JP4003172B2 - Image signal processing apparatus and electronic camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image signal processing apparatus and an electronic camera, and more particularly to an image signal processing apparatus and an electronic camera having an electronic zoom function for obtaining an enlarged image by electronically processing an image signal.
[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]
In this regard, the video camera disclosed in Japanese Patent Laid-Open No. 1-57248 is characterized in that information on the current photographing magnification and the maximum magnification of the optical zoom lens is displayed on the electronic viewfinder together with the subject.
[0004]
In the field of electronic cameras such as video cameras, an electronic zoom function is known in which an image signal is electronically processed to obtain an enlarged image, and there is a camera that uses both an optical zoom function and an electronic zoom function.
[0005]
[Problems to be solved by the invention]
However, in the conventional camera, it is impossible to grasp which part is cut out with respect to the display range when the image enlarged and displayed by the electronic zoom is not used (all areas of the image sensor). In the above publication, there is no description about such means.
[0006]
The present invention has been made in view of such circumstances, and when using electronic zoom at the time of shooting or playback, it is possible to see at a glance where the currently expanded range is relative to the entire original image. An object is to provide an image signal processing apparatus and an electronic camera that can be confirmed.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an image signal processing apparatus according to the present invention comprises an electronic zoom means for obtaining an enlarged image by electronically processing an image signal, an image display means for displaying image contents, and the electronic Magnification change operation means for inputting an instruction to change the enlargement magnification by the zoom means, a movement operation means for inputting an instruction to move the display range of the enlarged image displayed on the screen of the image display means, and the magnification change operation In accordance with the operation of the means, the image enlarged by the electronic zoom means is displayed on the screen of the image display means, and the region range of the enlarged image currently displayed is enlarged with respect to the entire image having the maximum angle of view. When the movement operation means is inputted by the movement operation means, the enlarged range information indicating whether or not the enlarged image is displayed on the enlarged image. Display control means for performing processing of changing the display position of the display range and expanding the range information of the enlarged image, characterized by comprising a.
[0008]
According to the image signal processing apparatus of the present invention, when the user performs a zoom operation (magnification operation) from the magnification change operation unit, the electronic zoom unit operates according to the operation instruction, and image enlargement signal processing is performed. An enlarged image is displayed on the screen of the image display means. Further, at this time, enlargement range information indicating which region range the enlarged image currently displayed is cut out and enlarged with respect to the range of the entire image having the maximum angle of view (that is, the original image without zooming). Overlaid on the enlarged image. In such an enlarged image display state, when the user operates the movement operation means and inputs a command to move the display range of the enlarged image on the screen of the image display means, signal processing is performed in accordance with the command, and the electronic zoom enlargement range is set. Moving. As a result, the display range of the enlarged image displayed on the image display means is changed, and the display of the enlarged range information corresponding to this is also changed.
[0009]
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 enlarged range information corresponding to the enlarged image are simultaneously performed in a single screen by the superimposed display function of the enlarged range information, the user is currently expanding. It is possible to confirm at a glance where the range is relative to the entire original image. Therefore, the user can set the composition more efficiently during shooting. Also, during playback, the electronic zoom range is known in relation to the entire image, so it is possible to determine at a glance how much of the surrounding area is left, and predict the overall balance when performing trimming etc. Cheap.
[0010]
In order to provide an electronic camera to which the image processing apparatus having the above configuration is applied, an electronic camera according to the present invention records an image captured through the imaging unit, an imaging unit that converts an optical image of a subject into an electronic signal, and the like. Recording means for recording on a medium, image display means for displaying an image acquired via the imaging means or an image recorded on the recording medium, and an image acquired via the imaging means or the recording medium An electronic zoom means for obtaining an enlarged image by electronically processing an image signal of an image recorded on the image; a magnification changing operation means for inputting an instruction to change an enlargement magnification by the electronic zoom means; and the image display means The zoom operation is performed by the electronic zoom unit according to the operation of the moving operation unit that inputs an instruction to move the display range of the enlarged image displayed on the screen and the magnification change operation unit. The enlarged image is displayed on the screen of the image display means, and enlarged region information indicating which region range the enlarged image currently displayed is enlarged with respect to the entire image having the maximum angle of view is displayed in the enlarged image. Display control means for performing a process of changing the display range of the enlarged image and the display position of the enlarged range information in accordance with the instruction when a movement instruction is input by the movement operation means, It is characterized by having.
[0011]
That is, the electronic camera according to the present invention has an electronic zoom function, and the video acquired via the imaging unit is displayed on the screen of the image display unit. When the photographer (user) operates the magnification change operation means to perform a zoom operation (magnification operation), the electronic zoom means operates in accordance with the operation instruction, and an enlarged image of the image related to imaging on the screen of the image display means Is displayed. 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.
[0012]
In such an enlarged image display state, when the user operates the movement operation means and inputs a command to move the display range of the enlarged image on the screen of the image display means, signal processing is performed in accordance with the command, and the electronic zoom enlargement range is set. Moving. As a result, the display range of the enlarged image displayed on the image display means is changed, and the display of the enlarged range information corresponding to this is also changed.
[0013]
As described above, since the display of the enlarged image and the display of the enlarged range information corresponding to the enlarged image are simultaneously performed in a single screen by the superimposed display function of the enlarged range information, the user is currently expanding. It is possible to check at a glance where the range is relative to the entire original image, and it is possible to set the shooting composition more efficiently.
[0014]
In addition, since the enlargement range by the electronic zoom can be moved other than the center of the optical axis, for example, even when the camera is fixed using a tripod at the time of shooting, the enlargement range of the electronic zoom is moved without moving the camera. This makes it possible to grasp the shooting target position for the entire image.
[0015]
Furthermore, when the electronic camera has a reproduction function (a function for reproducing and displaying the recorded image on the image display means), the reproduction image is enlarged and displayed with the above-described electronic zoom function and the enlarged range information superimposed on the reproduction image. Is done.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of an image signal processing apparatus and an electronic camera according to the present invention will be described below in detail with reference to the accompanying drawings.
[0017]
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.
[0018]
Although a single focus lens is used as the photographing lens 14, a lens with a variable focal length such as a zoom lens may be used. The camera 10 has an electronic zoom function, and an enlarged image can be obtained by the electronic zoom. 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.
[0019]
For example, assuming that the number of recorded pixels (shooting resolution) can be set to “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. Therefore, when the recording pixel number “2400 × 1800” is set, the use of the electronic zoom is prohibited in the photographing mode. 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.
[0020]
Conversely, with regard to the electronic zoom function during playback (playback zoom function), enlargement display by electronic zoom is possible within a range that does not cause deterioration in image quality during playback, so the maximum zoom magnification increases as the number of recording pixels increases. .
[0021]
The zoom switch 18 is an operation unit used for an enlargement / reduction instruction by the electronic zoom function. Further, the camera 10 is provided with a movement key 20 for instructing to move an enlarged cutout range by the electronic zoom function, and a cross key 22 for instructing the movement direction and the movement amount. A mode in which the up / down key of the cross key 22 is also used as a zoom key is possible.
[0022]
In this example, the enlarged cutout range can be moved by pressing the movement key 20 to switch to the cutout range move mode and then pressing the cross key 22. Thereafter, when the movement key 20 is pressed again, the movement mode is canceled. Note that the enlarged cutout range may be moved by pressing the cross key 22 while pressing the movement key 20 (simultaneous pressing with the movement key 20).
[0023]
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.
[0024]
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).
[0025]
The signal output from the CCD 16 is input to the camera signal processing circuit 24. The camera signal processing circuit 24 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 24 is converted into a digital signal by an A / D converter and then input to the system control circuit 30.
[0026]
The system control circuit 30 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 / AF calculation. Functions as a calculation means. Further, the system control circuit 30 includes an image processing circuit (signal processing means) for processing a digital image signal, and a display mixing (MIX) circuit for adding information on an enlarged cut-out range to be described later to an image for display output. 32.
[0027]
The image processing circuit in the system control circuit 30 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 24 to the system control circuit 30 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.
[0028]
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.
[0029]
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.
[0030]
When the user operates the zoom switch 18 during the through-movie display, the electronic zoom processing circuit in the system control circuit 30 performs image signal enlargement processing. The enlarged image is displayed on the entire screen of the image display device 36.
[0031]
The system control circuit 30 controls each circuit in the camera 10 based on signals input from operation units such as the zoom switch 18, the movement key 20, the cross key 22, and the release switch 38, for example, a lens necessary for camera operation. Drive control, shooting operation control, image processing control, read / write control of the recording medium 12, display control of the image display device 36, and the like are performed.
[0032]
When the release switch 38 is pressed, a shooting start instruction (release ON) signal is issued. The system control circuit 30 detects the release ON signal and executes a photographing operation. That is, the system control circuit 30 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.
[0033]
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 30, 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.
[0034]
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 30 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.
[0035]
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).
[0036]
Next, the zoom operation and zoom display range display function of the camera 10 configured as described above will be described.
[0037]
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 electronic zoom (electronic zoom magnification is 1). 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). The enlargement range information 46 clearly indicates which part of the image enlarged by the electronic zoom 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.
[0038]
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.
[0039]
A signal of area information necessary for displaying the enlarged range information 46 (a signal to be added, a frame line signal, etc.) is generated in a signal generation unit (not shown) in the system control circuit 30. 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 30 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 30 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.
[0040]
Thus, on the image display device 36, the zoomed image is displayed on the entire screen frame 44, and at the same time, the enlarged range information 46 indicating the enlarged cutout range for the entire image without the electronic zoom (1x magnification) is simultaneously displayed. . Since the user can understand at a glance how much the enlarged image is relative to the entire image (the image range of the original image implied by the screen frame 44), image frame setting (composition setting) can be performed. It can be done more efficiently.
[0041]
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. That is, by operating the movement key 20 and the cross key 22 while the electronic zoom is enlarged, the display position by the electronic zoom can be changed.
[0042]
As shown in FIG. 3, 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 image on the screen is moved according to the designated position, and the display of the enlarged range information 46 is moved so that the entire enlarged range and its positional relationship can be understood.
[0043]
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.
[0044]
According to the above-described embodiment of the present invention, when shooting with the camera 10 fixed on a tripod or the like, the shooting magnification is changed by the electronic zoom function, and the enlargement range is moved without moving the camera 10. It is possible to grasp the shooting target position for the entire image.
[0045]
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 is mounted on the camera 10 is also preferable.
[0046]
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.
[0047]
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 an electronic camera that converts an image into an image, an apparatus equipped with the electronic camera, an image reproducing apparatus that does not have an image recording function, and the like.
[0048]
The image signal processing apparatus according to the present invention can be realized by a computer. The program for realizing the superimposing display function of the expansion range information of the present invention is recorded on a CD-ROM, a magnetic disk or other recording media, and the program is provided to a third party through the recording media, or a communication line such as the Internet. It is also possible to provide a download service for the program.
[0049]
【The invention's effect】
As described above, according to the present invention, the enlarged image is displayed on the screen of the image display means by the electronic zoom function, and at the same time, the enlarged image currently displayed is cut out and enlarged with respect to the image without the zoom. Since the enlarged range information indicating whether or not the image is being displayed is overlaid, the user can check at a glance where the currently expanded range is relative to the entire image with the maximum angle of view, making the composition setting more efficient. Can be done automatically.
[0050]
Further, in the present invention, since the enlargement range of the electronic zoom can be moved other than the center of the optical axis, and the display of the enlargement range information is also moved along with the movement, the positional relationship of the current enlargement range with respect to the entire image Can be easily grasped.
[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 diagram showing a display example of enlarged range information in an image display device. Figure showing an example of movement [Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Camera, 12 ... Recording medium, 14 ... Shooting lens, 16 ... CCD, 18 ... Zoom switch, 20 ... Movement key, 22 ... Cross key, 30 ... System control circuit, 32 ... Display MIX circuit, 34 ... Display signal processing Circuit, 36 ... image display device

Claims (2)

Electronic zoom means for obtaining an enlarged image by electronically processing an image signal;
Image display means for displaying image content;
A magnification change operation means for inputting an instruction to change the magnification by the electronic zoom means;
A moving operation means for inputting an instruction to move the display range of the enlarged image displayed on the screen of the image display means;
An image enlarged by the electronic zoom unit in accordance with the operation of the magnification changing operation unit is displayed on the screen of the image display unit, and the currently displayed enlarged image is displayed in which region with respect to the entire image having the maximum angle of view. While performing the control to display the enlarged range information indicating whether the range is enlarged on the enlarged image, when a movement instruction is input by the moving operation means, the display range and the enlarged range of the enlarged image according to the instruction Display control means for performing processing for changing the display position of information;
An image signal processing apparatus comprising: Imaging means for converting an optical image of a subject into an electronic signal;
Recording means for recording an image taken via the imaging means on a recording medium;
Image display means for displaying an image acquired via the imaging means or an image recorded on the recording medium;
Electronic zoom means for obtaining an enlarged image by electronically processing an image signal of an image acquired via the imaging means or an image recorded on the recording medium;
A magnification change operation means for inputting an instruction to change the magnification by the electronic zoom means;
A moving operation means for inputting an instruction to move the display range of the enlarged image displayed on the screen of the image display means;
An image enlarged by the electronic zoom unit in accordance with the operation of the magnification changing operation unit is displayed on the screen of the image display unit, and the currently displayed enlarged image is displayed in which region with respect to the entire image having the maximum angle of view. While performing the control to display the enlarged range information indicating whether the range is enlarged on the enlarged image, when a movement instruction is input by the moving operation means, the display range and the enlarged range of the enlarged image according to the instruction Display control means for performing processing for changing the display position of information;
An electronic camera characterized by comprising:

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