JP4253407B2 - Electronic camera device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention particularly relates to an electronic camera device having an electronic zoom function.
[0002]
[Prior art]
In recent years, an electronic camera that converts a subject into image data using an electronic imaging function and records the image data on a recording medium has become widespread. The electronic camera includes a digital video camera whose main function is moving image shooting, in addition to an electronic still camera called a digital camera.
[0003]
An electronic camera is generally provided with a display panel (hereinafter referred to as a liquid crystal panel) composed of an LCD (liquid crystal device) on the back side of the camera body. The captured image is displayed on the liquid crystal panel. The captured image is a through image that continuously displays a still image (corresponding to a so-called photograph) or an output of an image sensor (CCD or the like). A liquid crystal panel that displays a through image is used as a display screen of a so-called EVF (Electro-view finder). Recently, an electronic camera in which this EVF is mounted as a viewing-type EVF instead of a viewing-type optical viewfinder has been developed.
[0004]
By the way, the electronic camera performs various types of image processing after converting an image pickup signal obtained by photographing into digital image data by A / D conversion processing. Therefore, various processes such as correction to EVF display information (digital photographed image) displayed on the liquid crystal panel can be easily performed. Accordingly, it is possible to realize an electronic zoom function (digital zoom function) which is a function for enlarging and displaying a part of an EVF display image.
[0005]
[Problems to be solved by the invention]
Unlike the so-called optical zoom function, the electronic zoom function does not optically change the shooting area, but is a function of taking out a part (partial area) of the shot image and displaying it in an enlarged manner. Therefore, the enlarged imaged portion is the same as the imaged and displayed image with substantially fewer pixels compared to the case where only that portion is used as the imaging region. For this reason, when the enlargement ratio of the electronic zoom function is increased, the resolution is lowered and the image quality of the display image is deteriorated.
[0006]
On the other hand, the number of pixels of an image sensor used in an electronic camera is increasing with the improvement of semiconductor technology and the demand for higher image quality. Specifically, the number of pixels is about several hundreds of thousands for moving image shooting, but has reached several million pixels for still image shooting. However, for example, when a CCD (Charge Coupled Device) is used as an imaging device, the time for reading image data from the CCD is becoming longer as the number of pixels increases. Further, as the number of pixels increases, the amount of image data also increases, so that it takes time for image processing after reading from the CCD. For this reason, as the number of pixels increases, it is becoming difficult to perform EVF display processing of captured images at a normal video rate (30 frames / second).
[0007]
Accordingly, an object of the present invention is to perform an electronic zoom function capable of performing high-speed display processing in normal EVF display and suppressing image quality deterioration of the zoom display screen when electronic zoom processing is performed. It is to provide a camera device.
[0008]
[Means for Solving the Problems]
The present invention relates to an electronic camera device having an electronic zoom function, and includes a first image sensor for recording a still image and a high number of pixels, and a second image sensor for recording a moving image with a relatively small number of pixels. And an electronic camera device having a first image processing means and a second image processing means for processing an image pickup signal output from each image pickup device.
[0009]
Further, the present apparatus is obtained by an electronic zoom processing means for enlarging a part of the photographed image using the first image data, and the second image data or the electronic zoom processing means. An image display unit that selectively uses the zoom image data to display a captured image, and a captured image to be displayed on the image display unit according to the setting of the electronic zoom mode, from the second image data to the electronic image. Image switching means for switching to zoom image data obtained by the zoom processing means and supplying the zoom image data to the image display means .
[0010]
With such a configuration, during normal shooting, the EVF display process for displaying the shot image on the liquid crystal panel using the second image data (moving image data) of relatively low pixels is executed. Display processing can be realized. On the other hand, when an electronic zoom function for enlarging and displaying a part of a captured image is used, zoom image data is generated using first image data (still image data) having relatively high pixels. . Since the EVF display process is executed using the zoom image data, a high-quality captured image can be displayed on the liquid crystal panel.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0012]
(Configuration of electronic camera)
FIG. 1 is a block diagram showing a main part of the electronic camera related to the embodiment. The electronic camera of the embodiment is assumed to be an electronic still camera (digital camera) having an electronic zoom function as well as a still image shooting function and a moving image shooting function. Of course, the present invention can also be applied to a digital video camera having a moving image shooting function as a main function and also having a still image shooting function.
[0013]
As shown in FIG. 1, the electronic camera of this embodiment is roughly composed of a photographing system 1, an image processing system 2, a system controller 3, an input operation system 4, a recording system 5, and a display system 6. In addition to this, there is an output system for outputting image data to the outside, but the description thereof is omitted in this embodiment.
[0014]
The imaging system 1 of the embodiment has two imaging elements 14S and 14M made of a CCD. That is, a still image pickup device (hereinafter referred to as a still image CCD) 14S having a relatively high pixel number of about several million pixels and a moving image pickup device (hereinafter referred to as a CCD for still image) having a relatively low number of pixels of about several hundred thousand pixels. 14M). Corresponding to the CCDs 14S and 14M, the photographing system 1 includes imaging circuits 15S and 15M, and A / D converters 16S and 16M. The imaging circuits 15S and 15M perform processing such as exposure, imaging signal readout processing, element shutter control, and power supply on / off control. The A / D converters 16S and 16M convert imaging signals read from the CCDs 14S and 14M into digital image data.
[0015]
Further, the photographing system 1 includes a lens 10, a diaphragm unit 11, a spectroscopic unit (beam splitter) 12, a shutter 13, and an autofocus (A / F) mechanism 17. The spectroscopic unit 12 supplies incident light incident from the lens 10 to the still image CCD 14 </ b> S via the moving image CCD 14 </ b> M and the shutter 13. The shutter 13 opens and closes in response to a shutter / release signal SC3 from the system controller 3 to be described later, and is closed when an imaging signal is read from the still image CCD 14S. The lens 10 is configured to be driven by a focus (zoom) by the A / F mechanism 17.
[0016]
The power supply of the still image CCD 14S is normally turned off, and the power supply is turned on by the imaging circuit 15S in response to the shutter / release on operation or the setting input of the electronic zoom mode. The shutter / release on operation is executed by an operation key 41 of the input operation system 4 to be described later. The setting input of the electronic zoom mode is executed by operating the electronic zoom button 40.
[0017]
Specifically, the image processing system 2 includes an image processing CPU (microprocessor) and a memory that stores a control program thereof. The still image processing unit 20, the moving image processing unit 21, and the compression / decompression processing units 24 and 25 illustrated in FIG. 1 are functional elements by the CPU. The buffer memories 22 and 23 are also called frame memories, and store image data for one screen (one frame), for example.
[0018]
The still image processing unit 20 processes the high pixel image data obtained from the A / D converter 16 </ b> S to generate still image data for one screen, and stores the still image data in the buffer memory 22. In the image recording operation, the compression / decompression processing unit 24 compresses still image data stored in the buffer memory 22 by, for example, the JPEG method and outputs the compressed image to the disk drive 51 of the recording system 5. The disk drive 51 drives the disk recording medium 50 to record compressed still image data. On the other hand, in the image reproduction operation, the compression / decompression processing unit 24 decompresses the compressed data read from the disk recording medium 50 via the disk drive 51 into the original still image data and stores it in the buffer memory 22.
[0019]
The moving image processing unit 21 processes the low-pixel image data obtained from the A / D converter 16M to generate moving image data for each frame (moving image frame), and stores the moving image data in the buffer memory 23. In the image recording operation, the compression / decompression processing unit 25 compresses the moving image data stored in the buffer memory 23 in accordance with, for example, a motion JPEG method in accordance with an operation of a moving image shooting button (not shown), and the recording system 5 Are output to the disk drive 51. The disk drive 51 drives the disk recording medium 50 to record compressed moving image data (consisting of a plurality of moving image frames). On the other hand, in the image reproduction operation, the compression / decompression processing unit 25 decompresses the compressed data read from the disk recording medium 50 via the disk drive 51 to the original moving image data and stores it in the buffer memory 23.
[0020]
Here, the recording system 5 is assumed to be a magneto-optical disk system, for example, and includes a disk drive 51 and a disk recording medium 50 that is a magneto-optical disk. The recording system 5 may be a memory card using a flash EEPROM or a hard disk drive using a magnetic disk.
[0021]
The display system 6 includes a liquid crystal panel 60, a display control unit 61, a video RAM 62, an electronic zoom processing unit 63, and an image switching unit 64. The liquid crystal panel 60 constitutes a finder (liquid crystal monitor) having an EVF display screen. The display control unit 61 is a control driver that performs display driving of the liquid crystal panel 60 using image data held in the video RAM 62. The liquid crystal panel 60 may be either an EVF or a view-type EVF arranged on the back side of the camera body.
[0022]
The screen switching unit 64 switches image data to be supplied to the display system 6 according to the display mode or the playback mode. At the time of still image shooting or still image playback, the screen switching unit 64 outputs the still image data from the buffer memory 22 to the VRAM 62 to display the captured image on the liquid crystal panel 60. This display mode is a shooting confirmation display (REC view display) mode. Further, at the time of moving image shooting or moving image reproduction, the screen switching unit 64 outputs the moving image data from the buffer memory 23 to the VRAM 62 to display the shot image on the liquid crystal panel 60.
[0023]
Furthermore, in the same embodiment, in the normal EVF display mode, the screen switching unit 64 outputs the moving image data (the imaging signal of the moving image CCD 14M) from the moving image processing unit 21 to the VRAM 62, thereby taking a captured image on the liquid crystal panel 60. Is displayed in EVF. In the electronic zoom mode, the screen switching unit 64 outputs zoom image data (to be described later) output from the electronic zoom processing unit 63 to the VRAM 62, thereby displaying a zoom display (enlarged display) of the captured image on the liquid crystal panel 60. Let it run.
[0024]
The moving image data from the moving image processing unit 21 (the image pickup signal of the moving image CCD 14M) is input to the system controller 3 to set the shooting conditions (automatic focusing (AF), automatic exposure (AE), etc.). used. Therefore, the moving image CCD 14M is also a photographing condition setting CCD.
[0025]
The system controller 3 includes a control CPU (microprocessor) and a memory storing its control program, and controls each element of the photographing system 1, the image processing system 2, the recording system 5, and the display system 6. Further, the system controller 3 accepts operation inputs of various operation keys 41 of the input operation system 4 and the electronic zoom button 40 related to the embodiment. The electronic zoom button 40 is a button for setting an electronic zoom mode. The operation key 41 includes a zoom operation input key (specifically, a cross key and an operation determination input key) related to the electronic zoom function, and a reproduction instruction key for instructing reproduction of a still image or a moving image. . The input operation system 4 includes a shutter / release button (still image shooting button) and a moving image shooting button (not shown).
[0026]
The system controller 3 includes an electronic zoom control unit 30 and a reproduction control unit 31, and controls an electronic zoom function and a reproduction operation of a recorded image of a still image or a moving image related to the embodiment. The electronic zoom control unit 30 accepts an electronic zoom mode setting in response to an operation input of the electronic zoom button 40, and controls electronic zoom processing in EVF display. Specifically, the electronic zoom control unit 30 outputs a plurality of electronic zoom control signals ZC1 to ZC5, the imaging circuit 15S, the moving image processing unit 21, the still image processing unit 20, the electronic zoom processing unit 63, and the image switching. The operation of the unit 64 is controlled. Further, the reproduction control unit 31 outputs the reproduction control signals RC1 and RC2 to control the operations of the image switching unit 64 and the disk drive 51.
[0027]
The system controller 3 outputs various control signals SC1 to SC5, and displays the A / F mechanism 17, the aperture 11, the shutter 13, and the display system 6 of the photographing system 1 necessary for the operation of a normal electronic camera. The operation of the control unit 61 and the compression / decompression processing units 24 and 25 is controlled.
[0028]
(Electronic zoom operation)
Hereinafter, the electronic zoom operation related to the embodiment will be described with reference to the flowchart of FIG. 2 and the conceptual diagram of FIG. 3 together with FIG.
[0029]
First, after the power of the electronic camera is turned on, display processing by a moving image processing system is executed in normal EVF display (step S1). That is, the image pickup signal output from the moving image CCD 14M is converted into photographed image data (digital moving image data) by the A / D converter 16M (image 300 shown in FIG. 3A). The moving image processing unit 21 converts, for example, image data of 640 × 480 pixels (image 301 illustrated in FIG. 3A). The image switching unit 64 normally transfers the image data (301) from the moving image processing unit 21 to the display system 6 as a through image. As shown in FIG. 3A, the display system 6 displays, on the liquid crystal panel 60, a captured image 302 obtained by converting 640 × 480 pixels into constituent pixels of the liquid crystal panel, for example, 480 × 320 pixels, by EVF.
[0030]
As described above, at the normal time, the EVF display process is executed by the imaging signal from the moving image CCD 14M having a low number of pixels (several hundreds of thousands of pixels). In this case, since the number of pixels of the captured image of EVF display is relatively small, high-speed display processing is possible. At this time, the power supply to the still image CCD 14S having a high pixel count is turned off by the imaging circuit 15S. Therefore, the power consumption of the electronic camera is reduced.
[0031]
On the other hand, when the electronic zoom button 40 is operated by the user, the electronic zoom mode is set, and the system controller 3 shifts to the electronic zoom mode (YES in step S2). That is, the electronic zoom control unit 30 outputs the control signal ZC1, turns on the power supply to the still image CCD 14S by the imaging circuit 15S, and causes the still image processing system to function (step S3). Further, the electronic zoom control unit 30 outputs a control signal ZC4 to cause the electronic zoom processing unit 63 to function. At this time, the system controller 3 controls the shutter 13 to the open state by the control signal SC3. Further, the electronic zoom control unit 30 outputs a control signal ZC5 and controls the image switching unit 64 to transfer the output of the electronic zoom processing unit 63 to the display system 6 (step S4).
[0032]
The imaging signal output from the still image CCD 14S is converted into photographed image data by the A / D converter 16S (image 310 shown in FIG. 3B). The electronic zoom processing unit 63 converts the image data ZI from the still image processing unit 20 into high pixel image data (image 311) having, for example, 1600 × 1200 pixels, and executes electronic zoom processing described later (step S7). ).
[0033]
Here, the electronic zoom processing unit 63 generates zoom image data for enlarging (or reducing) the entire captured image in response to a zoom operation input from the operation key 41. When there is no zoom operation input (non-zoom processing), the electronic zoom processing unit 63 converts the high pixel image data (311) into display image data of 480 × 320 pixels (image 312 shown in FIG. 3B), for example. Convert to The image switching unit 64 transfers the image data (312) to the display system 6 as a through image. As shown in FIG. 3B, the display system 6 displays the captured image 313 of 480 × 320 pixels on the liquid crystal panel 60 by EVF (step S5).
[0034]
On the other hand, in response to the zoom operation input, the electronic zoom processing unit 63 cuts out a specified partial region (region 314 shown in FIG. 3B) from the high-pixel image data (311) of 1600 × 1200 pixels, for example, Zoom image data of 1024 × 768 pixels (image 320 shown in FIG. 3C) is generated (steps S6 and S7). Further, the electronic zoom processing unit 63 converts the partially enlarged image data (320) into display image data (image 321 shown in FIG. 3C), for example, of 480 × 320 pixels. The image switching unit 64 transfers the image data (321) to the display system 6 as a through image. As shown in FIG. 3C, the display system 6 displays the captured image 322 of 480 × 320 pixels by EVF on the liquid crystal panel 60 (step S8).
[0035]
When the electronic zoom processing is completed, the electronic zoom control unit 30 turns off the power supply to the still image CCD 14S via the imaging circuit 15S (YES in step S9, S10). Further, the electronic zoom control unit 30 controls the control signal ZC2 to cause the moving image processing unit 21 to function, and the control signal ZC5 controls the image switching unit 64 to transfer the output of the moving image processing unit 21 to the display system 6 (step S11).
[0036]
With such an electronic zoom function, the user can check a partially enlarged photographed image on the liquid crystal panel 60. In this case, the EVF display process is executed by the imaging signal from the still image CCD 14S having a relatively high number of pixels (million pixels). Accordingly, it is possible to display a high-quality partially enlarged image.
[0037]
In the electronic zoom process, the EVF display image is continuously enlarged (or reduced) according to the zoom operation amount of the operation key 41. When the shutter / release button is operated while zoomed up by this zoom processing, still image data is recorded on the disc recording medium 50 with the composition at that time. However, the image quality of the recorded image at this time can be realized by the number of CCD pixels corresponding to the enlarged display portion. Further, under the control of the system controller 3, the one closest to the image quality (standard SQ, high image quality HQ, super image quality SHQ, etc.) designated by the user is selected.
[0038]
(Modification 1)
FIG. 4 is a modified example regarding the electronic zoom processing of the embodiment. FIG. 4A shows a normal EVF display process by the moving image processing system, as in FIG. In the embodiment, as shown in FIGS. 3B and 3C, the electronic zoom processing unit 63 temporarily converts the image data 310 (ZI) obtained by the still image CCD 14S into high pixels (1600 × 1200 pixels). Image data (image 311), and zoom image data (320) is generated therefrom.
[0039]
On the other hand, in this modification, as shown in FIGS. 4B and 4C, the electronic zoom processing unit 63 uses the zoom partial region (from the image data 310 (ZI) obtained by the still image CCD 14S. 314) is generated (for example, a cut image 400 of 790,000 pixels). The electronic zoom processing unit 63 converts the zoom image data (400) into display image data 321 (for example, 480 × 320 pixels). The display system 6 performs EVF display on the liquid crystal panel 60 of the display photographed image 322 of 480 × 320 pixels. On the other hand, in the non-zoom processing, the electronic zoom processing unit 63 generates display image data 312 (for example, 480 × 320 pixels) without generating zoom image data (400), and displays the display system via the image switching unit 64. Forward to 6. Note that the image data 310 (ZI) obtained by the still image CCD 14S is data of one color per pixel, and each pixel is one of RGB, and does not correspond to so-called display image data.
[0040]
(Modification 2)
The moving image processing unit 21 of the embodiment always performs processing for converting into a display image of 480 × 320 pixels using the output of the moving image CCD 14M. Therefore, the electronic zoom processing unit 63 may be configured to transfer the zoom image data to the moving image processing unit 21 without executing the conversion process to the display image after generating the zoom image data (320 or 400). In this case, the moving image processing unit 21 causes the EVF display to be executed via the image switching unit 64, and the transfer processing of the image data from the electronic zoom processing unit 63 to the image switching unit 64 becomes unnecessary.
[0041]
In this modification, the moving image shooting image recording process is executed using the zoom image data transferred from the electronic zoom processing unit 63 to the moving image processing unit 21 only when the electronic zoom mode is set during the moving image shooting operation. Also good. During this period, the frame rate is lowered, but there is an effect that image quality deterioration due to the electronic zoom mode can be prevented.
[0042]
(Modification 3)
FIG. 5 is a configuration diagram of an electronic camera related to a modification of the embodiment. In this modification, the electronic zoom processing unit 63 is included in the still image processing unit 20. Therefore, in the electronic zoom mode, the still image processing unit 20 includes the zoom image data (320 or 400) generated by the electronic zoom processing unit 63 in the image data ZI transferred to the image switching unit 64. About another structure, it is the same as that of the electronic camera of the embodiment. Note that the contents of the first and second modifications described above can also be applied to this modification.
[0043]
【The invention's effect】
As described above in detail, according to the present invention, in an electronic camera device having an electronic zoom function and an image sensor having a high number of pixels, high-speed display processing is executed in normal EVF display, and in electronic zoom mode. High-quality zoom EVF display can be realized.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a main part of an electronic camera related to an embodiment of the present invention.
FIG. 2 is a flowchart for explaining an electronic zoom operation related to the embodiment;
FIG. 3 is a conceptual diagram for explaining an electronic zoom operation related to the embodiment;
FIG. 4 is a conceptual diagram for explaining an electronic zoom operation related to a modification of the embodiment.
FIG. 5 is an exemplary block diagram showing a main part of an electronic camera related to a modification of the embodiment;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Shooting system 2 ... Image processing system 3 ... System controller 4 ... Input operation system 5 ... Recording system 6 ... Display system 10 ... Lens 11 ... Aperture part 12 ... Spectroscopic part (beam splitter)
13 ... Shutter 14S ... Still image sensor (CCD for still image)
14M ... Moving image pickup device (moving image CCD)
15S, 15M ... Imaging circuits 16S, 16M ... A / D converter 17 ... Autofocus (A / F) mechanism 20 ... Still image processing unit 21 ... Movie processing unit 22, 23 ... Buffer memory 24, 25 ... Compression / decompression processing unit DESCRIPTION OF SYMBOLS 30 ... Electronic zoom control part 31 ... Playback control part 40 ... Electronic zoom button 41 ... Operation key 50 ... Disc recording medium 51 ... Disk drive 60 ... Liquid crystal panel 61 ... Display control part 62 ... Video RAM (VRAM)
63 ... Electronic zoom processing unit 64 ... Image switching unit

Claims (6)

A first imaging element that outputs a relatively high pixel imaging signal;
A second image sensor for outputting an image signal of a relatively low pixel and photographing an image area substantially the same as the first image sensor;
First image processing means for processing image signals obtained from the first image sensor to generate first image data;
Second image processing means for processing image signals obtained from the second image sensor to generate second image data;
An electronic zoom processing means for enlarging a part of the captured image using the first image data;
Image display means for selectively using the second image data or zoom image data obtained by the electronic zoom processing means to display a captured image;
In accordance with the setting of the electronic zoom mode, an image switching to be supplied to the image display unit by switching from the second image data to the zoom image data obtained by the electronic zoom processing unit as a captured image to be displayed on the image display unit And an electronic camera device. The first image processing means generates still image data as first image data, the second image processing means generates moving image data as second image data,
2. The electronic camera apparatus according to claim 1, wherein the image display means displays the captured image using the moving image data except when the electronic zoom mode is set.   Still image data is recorded as first image data generated by the first image processing means, and moving image data is recorded as second image data generated by the second image processing means. The electronic camera device according to claim 1, further comprising a recording medium.   When the electronic zoom mode is set and the moving image data is recorded on the recording medium during a period in which a captured image enlarged using the still image data is displayed by the image display means 4. The electronic camera device according to claim 3, wherein the photographed image enlarged and displayed by the image display means is recorded on the recording medium as a moving image.   2. The driving of the first image sensor is started in accordance with the setting of the electronic zoom mode, and the driving of the first image sensor is stopped after the processing of the electronic zoom processing means is completed. Electronic camera device. The first image processing means includes an electronic zoom function of the electronic zoom processing means;
Input means for inputting the setting of the electronic zoom mode;
The first image processing means executes the electronic zoom function that uses high-pixel image data that is the first image data in response to a setting input of the electronic zoom mode from the input means. The electronic camera device according to claim 1, wherein

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