JP4938989B2 - Electronic camera - Google Patents

Description

  The present invention relates to an electronic camera that captures a subject image and generates an image.

Conventionally, image compression processing has been performed in electronic cameras. For example, in the invention of Patent Document 1, compression processing is performed by automatically selecting a data compression coefficient. By compressing the image in this way, it is possible to reduce the amount of image data and increase the number of shootable images.
JP-A-6-165027

However, in the above-described invention, a uniform compression process is performed on the entire image using the selected compression coefficient. For this reason, the data amount of the image can be reduced, but the resolution of the image may be reduced by the compression process.
An object of the present invention is to provide an electronic camera that can reduce the amount of image data and increase the number of images that can be taken while suppressing a decrease in image resolution.

The electronic camera of the present invention includes a recording unit that records and records shooting conditions for each of a plurality of predetermined shooting scenes, a selection unit that selects one shooting scene from the plurality of shooting scenes, In the imaging unit that captures a subject image in accordance with the shooting condition associated with the one shooting scene selected by the selection unit and generates an image , and in the image generated by the imaging unit, at least one A region determining unit that determines a smoothing region, a degree determining unit that determines a degree of smoothing for each smoothing region according to the type of the one shooting scene selected by the selection unit, and the imaging For each of the smoothed areas, the image generated by the unit is included in a predetermined area in the smoothed area based on the smoothing degree determined by the degree determining unit. A smoothing processing unit that performs a smoothing process that averages the pixel values of the pixels to be processed, and the region determination unit places the smoothing region outside the region that is not subjected to the smoothing process by the smoothing processing unit. It is characterized by determining.

In addition, the area | region where the said smoothing process is not performed by the said smoothing process part may be a predetermined area | region of the center part in the said image.
The region determination unit determines at least a first smoothing region and a second smoothing region outside the first smoothing region as the smoothing region, and the degree determination unit includes the first smoothing region. In the smoothing region, the smoothing processing unit performs the smoothing process based on the first number of pixels, and in the second smoothing region, the smoothing processing unit increases the first number greater than the first number. The degree of smoothing may be determined so that the smoothing process is performed based on two pixels.

The imaging apparatus further includes a recording unit that records recording conditions in association with each of a plurality of predetermined shooting scenes, and a selection unit that selects one shooting scene from the plurality of shooting scenes. The unit generates the image according to the shooting condition associated with the one shooting scene selected by the selection unit, and the region determination unit is configured to select the one shooting scene selected by the selection unit. The smoothing region may be determined according to the type .

  According to the electronic camera of the present invention, it is possible to increase the number of images that can be taken by reducing the amount of image data while suppressing a decrease in the resolution of the image.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the electronic camera 1 is a single-lens reflex type electronic camera, and includes a photographing lens 3, a mirror 4, a screen 5, a pentaprism 6, an eyepiece lens 7, a condensing lens 8, and a photometric element 9. . The taking lens 3 may be detachable from the main body.
Shooting is possible when the mirror 4 is in the mirror-up state indicated by the solid line. Further, when the mirror 4 is in a mirror-down state indicated by a broken line, shooting is not possible and the user can visually observe the subject.

At the time of non-photographing, the light beam transmitted through the photographing lens 3 is reflected by the mirror 4 in the mirror-down state, and is guided to the eyepiece lens 7 through the screen 5 and the pentaprism 6.
Note that, at the time of non-photographing, part of the light beam reflected by the mirror 4 is guided to the photometric element 9 via the screen 5, the pentaprism 6, and the condenser lens 8. The output of the photometric element 9 is used for calculation of exposure time and white balance coefficient.

Further, as shown in FIG. 1, the electronic camera 1 includes a shutter 10, a CCD image sensor 11, a condenser lens 12, and a dimming element 13.
At the time of shooting, after an aperture (not shown) in the taking lens 3 is narrowed down, imaging by the CCD imaging device 11 is started by turning off a curtain opening magnet (not shown) of the shutter 10. At this time, the mirror 4 is in a mirror-up state, and the subject light that has passed through the photographing lens 3 is imaged on the CCD image sensor 11. Then, when the curtain closing magnet (not shown) of the shutter 10 is turned off, the imaging is finished.

Further, during the main light emission by a flash unit (not shown), a part of the light imaged on the CCD image pickup device 11 is reflected on the CCD image pickup device 11 and passes through the condenser lens 12 on the light control device 13. Is imaged. The photometry by the light control element 13 is continuously performed during the main light emission, and the flash unit is controlled based on the result of the photometry.
FIG. 2 is a functional block diagram of the electronic camera 1. The electronic camera 1 includes a control unit 14, a photometry unit 15, an imaging unit 16, an image processing unit 17, and a recording unit 18. These units are connected to each other via a bus. The electronic camera 1 also includes an operation unit 19 that includes a power button, a release button, and the like (not shown).

  The control unit 14 includes a CPU and a memory (not shown), and a program for controlling each unit is recorded in the memory in advance. The control unit 14 also determines a smoothing region and a degree of smoothing that are features of the present invention (details will be described later). The photometry unit 15 includes the photometry element 9 described with reference to FIG. 1 and measures the object scene. The imaging unit 16 includes the photographing lens 3, the shutter 10, and the CCD imaging device 11 described with reference to FIG. 1 and captures a subject image to generate an image.

In addition, the image processing unit 17 performs predetermined image processing such as white balance adjustment on the image generated by the imaging unit 16, and also performs smoothing processing and compression processing, which are features of the present invention. The recording unit 18 records the image subjected to the image processing by the image processing unit 17, and a removable memory such as a memory card is detachable.
The electronic camera 1 also has a scene shooting function when shooting a subject image. In the scene shooting function, shooting conditions are recorded in advance in a memory (not shown) in the control unit 14 for each of a plurality of types of shooting scenes such as “portrait”, “night scene portrait”, “landscape”, and the like. This is a function for performing shooting according to shooting conditions associated with the shooting scene selected by the user. Various selection operations related to the scene shooting function are performed by the user via the operation unit 19.

  The control unit 14 and the imaging unit 16 correspond to an “imaging unit” in the claims, and the control unit 14 corresponds to an “area determination unit” and a “degree determination unit” in the claims. The control unit 14 and the image processing unit 17 correspond to a “smoothing processing unit” in the claims, and the control unit 14 and the photometry unit 15 correspond to an “acquisition unit” in the claims. A memory (not shown) in the control unit 14 corresponds to a “recording unit” in the claims, and the control unit 14 and the operation unit 19 correspond to a “selection unit” in the claims.

The operation at the time of imaging of the electronic camera 1 having the above-described configuration will be described with reference to the flowchart of FIG.
In step S1, the control unit 14 determines whether or not the release button is half-pressed.
The control unit 14 waits until the release button is half-pressed, and when the release button is half-pressed, in step S2, AF / AE operations are performed via each unit.

In step S3, the control unit 14 determines whether or not the release button has been fully pressed.
The control unit 14 waits until the release button is fully pressed, and when the release button is fully pressed, in step S4, based on the AF / AE operation performed in step S2, imaging is performed via the imaging unit 16. Then, predetermined image processing (excluding compression processing) such as white balance adjustment, color correction, and gamma correction is performed via the image processing unit 17.

  In step S5, the control unit 14 determines a smoothing region. As shown in FIG. 4, the control unit 14 divides the image generated by the imaging in step S <b> 4 into 16 parts in the vertical direction and 16 parts in the horizontal direction. And a predetermined area | region is determined as a smoothing area | region among the divided | segmented 256 area | regions (a1-r16). In the smoothing area, some patterns are previously determined in a memory (not shown) in the control unit 14, and the control unit 14 performs a photometry result by the photometry unit 15 (may be a luminance value of an image generated by imaging). And an appropriate one is selected based on the type of shooting scene selected by the scene shooting function. 5 and 6 show examples of the smoothed region. In FIG. 5A, the area (I) indicated by hatching is a smoothing area, and in FIG. 6A, the area (I), area (II), and area (III) separately indicated by hatching are smoothing areas. When providing a plurality of smoothing regions, as shown in FIG. 6A, it is preferable to provide a shape close to a concentric circle with the center of the image as the center.

  In step S6, the control unit 14 determines the smoothing degree for each smoothing region determined in step S5. The degree of smoothing is determined in proportion to the number of pixels to be subjected to pixel addition in the smoothing process described later. That is, the greater the number of pixels that are subject to pixel addition, the greater the degree of smoothing, and the smaller the number of pixels that are subject to pixel addition, the smaller the degree of smoothing.

  In the image, the control unit 14 determines the degree of smoothing as the area farther from the center part and determines the degree of smoothing as the area closer to the center part. Further, when the luminance of the peripheral portion of the object scene is lower than the predetermined luminance based on the photometric result of the photometric unit 15 (which may be the luminance value of the image generated by imaging), the control unit 14 In the image, the degree of smoothing in the area corresponding to the peripheral part of the object scene is determined to be larger than the degree of smoothing in the other area. Further, when the scene shooting function is executed, the degree of smoothing is determined based on the type of the selected shooting scene. Note that the degree of smoothing may be determined by combining the above-described conditions, or the degree of smoothing may be determined based on any one of the conditions.

For example, the smoothing region (I) in FIG. 5A, as shown in Figure 5B, in the region of the divided 256, the pixels included in the four areas targeted for pixel addition. Further, in the smoothing region (I) in FIG. 6A, as shown in FIG. 6B, pixels included in eight regions among the divided 256 regions are subjected to pixel addition, and in the smoothing region (II), Pixels included in the four regions are targeted for pixel addition, and pixels included in the two regions are targeted for pixel addition in the smoothing region ( III ). That is, the smoothing region (I) in FIG. 5A and the smoothing region (II) in FIG. 6A have the same degree of smoothing, and the smoothing region (I) in FIG. The degree of smoothing is smaller in the smoothing region (III) in FIG. 6A.

FIGS. 7A to 7C and FIGS. 8A to 8C show other examples of the smoothing region and the smoothing degree.
In step S <b> 7, the control unit 14 performs a smoothing process via the image processing unit 17. The image processing unit 17 performs pixel addition for each smoothed region determined in step S5 based on the smoothing degree determined in step S6. In the example of FIG. 5A, the average luminance value of a group (A1 to H8 in FIG. 5B) composed of four regions in the smoothed region (I) is calculated.

That is, (A1 luminance average value) = (a1 + b1 + a2 + b2) / 4, (A2 luminance average value) = (c1 + d1 + c2 + d2) / 4 (Omitted) (H8 luminance average value) = (q15 + r15 + q16 + r16) / Each luminance average value is calculated as shown in FIG.
In the example of FIG. 6A, for A1 to A5, B1, B2, C1, C2, and D1 to D5, after adding eight groups, dividing by 8 instead of dividing by 4, E1 to E6, F1, and F2 , G1, G2, H1, H2, J1, J2, and K1 to K6 are similarly divided by 4, and L1 to L5, M1, M2, N1, N2, and P1 to P6 are added after adding two groups. Instead of dividing by 4, divide by 2. Then, when the smoothing process is finished in all the smoothing regions, the process proceeds to step S8.

In step S <b> 8, the control unit 14 performs a compression process via the image processing unit 17.
In step S9, the control unit 14 records the compressed image on the recording unit 18 and ends the series of processes.
As described above, according to this embodiment, a subject image is captured to generate an image, and at least one smoothing region is determined in the generated image, and the smoothing degree is determined for each smoothing region. To decide. Then, a smoothing process is performed on the generated image based on the determined degree of smoothing for each smoothing region. By performing the smoothing process, the compression rate can be increased, so that it is possible to reduce the data amount of the image and increase the number of shootable images while suppressing a decrease in the resolution of the image. Further, noise reduction can be expected for the smoothed portion.

Further, according to the present embodiment, when determining the degree of smoothing, the degree of smoothing is determined to be larger in the region farther from the central part of the image, and the degree of smoothing is reduced in the area closer to the central part. decide. Therefore, it is possible to reduce the amount of image data and increase the number of images that can be taken, while suppressing particularly a decrease in resolution at the central portion where the main subject is considered to exist.
Further, according to the present embodiment, when acquiring the luminance information of the object scene at the time of imaging and determining the smoothing region, the determination is based on the acquired luminance information and the degree of smoothing is determined. If the brightness of the peripheral part of the acquired scene is lower than the predetermined brightness, the degree of smoothing in the area corresponding to the peripheral part of the scene in the image, Is determined to be greater than the degree of smoothing in the area of the portion. Therefore, by increasing the degree of smoothing of the low-luminance part (mainly the peripheral part), it is possible to reduce the image data amount and increase the number of images that can be taken.

  In addition, according to the present embodiment, a shooting condition is recorded in association with each of a plurality of predetermined types of shooting scenes, and a function for selecting one shooting scene from a plurality of types of shooting scenes is selected and selected. When shooting is performed in accordance with the shooting conditions associated with one shooting scene and the smoothing area is determined, it is determined according to the type of shooting scene selected and the degree of smoothing is determined. Determines the degree of smoothing according to the type of the selected shooting scene. Therefore, according to the shooting scene, it is possible to reduce the image data amount and increase the number of images that can be shot while suppressing a decrease in the resolution of the image.

In the present embodiment, an example in which the pixel addition based on the average value is performed to realize the smoothing process is shown, but the smoothing process may be performed by other methods. For example, instead of pixel addition, a representative value for each region may be obtained.
In the present embodiment, an example in which the smoothing area and the smoothing degree are selected from predetermined combinations has been described. However, the smoothing area and the smoothing degree are selected based on a user operation via the operation unit 19. May be specified.

It is an internal block diagram of the electronic camera 1 of this embodiment. It is a functional block diagram of electronic camera 1 of this embodiment. It is a flowchart which shows operation | movement of the electronic camera 1 of this embodiment. It is a figure explaining determination of a smoothing field. It is a figure explaining determination of a smoothing field and a smoothing degree. It is another figure explaining determination of a smoothing area | region and a smoothing degree. It is another figure explaining determination of a smoothing area | region and a smoothing degree. It is another figure explaining determination of a smoothing area | region and a smoothing degree.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic camera 3 Shooting lens 4 Mirror 5 Screen 6 Penta prism 7 Eyepiece lens 8, 12 Condensing lens 9 Photometry element 10 Shutter 11 CCD image sensor 13 Light control element 14 Control part 15 Photometry part 16 Image pickup part 17 Image processing part 18 Recording unit 19 Operation unit

Claims (4)

A recording unit that records and records shooting conditions for each of a plurality of predetermined shooting scenes;
A selection unit for selecting one of the plurality of types of shooting scenes;
An imaging unit that captures an image of a subject in accordance with the shooting conditions associated with the one shooting scene selected by the selection unit ;
An area determination unit that determines at least one smoothing area in the image generated by the imaging unit;
A degree determining unit that determines the degree of smoothing for each smoothing region according to the type of the one shooting scene selected by the selection unit ;
Based on the degree of smoothing determined by the degree determining unit for each of the smoothed areas, pixels of pixels included in a predetermined area in the smoothed area are generated for the image generated by the imaging unit. A smoothing processing unit that performs a smoothing process for averaging pixel values,
The area determination unit determines the smoothing area outside an area not subjected to the smoothing process by the smoothing processing unit. The electronic camera according to claim 1,
The area where the smoothing processing unit does not perform the smoothing process is a predetermined area in the center of the image. The electronic camera according to claim 1 or 2,
The region determination unit determines at least a first smoothed region and a second smoothed region outside the first smoothed region as the smoothed region;
In the first smoothing region, the degree determination unit performs the smoothing process based on the first number of pixels by the smoothing processing unit, and the smoothing process in the second smoothing region. The degree of smoothing is determined so that the smoothing process is performed based on a second number of pixels larger than the first number by the unit. The electronic camera according to claim 1,
A recording unit that records and records shooting conditions for each of a plurality of predetermined shooting scenes;
A selection unit that selects one of the plurality of types of shooting scenes;
The imaging unit generates the image according to the shooting condition associated with the one shooting scene selected by the selection unit,
The electronic camera according to claim 1, wherein the area determination unit determines the smoothing area according to a type of the one shooting scene selected by the selection unit.

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