JP2016103682A - Level of optical equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display method for a level of optical equipment having mis-display preventing function for panning photography time.SOLUTION: An imaging device has a singular point extraction part which extracts a background singular point from two or more different successively picked-up images before primary photography, a moving vector calculation part which detects a moving vector at the background singular point, an angle calculation part which calculates an angle of inclination of the moving vector, and an angle result display part which displays an angle inclination of a camera.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display of a level of an optical apparatus having a function of preventing erroneous display during panning photography.

  In recent digital single-lens reflex cameras, the tilt angle of the camera is detected based on the detection result of the acceleration sensor and displayed on a level. Specifically, the gravitational acceleration is detected by the acceleration sensor in the camera, the gravitational acceleration direction is assumed to be the center direction of the earth, and the normal direction of the gravitational acceleration direction is set to the horizontal direction with respect to the ground. The angle formed by the horizontal direction of the camera and the horizontal direction of the camera is displayed as the camera tilt angle.

  As a technique for improving detection accuracy of a level built in a camera, in Patent Document 1, depending on whether the camera is held or fixed, the resolution is automatically switched from two types, a high level and a low level. Proposed.

JP 2009-89345 A

  However, in the conventional level that detects gravitational acceleration, when acceleration other than gravity is applied to the camera, the acceleration cannot be separated from the applied acceleration and the correct level cannot be determined. When using the camera in hand, there are many situations where acceleration is applied. Especially in panning shooting, the acceleration in the direction of camera movement that occurs during panning can cause the level to display incorrectly. It has become difficult to maintain levelness. In the technique disclosed in Patent Document 1 described above, when panning is performed while holding the camera, acceleration other than gravitational acceleration is applied to the camera, and there is a problem in that acceleration cannot be separated and the level is erroneously displayed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical instrument level that can prevent erroneous display during panning photography.

  In order to achieve the above object, the present invention is designed to extract a background singularity in at least two different continuous images before the main photographing in order to prevent erroneous display of the level during panning photographing. A point extraction unit; a movement vector calculation unit that detects a movement vector of the background singular point; an angle calculation unit that calculates an inclination angle of the movement vector; and an angle result display unit that displays an inclination angle of the camera. Features.

  According to the present invention, it is possible to provide a level of an optical apparatus that can prevent erroneous display during panning photography.

Configuration diagram of the camera Camera electrical block diagram Imaging sequence flowchart Panning shooting flowchart Example of speed and acceleration during panning shooting Explanatory drawing of level display when there is no acceleration other than gravitational acceleration Explanatory drawing which decomposed gravity into camera horizontal direction (X direction) and vertical direction (Y direction) Explanatory drawing of level indication error when having acceleration other than gravitational acceleration 1 Illustration of the combined vector of gravity and inertia Explanatory drawing of level indication error when having acceleration other than gravitational acceleration 2 Illustration of the combined vector of gravity and inertia Illustration of movement vector of background singularity (panning start position) Illustration of movement vector of background singularity (panning end position) Illustration of the coordinate system in the image sensor

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Example]
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 7. In FIG. 1 to FIG. 7, the same number is assigned to the same component part.

  FIG. 1 is a diagram showing a schematic configuration of a digital single-lens reflex camera to which the present invention is applied. In the figure, reference numeral 101 denotes a CPU (central processing unit), and the operation of the camera is controlled by the CPU 101. Reference numeral 105 denotes a photographing lens (objective lens) which is driven by a lens driving unit 131 to form a subject image on a CMOS sensor 106 which is an image sensor. The photographing lens 105 shown in the figure is expressed by a single lens 105a for convenience, but actually includes a plurality of lenses.

  Reference numeral 120 denotes a focus detection plate (hereinafter referred to as a focus plate) placed on an image formation surface (primary image formation surface) equivalent to the image formation surface of the CMOS sensor 106 of the photographing lens 105, and the subject image is reflected by the main mirror 123. The primary image is formed on the focus plate 120. The photographer has a so-called TTL type optical viewfinder configuration in which the subject image can be seen through the pentaprism 124 and further through the eyepiece lens group 121. The PNLCD 300 disposed between the focus plate 120 and the pentaprism 124 is composed of a liquid crystal display element using polymer dispersed liquid crystal, and superimposes information in the viewfinder on the subject image formed on the focus plate 120. And display. The information in the finder indicates various information such as a mark indicating a focus detection area and a photometry area provided in the finder field, characters, symbols, and the like.

  On the other hand, the main mirror 123 is a semi-transmission mirror, and a part of the light beam transmitted through the main mirror 123 is guided to the focus detection unit 119 which is a focus detection means through the sub mirror 170, and the focus of the well-known phase difference detection method. Perform detection operation. The focus detection unit 119 can detect the focus for a plurality of areas on the shooting screen.

  A photometric sensor 125 includes a plurality of light receiving units, and can detect luminance / color information obtained by dividing the subject image formed on the focusing plate 120 by the photometric lens 126 into a plurality of regions. Further, by using the output result of the photometric sensor 125, it is possible to perform subject recognition by interlocking with the face recognition, color recognition, and focus detection unit 119. Therefore, the photometric sensor 125 is also an imaging unit. I can say that.

  When the photographer presses a release button 114 (not shown), the main mirror 123 is retracted out of the optical path of the photographing lens 105. On the other hand, the light of the subject focused by the photographing lens 105 is controlled by a focal plane shutter 133 and is displayed as a subject image by a CMOS sensor (imaging device) 106, and then displayed as a photographed image as a recording medium. And the captured image is displayed on the external display unit 113. In the light amount control by the focal plane shutter 133, the CPU 101 obtains an appropriate aperture value, shutter speed, and image sensor sensitivity based on object luminance information based on the output of the photometric sensor 125. This is normal still image shooting, but this camera can also perform live view shooting and movie shooting. The above is the configuration of the digital single-lens reflex camera of the present invention.

  FIG. 2 is an electric block diagram showing a schematic configuration of the digital camera according to the embodiment of the present invention. In the figure, reference numeral 101 denotes the CPU (central processing unit) described above, and an EEPROM 101a which is a nonvolatile memory is configured therein.

  Further, the CPU 101 detects a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a data storage means 104, an image processing unit 108, an image display control unit 111, and a camera posture which store control programs. Attitude detection unit 115, angle result display unit 122, lens drive unit 131, focus detection control unit 119, information display control unit 133, photometry control unit 132, shutter control unit 134, switch input unit 142, DC for supplying power / DC converter 117 is connected, and CMOS sensor control unit 107 and further CMOS sensor 106 are connected to image processing unit 108. The CMOS sensor 106 has about 10 million effective pixels (3888 × 2592 pixels).

  The lens driving unit 131 includes a driving source such as a known electromagnetic motor and ultrasonic motor, a driver circuit that controls these driving sources, an encoder device that detects the position of the lens, and the like. In zoom control and focus control, the lens driving unit 131 controls the position of the photographing lens 105 in the optical axis direction. In the image stabilization control, the lens driving unit 131 controls the position of the photographing lens 105 in the direction orthogonal to the optical axis. The external display unit 113 provided on the camera exterior back surface is a TFT color liquid crystal capable of displaying an image captured by the CMOS sensor 106. The image display control unit 111 drives display of still images and moving images captured by the CMOS sensor 106 on the external display unit 113. Further, the DC / DC converter 117 is supplied with power from the battery 116.

  The CPU 101 performs various controls based on a control program in the ROM 102. Among these controls, the captured image signal output from the image processing unit 108 is read and transferred to the RAM 103, the data is similarly transferred from the RAM 103 to the image display control unit 111, and the image data is converted to JPEG. There is a process of compressing and storing the data in the data storage means 104 in a file format. In the case of moving image data, the same processing is performed to compress it into a MOV format file and store it in the data storage means 104. Further, the CPU 101 instructs the CMOS sensor 106, the CMOS sensor control unit 107, the image processing unit 108, the image display control unit 111, and the like to change the number of data fetching pixels and digital image processing.

  Based on the output of the CMOS sensor 106, the focus detection control unit 119 searches the place where the contrast (contrast) is large while moving the photographing lens 105 and performs focus adjustment. The CMOS sensor 106 is a focus detection control unit 119 including a line sensor, A / D-converts the voltage obtained from the line sensor, and sends it to the CPU 101. Under the instruction of the CPU 101, the line sensor accumulation time and AGC (auto gain control) are also controlled. Further, the CPU 101 also performs various processes such as an instruction for a photographing operation associated with an operation of a release button 114 (not shown) and a control signal for controlling power supply to each element to the DC / DC converter 117. It is based on control.

  The RAM 103 includes an image development area 103a, a work area 103b, a VRAM 103c, and a temporary save area 103d. The image development area 103a is a temporary buffer for temporarily storing a captured image (YUV digital signal) sent from the image processing unit 108 or JPEG compressed image data read from the data storage unit 104, or an image Used as an image-dedicated work area for compression processing and decompression processing. The work area 103b is a work area for various programs. The VRAM 103 c is used as a VRAM that stores display data to be displayed on the external display unit 113.

  The temporary save area 103d is an area for temporarily saving various data. The data storage means 104 is a flash memory for storing captured image data or MOV format moving image data compressed by JPEG by the CPU 101 in a file format. The CMOS sensor 106 can output thinned pixel data in the horizontal direction and the vertical direction in accordance with a resolution conversion instruction from the CPU 101.

  The CMOS sensor control unit 107 is a timing generator for supplying a transfer clock signal and a shutter signal to the CMOS sensor 106, a circuit for performing noise removal and gain processing of the CMOS sensor output signal, and an analog signal as a 10-bit digital signal. An A / D conversion circuit for converting the image into a pixel, and further, for performing live view display and moving image shooting on the external display unit 113, in order to perform pixel thinning processing in accordance with a resolution conversion instruction from the CPU 101 Includes circuits and so on.

  The image processing unit 108 performs gamma conversion, color space conversion, white balance, exposure adjustment, flash correction, and other image processing on the 10-bit digital signal output from the CMOS sensor control unit 107, and YUV (4: 2). : 2) Outputs 8-bit digital signal in the format. The photographing lens 105, the CMOS sensor 106, the CMOS sensor control unit 107, and the image processing unit 108 constitute an imaging unit. The image display control unit 111 receives the YUV digital image data transferred from the image processing unit 108 or the YUV digital image data obtained by performing JPEG decompression on the image file in the data storage unit 104, and converts it into an RGB digital signal. Thereafter, a process of outputting to the external display unit 113 is performed.

  The information display control unit 133 displays the camera shutter time (TV value) in the shooting mode set for the camera, such as the aperture control value (AV value) of the shooting lens 105, outside the viewfinder screen (not shown) (not shown). The internal display unit 301 composed of a liquid crystal panel is controlled. Here, the CPU 101 adjusts the aperture of the lens aperture with the obtained aperture value. Further, the CPU 101 drives the shutter 100 via the shutter control unit 134 at the obtained shutter time.

  On the other hand, the PNLCD 300 superimposes and displays marks, characters, symbols, and the like indicating focus detection areas and photometry areas provided in the viewfinder field on the subject image formed on the focus plate 120. The release button 114 is for instructing the start of the photographing operation. The release button 114 is a camera operation member (not shown).

  This has a two-stage switch position depending on the pressing pressure of the release button 114, and the camera setting lock operation such as white balance and photometry can be performed by detecting the first-stage position (first release switch ON). When the second stage position (second release switch ON) is detected, the subject image signal capturing operation is performed. The photometry control unit 132 controls driving of the photometry sensor 125 including an image sensor in accordance with an instruction from the CPU 101, takes in a subject luminance signal, and sends data to the CPU 101. The CPU 101 performs an optimum exposure calculation of the camera based on these pieces of information, and the camera can obtain an optimum exposure by optimally controlling the shutter speed of the camera and the aperture of the photographing lens 105.

  Reference numeral 116 denotes a rechargeable secondary battery or a dry battery. A DC / DC converter 117 receives a power supply from the battery 116 and generates a plurality of power supplies by boosting and regulating the power supply to each element including the CPU 101. The power supply of the necessary voltage is supplied. The DC / DC converter 117 can control the start and stop of each voltage supply by a control signal from the CPU 101.

The posture detection unit 115 uses an acceleration sensor as a small sensor using micromechanics technology. This is a method of detecting acceleration using a change in capacitance. In the configuration of the posture detection unit 115, an electrode and a cantilever are formed on a silicon substrate by microfabrication. The cantilever is made of an oxide film, and a metal electrode is formed on the upper surface. The sensitivity to acceleration is enhanced by a weight provided at the tip.
The movement vector calculation unit 150 calculates a movement vector of a background singular point described later by the CPU 101.

  The angle calculation unit 110 calculates an angle formed by a movement vector of a background singular point, which will be described later, and the camera horizontal direction by the CPU 101. This result is displayed on the PNLCD 300 as the angle result display unit 122 when the observer uses an optical viewfinder (hereinafter referred to as OVF), and is displayed on the external display unit 113 during live view shooting or moving image shooting. To do. The singular point extraction units 106 and 125 for extracting the background singular point are either the CMOS sensor 106 or the photometric sensor 125. When the main mirror 123 is retracted, the detection is performed by the CMOS sensor 106, and the main mirror 123 is lowered. If so, the photometric sensor 125 is used. The above is the description of the operation of the single-lens reflex camera using the electric block diagram.

  Next, an imaging sequence before actual photographing in the digital single-lens reflex camera having the above configuration will be described with reference to a flowchart of FIG. When the release button 114 is half-pressed during shooting, camera shake is detected (S1). When the detected shake amount is smaller than the predetermined threshold value a, the CPU 101 determines that the shake amount is negligible and performs shooting without correction processing (S2). If the detected shake amount is greater than the threshold value: a, it is further determined whether or not the shake amount is greater than the threshold value: a threshold value: b (S3). When the shake amount is smaller than the threshold value b, the CPU 101 determines that the shake cannot be ignored, and performs shake correction (S4).

  On the other hand, when the shake amount exceeds the threshold value b, the CPU 101 determines that panning shooting is performed, performs panning correction described later in FIG. 4 (S5), and performs shooting (S6). That is, the threshold value “a” is the lower limit of the shake amount that needs to be corrected, and the threshold value “b” is the upper limit of the shake state that needs to be corrected. When the shake amount exceeds the threshold value b, the photographer determines that panning shooting is being performed.

Next, the flowchart regarding the panning correction of FIG. 4 will be described. If it is determined in S5 of FIG. 3 that panning correction is necessary, the posture detection unit 115 determines whether the vehicle has acceleration other than gravitational acceleration, that is, whether it has acceleration in the panning direction ( S7).
Here, an example having acceleration other than gravitational acceleration will be described with reference to FIG.

  For example, there is a photographer who is trying to perform panning shooting with a camera in hand. It is assumed that the photographer pans the subject moving at a constant speed by moving only the body direction from a stationary state. The AB section that has started to move has acceleration, while the BC section that has caught up with the speed of the subject has no acceleration. When the time further advances and the CD section in which the photographer is about to finish panning shooting is reached, acceleration occurs in the opposite direction to the AB section.

  Returning to the description of FIG. When it is determined that the camera has no acceleration other than the gravitational acceleration, that is, in the BC section, the posture detection unit 115 does not detect erroneously even if panning shooting is performed, so the result of the posture detection unit 115 is displayed as an angle result display unit. It is displayed on 122 (S8). As shown in FIG. 6, the one-dot broken line indicates a horizontal line in the camera, and the dotted dotted line indicates a normal line with respect to gravity. The angle result display unit 122 is an area of the PNLCD 300 in the case of OVF shooting, and is a part of the display of the external display unit 113 in the case of live viewfinder shooting or moving image shooting. The force component acting on the camera at this time is only gravity as shown in FIG. The angle at which the camera is tilted is the angle formed by the one-dot broken line in FIG. 6 and the dotted dotted line.

  On the other hand, when there is no acceleration other than gravitational acceleration, that is, in the AB and CD sections, the posture detection unit 115 makes a false detection, so the result of the posture detection unit 115 is not displayed on the angle result display unit 122 but S9. Then, the movement vector calculation unit 150 calculates the movement vector of the background singularity (a method for calculating the movement vector of the background singularity will be described later). Here, if the result of the AB section (FIG. 5) in the posture detection unit 115 is displayed on the angle result display unit 122, the result is as shown in FIG. Here, in FIG. 8, the one-dot broken line indicates a line horizontal to the camera, and the dotted dotted line indicates a normal line with respect to the combined vector of gravity and inertial force. FIG. 9 is an explanatory diagram in which the combined vector of gravity and inertial force used in FIG. 8 is easy to understand, and the inertial force is generated in the direction opposite to the acceleration.

  Similarly, FIG. 10 shows the result of the posture detection unit 115 in which the acceleration is in the CD section of FIG. A one-dot broken line indicates a line horizontal to the camera, and a dotted dotted line indicates a normal line of a combined vector of gravity and inertial force. FIG. 10 is an explanatory diagram in which the combined vector of gravity and inertial force used in FIG. 9 is easy to understand, and the inertial force is generated in the direction opposite to the acceleration.

  The angle formed by the one-dot broken line in FIG. 8 and FIG. 10 and the dotted line of dot display corresponds to an erroneous display of a level that does not indicate the tilt of the camera. The angle calculation unit 110 calculates the tilt angle of the camera from the movement vector of the background singular point and the coordinate value of the photometric sensor 125 (S10). By displaying the result of the angle calculation unit 110 on the angle result display unit 122, the photographer is notified of the angle at which the camera is tilted (S11). The above is a flowchart regarding panning correction.

  Next, background singularity extraction conditions and tracking methods will be described. The imaging element finds at least two or more background singularities from one captured image. Furthermore, the background singularity is always updated whenever the captured image is updated. This is because if the number of background singularities is one, the movement vector of the background singularities cannot be continuously updated when the background singularities are cut off from the imaging region. A method for extracting a background singularity by separating a main subject and a background is, for example, as shown in Japanese Patent Laid-Open No. 2000-23036, in which each frame is divided into regions of an arbitrary size and pixels in each region are extracted. For each piece of data, distribution information indicating the probability that the target object is included in the pixel data may be created, and each subject in the image may be determined step by step based on the distribution information.

  Next, a method for calculating the movement vector of the background singularity will be described with reference to FIGS. FIG. 12 shows the panning start position when imaging the subject X traveling rightward, and FIG. 13 shows the panning end position. Because of panning shooting, the main subject X is always in the center of the screen.

  Background singular points a and b in FIG. 12 have moved to the positions of background singular points a ′ and b ′ in FIG. 13, respectively. The coordinates of the background singular points a and b at that time are stored in the CPU 101, and after tracking each, the coordinates of the background singular points a 'and b' are also stored. The background singularities here are edge ends indicated by dots, respectively. Thereafter, the movement vector calculation unit 150 moves the movement vector.

As well as the movement vector

Is also calculated. here,

When

Since the average vector is a movement vector of the background singularity, the following equation is established.

The above applies to the case where there are two background singularities, but the movement vector can be calculated using only a or b in FIG. In that case, only a 'or b' is shown in FIG. However, as the number of background singularities is larger, the accuracy of the movement vector is improved. When there are n background singularities, the above equation is

become. Next, a camera tilt angle calculation method will be described.

  FIG. 14 is a diagram showing the outer shape of the image sensor light receiving unit in a coordinate system. As shown in FIG. 14, the horizontal direction of the camera is a line connecting the coordinates (0,0) and (x, 0) of the image sensor or a line connecting (0, y) and (x, y). Or the vertical line of the camera is used as the reference line. The angle calculation unit 110 calculates an angle formed by the reference line and the movement vector. Here, when the photographer performs panning photographing, it is considered that horizontal panning or vertical panning is most frequently used. This is because panning a moving subject such as a train or a car is often directed toward the front, and when viewed from the photographer, the train or car is moving in the horizontal direction.

  Therefore, if the movement vector calculated by the movement vector calculation unit 150 is panning in the horizontal direction or panning in the vertical direction, a general subject can be handled. By doing so, the horizontal line on the ground or the normal line of the horizontal line and the movement vector are in the same direction, and the angle at which the camera is tilted can be calculated by the angle calculation unit. Thereafter, the angle calculation unit 110 calculates an angle formed by the reference line and the movement vector, and displays the result on the angle result display unit 122.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

106 CMOS sensor, 110 angle calculation unit, 113 external display unit,
115 posture detection unit, 122 angle result display unit, 125 photometric sensor,
150 Movement vector calculation unit, 300 PNLCD

Claims (5)

  Singular point extraction units (106) and (125) for extracting background singularities and a movement vector calculation unit (150) for detecting a movement vector of the background singular points in at least two different continuous captured images before the main photographing. ), An angle calculation unit (110) for calculating the tilt angle of the movement vector, and an angle result display unit (122) for displaying the tilt angle of the camera.   The angle result display unit (122) displays the result of the angle calculation unit (110) when it has an acceleration other than gravitational acceleration, and the posture detection unit (115) when it has no acceleration other than gravitational acceleration. The image pickup apparatus according to claim 1, wherein the result is displayed.   The imaging device according to claim 1 or 2, wherein the singular point extraction units (106) and (125) use a background singular point when the contrast value of the edge portion of the subject is equal to or greater than a certain threshold value. .   The singular point extraction units (106) and (125) track a background singular point in conjunction with the focus detection control unit (119) based on color information including the contrast value of the background singular point, The imaging apparatus according to claim 1 or 2, wherein the movement vector calculation unit (150) calculates the coordinate values of background singularities before and after tracking.   The imaging apparatus according to claim 1 or 2, wherein the angle calculation unit (110) calculates an angle formed by the movement vector and a camera horizontal direction or a vertical direction.