or the entire effective pixels in the range related to the actual shooting may be averaged, but the average value of the brightness is calculated from the data of the thinned pixels, for example, every 8 pixels and every 8 lines. You may make it calculate.

Further, all pixels or effective pixels may be divided into a plurality of blocks, for example, nine blocks, and each block may be weighted to calculate brightness. In the present embodiment, for example, as shown in FIG.
768 × 1024 effective pixels B of all pixels A of 050
Into nine blocks B11-B13, B21-B23, B31-B33
, And the brightness of each block is averaged in consideration of the weights to obtain the overall brightness.

For example, each block B11-B13, B21-B
23, the brightness of B31-B33 is X11-X13, X21-X23, X
31 to X33, and the weighting coefficient of each block is 1, 2, 2,
When 1, 2, 4, 2, 1, 2, 1 is the average value of the product of the brightness of each block and the weighting coefficient, (X11 + 2 · X12 + X13 + 2 · X21 + 4 · X22 + 2 · X23 + X31
+ 2 · X32 + X33) / 16 is used as the reference for the overall brightness. The brightness of each block may be obtained from all pixels, or the brightness of each block may be calculated from a value extracted from each block by a plurality of pixels.

In addition, the attention part extracting means 14 of the present embodiment.
Performs panoramic image processing. That is, when a specific button is pressed and the panoramic image display is selected while the LCD 13 is displaying a moving image,
The panorama display data is output to D13, and when a specific button is pressed while outputting the panorama display data to instruct image recording, panorama image data is created and the panorama image data is stored in the recording medium control unit 8 Output to

Such a panoramic display is, for example, shown in FIG.
As shown in FIG. 3, the image data in the frame memory 6 (FIG. 3)
In D1), pixels of a specific color such as black and blue are embedded in predetermined portions of the upper and lower sides, the remaining central portion is created as transparent data, and, for example, another frame memory is used. Is performed by superimposing and displaying the panoramic graphic surface (D2 in FIG. 3) stored on the LCD 13 on the LCD 13, and a panoramic display screen D12 is created.
Note that when such panorama display is performed and a shooting is performed by an instruction of a specific button or the like, a predetermined ratio of upper and lower sides is deleted from the image data being displayed to create a panorama image. Is done. That is, of the image data in the frame memory 6 in which the image data being displayed is stored, the R, G, B raster data of only a predetermined central portion is converted into a luminance component Y and color difference components U, V, and JPEG. The image is compressed, and a reduction process for creating a thumbnail image is performed. This data is output to the recording medium control unit 8, and the recording medium control unit 8 stores the data in the recording medium 9.

The created panoramic image data is
40 to 5 in total from upper and lower sides from normal image data
It is preferable to remove 0%, especially about 50%. Also,
At this time, it is preferable to delete the upper and lower sides equally, and in particular, it is preferable to delete the upper and lower quarters at a time, but it is not always necessary to delete them equally.

In this embodiment, when the panoramic photographing mode is selected as described above, the above-described optical system control unit 1
1 performs automatic exposure control corresponding to the panorama shooting mode. That is, exposure control is performed with emphasis on a part displayed in panorama. Various methods can be adopted for this exposure control, but it is important to control the exposure based on data from a part directly related to shooting.
Thereby, a more appropriate exposure can be obtained.

For example, in the case where the upper and lower portions of the screen are sky, sea, or snow, if the exposure is controlled by the entire data, the panorama photographing of only the central portion may be underexposed. If the exposure is controlled only in the central part as shown in FIG.

In the present embodiment, the above-described weighting coefficients used for detecting the brightness are changed, and the blocks B21 to B21 are changed.
By setting the weighting coefficients other than 31 to zero, the exposure is controlled based on the data of the part directly related to panoramic shooting. Such control has an advantage that it can be realized very easily only by changing the weighting coefficient. The blocks B21 to B23 are slightly smaller than the panorama shooting area, but do not hinder the obtaining of proper exposure. Exposure control may be performed in two rows of blocks.

As a method of changing the exposure control according to the panorama shooting mode, in addition to changing the weighting coefficient for each divided block, the brightness is controlled based only on data from pixels actually used for panorama shooting. Is calculated,
The exposure may be controlled. In this case, the brightness is calculated only from the relevant pixels without dividing the image into blocks as described above.

Further, in the above embodiment, the panoramic photographing mode has been described, but the same applies to, for example, digital zoom. That is, in the case of having the digital zoom mode, for example, image data from a predetermined pixel at the center of the screen is displayed in an enlarged manner. In this case, the brightness is calculated from the pixel corresponding to the cut portion. To control exposure. This makes the exposure of the zoomed part more appropriate. In the exposure control in this case, by changing the weighting coefficient for each block as described above, for example, the exposure may be controlled by setting the weighting coefficient other than the block B22 described above to zero. Exposure control may be performed based on data of only relevant pixels.

In the above-described embodiment, when a predetermined target part is extracted and photographed, the exposure control is performed with emphasis on the target part. However, the white balance control is also performed in the target part. The control may be performed with an emphasis on the image quality, so that a more appropriate image can be obtained.

In the above-described embodiment, the description has been made based on an example of panoramic photography. In any case, in a special photography in which a certain part of interest is cut out and photographed, automatic exposure is performed according to the part of interest. The present invention can of course be applied to any kind of special photography.

Further, in the above-described embodiment, the description has been made such that the pixel data for calculating the brightness of the screen is read out from the frame memory 6. However, this is merely an example. Exposure control may be performed using data before the exposure is performed. In any case, the present invention is not affected by the automatic exposure mechanism itself.

In any case, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made.

[0065]

As described above, according to the present invention, in a special photographing such as a panoramic photographing or a digital zoom photographing, the exposure control and the like are performed in accordance with the attention portion, so that a more appropriate image can be obtained. This has the effect.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a digital camera with a panoramic image shooting function according to the present invention.

FIG. 2 is an explanatory diagram illustrating an example of exposure control.

FIG. 3 is an explanatory diagram illustrating an example of a panoramic display.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens 2 Aperture mechanism 3 Shutter 4 CCD 5 Image data creation unit 6 Frame memory 7 Image data output unit 8 Recording medium control unit 9 Recording medium 10 Interface 11 Optical system control unit 12 Moving image display control unit 13 Liquid crystal display (LCD) 14 Attention Unit extraction means 15 control unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 9/04 H04N 5/92 HF term (Reference) 5C022 AA13 AB06 AC42 5C052 AA17 GA02 GA03 GA05 GA08 GA09 GB06 GE04 5C053 FA08 GB36 LA01 LA03 LA06 LA11 LA14 5C065 AA03 DD02 EE20 FF02 GG30 GG44 GG49 HH02

Claims (15)

[Claims] 1. A digital camera that photoelectrically converts imaging light incident on an imaging device via an optical system and then records predetermined image data on a recording medium. Exposure control means for performing control; and attention part extraction means for selecting image data of a predetermined attention part from the imaging light in a predetermined shooting mode and enlarging and selecting the predetermined image data as necessary. The exposure control means, when the attention part extracting means selects image data of a predetermined attention part, picks up an image corresponding to at least a main part of the attention part and, if necessary, a peripheral part of the attention part. A digital camera, wherein the exposure control is performed based on the amount of light. 2. The digital camera according to claim 1, wherein said attention portion extraction means forms a panoramic image. 3. The digital camera according to claim 1, wherein the target portion extraction unit forms a digitally zoomed image. 4. The exposure control device according to claim 1, wherein the exposure control unit divides the image pickup device into a plurality of blocks and uses the image pickup light corresponding to at least one pixel in each block to control the exposure. A digital camera. 5. The digital camera according to claim 4, wherein the exposure control means performs the exposure control by adding a weighting coefficient to the plurality of blocks and performing weighting. 6. The exposure control unit according to claim 4, wherein the at least one attention unit corresponding to the attention unit is included in the plurality of blocks when the attention unit extraction unit extracts the attention unit. A digital camera, wherein a block is selected, and the exposure control is performed using image pickup light from the target portion. 7. The digital camera according to claim 6, wherein the exposure control means performs the exposure control by selecting the target block by changing the weighting coefficient. 8. The digital camera according to claim 7, wherein said exposure control means performs weighting in said attention area block. 9. The digital device according to claim 1, further comprising a white balance control unit that performs appropriate white balance control by comparing luminance of color components from the imaging light. camera. 10. The white balance control means according to claim 9, wherein, when the attention part extracting means selects the image data of the predetermined attention part, at least a main part of the attention part and, if necessary, the attention part. A digital camera for performing the white balance control based on luminance from imaging light corresponding to a peripheral portion of the digital camera. 11. The white balance control unit according to claim 10, wherein the white balance control unit divides the image sensor into a plurality of blocks and performs the white balance control from imaging light corresponding to at least one pixel in each block. Digital camera characterized by the following. 12. The digital camera according to claim 11, wherein said white balance control means performs the white balance control by integrating and weighting a plurality of blocks with a weighting coefficient. 13. The method according to claim 11, wherein the white balance control unit includes at least one attention unit corresponding to the attention unit from the plurality of blocks when the attention unit extraction unit extracts the attention unit. A digital camera, wherein the white balance control is performed by selecting a block of the unit and using imaging light from the target unit. 14. The digital camera according to claim 13, wherein the white balance control means performs the white balance control by selecting the block of interest by changing the weighting coefficient. 15. The digital camera according to claim 14, wherein the white balance control means performs weighting in the target block.