JP4003171B2 - Electronic camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic camera, and more particularly to an electronic camera having an image enlargement function such as an optical zoom and an electronic zoom.
[0002]
[Prior art]
A general digital camera can check the angle of view by displaying an image being captured on a liquid crystal monitor (LCD) of the camera body. At this time, when a zoom operation is performed, an image enlarged according to the designated magnification is displayed on the entire LCD screen. Therefore, it is simultaneously confirmed to what extent the image (enlarged image) displayed on the LCD is enlarged with respect to the entire original image (that is, the image without zoom, for example, the wide end image). It is not possible.
[0003]
Japanese Patent Laid-Open No. 1-57248 proposes a method for displaying information on the current photographing magnification and the maximum magnification of an optical zoom lens together with a subject on an electronic viewfinder.
[0004]
[Problems to be solved by the invention]
However, in the above publication, it is possible to grasp which part is cut out from the display range of the maximum image frame (for example, the wide end image) of the current image enlarged and displayed by zooming. Is not described.
[0005]
The present invention has been made in view of such circumstances, and when using at least one of an optical zoom and an electronic zoom in a camera, it is determined which area the currently expanded range is relative to the entire original image. An object is to provide an electronic camera that can be confirmed at a glance.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an electronic camera according to the present invention includes an imaging unit that converts an optical image of a subject into an electronic signal, an image display unit that displays an image captured through the imaging unit, and an image of the subject. At least one of zoom means for optically changing the magnification, and electronic zoom means for changing an image magnification of a subject by electronically processing an image signal acquired via the imaging means; and an image Zoom operation means for giving an instruction to change the magnification, and an image enlarged by the zoom means in accordance with the operation of the zoom operation means is displayed on the screen of the image display means, and an enlarged image currently displayed is displayed Display control means for displaying, on the enlarged image, enlarged range information indicating which region range is enlarged with respect to the entire image having the maximum angle of view. The features.
[0007]
The electronic camera according to the present invention has at least one of a zoom function of an optical zoom function and an electronic zoom function, and an image acquired via the imaging unit is displayed on the screen of the image display unit. When the photographer (user) operates the zoom operation unit to perform the zoom operation (magnification operation), the optical zoom unit and / or the electronic zoom unit operate according to the operation instruction to perform zooming processing, and the image display unit An enlarged image of the image related to imaging is displayed on the screen. At this time, enlarged range information indicating which region range the enlarged image currently displayed is cut out and enlarged with respect to the display range of the image at the time of shooting at the maximum angle of view (that is, the image without zooming) is the enlarged image. Is displayed overlaid on.
[0008]
As a display form of the enlarged range information, a frame line indicating the enlarged cutout range may be displayed, or a uniform signal addition may be performed on the image signal of the area to change the display density (brightness). As described above, since the display of the enlarged image and the display of the corresponding enlarged range information are simultaneously performed in a single screen by the superimposed display function of the enlarged range information, the user uses the zoom function. At this time, since it is possible to check at a glance where the currently expanded range is relative to the maximum angle-of-view image (entire image of the original image), it is possible to set the shooting composition more efficiently.
[0009]
An electronic camera according to an aspect of the present invention includes both the optical zoom unit and the electronic zoom unit, and enlargement range information of the zoom region by the optical zoom unit and enlargement range information of the zoom region by the electronic zoom unit Are displayed in different display forms.
[0010]
According to this aspect, it is possible to easily identify whether the image currently displayed on the image display means is a zoom image in the optical zoom area or a zoom image in the electronic zoom area.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of an electronic camera according to the present invention will be described in detail below with reference to the accompanying drawings.
[0012]
FIG. 1 is a block diagram showing a configuration of an electronic camera according to an embodiment of the present invention. The camera 10 is a digital camera that converts an optical image of a subject into digital image data and records it on a recording medium 12, and includes a photographing lens 14 and a CCD solid-state imaging device (hereinafter referred to as a CCD) 16 as a photographing optical system. I have. In place of the CCD 16, an image pickup device of another type such as a MOS type solid-state image pickup device may be used.
[0013]
The photographing lens 14 is constituted by an electric zoom lens. When the photographer operates the zoom switch 18, a control signal is output from the system control circuit 20 to the lens driving circuit 22 in accordance with the switch operation. The lens driving circuit 22 generates a lens driving signal based on the control signal from the system control circuit 20 and supplies it to the zoom motor 24. Thus, the zoom motor 24 is actuated by the motor drive voltage output from the lens drive circuit 22 and the photographing lens 14 moves back and forth along the optical axis, whereby the focal length (optical zoom magnification) of the photographing lens 14 is changed. The
[0014]
The zoom position and focus position of the photographic lens 14 are detected by the lens position sensor 26. The lens position sensor 26 is a block including a zoom position sensor and a focus position sensor. The lens position sensor 26 may be a circuit that generates a pulse by the rotation of the zoom motor 24 or the like, or may have a configuration in which a position detection encoding plate is disposed on the outer periphery of the lens barrel. At that time, there is no particular limitation.
[0015]
Information on the zoom position and focus position acquired by the lens position sensor 26 is input to the system control circuit 20. The system control circuit 20 controls lens driving based on the detection signal of the lens position sensor 26.
[0016]
The camera 10 of this example has an electronic zoom function in addition to the optical zoom function described above. The electronic zoom function is a function for obtaining an enlarged image by electronically processing an image signal by an image processing technique. That is, the camera 10 has an electronic zoom area added to the enlargement side further than the tele end of the optical zoom area (hereinafter referred to as the optical tele end), and as a whole the wide end of the optical zoom (hereinafter referred to as the optical wide end). The zoom range is from the tele end of electronic zoom (hereinafter referred to as electronic tele end).
[0017]
The zoom switch 18 is an operation unit that is also used for adjusting the focal length of the photographing lens 14 and instructing enlargement / reduction by an electronic zoom (digital zoom) function. When the zoom switch 18 is operated in the tele direction in the optical zoom region, the focal length of the photographic lens 14 is driven in the tele direction via the lens driving circuit 22 and the zoom motor 24. If the zoom switch 18 is continuously pressed and a command for increasing the photographing magnification is continuously input, the tele end (optical tele end) of the optical zoom area is eventually reached. When a zoom instruction in the tele direction (enlargement direction) is given from the optical tele end, the process proceeds to enlargement processing by electronic zoom.
[0018]
In the camera 10 of this example, the magnification can be changed by the electronic zoom within a range in which the image quality does not deteriorate according to the selected recording pixel number mode. For example, assuming that the number of recorded pixels (photographing resolution) can be selected from “2400 × 1800”, “1600 × 1200”, “1280 × 960”, or “640 × 480”, the image quality depends on the selected resolution. The magnification variable range by electronic zoom is limited within a range where no deterioration occurs. When the number of recording pixels is set to “2400 × 1800”, since full pixels are used, image quality degradation occurs when enlargement processing is performed with electronic zoom. Accordingly, at “2400 × 1800”, the use of the electronic zoom is prohibited, and a zoom function only for the optical zoom region can be used. When the number of recording pixels is “1600 × 1200”, “1280 × 960”, or “640 × 480”, the electronic zoom function can be used. The smaller the number of pixels, the larger the magnification variable range of the electronic zoom.
[0019]
The camera 10 also includes an optical viewfinder 28. The optical finder 28 is a zoom finder. The optical finder 28 is connected to the drive system of the photographic lens 14 through a mechanical power transmission mechanism (not shown), and in conjunction with the magnification changing operation of the photographic lens 14 by the power of the zoom motor 24 accompanying the zoom operation, The viewfinder magnification is changed so that a viewfinder field almost equivalent to the shooting angle of view can be obtained.
[0020]
In the optical zoom area, the magnification of the optical viewfinder 28 is also changed accordingly. However, after shifting to the electronic zoom area, the magnification of the optical viewfinder 28 does not follow and stops at the tele end angle of viewfinder optical system. ing. When zooming operation is performed in the electronic zoom area, if a zoom instruction in the wide direction is further given from the wide end of the electronic zoom area (minimum magnification of the electronic zoom), the zoom operation moves to the wide direction by the optical zoom. When returning to the optical zoom area, the optical viewfinder 28 follows this to change the viewfinder magnification.
[0021]
Explaining the photographing function of the camera 10, the light passing through the photographing lens 14 forms an image on the light receiving surface of the CCD 16. A large number of photodiodes (light receiving elements) are two-dimensionally arranged on the light receiving surface of the CCD 16, and primary color filters of red (R), green (G), and blue (B) are provided for each photodiode. They are arranged in a predetermined arrangement structure (Bayer, G stripe, etc.). The CCD 16 has an electronic shutter function for controlling the charge accumulation time (shutter speed) of each photodiode.
[0022]
The subject image formed on the light receiving surface of the CCD 16 is converted into a signal charge of an amount corresponding to the amount of incident light by each photodiode. The signal charge accumulated in each photodiode is sequentially read out as a voltage signal (image signal) corresponding to the signal charge based on a drive pulse given from a CCD drive circuit (not shown).
[0023]
The signal output from the CCD 16 is input to the camera signal processing circuit 30. The camera signal processing circuit 30 includes a correlated double sampling (CDS) circuit, a gain control (GC) circuit, an A / D converter, and the like. An image signal that has undergone required processing such as sampling processing, color separation, and white balance adjustment in the camera signal processing circuit 30 is converted into a digital signal by an A / D converter and then input to the system control circuit 20.
[0024]
The system control circuit 20 includes a central processing unit (CPU) and a CPU peripheral circuit (ROM, RAM, memory controller, etc.), functions as control means for the camera 10, and performs various calculations such as AE calculation and AF calculation. Functions as a calculation means. The system control circuit 20 includes an image processing circuit (signal processing means) that processes a digital image signal, and a display mixing (MIX) circuit that adds information on an enlarged cut-out range, which will be described later, to a display output image. 32.
[0025]
The image processing circuit in the system control circuit 20 includes a luminance / color difference signal generation circuit, a gamma correction circuit, a contour enhancement circuit, a white balance correction circuit, an electronic zoom processing (enlargement / reduction processing) circuit, and the like. The image signal input from the camera signal processing circuit 30 to the system control circuit 20 is converted into a luminance signal (Y signal) and a color difference signal (Cr, Cb signal) and subjected to predetermined processing such as gamma correction. Thereafter, it is stored in the RAM.
[0026]
When the captured image is output to the monitor, the image data is read from the RAM and sent to the display signal processing circuit 34. The display signal processing circuit 34 converts the input image data into a predetermined display signal (for example, an NTSC color composite video signal) and outputs it to an image display device 36 such as a liquid crystal monitor. The image display device 36 is not limited to a liquid crystal monitor, and other types of display means such as an organic EL may be used.
[0027]
The image data in the RAM is periodically rewritten by the image signal output from the CCD 16, and the image signal generated from the image data is supplied to the image display device 36, whereby the image being captured is displayed in real time. The The photographer can confirm the angle of view (composition) from the video (so-called through movie) displayed on the image display device 36.
[0028]
When the user operates the zoom switch 18 during the through movie display, a scaling process is performed. When a further enlargement direction command is input beyond the optical zoom area, the electronic zoom processing circuit in the system control circuit 20 performs image signal enlargement processing.
[0029]
The system control circuit 20 controls each circuit in the camera 10 based on a signal input from an operation unit such as the zoom switch 18 or the release switch 38. For example, lens drive control, shooting operation control, and image necessary for camera operation are controlled. Processing control, read / write control of the recording medium 12, display control of the image display device 36, and the like are performed.
[0030]
When the release switch 38 is pressed, a shooting start instruction (release ON) signal is issued. The system control circuit 20 detects the release ON signal and executes a photographing operation. That is, the system control circuit 20 performs AE calculation and AF calculation in response to the input of the release signal, and performs CCD exposure and readout control for capturing a recording image.
[0031]
The image data taken in response to the input of the release signal is sent to the image processing circuit of the system control circuit 20, and after undergoing luminance / color difference signal conversion (YC conversion) processing and other predetermined signal processing in the image processing circuit. And sent to the recording / reproducing processing circuit 40.
[0032]
The recording / reproduction processing circuit 40 includes a signal processing unit that performs data compression and expansion, and a media interface unit. The recording image data input from the system control circuit 20 to the recording / reproduction processing circuit 40 is compressed by the recording / reproduction processing circuit 40 according to a predetermined compression format (for example, JPEG method) and recorded on the recording medium 12. . The recording format is not limited to the JPEG format, and an MPEG or other recording format may be adopted. The means for storing image data is not limited to a semiconductor memory represented by a memory card, and various media such as a magnetic disk, an optical disk, and a magneto-optical disk can be used. Further, a mode in which image data is stored in a recording medium (internal memory) built in the camera 10 instead of or in combination with the removable medium is also possible.
[0033]
When a playback mode is selected by a mode selection operation means (not shown) (mode dial or the like), an image file is read from the recording medium 12, decompressed by the recording / playback processing circuit 40, and then displayed on the display signal processing circuit 34. To the image display device 36. In this way, the recorded image is reproduced and displayed. By operating the cross key (for example, the right key or the left key) of the operation unit during the reproduction display of the image, the file to be reproduced can be switched (forward frame advance / reverse frame advance).
[0034]
Next, the zoom operation and zoom display range display function of the camera 10 configured as described above will be described.
[0035]
FIG. 2 is a diagram illustrating a display example of the image display device 36. A screen frame 44 of the image display device 36 shows a screen display range when there is no zoom (optical zoom 1 ×, that is, optical wide end). When the zoom operation is performed during the through movie display, the image is enlarged according to the command magnification, the enlarged image is displayed on the full screen frame 44, and the enlarged cutout range is indicated as indicated by reference numeral 46 in FIG. Area information (hereinafter referred to as “enlarged range information”) is overlaid (simultaneously displayed). This enlargement range information 46 clearly indicates which part of the zoomed image is cut out and enlarged with respect to the original image without zooming. The display form of the enlarged range information 46 may be a simple frame line, a bracket display showing only the four corners (corners) of the region frame, or the like, and highlighted (special) so that the target region can be distinguished from other regions. It may be a frame surface displayed.
[0036]
As a specific display example, for example, the frame lines are displayed so as to overlap in the image display so that the enlarged cutout range can be seen. Alternatively, there is a mode in which uniform signal addition is performed on the image signal in the area, and the area is displayed brighter than other areas. When the enlarged range information 46 is displayed, it is desirable to display it at a level that does not significantly affect the confirmation of the image being displayed.
[0037]
A signal of area information (such as a signal to be added or a frame line) necessary for displaying the enlarged range information 46 is generated in a signal generation unit (not shown) in the system control circuit 20. Signal addition and frame line superimposition processing are performed in the display MIX circuit 32 described with reference to FIG. In FIG. 1, the display MIX circuit 32 in the system control circuit 20 mixes the image signal related to photographing and the area information signal and then outputs them to the display signal processing circuit 34. A mode in which a display MIX circuit is provided in the display signal processing circuit 34 is also possible. In this case, the system control circuit 20 may separately provide an image signal for shooting and an area information signal to the display signal processing circuit 34, and the display signal processing circuit 34 may add these two signals.
[0038]
In this way, the zoomed image is displayed on the entire screen on the image display device 36, and enlarged range information 46 indicating the enlarged cutout range for the optical wide end screen (maximum image frame) is displayed. Since the user can understand at a glance how much the enlarged image is in the maximum image frame, the image frame setting (composition setting) can be performed more efficiently.
[0039]
Although FIG. 2 illustrates the optical zoom area, the present invention is similarly applied not only to the optical zoom area but also to the electronic zoom area.
[0040]
Further, as shown in FIG. 3, the display form is different between the display of the cutout range in the optical zoom area (reference numeral 47) and the display of the cutout area in the electronic zoom area (reference numeral 48), and can be identified. An embodiment is preferable. For example, as shown in FIG. 3, there is an aspect in which the display density (density) is changed between a display range display 47 in the optical zoom region and a display range display 48 in the electronic zoom region. Also, there are modes for changing the color and modes for changing the line type of the frame line (one frame line is displayed as a solid line and the other is displayed as a dotted line).
[0041]
In this way, by changing the display form of the cut-out display between the optical zoom area and the electronic zoom area, it can be seen at a glance whether the current display image is an enlarged image of the optical zoom area or an enlarged image of the electronic zoom area. Can be judged.
[0042]
In the above-described embodiment, a camera using both optical zoom and electronic zoom has been exemplified. However, the scope of application of the present invention is not limited to this, and a camera that can use only optical zoom (a camera that does not have an electronic zoom function), Alternatively, the present invention can be applied to a camera that can use only an electronic zoom (a camera that does not have an optical zoom function).
[0043]
The enlargement range is not limited to the center center (optical axis center) of the screen, and can be moved to an arbitrary position in the screen.
[0044]
Next, another embodiment of the present invention will be described.
[0045]
FIG. 4 is a block diagram showing a configuration of an electronic camera according to another embodiment of the present invention. 4 that are common to FIG. 1 are assigned the same reference numerals, and descriptions thereof are omitted.
[0046]
The camera 50 shown in FIG. 4 uses a single focus lens as the photographing lens 54, and can perform a zooming operation only by the electronic zoom function. The operation unit of the camera 50 is provided with a movement key 56 for instructing to move the enlarged cutout range within the screen and a cross key 58 for instructing the movement direction. A mode in which the up / down key of the cross key 58 is also used as a zoom key is also possible.
[0047]
In this example, the enlarged cutout range can be moved by pressing the cross key 58 after pressing the move key 56 to switch to the cutout range move mode. Thereafter, when the movement key 56 is pressed again, the movement mode is canceled. It is also possible to move the enlarged cutout range by pressing the cross key 58 while pressing the movement key 56 (simultaneous pressing with the movement key 56).
[0048]
As shown in FIG. 5, the enlarged cutout range by the electronic zoom function can be moved to any position in the vertical and horizontal directions within the screen. The display of the enlarged range information 46 is moved in accordance with the designated position so that the entire enlarged range and its positional relationship can be understood.
[0049]
The above-described enlarged range information 46 is displayed not only during shooting but also during playback. By displaying the enlarged range information 46 together with the enlarged image, the electronic zoom range can be understood, so it is possible to determine at a glance how many areas are around the enlarged range, and when performing trimming during playback. It is easy to predict the overall balance.
[0050]
According to the above-described embodiment of the present invention, when shooting with the cameras 10 and 50 fixed on a tripod or the like, the shooting magnification is changed by the electronic zoom function, and the enlargement range can be expanded without moving the cameras 10 and 50. By moving, it is possible to grasp the shooting target position with respect to the entire image.
[0051]
In addition to the function of displaying the enlarged range information 46, a function of cutting out a partial range of the image signal recorded on the recording medium 12 and newly recording the image of the cut-out part on the recording medium 12 (trimming storage function) A mode in which the camera 10 is mounted on the camera 10 is also preferable.
[0052]
Furthermore, immediately after shooting, before the shot image is recorded on the recording medium 12, the shot image is displayed on the image display device 36 (preview display) to select whether or not recording is possible, and recording execution input from the instruction input means is performed. It is also preferable to have a preview function that performs a process of recording a captured image on the recording medium 12 in accordance with an instruction, and allows trimming during the preview display.
[0053]
In the above embodiment, a digital camera has been described as an example. However, the scope of application of the present invention is not limited thereto, and a subject image is converted into an electrical signal using an imaging element such as a video camera, a mobile phone with a camera, or a personal computer with a camera. The present invention can be widely applied to electronic cameras that convert images into images and devices equipped with the same.
[0054]
【The invention's effect】
As described above, according to the present invention, in an electronic camera equipped with a zoom function and image display means, a zoom enlarged image is displayed on the entire screen of the image display means, and at the same time, an enlarged image currently displayed is an image without zooming. Since the enlarged range information indicating which range is cut out and enlarged is displayed in an overlapping manner, the user can see at a glance where the currently enlarged range is relative to the entire image with the maximum angle of view. It is possible to confirm and set the shooting composition more efficiently.
[0055]
According to an aspect of the present invention, in the electronic camera having both the optical zoom unit and the electronic zoom unit, the enlarged range information of the optical zoom region and the enlarged range information of the electronic zoom region are displayed in different display forms. Thus, the user can easily determine whether the current image is an enlarged image in the optical zoom area or an enlarged image in the electronic zoom area.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an electronic camera according to an embodiment of the present invention. FIG. 2 is a view showing a display example of enlarged range information in an image display device. FIG. 3 is enlarged in an optical zoom area and an electronic zoom area. FIG. 4 is a block diagram showing a configuration of an electronic camera according to another embodiment of the present invention. FIG. 5 is a diagram showing an example of changing the display form of range information. Diagram showing an example [Explanation of symbols]
DESCRIPTION OF SYMBOLS 10,50 ... Camera, 12 ... Recording medium, 14 ... Shooting lens, 16 ... CCD, 18 ... Zoom switch, 20 ... System control circuit, 24 ... Zoom motor, 28 ... Optical viewfinder, 32 ... Display MIX circuit, 36 ... Image Display device

Claims (2)

Imaging means for converting an optical image of a subject into an electronic signal;
Image display means for displaying an image picked up via the image pickup means;
At least one of zoom means for optically changing the image magnification of the subject, and an electronic zoom means for changing the image magnification of the subject by electronically processing an image signal acquired via the imaging means. When,
Zoom operation means for giving an instruction to change the image magnification;
An image enlarged by the zoom means in accordance with the operation of the zoom operation means is displayed on the screen of the image display means, and the region range in which the currently displayed enlarged image is relative to the entire image with the maximum angle of view Display control means for displaying enlarged range information indicating whether or not the enlarged image is superimposed on the enlarged image;
An electronic camera characterized by comprising: Having both the optical zoom means and the electronic zoom means;
2. The electronic camera according to claim 1, wherein the zoom area enlargement range information by the optical zoom means and the zoom area enlargement range information by the electronic zoom means are displayed in different display forms.

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