JP2004120568A - Photographing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide photographing equipment which shortens time for compensating distortion. <P>SOLUTION: When a still image mode is selected by a switch 146 in a step 202, an object is photographed in the still image mode in a step 204. Whether a post view mode of a switch 150 is ON or OFF is judged in a step 212, and when the mode is OFF and a switch 148 is in a scenery mode in a step 216, lens distortion is compensated by an image signal processing circuit 124 in a step 218. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus, and more particularly to an imaging apparatus that performs distortion correction.
[0002]
[Prior art]
In order to acquire a high-quality image when shooting a subject using a shooting device such as a video camera, in addition to increasing the density of an image sensor, for example, a CCD image sensor, and improving the performance of image signal processing, imaging is performed. The performance of the imaging lens that forms an image on the element is important. That is, it is necessary that each aberration of the lens is below a certain level and that the lens is well balanced. However, it is impossible to remove geometric distortion with a short focus lens or the like, and the image acquired by photographing is also distorted. Further, even in a relatively long focal length lens, in order to reduce all aberrations to a certain level or less, the lens configuration is complicated and the size is increased, for example, the number of lenses is increased.
[0003]
For this reason, the conventional photographing apparatus incorporates an arithmetic means for correcting geometric distortion caused by the lens in the video camera, and automatically corrects the geometric distortion of the lens and the chromatic aberration of magnification. (For example, refer to Patent Document 1). According to this, it is possible to obtain a high-quality image without complicating the lens configuration and increasing the size. However, such an imaging apparatus requires time for correction processing.
[0004]
[Patent Document 1]
JP-A-6-205273 (paragraph numbers “007” to “0017”, FIG. 1)
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described facts, and an object thereof is to shorten the time for correcting distortion.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a photographing apparatus for photographing a subject according to claim 1, a photographing means for photographing a subject, a mode setting means for setting a photographing mode by the photographing means, and correcting image distortion And a control for controlling the distortion correction means so as to correct the distortion of the image captured and generated by the photographing means only when a predetermined mode is set by the mode setting means. Means.
[0007]
That is, the image capturing apparatus controls the distortion correction unit so as to correct the distortion of the image captured and generated by the image capturing unit only when the predetermined mode is set by the mode setting unit. As described above, when the predetermined mode is set by the mode setting means, the image distortion is corrected, and when the predetermined mode is not set, the image distortion is not corrected. Therefore, the time for correcting distortion can be shortened.
[0008]
As described in claim 2, the predetermined mode is a mode in which the subject is photographed as a still image in the photographing apparatus according to claim 1. In other words, in the mode in which the subject is shot with a moving image, the process of shooting the subject and playing back the generated image is continuously performed, so there is a time interval for distortion correction between shooting and playback. Is not preferred. For this reason, distortion correction is performed only in a mode in which the subject is photographed as a still image. As described above, since distortion correction is performed only in a mode in which a subject is photographed with a still image, it is possible to shorten the time for correcting the distortion and improve the image quality of the still image.
[0009]
As described in claim 3, the predetermined mode is a mode for photographing a landscape in the daytime or nighttime in the photographing apparatus according to claim 1 or claim 2.
[0010]
The lens distortion becomes noticeable when, for example, a landscape including a horizontally long building is photographed at a wide angle. In such a case, image distortion correction is required. On the other hand, in a mode for shooting a person or a mode for shooting a sport or the like, since it is rare to shoot a subject at a wide angle, image distortion hardly occurs. Therefore, in such a mode, image distortion correction is not required. For this reason, image distortion correction is performed in a mode for photographing daytime or nighttime scenery. In this way, image distortion correction is performed in a mode that captures daytime or nighttime scenery, so that the time for correcting distortion can be shortened and the quality of landscape images that are prone to distortion can be improved. Can do.
[0011]
The predetermined mode is the imaging device according to any one of claims 1 to 3, wherein the predetermined mode is a display unit that displays an image captured and generated by the imaging unit. The predetermined mode is a mode in which the image is not displayed immediately after shooting.
[0012]
That is, in a mode in which an image is displayed immediately after shooting, it is not preferable that a time interval for correcting image distortion occurs between shooting and display. For this reason, image distortion correction is performed in a mode in which an image is not displayed immediately after shooting. As described above, since image distortion correction is performed in a mode in which an image is not displayed immediately after shooting, the time for correcting the distortion can be shortened and the image quality of an image not displayed immediately after shooting can be improved. it can.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
As shown in FIG. 1, a digital video camera 10 that is a photographing apparatus according to an embodiment of the present invention includes lens units 102 and 108 that receive light from a subject, a CCD 114 that forms an image of the received light, and timing. A timing generator 116 that generates a signal, a CDS that performs correlated double sampling and an AMP 118 that performs gain control amplification, an A / D converter 120 that converts an analog signal into a digital signal, an image input controller 122 that controls image input, and an image Image signal processing circuit 124 as distortion correction means for performing image signal processing including image distortion correction, compression processing circuit 126 for compressing the image signal, Video Encoder 128 for converting the image signal to the NTSC system, and AE detection for detecting the auto effect Circuit 134, An AF detection circuit 136 for detecting autofocus, a memory 138 for storing image signals, a recording medium 142 for recording image signals, a media controller 140 for controlling the recording media 142, and a display for displaying an image generated by photographing a subject. The image display apparatus 130 as a means is included.
[0015]
The digital video camera 10 is further controlled by the CPU 132 as a control unit for controlling these components, a motor driver 106 that adjusts the lens unit 102 to change the zoom, and the focus is changed. Therefore, a motor driver 112 for adjusting the lens unit 108 is provided. The digital video camera 10 also includes a shutter 144 that is pressed by the user when taking a still image, a switch 146 for switching between a still image shooting mode, a moving image shooting mode, and a playback mode, a landscape shooting mode, a night view shooting mode, A switch 148 for switching between the person photographing mode and the sport mode, and a switch 150 for setting the post view for displaying an image on the image display device 130 immediately after photographing to ON or OFF are included. The lens units 102 and 108 and the CCD 114 constitute a photographing unit, and the switches 146, 148 and 150 constitute a mode setting unit.
[0016]
Next, the operation of the embodiment of the present invention will be described.
[0017]
Before starting shooting, the user sets the switches 146, 148, and 150 according to the subject, situation, and the like that the user wants to shoot. The switch 146 is set to the still image mode when the user desires to take a still image, and is set to the moving image mode when the user desires to take a moving image.
[0018]
The switch 148 is provided to save the user's trouble of adjusting camera settings such as image brightness and shutter speed according to the subject. That is, by setting a mode suitable for the subject, a camera suitable for the subject is automatically set. Here, there are modes such as a landscape mode for photographing a daytime landscape, a landscape mode for photographing a nighttime landscape, a person mode for photographing a person, and a sports mode for photographing a sporting event.
[0019]
If the post view of the switch 150 is ON, the camera displays the captured and generated image on the image display device 130 immediately after shooting. If the postview is OFF, no display is performed.
[0020]
In step 202 of FIG. 2, the process is started by determining the state of the switch 146 set by the user. If the still image mode is selected by the switch 146, the process proceeds to step 204. In step 204, when the user presses the shutter 144, the subject is shot in the still image mode. In step 206, the captured and generated image is stored in the memory area 0 included in the memory 138. After the basic image signal processing is performed by the image signal processing circuit 124 in step 208, the image signal output from the image signal processing circuit 124 is stored in the memory area 1 included in the memory 138 in step 210.
[0021]
In step 212, it is determined whether the switch 150 is in the post-view mode ON or OFF. If it is OFF, in step 216, the switch 148 is set as shown in FIG. 3B, for example. It is determined whether the mode is a landscape mode for shooting a landscape or a night view mode, a person mode for shooting a person as shown in FIG. 3A, or a sports mode. If the switch 148 is in the landscape mode or night scene mode, the image signal processing circuit 124 performs lens distortion correction in step 218.
[0022]
As the correction algorithm, for example, the method shown in “Geometric correction method of images that do not require positioning” (Yasuhiro Onodera, Kenichi Kanaya) of the IEICE technique (PRU91-113) may be used. In this method, a new coordinate value (u, v) is obtained by converting the uncorrected coordinate value (x, y) by the equations (1) and (2).
[0023]
u = x + Ax ³ + Bxy ² (1)
v = y + Cx ² y + Dy ³ (2)
In Eqs. (1) and (2), A and D represent corrections that non-linearly expand on the x-axis and y-axis, and B and C give the object deflection with respect to the x-axis and y-axis Represents correction.
[0024]
In step 220, the image signal output from the image signal processing circuit 124 is stored in the memory area 2 included in the memory 138, and the process ends. If it is determined in step 202 that the switch 146 is in the moving image mode, details are omitted, but in step 222, shooting in the moving image mode is performed. In this case, distortion correction is not performed. If it is determined in step 212 that the switch 150 is set to the postview mode ON, the image in the memory area 1 is displayed on the image display device 130 in step 214, and the process ends. Also in this case, distortion correction is not performed.
[0025]
In this embodiment, the memory areas 0 to 3 are included in the memory 138. However, the present invention is not limited to this. For example, a plurality of memories individually including the memory areas 0 to 3 are digital video. It may be included in the camera 10. Moreover, the algorithm used for distortion correction is not limited to the one based on the conversion by the equations (1) and (2).
[0026]
As described above, the image capturing apparatus of the present invention is an image that is a distortion correction unit so that the distortion of an image is corrected only when a predetermined mode is set by the switches 146, 148, and 150 that are mode setting units. The signal processing circuit 124 is controlled. That is, when the predetermined mode is set, the image distortion is corrected, and when the predetermined mode is not set, the image distortion is not corrected. According to this, the time for correcting distortion can be shortened.
[0027]
The predetermined mode is a mode in which the subject set by the switch 146 is photographed as a still image. That is, in the mode in which the subject is photographed with a moving image, the process of photographing the subject and reproducing the generated image is continuously performed. Therefore, a time interval for correcting image distortion occurs between photographing and reproduction. That is not preferable. For this reason, image distortion correction is performed in a mode in which a subject is photographed as a still image. According to this, it is possible to shorten the time for correcting distortion and improve the image quality of still images.
[0028]
The predetermined mode may be a mode that is set by the switch 148 and captures a daytime or nighttime landscape. The lens distortion becomes noticeable when, for example, a landscape including a horizontally long building is photographed at a wide angle. In such a case, image distortion correction is required. On the other hand, in a mode for shooting a person or a mode for shooting a sport or the like, it is rare to shoot a subject at a wide angle, so image distortion does not occur. Therefore, in such a mode, image distortion correction is not required. For this reason, image distortion correction is performed in a mode for photographing daytime or nighttime scenery. According to this, it is possible to shorten the time for correcting the distortion and improve the quality of the landscape image.
[0029]
Further, the predetermined mode may be a mode that is set by the switch 150 and is in a post-view mode OFF state, in which an image is not displayed immediately after shooting. That is, in a mode in which an image is displayed immediately after shooting, it is not preferable that a time interval for correcting image distortion occurs between shooting and display. For this reason, image distortion correction is performed in a mode in which an image is not displayed immediately after shooting. According to this, it is possible to shorten the time for correcting distortion and improve the image quality.
[0030]
The predetermined mode is not limited to the mode set by the switches 146, 148, and 150. For example, when the shooting condition is set manually, the shooting condition is automatically detected. In the case of wide-angle shooting, a predetermined mode may be set.
[0031]
【The invention's effect】
As described above, the photographing apparatus of the present invention controls the distortion correction unit so as to correct the distortion of the image only when the predetermined mode is set by the mode setting unit. The effect that the time for this can be shortened is acquired.
[Brief description of the drawings]
FIG. 1 shows a configuration diagram of a digital video camera according to an embodiment of the present invention.
FIG. 2 shows a flowchart of a photographing process in the embodiment of the present invention.
FIG. 3A shows an image shot in a person mode or a sports mode, and FIG. 3B shows an image shot in a landscape mode or a night view mode.
[Explanation of symbols]
146, 148, 150 Switch 102, 108 Lens unit 114 CCD
132 CPU
124 Image signal processing circuit

Claims (4)

Photographing means for photographing the subject;
Mode setting means for setting a mode of photographing by the photographing means;
Distortion correction means for correcting image distortion;
Control means for controlling the distortion correction means so as to correct distortion of the image captured and generated by the photographing means only when a predetermined mode is set by the mode setting means;
An imaging apparatus having The photographing apparatus according to claim 1, wherein the predetermined mode is a mode for photographing a subject with a still image. The photographing apparatus according to claim 1, wherein the predetermined mode is a mode for photographing a landscape at daytime or at night. The imaging device
A display unit for displaying an image captured and generated by the imaging unit;
The photographing apparatus according to claim 1, wherein the predetermined mode is a mode in which the image is not displayed immediately after photographing.

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