JP2005012423A - Image pickup device, and signal processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup device capable of suitably correcting a composition (angle of field) by an image angle operation such as zooming in an image recording after recording the image, and to provide a signal processing apparatus. <P>SOLUTION: When a zoom operation is performed by an electronic zoom in recording a moving image such as a digital camera, the image data of all pixel ranges obtained from full-effective pixel of a CCD 50 are recorded in a recording medium 62, and the pixel range (zoom range) of an image to be enlarged and displayed by electronic zooming is recorded as zooming information in the recording medium 62. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus and a signal processing apparatus, and more particularly to an imaging apparatus applied to a digital camera or the like capable of recording a moving image.
[0002]
[Prior art]
There are so-called optical zoom and electronic zoom (digital zoom) as zoom functions in digital cameras and digital video cameras. Optical zoom is a method of enlarging an image by moving a part of lenses constituting a photographing lens to change the focal length of the photographing lens. On the other hand, the electronic zoom is a method for enlarging a part of a captured image by electrical processing.
[0003]
In general, in the case of electronic zoom, the image quality deteriorates because an image captured in a part of the pixel range of the image sensor is enlarged. For this reason, with cameras that can use both optical zoom and electronic zoom, optical zoom is usually given priority, and after reaching the maximum zoom magnification of optical zoom, the camera switches to electronic zoom when it is desired to increase the zoom magnification further. ing.
[0004]
When zooming by electronic zoom, the pixel range of image data to be output to a display system such as a monitor is generally determined by the zoom magnification of the electronic zoom, out of all effective pixel ranges of the image sensor. On the other hand, in Patent Document 1, the position of the pixel range can be changed, and a desired subject imaged within the effective pixel range of the image sensor can be enlarged by electronic zoom without changing the direction of the camera. The invention has been proposed.
[0005]
In recent years, many digital cameras and digital movie cameras can perform both still image recording and moving image recording. In general, the image size for still image recording is larger than the image size for moving image recording. In particular, the image size of a still image increases with the number of pixels of the image sensor. On the other hand, the resolution of a display system that displays a moving image is not required to be as high as that of a still image, although there are high-definition and PC monitors. The image size of a moving image is usually VGA (640 × 480 pixels) size. Therefore, in a camera capable of recording still images and moving images, an image of an image size obtained by all effective pixels of the image sensor is recorded in the case of still image recording. An image having a reduced image size is recorded by thinning the image obtained by the pixels.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-271381
[Problems to be solved by the invention]
By the way, when shooting a moving subject or the like, if an angle of view operation such as zooming or panning is performed, it is difficult to achieve an intended composition such as the subject being out of frame. Further, there is a limitation that even if the composition of an image recorded on a recording medium is corrected by image processing, a subject that is not included in the image cannot be included within the angle of view. However, when zooming using the electronic zoom, it is possible to read an image outside the pixel range corresponding to the zoom magnification at the time of image recording as long as it is within the effective pixel range of the image sensor. There is a possibility that the composition can be corrected in a wider range than the angle of view.
[0008]
Conventionally, optical zoom is given priority in cameras that can use both optical zoom and electronic zoom. However, as in the case of moving image recording with a camera that can record still images and moving images, it depends on all the effective pixels of the image sensor. When an image having an image size smaller than the obtained image size is recorded, the image quality does not deteriorate even if the zoom magnification of the electronic zoom is increased to a pixel range in which the image size for recording can be obtained. Therefore, in such a case, it is not always necessary to prioritize the optical zoom over the electronic zoom.
[0009]
The present invention has been made in view of such circumstances, and provides an imaging apparatus and a signal processing apparatus that can suitably correct a composition (angle of view) by an angle of view operation such as zooming during image recording after image recording. The purpose is to do.
[0010]
[Means for Solving the Problems]
In order to achieve the object, the invention described in claim 1 is an image sensor that captures an optical image formed by an optical system, a zoom operation unit that receives a zoom operation, and an image obtained by the image sensor. Among the data, zoom range setting means for setting a zoom range indicating a pixel range for acquiring image data to be output to a display system based on a zoom operation of the zoom operation unit, and the image data obtained by the imaging device Recording means for recording on the recording medium image data of a pixel range at least larger than the zoom range set by the zoom range setting means, and for recording zooming information indicating the zoom range set by the zoom range setting means on the recording medium It is characterized by having.
[0011]
In other words, the zoom range indicates a pixel range in which an image is enlarged and displayed on a display system such as an electronic viewfinder among image data obtained by the image sensor, and according to the present invention, the electronic zoom is displayed. The image data of the zoom range is not recorded on the recording medium, but the image data of the larger pixel range is recorded on the recording medium, and the zoom range is recorded as zooming information. An image of a subject that is not included in the composition by a view angle operation such as zooming during recording is also recorded. Therefore, even if an image of a subject that was unintentionally out of frame at the time of image recording, the image of the subject can be included in the composition by correcting the zoom range of the electronic zoom after image recording. It is suitable for correction.
[0012]
According to a second aspect of the present invention, in the first aspect of the present invention, the image size of the image data obtained by all the effective pixels of the image sensor is larger than the image size of the image data output to the display system. In this case, the size of the zoom range that can be changed by the zoom operation of the zoom operation unit is an image size that matches the image data output to the display system, or an image size that is larger than the image data output to the display system The image data obtained by reducing the image size of the image data acquired from the zoom range is used as image data to be output to the display system.
[0013]
For example, in the case of a digital camera or the like capable of recording still images and moving images, the image size of image data obtained by all effective elements of the image sensor is larger than the image size when moving image data is output to a display system. At this time, the size of the zoom range of the electronic zoom at the time of moving image recording is limited to an image size that matches the image data of the moving image output to the display system or a larger image size, thereby reducing the image quality due to the electronic zoom. Can be prevented.
[0014]
According to a third aspect of the present invention, in the imaging apparatus according to the second aspect, in which the optical zoom is possible, the optical zoom is not performed when the zoom range is larger than the limited image size, and the optical zoom is performed. The optical zoom is performed when a zoom operation for increasing the zoom magnification is performed by the zoom operation unit in a state where the zoom range matches the limited image size. In other words, the electronic zoom has priority over the optical zoom. According to this, there is no deterioration in image quality due to the electronic zoom, and when zoom operation is performed, image data in a pixel range that is always larger than the image data output to the display system is recorded on the recording medium. The composition of the image can be corrected appropriately.
[0015]
According to a fourth aspect of the present invention, in the first aspect of the present invention, the image data recorded on the recording medium by the recording means is moving image data. It is said.
[0016]
According to a fifth aspect of the present invention, the signal processing device has a function of changing the position or size of the zoom range indicated by the zooming information recorded on the recording medium according to the first to third aspects. It is a feature. According to this, the composition of the image recorded on the recording medium can be corrected.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of an imaging apparatus and a signal processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
[0018]
1 and 2 are a front view and a rear view, respectively, showing an embodiment of a digital camera to which the present invention is applied. As shown in these figures, a photographing lens 12, a finder window 14 and the like are provided on the front of the digital camera 10, and a shutter button 16 is provided on the upper surface. On the back side, a finder 18, a power button 20, a mode lever 22, a cross button 24, a menu / OK button 26, a cancel button 28, a liquid crystal monitor 30, a mode dial 32, and the like are provided. Further, a card slot insertion slot or the like for inserting a memory card (for example, smart media) is provided on a side surface not shown.
[0019]
When the setting position is switched by rotating the mode lever 22, the camera mode can be switched between the recording mode and the reproduction mode. Further, when the setting position of the mode dial 32 is switched in the recording mode, for example, a still image is displayed. It is possible to switch between a still image shooting mode in which recording is performed and a moving image shooting mode in which moving image recording is performed.
[0020]
When the still image shooting mode or the moving image shooting mode is selected, an image of the shooting range (through image) is displayed on the liquid crystal monitor 30, the composition is determined with reference to the through image, and the shutter button 16 is pressed. When fully pressed, the image is recorded on the memory card. In the still image shooting mode, one still image is recorded every time the shutter button 16 is fully pressed, and in the moving image shooting mode, an image from when the shutter button 16 is fully pressed until the shutter button 16 is fully pressed again. (Moving image) is recorded.
[0021]
Further, when the cross button 24 is operated in the vertical direction in the still image shooting mode or the moving image shooting mode, a zoom operation for changing the shooting angle of view to the wide side or the tele side can be performed.
[0022]
FIG. 3 is a block diagram showing the flow of image data when moving image recording is performed in the moving image shooting mode in the digital camera as described above. The light from the subject is imaged by the photographing lens 12 shown in the figure to form an optical image. The optical image is photoelectrically converted by an image sensor (CCD) 50 and output from the CCD 50 as an image signal. The image signal output from the CCD 50 is converted into digital image data by the A / D converter 52 and input to the data control unit 54. The analog image signal and digital image data are subjected to various signal processing by a signal processing circuit (not shown).
[0023]
Thus, the image data obtained from the CCD 50 is sequentially input to the data control unit 54, and the image data input to the data control unit 54 is displayed on the display control unit 56 and the moving image processing unit as will be described in detail later. 60. The display control unit 56 generates a video signal for moving image display based on the image data supplied from the data control unit 54, and the video signal is output to the liquid crystal monitor 30 or a video signal output terminal to which an external display device is connected. The data is output to the display system 58. As a result, the video currently being shot (through image) is displayed on the liquid crystal monitor 30 or the like.
[0024]
On the other hand, when the shutter button 16 is pressed and the execution of moving image recording is instructed, the moving image processing unit 60 generates a moving image recording signal (motion JPEG or other moving image signal) based on the image data supplied from the data control unit 54. Image data). Then, the image data of the moving image is recorded on a recording medium 62 such as a memory card. The moving image data is a continuous recording of images of each frame from the start to the end of moving image recording, and is recorded on the recording medium 62 as one moving image file.
[0025]
Further, the data control unit 54 is given a zoom operation signal corresponding to the operation from the zoom operation unit 64 for performing the zoom operation like the cross button 24. The data control unit 54 changes the zoom magnification of the electronic zoom based on the zoom operation signal. That is, a pixel range in which image data is cut out by electronic zoom and an image is enlarged and displayed with respect to a range of all effective pixels of the CCD 50 (all pixel ranges of image data obtained by all effective pixels of the CCD 50). The pixel range of the image data output to 58 (hereinafter referred to as the electronic zoom zoom range) is changed based on the zoom operation signal. In a state where the zoom range of the electronic zoom matches the entire pixel range, the zoom magnification of the electronic zoom is 1, and the zoom is set to the wide end (no zoom state).
[0026]
The data control unit 54 gives the image data of the zoom range among the image data of the entire pixel range obtained from the CCD 50 to the display control unit 56 and causes the display system 58 to output the image of the zoom range. As a result, an image output to the display system 58, for example, an image (through image) displayed on the liquid crystal monitor 30, is enlarged or reduced according to a zoom operation.
[0027]
In contrast, the moving image processing unit 60 is provided with image data of the entire pixel range obtained from the image sensor 50 and zooming information indicating the zoom range. The moving image processing unit 60 causes the recording medium 62 to record the image data of the entire pixel range obtained from all the effective pixels of the CCD 50 as moving image data regardless of the zoom magnification, and zoom information indicating the zoom range. To record. The zooming information is recorded as information of one moving image file together with moving image data, for example. Also, the zoom range changes according to the zoom operation during the recording of the moving image, but in zooming information, the zoom range set at that time is associated with the image data of each frame constituting the image data of the moving image. Remembered. As a specific example of zooming information indicating the zoom range, if the center point of the zoom range always coincides with the center point of the entire pixel range, the size of the zoom range (vertical and horizontal pixel sizes) is stored. It is possible.
[0028]
Here, in the present embodiment, the electronic zoom is prioritized over the optical zoom, and the image is enlarged by the electronic zoom in the range from the zoom magnification value (1) to the predetermined value. Yes.
[0029]
For example, the image size of the image obtained by all the effective pixels of the CCD 50 is set to 2048 × 1536 pixels, and the image size of the moving image output to the display system 58 is set to 640 × 480 pixels. At this time, when the zoom range is in the range from the image size 2048 × 1536 of the image obtained by all the effective pixels of the CCD 50 to the image size 640 × 480 pixels of the moving image, the electronic zoom is prioritized and the zoom operation signal is used. Change the zoom range based on. Thereby, the zoom range is larger than the image size of the moving image, and the image quality does not deteriorate when an image in the zoom range is displayed on the screen. The center of the zoom range is fixed to the center of the entire pixel range of the image data obtained from the CCD 50, but may be changed by a predetermined operation together with the zoom operation.
[0030]
Next, the case where the camera mode is set to the playback mode will be described. In the playback mode, image data of a desired moving image recorded on the recording medium 62 can be played back by a predetermined operation. . At this time, zooming information together with the image data of the moving image is read from the recording medium 62 by the moving image processing unit 60, and the information is given to the data control unit 54. The data control unit 54 displays the image data in the zoom range indicated by the zooming information among the image data of the moving image in which the image data of the entire pixel range obtained from the CCD 50 is recorded, as in the case of moving image recording. And the display system 58 outputs an image in the zoom range. As a result, an image output to the display system 58, for example, an image reproduced and displayed on the liquid crystal monitor 30, is enlarged or reduced according to a zoom operation at the time of moving image recording.
[0031]
In addition, a function of correcting zooming information recorded on the recording medium 62 together with moving image data can be mounted on the digital camera, and this case will be described. For example, moving image data and zooming information are read from the recording medium 62 to the data control unit 54, and moving image data of the entire pixel range is provided to the display control unit 56 so that the image of the entire pixel range is displayed on the liquid crystal monitor 30. . At the same time, zooming information is given to the display control unit 56 to display a frame indicating the zoom range on the liquid crystal monitor 30. When the operator corrects the size and position of the zoom range frame to a suitable composition by a predetermined operation while looking at the liquid crystal monitor 30, the information on the corrected zoom range is used as new zooming information as the recording medium 62. To be able to record. As a result, the image in the corrected zoom range can be reproduced and output to the display system 58 in the next reproduction mode.
[0032]
It should be noted that such a function of correcting the zoom range may be performed by another signal processing device (such as a personal computer) instead of being performed by a camera that has recorded a moving image.
[0033]
Next, the relationship between the image data obtained by the CCD 50, moving image data and zooming information recorded on the recording medium 62, and image data output to the display system 58 during moving image recording and reproduction is shown in FIGS. This will be described with reference to FIG. FIG. 4 shows a case where the zoom operation is not performed, that is, a case where the zoom magnification of the electronic zoom is the wide end value (1). Assume that the image size of the image data obtained by the CCD 50 is 2048 × 1536 pixels as shown in FIG. At this time, the image of the entire pixel range obtained by the CCD 50 is displayed on the display system 58 at the time of moving image recording or reproduction, as shown in FIG. If the number of pixels of the display system 58 is 640 × 480 pixels, the image data of the entire pixel range obtained from the CCD 50 is thinned out and displayed on the display system 58.
[0034]
Further, as shown in FIG. 5C, the image data of the entire pixel range obtained by the CCD 50 is recorded on the recording medium 62 with an image size of 2048 × 1536 pixels. Since the zoom range is the entire pixel range, zooming information is omitted.
[0035]
FIG. 5 shows a case where the zoom operation is performed and at least the zoom magnification of the electronic zoom becomes a value on the tele side from the wide end. Assume that the image size of the image data obtained by the CCD 50 is 2048 × 1536 pixels as shown in FIG. 5A, as in FIG. 4A, and an image as shown in FIG. 4A is obtained. Further, it is assumed that the zoom range is set as indicated by a frame line Z in FIG. 5A based on the zoom operation. At this time, an image within the zoom range Z is displayed on the display system 58 during moving image recording or reproduction, as shown in FIG. On the other hand, the image data of the entire pixel range obtained by the CCD 50 is recorded on the recording medium 62 with an image size of 2048 × 1536 pixels as shown in FIG. Further, zooming information indicating the zoom range Z is recorded on the recording medium 62.
[0036]
As described above, when the zoom magnification of the electronic zoom is changed and the zoom magnification of the electronic zoom reaches the maximum (the zoom range is minimum), the optical zoom is executed. At this time, the zoom range is fixed in a minimum state (a state in which the zoom magnification of the electronic zoom is maximum). FIG. 6 shows a state in which the image obtained by the CCD 50 is enlarged by optical zoom with respect to FIG. 5, and the zoom range Z shown in FIG. 6A is fixed in the minimum range. . Also in this case, display and recording processing is performed in exactly the same way as in FIG. 5, and an image within the zoom range Z is displayed on the display system 58 as shown in FIG. On the recording medium 62, image data of the entire pixel range obtained by the CCD 50 is recorded with an image size of 2048 × 1536 pixels as shown in FIG. Also, zooming information indicating the zoom range Z is recorded on the recording medium.
[0037]
As described above, the case where moving image data is recorded has been described in the above embodiment, but the present invention is also applicable to the case where still image data is recorded. The present invention can also be applied to an imaging apparatus other than a digital camera.
[0038]
【The invention's effect】
As described above, according to the imaging device and the signal processing device of the present invention, when zooming operation is performed by electronic zoom, only image data in a zoom range in which an image is enlarged and displayed by electronic zoom is recorded on the recording medium. Instead, since the image data of a larger pixel range is recorded on the recording medium and the zoom range is recorded as zooming information, the recording medium is included in the composition by the angle of view operation such as zooming at the time of image recording. An image of a subject that cannot be recorded is also recorded. Therefore, even if an image of a subject that was unintentionally out of frame at the time of image recording, the image of the subject can be included in the composition by correcting the zoom range of the electronic zoom after image recording. Can be suitably corrected.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of a digital camera to which the present invention is applied.
FIG. 2 is a rear view showing an embodiment of a digital camera to which the present invention is applied.
FIG. 3 is a block diagram showing a flow of image data when moving image recording is performed in a moving image shooting mode.
FIG. 4 is a diagram showing the relationship between image data obtained by a CCD, moving image data and zooming information recorded on a recording medium, and image data output to a display system during moving image recording and reproduction.
FIG. 5 is a diagram showing the relationship between image data obtained by a CCD, moving image data and zooming information recorded on a recording medium, and image data output to a display system during moving image recording and reproduction.
FIG. 6 is a diagram showing the relationship between image data obtained by a CCD, moving image data and zooming information recorded on a recording medium, and image data output to a display system during moving image recording and reproduction.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Digital camera, 12 ... Shooting lens, 22 ... Mode lever, 30 ... Liquid crystal monitor, 32 ... Mode dial, 50 ... Image sensor (CCD), 52 ... A / D converter, 54 ... Data control part, 56 ... Display control 58, display system, 60 ... moving image processing unit, 62 ... recording medium, 64 ... zoom operation unit

Claims (5)

An image sensor that images an optical image formed by the optical system;
A zoom operation unit that accepts zoom operations;
Zoom range setting means for setting a zoom range indicating a pixel range for acquiring image data to be output to a display system among image data obtained by the imaging device, based on a zoom operation of the zoom operation unit;
Among the image data obtained by the imaging device, image data of a pixel range at least larger than the zoom range set by the zoom range setting unit is recorded on a recording medium, and indicates the zoom range set by the zoom range setting unit Recording means for recording zooming information on the recording medium;
An imaging apparatus comprising: The size of the zoom range that can be changed by the zoom operation of the zoom operation unit when the image size of the image data obtained by all the effective pixels of the image sensor is larger than the image size of the image data output to the display system Is limited to an image size that matches the image data output to the display system or an image size larger than the image data output to the display system, and reduces the image size of the image data acquired from the zoom range. The image pickup apparatus according to claim 1, wherein the obtained image data is image data to be output to the display system. In an imaging apparatus capable of optical zoom, when the zoom range is larger than the restricted image size, the optical zoom is not performed, and the zoom operation is performed in a state where the zoom range matches the restricted image size. The imaging apparatus according to claim 2, wherein the optical zoom is executed when a zoom operation for increasing a zoom magnification is performed by a unit. 4. The image pickup apparatus according to claim 1, wherein the image data recorded on the recording medium by the recording unit is moving image data. A signal processing apparatus comprising a function of changing a position or a size of a zoom range indicated by zooming information recorded on the recording medium according to claim 1.

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