JP2016158106A - Imaging device and control method of imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that the high frequency components of a display image are conventionally extracted and displayed without relying upon the distance from the imaging device to a subject, and since a large number of high frequency components of a subject remote from the imaging device are extracted and displayed, even when MF of a subject close to the imaging device is performed, operability and visibility of MF are lowered.SOLUTION: In an imaging device including an imaging unit, a display unit for displaying an image captured by the imaging unit, an information acquisition unit for acquiring the distance information of a subject included in an image, and a waveform creation unit for extracting the high frequency components of an image, and creating a waveform image indicating the focusing degree of a subject based on the high frequency components, the waveform creation unit creates the waveform image of an image area corresponding to a subject included in a predetermined distance range, by using the distance information, and the display unit displays the waveform image along with the image.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging apparatus and a method for controlling the imaging apparatus, and more particularly to a technique for displaying a waveform indicating a degree of focus of a subject together with an image being captured.

  In recent years, auto focus (AF) technology has advanced, and AF technology is mainly used for focus detection of an imaging apparatus such as a digital video camera or a digital camera. However, manual focus adjustment (Manual Focus: MF) technology is used when the degree of focus of a subject is intentionally adjusted, or under shooting conditions where it is difficult to focus on the subject with AF.

  The photographer performs MF while confirming the degree of focus of the subject on the display device mounted on the imaging device. However, in a small imaging device, the size of the display device and the number of displayable pixels are reduced, and high-precision MF is obtained. It was sometimes difficult.

  Therefore, an auxiliary display method has been devised for the photographer to check the degree of focus. For example, a method for enlarging and displaying a part of an image on a display device, a method for displaying a contour line of a subject in an image called peaking by thick coloring, and the like are common.

  Further, Patent Document 1 discloses a method for improving the operability and visibility of MF by displaying a waveform image generated by extracting a high-frequency component (object edge information) of a display image so as to overlap the original display image. Proposed.

JP 2010-243923

  However, the conventional technique extracts and displays a high-frequency component of a display image without depending on the distance from the imaging device to the subject, and even when performing MF of a subject close to the imaging device, the subject far from the imaging device Many high-frequency components are extracted and displayed. Accordingly, there is a problem that the operability and visibility of the MF are lowered depending on the shooting situation.

  In order to solve the above problems, an embodiment of the present invention includes an imaging unit, a display unit that displays an image captured by the imaging unit, and an information acquisition unit that acquires distance information of a subject included in the image And a waveform image generation unit that extracts a high-frequency component of the image and generates a waveform image that indicates a degree of focus of the subject based on the high-frequency component, wherein the waveform image generation unit includes the distance A waveform image of an image area corresponding to a subject included in a predetermined distance range is generated using information, and the display unit displays the waveform image together with the image. Features.

  According to the present invention, it is possible to further improve the operability and visibility of the MF.

It is a block diagram which shows the structure of the imaging device which concerns on Embodiment 1 of this invention. FIG. 3 is a diagram illustrating an example of a distance between the imaging apparatus of the first embodiment and a subject. FIG. 3 is a diagram illustrating an operation flow of the imaging apparatus according to the first embodiment. FIG. 6 is a diagram illustrating an operation flow of the imaging apparatus according to the second embodiment. FIG. 10 is a diagram illustrating an example of a distance between an imaging device and a subject when the subject is tracked in the imaging device according to the second embodiment. FIG. 10 is a diagram illustrating an example of a distance between an imaging apparatus of Embodiment 3 and a subject. It is a figure showing composition of an image sensor in an imaging device concerning an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. An imaging apparatus according to an embodiment of the present invention is a digital camera that can capture still images and moving images, for example.

(First embodiment)
The imaging apparatus according to the present embodiment performs live view display of an image being captured on a display unit attached to the imaging apparatus, and a waveform indicating the degree of focus of the subject generated using the distance information of the subject included in the captured image. An embodiment in which an image is displayed as auxiliary information and MF is described as an example.

  First, the configuration and operation of each block of the imaging apparatus will be described with reference to FIG. 1 which is a block diagram showing the configuration of the imaging apparatus of the present embodiment.

  The imaging sensor unit 101 is an imaging element that functions as an imaging unit such as a CCD or a CMOS, photoelectrically converts a captured image formed by adjusting the amount of incident light and focusing by the imaging lens group 100, and further converts analog / Outputs digital signal after digital conversion.

  For each pixel of the image sensor, any one of R (red), G (green), and B (blue) color filters is arranged in a mosaic for each pixel as shown in FIG. Each pixel has a structure in which one red pixel, one blue pixel, and two green pixels are regularly arranged. Such an arrangement of pixels is generally called a Bayer array. FIG. 7A illustrates an example in which one pixel is configured by one region, and FIG. 7B illustrates an example in which one pixel is configured by two regions (A and B). In the present embodiment, an example in which an imaging sensor (divided pixel sensor) having the structure of FIG.

  FIG. 7 (3) shows an example of the structure of the image sensor unit 101 that employs the image sensor having the structure of FIG. 7 (2). The light receiving element for A image receives light that has passed through the A image area of the imaging lens, and the light receiving element for B image receives light that has passed through the B image area of the imaging lens. By receiving the A image and the B image of the same imaging lens with a divided pixel through one microlens, it is possible to acquire two image signals with parallax.

  The electrical signal converted by the imaging sensor unit 101 is transmitted to the development processing unit 102 as Bayer image information obtained by adding the image information obtained from the A area and the B area shown in FIG. Further, the distance information acquisition unit 104 calculates the distance of the subject from the parallax information obtained from the A area and the B area.

  The development process 102 receives the Bayer image signal and first performs RGB offset adjustment, gain adjustment, and gamma correction processing. The gamma correction is processed with characteristics for generating a recorded image desired by the user in consideration of characteristics of the image sensor unit 101, the lens group 100, and the like. By changing this gamma correction value, it is possible to generate a recorded image for display on a TV monitor, or a recorded image that reproduces the texture and gradation of a movie film. Next, the RGB image signal is converted into a luminance signal (Y) and a color difference signal (Cb, Cr) and output. In addition, correction processing for lens distortion, image stabilization processing for the imaging apparatus, noise reduction processing, and the like are also performed.

  The recognition unit 105 has a function of detecting and recognizing subject information in image information. For example, a face in the screen represented by the image information is detected, information indicating the position of the detected face is output, and person authentication is performed based on feature information such as the face. In addition, by receiving distance information of each subject included in the captured image from the distance information acquisition unit 104, detected subject information having distance information is generated.

  The high frequency component extraction unit 106 extracts high frequency components (subject edge information) from the image information from the development processing unit 102. The extraction method of the edge information is not limited. For example, the edge information is extracted by a FIR (Finite Impulse Response) type bandpass filter. Further, the extracted portion of the edge information may be the entire image information, or the image information may be partially designated as the extracted portion by the detected subject information from the recognition unit 105.

  The waveform generation unit 107 adds information obtained by multiplying the edge information extracted by the high-frequency component extraction unit 106 by an arbitrary gain for each frequency (edge strength), and arranges the information in the image horizontal direction or image vertical direction (waveform image). Is generated. The waveform image is a waveform having a length corresponding to the strength of the edge component as an index, and indicates the position and strength of the edge component in the image. The longer waveform indicates that the subject is more focused than the shorter waveform.

  The image synthesis unit 108 superimposes the image signal (luminance signal and color difference signal) output from the development processing unit 102 and the waveform image signal output from the waveform generation unit 107 to generate one image signal. It is also possible to adjust the transparency of the waveform image when the waveform image is superimposed on the captured image and synthesized. Here, the configuration in which the captured image and the waveform image are combined to display the combined image is shown, but it is not always necessary to perform the combining process, and the waveform image may be displayed superimposed on the captured image.

  The MF instructs the focus adjustment amount from the input operation unit 110, and the lens control unit 112 and the sensor control unit 103 perform adjustment control of the incident light amount and focus.

  An imaging apparatus is configured by the above processing units.

  Next, the operation of the imaging apparatus according to the present embodiment will be described with reference to the operation timing chart of FIG.

  In step S300, shooting is started.

  In step S301, it is selected whether to display a waveform image together with the captured image, and in the case of waveform display, an edge component is extracted in step S302 to generate a waveform, and the waveform image is displayed as shown in FIG. .

  Referring to FIG. 2B, the captured image includes four subjects (A, B, C, D), and edge components corresponding to all the subjects are displayed on the entire screen. When the waveform image is not displayed, the lens control unit 112 adjusts the lens group 100 to perform MF adjustment by operating a focus adjustment mechanism such as a focus ring while observing only the image in step S306.

  Next, in step S303, it is selected whether or not a distance range for waveform display is designated. When a distance range is designated, in step S304, at least one distance range is selected from the four distance ranges shown in FIG. . For the selection of the distance range, a method of setting as distance information from the input operation unit 110 or a selection method by specifying a subject in an image displayed on the display device 109 can be used. For example, the setting unit for setting the distance range can be configured with an interface screen in the display device 109.

  In the above example, when the distance range 1 is selected, only the edge components around the subject A included in the distance range 1 are waveform-displayed as shown in FIG. Similarly, when the distance range 2 is selected, only the edge components around the subjects D and B included in the distance range 2 are displayed as waveforms as shown in FIG.

  Although an example in which one distance range is selected is shown here, a plurality of distance ranges may be selected. When a plurality of distance ranges are selected, a waveform image of an area corresponding to the subject included in the selected plurality of distance ranges is generated. When a plurality of distance ranges are selected, the waveform color in the waveform image may be varied according to the distance range. By changing the color of the waveform, the photographer can recognize in which distance range the subject is included.

  Further, as shown in the figure, by displaying the waveform in correspondence with the position of the subject, it is possible to easily recognize to which subject the focusing degree is indicated by the waveform.

  In step S305, the photographer operates the focus adjustment mechanism such as a focus ring while observing the waveform display displayed together with the captured image on the display device 109, whereby the lens control unit 112 adjusts the lens group 100, and the MF. Adjustments can be made. After the subject intended by the photographer is focused, recording is started in step S307.

  As described above, according to the present embodiment, using the distance information of the subject, the waveform image indicating the degree of focus of the subject is generated based on the high frequency component of the image region corresponding to the subject included in the predetermined distance range, By displaying together with the captured image, the operability and visibility of the MF can be improved.

(Second Embodiment)
The imaging apparatus according to the present embodiment will be described by way of an example in which MF is performed while displaying a waveform image indicating the degree of focus of a subject as auxiliary information using subject distance information and subject tracking information.

  The block diagram showing the configuration of the imaging apparatus of the present embodiment is as shown in FIG.

  An operation that is a feature of the imaging apparatus according to the present embodiment will be described with reference to an operation timing chart of FIG.

  In step S320, shooting is started.

  In step S321, it is selected whether or not to display a waveform image. When displaying a waveform, an edge component is extracted and a waveform is generated in step S322, and the waveform image is displayed as shown in FIG. In FIG. 2B, there are four subjects (A, B, C, D) and the edge components of the entire screen are displayed. If the waveform is not displayed, the lens control unit 112 adjusts the lens group 100 and performs MF adjustment by operating a focus adjustment mechanism such as a focus ring while observing only the image in step S328.

  Next, in step S323, it is selected whether or not the distance range of the waveform display is designated. When the distance range is designated, the distance range is selected from the four distance ranges shown in FIG. The distance range is selected by a method of setting distance information from the input operation unit 110 or by specifying a subject in an image displayed on the display device 109. For example, when the distance range 2 is selected, only the edge components around the subjects D and B existing in the distance range 2 are displayed in a waveform as shown in FIG.

  In step S325, it is selected whether to track the subject within the designated distance range. When the subject is to be tracked, the tracking subject is designated in step S326. For example, when the subject D is designated as a tracking target, when the subject D moves from the distance range 2 to the distance range 1 as shown in FIG. 5 (1), the waveform display changes from the display of FIG. 5 (2) to FIG. 5 (3). The display switches to. That is, the waveform display corresponding to the subjects D and A is switched from the waveform display corresponding to the subjects D and B to the waveform display corresponding to the subjects D and A according to the movement to be changed to another distance range of the tracking subject D.

  This embodiment is an effective function when it is desired to focus on the main subject D intended by the photographer and the surrounding subjects whose distance range is close to the main subject D.

  If the subject is selected not to be tracked in step S325, and the subject D is moved from the distance range 2 to the distance range 1 as shown in FIG. 5 (1), the waveform display is changed from the display of FIG. 5 (2) to FIG. The display switches to (4). This is effective when the subject that the photographer wants to focus is within the distance range specified in step S325.

  In step S327, the photographer operates the focus adjustment mechanism such as a focus ring while observing the displayed waveform display, so that the lens control unit 112 adjusts the lens group 100 and performs MF adjustment. After the subject intended by the photographer is focused, recording is started in step S329.

  According to the present embodiment, even when the tracking target subject is not included in the predetermined distance range, the waveform image of the image region corresponding to the tracking target subject is generated according to the distance range to which the tracking target belongs. It becomes possible.

(Third embodiment)
The configuration of the imaging apparatus of the present embodiment is the same as that shown in FIG. 1 as in the first embodiment, and the operation timing chart is the same as that in FIG. 3 of the first embodiment and FIG. 4 of the second embodiment. A feature of this embodiment is a waveform display method.

  When the waveform display is performed in step S302 of FIG. 3 and step S322 of FIG. 4, the imaging apparatus of the present embodiment can set the waveform display color for each distance range as shown in FIG.

  If the distance range 1 is set to color 1, the waveform in the distance range 1 is displayed in color 1 as shown in FIG. 6 (2), and the waveform corresponding to the subject in the other distance range is displayed for each distance range. Displayed in the set color. The color type and range setting are variable and are set by the system control unit 111.

  The present invention is also realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program code. It is a process to be executed. In this case, the program and the storage medium storing the program constitute the present invention.

DESCRIPTION OF SYMBOLS 100 Lens group 101 Imaging sensor part 102 Development processing part 103 Sensor control part 104 Distance information acquisition part 105 Recognition part 106 High frequency component extraction part 107 Waveform generation part 108 Image composition part 109 Display apparatus 110 Input operation part 111 System control part 112 Lens control Part

Claims (6)

An imaging unit;
A display unit for displaying an image captured by the imaging unit;
An information acquisition unit for acquiring distance information of a subject included in the image;
A waveform image generating unit that extracts a high-frequency component of the image and generates a waveform image that indicates a degree of focus of a subject based on the high-frequency component,
The waveform image generation unit generates a waveform image of an image region corresponding to a subject included in a predetermined distance range using the distance information,
The said display part displays the said waveform image with the said image, The imaging device characterized by the above-mentioned.   The imaging apparatus according to claim 1, further comprising a setting unit that allows a user to set the predetermined distance range.   The imaging apparatus according to claim 1, wherein the waveform image generation unit varies the color of the waveform in the waveform image according to the distance of the subject. Tracking means for tracking the subject;
The waveform image generation unit generates a waveform image of an image region corresponding to the subject to be tracked even when the subject to be tracked is not included in the predetermined distance range. 4. The imaging device according to any one of 3. The waveform image generation unit is capable of adjusting the transparency of the waveform image,
5. The imaging apparatus according to claim 1, wherein the display unit displays the waveform image so as to overlap the image. 6. A method of controlling an imaging apparatus that displays a degree of focus of a subject together with an image being captured,
Obtain distance information of the subject included in the image,
Using the distance information, extract a high frequency component of a region corresponding to a subject included in a predetermined distance range from the image, and generate a waveform image indicating the degree of focus of the subject based on the high frequency component,
A control method for an imaging apparatus, wherein the waveform image is displayed together with the image.

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