Image capturing device for performing auto focus adjustment on basis of rotation information and frequency component

Abstract

Embodiments of the present invention relate to a technology for performing auto focus adjustment on the basis of a frequency component according to rotation information. An image capturing device according to an embodiment of the present specification for achieving the purpose described above comprises: a capturing unit that captures an image; a sensor unit that measures rotation information corresponding to the capturing unit; and a control unit that selects a preset frequency band on the basis of the rotation information measured by the sensor unit, and identifies the sharpness of the image on the basis of the selected frequency band so as to adjust the focal position of the capturing unit.

Description

An imaging device that performs automatic focus adjustment based on rotation information and frequency components

[0001] Embodiments of the present invention relate to a technique for performing automatic focus adjustment based on frequency components according to rotation information.

[0002] Autofocus (AF) is the automatic focusing function of a video camera. This autofocus function can be implemented in two ways: phase detection, which detects the phase difference in reflected light to focus, and contrast detection, which detects the contrast of the image to determine the optimal focus.

[0003] Additionally, PTZ cameras allow users to set their desired shooting angle and magnification based on PAN, TILT, and ZOOM settings. These PTZ cameras store these settings to quickly display images from specific angles in response to user commands.

[0004] The background technology described above is technical information that the inventor possessed for the purpose of deriving the present invention or acquired in the process of deriving the present invention, and cannot necessarily be considered as publicly known technology disclosed to the general public prior to the application for the present invention.

[0005] The embodiment of the present specification is proposed to solve the above-described problem and provides a method and device for performing automatic focus adjustment based on a frequency component according to rotation information.

[0006] In order to achieve the above-described task, an image capturing device according to one embodiment of the present specification is provided, comprising a capturing unit for capturing an image, a sensor unit for measuring rotation information corresponding to the capturing unit, and a control unit for selecting a preset frequency band based on the rotation information measured by the sensor unit, and identifying the sharpness of the image based on the selected frequency band to adjust the focus position of the capturing unit.

[0007] The above control unit can control the photographing unit to photograph an image based on the adjusted focus position.

[0008] An image capturing device according to one embodiment of the present invention further includes a PTZ control unit for controlling PTZ (Pan-Tilt-Zoom) of the capturing unit, wherein the control unit selects a preset frequency band based on control information corresponding to the PTZ control unit and the rotation information, and identifies the sharpness of the image based on the selected frequency band to control the focus position of the capturing unit.

[0009] The control unit selects a first frequency band when the size of the rotation information is greater than or equal to a preset threshold value, and selects a second frequency band when the size of the rotation information is less than or equal to a preset threshold value, and the first frequency band may have a lower frequency band than the second frequency band.

[0010] The above preset frequency band is set to correspond to each rotation information among a plurality of rotation information corresponding to the shooting unit, and can be set based on the clarity of the image and the focus adjustment completion time for each frequency band.

[0011] The control unit can adjust the focus position of the photographing unit based on whether a preset event has occurred, select a preset frequency band corresponding to the preset event, and identify the sharpness of the image based on the selected frequency band to adjust the focus position of the photographing unit.

[0012] The control unit selects a first frequency band when the size of the rotation information due to the occurrence of the preset event is greater than or equal to a preset threshold value, and selects a second frequency band when the size of the rotation information due to the occurrence of the preset event is less than the preset threshold value, and the first frequency band may have a lower frequency band than the second frequency band.

[0013] The above control unit can re-acquire the size of the rotation information after waiting for a preset time if the size of the rotation information is greater than a preset threshold value.

[0014] The control unit can, when the size of the rotation information is greater than or equal to a preset threshold value, wait for a preset time and then identify the sharpness of the image based on a preset frequency band to adjust the focus position of the photographing unit.

[0015] In order to achieve the above-described task, a method for adjusting a focus position of an image capturing device according to one embodiment of the present specification is provided, comprising the steps of: capturing an image using the image capturing device; measuring rotation information of the image capturing device; selecting a preset frequency band based on the rotation information; and adjusting the focus position of the image capturing device by identifying the sharpness of the image based on the selected frequency band.

[0016] A computer program according to an embodiment of the present invention can be stored in a medium to execute any one of the methods according to an embodiment of the present invention using a computer.

[0017] Other aspects, features and advantages other than those described above will become apparent from the following drawings, claims and detailed description of the invention.

[0018] According to the present invention, AF of an image capturing device can be performed more effectively.

[0019] The effects of the embodiment are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by a person skilled in the art from the description of the claims.

[0020] FIG. 1 is a drawing illustrating an image capturing system according to one embodiment of the present invention.

[0021] FIG. 2 is a block diagram schematically illustrating the configuration of an image capturing device according to an embodiment of the present invention.

[0022] FIG. 3 is a flowchart schematically illustrating a method for adjusting the focus position of an image capturing device according to one embodiment of the present invention.

[0023] FIG. 4 is a flowchart schematically illustrating a method for adjusting the focus position of an imaging device according to another embodiment of the present invention.

[0024] FIG. 5 is a flowchart schematically illustrating a method for adjusting the focus position of an imaging device according to another embodiment of the present invention.

[0025] FIGS. 6 to 8 are diagrams for explaining differences in AF data according to frequency bands according to one embodiment of the present invention.

[0026] The terms used in this invention are used only to describe specific embodiments and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by those of ordinary skill in the art described in this invention. Terms defined in general dictionaries among the terms used in this invention may be interpreted as having the same or similar meaning in the context of the related technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this invention. In some cases, even if a term is defined in this invention, it cannot be interpreted to exclude embodiments of the present invention.

[0027] Below, various embodiments are described in detail with reference to the attached drawings so that those skilled in the art can easily practice the present invention. However, the technical idea of ​​the present invention can be modified and implemented in various forms, and is therefore not limited to the embodiments described in this specification. In describing the embodiments disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the technical idea of ​​the present invention, a detailed description of the known technology will be omitted. Identical or similar components will be given the same reference numerals, and redundant descriptions thereof will be omitted.

[0028] Here, the term '~ part' used in this embodiment refers to a component that performs a specific function performed by software or hardware such as an FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit). However, the '~ part' is not limited to being performed by software or hardware. The '~ part' may exist in the form of data stored in an addressable storage medium, or may be implemented by instructions so that one or more processors are configured to perform a specific function.

[0029] Software may include a computer program, code, instructions, or a combination of one or more of these, and may configure a processing device to perform a desired operation or, independently or collectively, command the processing device. The software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal wave for interpretation by the processing device or for providing instructions or data to the processing device. The software may be distributed over networked computer systems and stored or executed in a distributed manner. The software and data may be stored on one or more computer-readable recording media. The software may be read into main memory from another computer-readable medium, such as a data storage device, or from another device via a communications interface. Software instructions stored in main memory may cause the processor to perform processes or steps, which will be described in detail below. Alternatively, processes consistent with the principles of the present invention can be implemented using hardwired circuitry instead of, or in combination with, software instructions. Therefore, embodiments consistent with the principles of the present invention are not limited to any specific combination of hardware circuitry and software.

[0030] In the drawings, the sizes of components may be exaggerated or reduced for convenience of explanation. The present invention is not necessarily limited to what is illustrated. In addition, in the present disclosure, the expressions "more than" and "less than" are used to determine whether a specific condition is satisfied or fulfilled. However, this is only a description to express an example and does not exclude descriptions of more than or less than. Conditions described as "more than" may be replaced with "more than," conditions described as "less than" may be replaced with "less than," and conditions described as "more than and less than" may be replaced with "more than and less than."

[0031] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used solely for the purpose of distinguishing one component from another.

[0032] FIG. 1 illustrates an image capturing system (100) according to one embodiment of the present invention. The image capturing system (100) is a system in which an image captured by an image capturing device (107) controlled by a user terminal (101) is transmitted to the user terminal (101) via a network (103), and the user terminal (101) displays the image using a display. In particular, the image capturing device (107) of the image capturing system (100) may be a PTZ (PAN, TILT, ZOOM) camera that performs capturing at a shooting angle and magnification instructed by a user through PAN, TILT, and ZOOM settings.

[0033] Referring to Fig. 1, the video recording system (100) includes a network (103), a server (105), a user terminal (101), and a video recording device (107). Fig. 1 is an example for explaining the present invention, and the number of devices connected to the network (103) in a system according to one embodiment of the present invention is not limited.

[0034] The network (103) refers to a network that connects communication between multiple devices, either wired or wirelessly. According to one embodiment of the present invention, the network (103) may include wired networks such as local area networks (LANs), wide area networks (WANs), metropolitan area networks (MANs), and integrated service digital networks (ISDNs), and wireless networks such as wireless LANs, CDMA, Bluetooth, and satellite communication. The network (103) may be a closed network without any contact points or nodes connected to an external network. In other words, the network (103) may be a communication line that connects only predetermined components. According to one embodiment of the present invention, the network (103) may include a communication line that connects a server (105), a user terminal (101), and an image capturing device (107).

[0035] The server (105) may be implemented as a computer device or multiple computer devices that communicate with the user terminal (101) through a network to provide commands, codes, files, content, and services. The server (105) may provide content to the user terminal (101). The user terminal (101) may access the server (105) under the control of at least one program and receive services or content provided by the server (105).

[0036] The user terminal (101) may refer to various types of computing devices that output images acquired by the image capturing device (107), acquire user input for the images, and generate control signals for controlling the image capturing device (107). For example, the user terminal (101) may be a fixed user terminal implemented as a computer device or a mobile user terminal. According to one embodiment of the present invention, the user terminal (101) may include a smart phone, a mobile phone, a navigation device, a computer, a laptop, a user terminal for digital broadcasting, a personal digital assistant (PDA), a portable multimedia player (PMP), or a tablet PC. The user terminal (101) may communicate with devices through a network (103) using a wireless or wired communication method.

[0037] The video recording device (107) refers to a device that captures an image by capturing a preset area for purposes such as surveillance or security. For example, the video recording device (107) may transmit the captured image to a server (105) or a user terminal (101). For example, the video recording device (107) may be a device that captures an image according to a PTZ value set, particularly as a PTZ camera (Pan, Tilt, Zoom camera). At this time, the PTZ value may be a value including at least one of a Pan value, a Tilt value, and a Zoom value. In an optional embodiment of the present invention, the PTZ value may not include any of the Pan value, the Tilt value, and the Zoom value. For example, the PTZ value may include only the Pan value and the Tilt value, or may include only the Tilt value and the Zoom value. However, this is exemplary and the spirit of the present invention is not limited thereto.

[0038] The video recording device (107) can measure rotation information corresponding to the shaking of the video recording device (107) and perform auto focus (AF) adjustment based on the rotation information. The operation of the video recording device (107) is described in detail below.

[0039] The shape and type of the video recording device (107) illustrated in Fig. 1 are exemplary, and the spirit of the present invention is not limited thereto. Any device that acquires an image and transmits the acquired image through a connected network may correspond to the video recording device (107).

[0040] FIG. 2 is a block diagram schematically illustrating the configuration of an image capturing device according to an embodiment of the present invention.

[0041] Referring to FIG. 2, the video recording device includes a camera unit (210), a sensor unit (220), a PTZ control unit (230), a memory (240), and a control unit (250). According to other embodiments, components of the video recording device may be selectively included or excluded. For example, the camera unit (210), the sensor unit (220), the PTZ control unit (230), the memory (240), and the control unit (250) may each be connected as separate, independent components.

[0042] The photographing unit (210) can capture images of a video recording device. The photographing unit (210) can include a lens and an image sensor, and the focus position can be adjusted by the control unit (250).

[0043] The sensor unit (220) can measure rotation information corresponding to the photographing unit (210). This sensor unit (220) may be a gyroscope, and can measure the degree of shaking of the photographing unit (210) through three-dimensional rotation information.

[0044] The PTZ control unit (230) can determine the angle of view of the shooting unit (210) by controlling the rotation (pan), tilt, and zoom of the shooting unit.

[0045] The memory (240) can store various data for the overall operation of the video recording device, such as a program for processing or controlling the control unit (250) in the video recording device. The memory (240) according to one embodiment of the present invention can include preset data, image data, AF data, and a set frequency band.

[0046] The memory (240) can store a number of application programs being run, data for the operation of the video recording device, and commands. The memory (240) can be implemented as an internal memory such as a ROM or RAM included in the control unit (250), or can be implemented as a memory separate from the control unit (250).

[0047] The control unit (250) may be configured to control the video recording device as a whole. For example, the control unit (250) may control the video recording device to perform operations according to the present invention.

[0048] Specifically, the control unit (250) can control the operation of the video recording device using various programs stored in the memory (240). The control unit (250) can include a CPU, RAM, ROM, a system bus, etc. The control unit (250) can be implemented with a single CPU or multiple CPUs (or DSP, SoC). In one embodiment, the control unit (250) may be implemented as a digital signal processor (DSP), a microprocessor, or a time controller (TCON) that processes digital signals. However, the present invention is not limited thereto, and may include one or more of a central processing unit (CPU), a micro controller unit (MCU), a micro processing unit (MPU), a controller, an application processor (AP), a communication processor (CP), or an ARM processor, or may be defined by the corresponding terminology. In addition, the control unit (250) may be implemented as a system on chip (SoC) or large scale integration (LSI) having a built-in processing algorithm, or may be implemented in the form of a field programmable gate array (FPGA).

[0049] According to one embodiment, the control unit (250) may select a preset frequency band based on rotation information corresponding to the photographing unit (210) measured by the sensor unit (220), and may identify the sharpness of the image based on the selected frequency band to adjust the focus position of the photographing unit (210). This preset frequency band may be a value in the form of a table in which the frequency band value set by comparing the sharpness of the image and the focus adjustment operation time for each frequency band while the image photographing device adjusts the focus position is stored.

[0050] According to one embodiment, the control unit (250) may select a frequency band based on rotation information corresponding to the shaking of the imaging device during an automatic focus adjustment operation of the imaging device, acquire AF data based on the selected frequency band, and adjust the focus position based on the AF data. For example, the AF data may represent data on frequency band components from which an image is filtered in the selected frequency band.

[0051] For example, the frequency band according to the shaking of the video recording device can be selectively used based on information (e.g., AF operation time, whether or not focus is positioned, etc.) obtained by using frequency components differently at a specific point in time during the operation of the video recording device in real time by utilizing table values ​​that have been tested in advance. For example, the pre-tested table values ​​can be obtained by using low-frequency component data according to the degree of shaking of the video recording device or by configuring frequency filter coefficients differently (configuring the degree to which low-frequency component data is included differently) and obtaining frequency band table values ​​according to the degree of shaking through comparison data. Here, the comparison data can include AF completion time, whether and how focus is positioned, information that can be used within the Contrast AF algorithm, etc.

[0052] Additionally, at certain points during the operation of a real-time video camera, data can be selectively utilized to suit the installed environment by accumulating and utilizing information with varying frequency components. For example, this specific point in time could be during repetitive operations, such as viewing the same scene through presets, a condition of actual camera use.

[0053] According to one embodiment, the control unit (250) can control the photographing unit (210) to photograph an image based on the adjusted focus position.

[0054] According to one embodiment, the control unit (250) may select a preset frequency band based on control information corresponding to the PTZ control unit (230) and rotation information corresponding to the photographing unit, and may identify the sharpness of an image based on the selected frequency band to adjust the focus position of the photographing unit (210). For example, the preset frequency band may be set to correspond to each rotation information among a plurality of rotation information corresponding to the photographing unit, and may be set based on the sharpness of the image and the focus adjustment completion time for each frequency band.

[0055] According to one embodiment, the control unit (250) may select a first frequency band when the size of the rotation information is greater than or equal to a preset threshold value, and may select a second frequency band when the size of the rotation information is less than the preset threshold value. Here, the first frequency band may have a lower frequency band than the second frequency band.

[0056] A control unit (250) according to one embodiment can adjust the focus position of a photographing unit based on whether a preset event has occurred, select a preset frequency band corresponding to the preset event, and identify the sharpness of an image based on the selected frequency band to adjust the focus position of the photographing unit.

[0057] According to one embodiment, the control unit (250) may select a first frequency band when the size of rotation information due to the occurrence of the preset event is greater than or equal to a preset threshold value, and may select a second frequency band when the size of rotation information due to the occurrence of the preset event is less than the preset threshold value. Here, the first frequency band may have a lower frequency band than the second frequency band.

[0058] According to one embodiment, the control unit (250) can re-acquire the size of the rotation information after waiting for a preset time if the size of the rotation information is greater than or equal to a preset threshold value.

[0059] According to one embodiment, the control unit (250) can, if the size of the rotation information is greater than or equal to a preset threshold value, wait for a preset time and then identify the sharpness of the image based on a preset frequency band to adjust the focus position of the photographing unit.

[0060] FIG. 3 is a flowchart schematically illustrating the operation of an image capturing device according to one embodiment of the present invention.

[0061] Referring to FIG. 3, the video recording device can adjust the PTZ of the recording unit based on control information corresponding to the PTZ control unit at step S310. For example, the video recording device can determine control information, which is rotation information for PTZ adjustment, based on a control signal received from a user terminal, and adjust the PTZ of the recording unit based on the control information. Here, the control information is a value corresponding to the shaking of the video recording device, and the larger the size of the control information, the greater the shaking of the video recording device.

[0062] In one embodiment, the imaging device can capture an image at step S320. At this time, the image can indicate an image captured based on an arbitrary focus setting value.

[0063] In one embodiment, the video recording device may determine, at step S330, whether the size of control information corresponding to the PTZ control unit is greater than or equal to a threshold value. This threshold value may indicate a threshold value predetermined by preset data. If the size of the control information is greater than or equal to the threshold value at step S330, the video recording device may proceed to step S340 to determine a first frequency band for filtering the image. In addition, if the size of the control information is less than the threshold value at step S330, the video recording device may proceed to step S350 to determine a second frequency band for filtering the image. At this time, the first frequency band may have a lower frequency band than the second frequency band.

[0064] According to one embodiment, the image capturing device may filter the image based on the frequency band selected in steps S330 to S350 in step S360. For example, if the size of the control information is greater than or equal to a threshold value, the image capturing device may convert the pixel values ​​of the image into a frequency domain and filter out the first frequency band component, which is a relatively low frequency band. In addition, if the size of the control information is less than the threshold value, the image capturing device may convert the pixel values ​​of the image into a frequency domain and filter out the second frequency band component, which is a relatively high frequency band component.

[0065] In one embodiment, the image capturing device can identify the sharpness of an image based on the intensity and size of the filtered components in step S370, and adjust the focus position of the capturing unit. The image capturing device can repeatedly adjust the focus position, identify the sharpness, and then compare the sharpness to determine the focus position with the highest sharpness, thereby adjusting the focus.

[0066] According to one embodiment, the imaging device can capture an image based on the focus adjusted in step S380.

[0067] FIG. 4 is a flowchart schematically illustrating the operation of an image capturing device according to another embodiment of the present invention.

[0068] Referring to FIG. 4, the video capturing device can capture an image at step S410. At this time, the image can indicate the captured image based on an arbitrary focus setting value.

[0069] According to one embodiment, the video recording device can measure rotational information corresponding to the photographing unit at step S420. For example, the video recording device can measure rotational information indicating the degree of shaking of the photographing unit using a sensor unit. Here, the rotational information is a value corresponding to the shaking of the video recording device, and the larger the rotational information, the greater the shaking of the video recording device.

[0070] In one embodiment, the video capturing device may determine, at step S430, whether the size of rotation information corresponding to the photographing unit is greater than or equal to a threshold value. This threshold value may indicate a threshold value predetermined by preset data. If the size of the rotation information is greater than or equal to the threshold value at step S430, the video capturing device may proceed to step S440 to determine a first frequency band for filtering the image. In addition, if the size of the rotation information is less than the threshold value at step S430, the video capturing device may proceed to step S450 to determine a second frequency band for filtering the image. At this time, the first frequency band may have a lower frequency band than the second frequency band. For example, the preset frequency band may be set to correspond to each rotation information among a plurality of rotation information, and may be set based on the sharpness of the image and the focus adjustment completion time for each frequency band.

[0071] According to one embodiment, the image capturing device may filter the image based on the frequency band selected in steps S430 to S450 in step S460. For example, if the size of the rotation information is greater than or equal to a threshold value, the image capturing device may convert the pixel values ​​of the image into a frequency domain and filter out the first frequency band component, which is a relatively low frequency band. In addition, if the size of the rotation information is less than the threshold value, the image capturing device may convert the pixel values ​​of the image into a frequency domain and filter out the second frequency band component, which is a relatively high frequency band component.

[0072] In one embodiment, the image capturing device can identify the sharpness of an image based on the intensity and size of the filtered components in step S470, and adjust the focus position of the capturing unit. The image capturing device can repeatedly adjust the focus position, identify the sharpness, and then compare the sharpness to determine the focus position with the highest sharpness, thereby adjusting the focus.

[0073] According to one embodiment, the imaging device can capture an image based on the focus position adjusted in step S480.

[0074] According to another embodiment of the present invention, an image capturing device can adjust a focus position based on a preset frequency band corresponding to a preset event, depending on whether a preset event occurs. For example, there are various events that trigger the AF function in a camera system, and the focus position can be adjusted based on a preset frequency band according to an event (e.g., AF Trigger Source Event) that can cause camera shake for various functions as follows.

[0075] For example, in the case of an event where AF is executed immediately after a function that involves repeatedly moving specific P / T / Z coordinates at regular intervals, such as Preset, Area Zoom (a function that controls P / T / Z to a block drawn on the screen with the mouse), a low-frequency band may be used.

[0076] Also, in the case of events where AF is executed for compensation purposes due to temperature or time, even if the lens does not move, to compensate for the phenomenon where the focus position changes due to temperature change or time change, when AF is executed in a narrow range, such as when the temperature differs by a certain value from a specific time or when the last AF was executed, a high-frequency band can be used even if there is shaking.

[0077] According to one embodiment of the present invention, when AF is triggered, if the current camera shake data exceeds a certain value, the camera may wait for a certain period of time until the image stabilizes. Furthermore, if the image continues to shake despite the waiting period, low-frequency components may be utilized. Alternatively, AF may be executed after the waiting period and the shake has decreased.

[0078] According to one embodiment of the present invention, when AF is triggered, if the size of the current camera shake data is greater than a certain value, the video recording device can perform AF after waiting for a certain amount of time.

[0079] According to the present invention, it is possible to avoid deterioration of AF performance due to external temporary shaking.

[0080] According to another embodiment of the present invention, an image capturing device can re-measure the size of the rotation information after waiting for a preset time if the size of the rotation information of the image capturing device is greater than a preset threshold value.

[0081] According to another embodiment of the present invention, when the size of the rotation information of the image capturing device is greater than a preset threshold value, the image capturing device can adjust the focus position by identifying the sharpness of the image based on a preset frequency band after waiting for a preset time.

[0082] FIG. 5 is a flowchart schematically illustrating the operation of an imaging device according to another embodiment of the present invention.

[0083] As described above, the video recording device repeatedly checks rotation information, determines the most suitable setting frequency band corresponding to the rotation information, stores it in a table, and then identifies the rotation information in the future and selects the setting frequency band to use for AF control.

[0084] Referring to FIG. 5, the video recording device can adjust the PTZ of the recording unit based on control information corresponding to the PTZ control unit at step S510. For example, the video recording device can determine control information for PTZ adjustment based on a control signal received from a user terminal, and adjust the PTZ of the recording unit based on the control information.

[0085] An image capturing device according to one embodiment can capture an image at step S520. At this time, the image can indicate an image captured based on an arbitrary focus setting value.

[0086] According to one embodiment, the video recording device can measure rotational information corresponding to the photographing unit at step S530. For example, the video recording device can measure rotational information indicating the degree of shaking of the photographing unit using a sensor unit.

[0087] In one embodiment, the video capturing device may, in step S540, adjust the focus based on at least one of control information and rotation information, and compare the sharpness of the image and the focus adjustment operation time for each frequency band to determine a set frequency. Specifically, the video capturing device may compare the AF focus adjustment operation time corresponding to the rotation information and the frequency band to determine an optimal focus with high image sharpness. The video capturing device may determine a frequency band with a short AF focus adjustment operation time at which the sharpness reaches a threshold value or higher as the set frequency band.

[0088] According to one embodiment, the video recording device can match the set frequency and rotation information in step S550 and store them in a table format. This table-like data can be included in the preset data.

[0089] Figures 6 to 8 are diagrams illustrating differences in AF data according to frequency bands according to one embodiment of the present invention. For example, AF data may represent data for a selected frequency band component in which an image is filtered in a selected frequency band.

[0090] First, referring to Fig. 6, AF data (61) including low-frequency components generally has a less steep peak position than AF data (62) including high-frequency components, so the AF operation time may be longer or the position where the focus lens stops may be wider. However, when using AF data (62) including high-frequency components, when the video recording device (e.g., camera) shakes, a false peak may occur, which may increase the AF time required and make it impossible to find the focus position.

[0091] Referring to FIGS. 7 and 8, graphs are shown showing AF data (61) including low-frequency components of FIG. 7 and AF data (62) including high-frequency components of FIG. 8 when shaking of an imaging device (e.g., a camera) occurs.

[0092] As a result of comparing the AF data (61) including the low-frequency component of Fig. 7 and the AF data (62) including the high-frequency component of Fig. 8, it can be seen that it is efficient to adjust the focus position using the AF data (61) including the low-frequency component when shaking of the video recording device occurs.

[0093] According to the present invention, in order to overcome the deterioration of Auto Focus (AF) performance due to the shaking of an image capturing device (e.g., a camera), the degree of shaking based on Gyro is analyzed and AF data is selectively used to improve performance.

[0094] The above description of exemplary embodiments of the present invention provides explanation and illustration of the present invention, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teachings, or may be learned from practicing the present invention. For example, while a series of acts has been described with respect to FIG. 9, the order of these acts may be changed in other embodiments consistent with the principles of the present invention. Furthermore, non-dependent acts may be executed in parallel.

[0095] Although the present invention has been described with reference to the preferred embodiments mentioned above, various modifications and variations are possible without departing from the spirit and scope of the invention. Therefore, the scope of the appended claims shall encompass such modifications and variations as long as they fall within the spirit of the present invention.

Claims

1. In video recording equipment, A camera that takes images; A sensor unit for measuring rotation information corresponding to the above shooting unit; and An image capturing device comprising a control unit that selects a preset frequency band based on the rotation information measured by the sensor unit, identifies the sharpness of the image based on the selected frequency band, and adjusts the focus position of the capturing unit.

2. In paragraph 1, An image capturing device, wherein the control unit controls the photographing unit to capture an image based on the adjusted focus position.

3. In paragraph 1, It further includes a PTZ control unit that controls the PTZ (Pan-Tilt-Zoom) of the above shooting unit, A video recording device in which the control unit selects a preset frequency band based on control information corresponding to the PTZ control unit and the rotation information, and identifies the sharpness of the image based on the selected frequency band to adjust the focus position of the shooting unit.

4. In paragraph 1, The control unit selects a first frequency band when the size of the rotation information is greater than or equal to a preset threshold value, and selects a second frequency band when the size of the rotation information is less than or equal to a preset threshold value. An image capturing device wherein the first frequency band has a lower frequency band than the second frequency band.

5. In paragraph 1, A video shooting device in which the preset frequency band is set to correspond to each rotation information among a plurality of rotation information corresponding to the shooting unit, and is set based on the sharpness and focus adjustment completion time of the image for each frequency band.

6. In paragraph 1, A video recording device, wherein the control unit adjusts the focus position of the photographing unit based on whether a preset event has occurred, selects a preset frequency band corresponding to the preset event, and identifies the sharpness of the image based on the selected frequency band to adjust the focus position of the photographing unit.

7. In paragraph 6, The control unit selects a first frequency band when the size of the rotation information due to the occurrence of the preset event is greater than or equal to a preset threshold value, and selects a second frequency band when the size of the rotation information due to the occurrence of the preset event is less than or equal to a preset threshold value. An imaging device wherein the first frequency band has a lower frequency band than the second frequency band.

8. In paragraph 1, The control unit is an image capturing device that, if the size of the rotation information is greater than a preset threshold value, waits for a preset time and then re-acquires the size of the rotation information.

9. In paragraph 1, The control unit is an image capturing device that, when the size of the rotation information is greater than a preset threshold value, waits for a preset time and then identifies the sharpness of the image based on a preset frequency band to adjust the focus position of the capturing unit.

10. In a method for adjusting the focus position of a video recording device, A step of capturing an image using the above imaging device; A step of measuring rotation information of the above video recording device; A step of selecting a preset frequency band based on the above rotation information; and A method for adjusting a focus position, comprising the step of identifying the sharpness of the image based on a selected frequency band and adjusting the focus position of the image capturing device.

11. In paragraph 10, The step of selecting the frequency band includes the step of selecting a first frequency band when the size of the rotation information is greater than or equal to a preset threshold value, and selecting a second frequency band when the size of the rotation information is less than or equal to a preset threshold value. A method for adjusting a focus position, wherein the first frequency band has a lower frequency band than the second frequency band.

12. In paragraph 10, A method for adjusting a focus position, wherein the preset frequency band is set to correspond to each rotation information among a plurality of rotation information, and is set based on the clarity of the image and the focus adjustment completion time for each frequency band.

13. In paragraph 10, A method for adjusting a focus position, wherein the step of adjusting the focus position includes a step of adjusting the focus position based on a preset frequency band corresponding to a preset event depending on whether a preset event has occurred.

14. In paragraph 10, A method for adjusting a focus position, wherein the step of measuring the rotation information includes a step of re-measuring the size of the rotation information after waiting for a preset time if the size of the rotation information is greater than a preset threshold value.

15. In paragraph 10, A method for adjusting a focus position, wherein the step of adjusting the focus position includes a step of adjusting the focus position by identifying the sharpness of the image based on a preset frequency band after waiting for a preset time when the size of the rotation information is greater than or equal to a preset threshold value.

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