JP2009124314A - Camera, and image processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a field angle from changing against the intention of a user by correcting inclination of an image clipped from a photographed image. <P>SOLUTION: A camera control circuit 123 corrects inclination of an image by clipping and rotating an image in a range according to an inclination angle detected from a photographed image when the inclination of a camera is detected based on the output from an inclination sensor 125. Then, input of the maximum angle from a user is previously accepted, and the inclination of the image is corrected when the inclination angle of the camera is not larger than the maximum correction angle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a camera and an image processing program.

  The following digital cameras are known. This digital camera corrects the inclination of an image by rotating a captured image and cutting out a predetermined range according to the output of a gyro built in the camera (for example, Patent Document 1).

JP 2006-245726 A

  However, since the conventional digital camera cuts out a predetermined range from the captured image, there is a problem that the angle of view of the obtained image changes against the user's intention.

The present invention detects the tilt of the camera, and when the tilt of the camera is detected, the image is tilted by cutting out and rotating an image in a range corresponding to the detected tilt angle from the captured image. Correction is performed, an input of a maximum angle for correction is received, a maximum correction angle is set, and the tilt of the image is corrected when the tilt angle of the camera is equal to or smaller than the maximum correction angle.
In the present invention, even when the tilt angle of the camera is smaller than the maximum correction angle, an image in the cutout range when the tilt angle of the camera is the maximum correction angle may be cut out from the captured image.
When the tilt angle of the camera is larger than the maximum correction angle, the user may be notified accordingly.
When receiving the input of the maximum correction angle from the user, the cutout range corresponding to the input maximum correction angle may be displayed on the image taken when the camera is not tilted.
When the input of the maximum correction angle is accepted from the user, the ratio of the angle of view of the image in the clipping range according to the input maximum correction angle and the angle of view of the image taken when the camera is not tilted May be displayed.
A viewfinder having a magnification changing mechanism may be controlled to change the size of the viewfinder according to the maximum correction angle.
You may make it display the frame which shows the magnitude | size of the image of the clipping range according to the set said maximum correction angle in a finder.
When the detected tilt angle is equal to or greater than a predetermined angle, the aspect ratio of the image cut out from the captured image may be switched.
When the tilt of the camera in the vertical direction is detected and the tilt angle is equal to or greater than a predetermined angle, the tilt correction of the image may be stopped.

  According to the present invention, it is possible to prevent the angle of view from changing against the user's intention.

  FIG. 1 is a block diagram illustrating a configuration of an embodiment of a camera according to the present embodiment. The camera 100 includes an objective lens 110 and a camera body 120. The objective lens 110 includes a lens 111, an encoder 112, and a lens control circuit 113. The camera body 120 includes an image sensor 121, an image processing circuit 122, a camera control circuit 123, a system memory 124, a tilt sensor 125, an external memory 126, an operation member 127, and a display device 128. . In this embodiment, an example in which the objective lens 110 and the camera body 120 are separable from each other is described in the camera 100, but these may be integrated.

  In the objective lens 110, the lens control circuit 113 detects the lens position of the lens 111 based on the output from the encoder 112. In the camera body 120, the imaging element 121 is, for example, a CCD or a CMOS, captures an image input through an objective lens, and outputs an image signal to the image processing circuit 122. The image processing circuit 122 performs various image processing on the input image signal to generate image data, and outputs the generated image data to the camera control circuit 123.

  The camera control unit 123 is a control circuit for controlling the entire camera 100. In the present embodiment, the image inclination caused by the inclination of the camera body 120 is corrected based on the image data input from the image processing circuit 122 based on the output from the inclination sensor 125 described later. Then, the image data after correcting the inclination is output to an external memory 126 described later and recorded.

  The system memory 124 includes, for example, SDRAM and flash memory. The SDRAM is a volatile memory, and is used as a work memory at the time of program execution by the image processing circuit 122 and the camera control circuit 123, or as a buffer memory for temporarily recording data. The flash memory is a non-volatile memory in which various parameters read during program execution are recorded.

  The tilt sensor 125 is, for example, a gyro sensor, and detects the rotation direction around the optical axis of the camera body 120 and the tilt in the vertical direction. That is, the tilt sensor 125 detects the tilt as 0 degree when the user holds the camera body 120 horizontally, and when the user holds the camera body 120 obliquely with respect to the optical axis, or When the camera body 120 is held obliquely with respect to the optical axis, the tilt angle of the camera body 120 with respect to the horizontal direction at that time is detected.

  The external memory 126 is, for example, a memory card inserted in a memory card slot (not shown), and image data output from the camera control unit 123 is recorded. The operation member 127 includes various buttons operated by the user, such as a power button, a release button, a menu button, a cross button, and a determination button. The display device 128 is a liquid crystal monitor mounted on the back surface of the camera body 120, for example, and displays a through image, a reproduced image, a menu screen, and the like.

  In the present embodiment, the user sets whether or not to correct the inclination of the image at the time of shooting on the setting screen shown in FIG. Specifically, the user operates the operation member 127 to set the “automatic inclination correction” 2a displayed on the setting screen shown in FIG. It can be set to correct the inclination of the image when the person holds the camera body 120 obliquely in the rotation direction with respect to the optical axis. On the other hand, the user can set not to correct the inclination of the image at the time of photographing by setting the “automatic inclination correction” 2a to “not” 2c.

  In addition, the user sets the “tilt angle display” 2d to “Yes” 2e on the setting screen shown in FIG. 2A, thereby setting the current tilt angle of the camera body 120 on the display device 128 at the time of shooting. Can be set to display. on the other hand. The user can set not to display the current tilt angle of the camera body 120 on the display device 128 at the time of shooting by setting the “tilt angle display” 2d to “not” 2f.

  In the camera 100 according to the present embodiment, the user can limit the angle to be corrected by setting the maximum value (maximum correction angle) of the inclination to be corrected when correcting the inclination of the image. Specifically, the user changes the angle displayed in the maximum correction angle setting field 2g on the setting screen shown in FIG. 2B by operating the up / down button 2h by operating the operation member 127. The maximum correction angle can be set. When the value of the maximum correction angle setting field 2g is changed by the user, the camera control circuit 123 displays the image clipping range 2j at the changed maximum correction angle in the full screen 2i.

  Further, when the cutout screen 2j is cut out from the full screen 2i, the camera control circuit 123 displays a magnification display field indicating how many times the shooting range of the cutout screen 2j with respect to the shooting range of the full screen 2j corresponds to the lens magnification. Display in 2k. When the setting of the maximum correction angle is completed, the user can confirm the setting content of the maximum correction angle by pressing the OK button 2l.

  The camera control circuit 123 corrects the tilt of the image within the range up to the maximum correction angle set by the user. For example, when the maximum correction angle set by the user is θ1 (degrees), the camera body 120 is inclined by θ1 (degrees) in the rotation direction of the optical axis as shown in FIG. When the inclination of (degree) has occurred, the camera control circuit 123 cuts out the corrected screen 3b from the entire screen 3a. Then, the camera control circuit 123 corrects the inclination of the image by rotating the cut image of the corrected screen 3b by θ1 (degrees) in the direction opposite to the inclination direction of the camera body 120.

  In the present embodiment, even when the tilt angle of the camera body 120 is smaller than the maximum correction angle, the camera control circuit 123 is within the same range as when the tilt angle of the camera body 120 is the maximum correction angle. The image is cut out as a corrected screen 3b. Accordingly, it is possible to prevent the range cut out as the corrected screen 3b from changing depending on the tilt angle of the camera body 120. That is, it is possible to prevent the angle of view of the post-correction screen 3b from changing depending on the tilt angle of the camera body 120.

  The camera control circuit 123 calculates a converted lens magnification indicating how many times the shooting range of the corrected screen 3b corresponds to the lens magnification with respect to the shooting range of the full screen 3a as follows. First, when the angle of the diagonal line of the entire screen 3a with respect to the horizontal direction is θ2, the camera control circuit 123 is based on θ1 and θ2, and the range of the image to be cut out as a corrected image (corrected screen) 3b with respect to the horizontal direction The diagonal angle θ is calculated.

Based on the calculated diagonal angle θ of the corrected screen 3b and the length c that is ½ of the short side of the entire screen 3a, the camera control circuit 123 calculates the corrected screen 3b according to the following equation (1). The half length a of the diagonal line is calculated.
a = c / sin θ (1)
The camera control circuit 123 can calculate the length of the diagonal line of the corrected screen 3b by doubling “a” calculated by the equation (1). The camera control circuit 123 can calculate the conversion lens magnification by calculating the ratio of the diagonal length of the corrected screen 3b thus calculated and the diagonal length of the known full screen 3a.

  In the present embodiment, when the corrected screen 3b is cut out from the full screen 3a, as described above, the maximum correction angle is set in advance. However, if the maximum correction angle is not set, FIG. As shown in 3 (b), the correction is performed without limitation. In this case, the larger the tilt angle of the camera body 120, the smaller the corrected screen 3b that is cut out. For this reason, there is a possibility that the shooting angle of view of the obtained image is not intended by the user. On the other hand, according to the present embodiment, correction is performed only up to the maximum correction angle set by the user, so that it is possible to prevent an image having an angle of view contrary to the intention of the user from being obtained. .

  In the present embodiment, the optical viewfinder having a zooming mechanism as shown in FIG. 4A corrects the change in magnification when the corrected screen 3b is cut out, and the user passes through the eyepiece. The cutout range of the corrected screen 3b can be observed. That is, the image of the objective lens 110 is reflected by the main mirror 4a and formed on the finder screen 4b. After that, the image formed on the finder screen 4b is refracted by several mirrors and then re-imaged on the variable magnification relay lens 4c, so that the range corresponding to the center portion of the image, that is, the corrected screen 3b is obtained. Enlarged. As a result, the user can observe the range corresponding to the corrected screen 3b with the eyepiece 4d.

  For example, as shown in FIG. 4B, when the corrected screen 3b is cut out from the entire screen 3a, the user can display the enlarged corrected screen 3b as shown in FIG. 4C. A corresponding range can be observed through the eyepiece 4d. The camera control circuit 123 displays the full screen 3a shown in FIG. 4B on the display device 128, and displays the corrected screen 3b cut out from the full screen 3a by surrounding it with a frame 4e. Thus, the user can confirm which range in the full screen 3a is cut out as the corrected screen 3b based on the display content on the display device 128.

  In the present embodiment, when the inclination of the camera body 120 is larger than the maximum correction angle set by the user, the camera control circuit 123, as shown in FIG. The display form of the frame 4e that surrounds is changed, and the user is notified, for example, by blinking, changing the display color, or changing the display brightness. Accordingly, the user can grasp that the current inclination of the camera body 120 is larger than the maximum correction angle.

  The camera control circuit 123 further changes the display form of the frame 4e and notifies the user, but if the user further tilts the camera body 120, the user moves the camera body 120 to the horizontal position. The aspect ratio of the corrected screen 3b cut out from the full screen 3a is switched.

  For example, as shown in FIG. 5A, when the camera body 120 is in a horizontal state, it is not necessary to perform image tilt correction, so the camera control circuit 123 does not cut out the corrected screen 3b from the full screen 3a. . On the other hand, when the camera body 120 is tilted by an angle within the maximum correction angle as shown in FIG. 5B, the camera control circuit 123 cuts out the corrected screen 3b from the full screen 3a. Correct the tilt. That is, the camera control circuit 123 cuts out the corrected image 3b in the horizontal direction from the full screen 3a.

  After that, when the tilt angle of the camera body 120 exceeds the maximum correction angle, the camera control circuit 123 switches the aspect ratio of the corrected screen 3b as shown in FIG. The corrected image 3b is cut out. Thus, the orientation of the corrected image 3b can be automatically changed according to the tilt angle of the camera body 120. As shown in FIG. 5D, when the camera body 120 is changed to a complete vertical position, it is not necessary to perform image inclination correction. Therefore, the camera control circuit 123 starts from the full screen 3a to the corrected screen 3b. Is not cut out.

  By the image tilt correction described above, it is possible to correct the image tilt caused by the camera body 120 tilting in the rotation direction around the optical axis when the optical axis is oriented in the horizontal direction. However, if the optical axis is not oriented in the horizontal direction, that is, if the camera body 120 is tilted vertically with respect to the optical axis, an object (horizontal line) extending in the horizontal direction exists in the image. In this case, it is not necessary to perform tilt correction. Therefore, in the present embodiment, the tilt correction described above is not performed when the camera body 120 is directed downward or upward at a predetermined angle or more as follows.

  For example, as shown in FIG. 6A, when the camera body 120 faces downward, when the half angle of view 1 / 2ω of the objective lens 110 is smaller than the tilt angle θ of the optical axis, the image Since there is no horizontal line, the camera control circuit 123 stops the inclination correction of the image. Similarly, as shown in FIG. 6B, when the camera body 120 faces upward and the half angle of view 1 / 2ω of the objective lens 110 is smaller than the tilt angle θ of the optical axis. The camera control circuit 123 stops the tilt correction of the image.

  FIG. 7 is a flowchart showing processing of the camera 100 in the present embodiment. The process shown in FIG. 7 is performed by the camera control circuit 123 as a program that is activated when the setting content of the maximum correction angle is confirmed by pressing the OK button 2l on the setting screen shown in FIG. Executed.

  In step S <b> 10, the camera control circuit 123 detects the tilt angle of the camera body 120 based on the output from the tilt sensor 125. Thereafter, the process proceeds to step S20, and the camera control circuit 123 determines whether or not the camera body 120 is tilted based on the detection result in step S10. If a negative determination is made, there is no need to perform image inclination correction, and the process proceeds to step S70 described later. On the other hand, if a positive determination is made, the process proceeds to step S30.

  In step S30, the camera control circuit 123 determines whether the tilt angle of the camera body 120 is within the maximum correction angle set by the user. If a negative determination is made, the process proceeds to step S60, and the camera control circuit 123 changes the display form of the frame 4e indicating the cutout range of the corrected screen 3b as described above with reference to FIG. Proceed to step S70. On the other hand, if a positive determination is made in step S30, the process proceeds to step S40.

  In step S40, as described above with reference to FIG. 6, the camera control circuit 123 determines whether the vertical tilt angle of the camera body 120 is equal to or greater than a predetermined angle, for example, the tilt angle θ of the optical axis is half of the objective lens 110. It is determined whether or not the angle of view is ½ω or more. If the determination is affirmative, the process proceeds to step S70 without performing the inclination correction. On the other hand, if a negative determination is made, the camera control circuit 123 corrects the tilt by cutting out the corrected screen 3b from the entire screen 3a and rotating it as described above, and the process proceeds to step S70.

  In step S70, the camera control circuit 123 determines whether or not shooting has been performed by pressing the release button by the user. If the determination is affirmative, the process proceeds to step S80, and the camera control circuit 123 records the image data acquired by shooting in the external memory 126. At this time, the camera control circuit 123 records the image data of the corrected screen 3b cut out from the full screen 3a when the tilt correction is performed in step S50, and the full screen when the tilt correction is not performed. The image data 3a is recorded. Thereafter, the process proceeds to step S90.

  In step S90, the camera control circuit 123 determines whether the power of the camera 100 is turned off when the power button is pressed by the user. If a negative determination is made, the process returns to step S10. On the other hand, when an affirmative determination is made, the process ends.

According to the present embodiment described above, the following operational effects can be obtained.
(1) When the camera control circuit 123 detects the tilt of the camera based on the output from the tilt sensor 125, the camera control circuit 123 cuts out and rotates an image in a range corresponding to the detected tilt angle from the captured image. To correct the tilt of the image. At this time, the input of the maximum angle from the user is received in advance, and the tilt of the image is corrected when the tilt angle of the camera is equal to or smaller than the maximum correction angle. This can prevent the angle of view from changing against the user's intention.

(2) The camera control circuit 123 cuts out an image in the cutout range when the camera tilt angle is the maximum correction angle from the captured image even when the camera tilt angle is smaller than the maximum correction angle. did. Thereby, the angle of view of the image on the corrected screen 3b can be kept constant regardless of the tilt angle of the camera.

(3) When the tilt angle of the camera is larger than the maximum correction angle, the camera control circuit 123 changes the display form of the frame 4e indicating the cutout range of the post-correction screen 3b and notifies the user to that effect. I did it. Thereby, the user can grasp that the tilt angle of the camera exceeds the maximum correction angle.

(4) On the setting screen shown in FIG. 2B, when receiving the input of the maximum correction angle from the user, the camera does not tilt the cutout range 2j according to the input maximum correction angle. It is displayed on the full screen 2i that is sometimes photographed. As a result, the user can confirm the cutout range 2j corresponding to the maximum correction angle on the setting screen.

(5) When the camera control circuit 123 receives an input of the maximum correction angle from the user, the camera control circuit 123 captures the angle of view of the image in the cutout range according to the input maximum correction angle and when the camera is not tilted. The ratio to the angle of view of the image to be displayed was displayed. The user can check the angle of view ratio between the full screen and the maximum correction angle on the setting screen.

(6) The magnification change when the corrected screen 3b is cut out is corrected by the optical finder provided with the magnification changing mechanism shown in FIG. Thus, the user can observe the cutout range of the corrected screen 3b through the eyepiece.

(7) The camera control circuit 123 changes the aspect ratio of the image cut out from the captured image when the tilt angle of the camera becomes a predetermined angle or more. Thus, the orientation of the corrected image 3b can be automatically changed according to the tilt angle of the camera body 120.

(8) When the camera control circuit 123 detects the vertical tilt of the camera, that is, the vertical tilt with respect to the optical axis, based on the output from the tilt sensor 125, the tilt angle is equal to or greater than a predetermined angle. In such a case, the image inclination correction is stopped. As a result, when the camera is tilted vertically with respect to the optical axis, tilt correction is performed in consideration of the low possibility that an object (horizontal line) extending in the horizontal direction exists in the image. It can be stopped and the processing load can be reduced.

-Modification-
The camera according to the above-described embodiment can be modified as follows.
(1) In the embodiment described above, the camera body 120 includes an optical viewfinder having a zooming mechanism as shown in FIG. 4A, and corrects a change in magnification when the corrected screen 3b is cut out. Thus, the user can observe the cutout range of the corrected screen 3b through the eyepiece. However, the display device for electrically displaying the frame on the finder screen 4b is provided, and the frame is displayed in the range corresponding to the corrected screen in the entire screen, so that the user can set the range of the corrected screen in the finder. You may make it understandable.

(2) In the above-described embodiment, the example in which the camera control circuit 123 executes the process illustrated in FIG. 7 has been described. However, a program for executing the processing shown in FIG. 7 may be recorded in an information device such as a personal computer and executed by a CPU included in the personal computer. In this case, the camera control circuit 123 writes the tilt angle of the camera body 120 detected by the tilt sensor 125 in the image file. Then, on the personal computer that has read this image file, the CPU accepts the input of the maximum correction angle from the user, and after reading the inclination angle from within the image file, the CPU may execute the processing shown in FIG. Good.

  Note that the present invention is not limited to the configurations in the above-described embodiments as long as the characteristic functions of the present invention are not impaired.

It is a block diagram which shows the structure of one Embodiment of a camera. It is a figure which shows an example of a setting screen. It is a figure which shows the specific example in the case of cutting out the correction | amendment screen 3b from the inside of the whole screen 3a. It is a figure which shows the specific example of the optical finder provided with the magnification changing mechanism. It is a figure which shows the example of a change of the image direction of the screen 3b after correction | amendment. It is a figure which shows the specific example in case the camera body 120 inclines to an up-down direction with respect to an optical axis. FIG. 6 is a flowchart showing processing of the camera 100.

Explanation of symbols

100 camera, 110 objective lens, 111 lens, 112 encoder, 113 lens control circuit, 120 camera body, 121 image sensor, 122 image processing circuit, 123 camera control circuit, 124 system memory, 125 tilt sensor, 126 external memory, 127 operation Member, 128 display device

Claims (10)

Tilt detection means for detecting the tilt of the camera;
An inclination correction means for correcting the inclination of the image by cutting out and rotating an image in a range corresponding to the detected inclination angle from the captured image when the inclination of the camera is detected by the inclination detection means; ,
A maximum correction angle setting means for receiving an input of a maximum angle to be corrected by the inclination correction means and setting a maximum correction angle;
The camera according to claim 1, wherein the tilt correction unit corrects the tilt of the image when the tilt angle of the camera is equal to or smaller than the maximum correction angle set by the maximum correction angle setting unit. The camera of claim 1,
In the case where the tilt angle of the camera is smaller than the maximum correction angle set by the maximum correction angle setting unit, the tilt angle of the camera is the maximum correction angle from the captured image. A camera characterized by cutting out an image of a cutout range. The camera according to claim 1 or 2,
The camera further comprising notification means for notifying the user when the tilt angle of the camera is larger than the maximum correction angle set by the maximum correction angle setting means. The camera according to any one of claims 1 to 3,
The maximum correction angle setting means, when receiving the input of the maximum correction angle from the user, the cutout range corresponding to the input maximum correction angle on the image photographed when the camera is not inclined. A camera characterized by displaying. In the camera according to any one of claims 1 to 4,
When the maximum correction angle is received from the user, the maximum correction angle setting means captures the angle of view of the image in the clipping range according to the input maximum correction angle and when the camera is not tilted. A camera characterized by displaying a ratio to the angle of view of an image to be displayed. In the camera according to any one of claims 1 to 5,
A camera, further comprising: a finder zooming unit that controls a finder having a zooming mechanism and performs zooming of the finder according to the maximum correction angle set by the maximum correction angle setting unit. In the camera according to any one of claims 1 to 5,
The camera further comprising frame display means for displaying in the finder a frame indicating the size of the image in the cutout range corresponding to the maximum correction angle set by the maximum correction angle setting means. In the camera according to any one of claims 1 to 7,
A camera, further comprising: a cut-out image switching unit that switches an aspect ratio of an image cut out from the captured image when an inclination angle detected by the inclination detection unit is equal to or greater than a predetermined angle. In the camera according to any one of claims 1 to 8,
The tilt correction means stops tilt correction of an image when the tilt detection means detects a tilt in the vertical direction of the camera and the tilt angle is equal to or greater than a predetermined angle. Tilt detection procedure to detect camera tilt during shooting,
When the tilt of the camera is detected by the tilt detection procedure, a tilt correction procedure for correcting the tilt of the image by cutting out and rotating an image in a range corresponding to the detected tilt angle from the captured image; ,
An image processing program for causing a computer to execute a maximum correction angle setting procedure for receiving an input of a maximum angle to be corrected by the inclination correction procedure and setting a maximum correction angle,
The image processing program characterized in that the tilt correction procedure corrects the tilt of an image when a camera tilt angle is equal to or less than the maximum correction angle set in the maximum correction angle setting procedure.

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