JP2013059045A - Imaging device, imaging system and imaging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device, an imaging system and an imaging method capable of performing impressive life-size reproduction display of a person in consideration of an image quality of a display device while effectively utilizing digital zoom without degrading the image quality.SOLUTION: Since a relation between a subject distance and a focal distance can be derived for each screen size of a television, if a user inputs the screen size to a camera, the camera can decide a zoom position of a zoom lens on the basis of a photographing distance.

Description

  The present invention relates to an image pickup apparatus, an image pickup system, and an image pickup method, and more particularly, an image pickup apparatus convenient for reproducing and displaying an image taken by an image pickup apparatus such as a digital camera on an external display device such as a television on a life-size basis, The present invention relates to an imaging system and an imaging method.

In a video conferencing system, it is possible to give a sense of realism when a remote person is projected in real size, and the conference can be held more smoothly. A system has been proposed (see Patent Document 1). This video conference system sends information on the projection distance and projection angle between the projector unit on the receiving side and the screen to the transmitting side, and the transmitting side uses the information transmitted from the receiving side and the distance information between the user who is the subject. Based on this, the angle of view of the camera on the transmission side is adjusted so that a life-size image can be displayed regardless of the position of the participant.
JP 2005-3030683 A

In addition, in an imaging device such as a digital camera, viewing of captured images is generally performed by printing, but in addition to this printing, a television is connected to a digital camera and displayed on the television. Yes. Patent Document 2 discloses a digital camera that performs display control in consideration of display magnification when displaying a captured image on a television.
JP 2000-354181 A

  Patent Documents 1 and 2 described above disclose displaying on a display device at a predetermined magnification, but no consideration is given to image quality. That is, the number of pixels in a recent imaging device such as a digital camera is larger than the number of pixels in a display device such as a television, and photography with high image quality is possible. However, in consideration of the image quality of the display device, it has been impossible to perform life-size and powerful reproduction display of a person while effectively using the digital zoom without causing image quality degradation.

  The present invention has been made in view of such circumstances, and in consideration of the image quality of the display device, it is possible to display a life-size and powerful reproduction of a person while effectively using the digital zoom without degrading the image quality. An object is to provide an imaging apparatus, an imaging system, and an imaging method that can be performed.

  In order to achieve the above object, an imaging apparatus according to a first invention includes an input unit for inputting a screen size of an external display device, a control unit for calculating a zoom position in accordance with the distance between the screen size and a subject, and the imaging A transmission unit that transmits the image to the external display device.

  An image pickup apparatus according to a second invention is characterized in that, in the first invention, the control unit calculates the zoom position in consideration of a difference in aspect ratio between the image pickup apparatus and the external display device. To do.

  According to a third aspect of the present invention, there is provided the imaging apparatus according to the first aspect, wherein the control unit determines execution of control or warning control to the zoom position according to the determined focal length.

  According to a fourth aspect of the present invention, in the first aspect, the screen size of the external display device is set so that the input unit communicates when the captured image is transmitted to the external device. It is acquired from an apparatus.

  According to a fifth aspect of the present invention, there is provided an imaging method according to an input step of inputting a screen size of an external display device, a distance between the screen size and a subject, and an aspect ratio difference between the imaging device and the external display device. And a transmission step of transmitting the captured image to the external display device.

  According to a sixth aspect of the present invention, there is provided an image pickup apparatus comprising: a control unit that calculates a converted focal length at the time of shooting according to a screen size input by a diagonal length of an external display device screen and a subject distance; And a transmission unit for transmitting to an external display device.

  According to a seventh aspect of the present invention, there is provided an imaging system comprising: a control unit that determines a converted focal length at the time of shooting according to a screen size of an external device and a subject distance; and a transmission unit that transmits the captured image to the external display device. And a communication device having a communication unit for inputting the screen size of the external device to the image pickup device.

  In the imaging system according to an eighth invention, in the seventh invention, the control unit of the imaging device determines the converted focal length in consideration of a difference in aspect ratio between the imaging device and the external display device. It is characterized by performing a calculation.

  According to the present invention, an image pickup apparatus, an image pickup system, and an image pickup apparatus capable of performing life-size and powerful reproduction display of a person while effectively using digital zoom without considering image quality degradation in consideration of the image quality of the display device An imaging method can be provided.

  Hereinafter, a preferred embodiment will be described using an imaging system to which the present invention is applied according to the drawings. FIG. 1 is a block diagram showing a configuration of a camera 10 according to an embodiment of the present invention. The camera 10 is a digital camera that captures a subject and acquires an image. The camera 10 includes a control unit 1, a photographing unit 2, an optical zoom unit 3, an electronic zoom control unit 4, an image recording unit 5, a face image determination unit 6, a face size determination unit 6a, a reproduction size and display pixel input unit 7, A display unit 8 and a television (TV) transmission unit 9 are provided. The control unit 1 includes a CPU and the like, and performs overall control of the camera 10.

  The photographing unit 2 includes an optical system including a zoom lens for forming a subject image, an image sensor that photoelectrically converts the subject image, an image processing unit that processes a signal output from the image sensor, and outputs image data. To do. The optical zoom unit 3 optically changes the focal length of the optical system described above. The electronic zoom control unit 4 trims the image data output from the above-described image sensor, that is, changes the image extraction range from the image sensor in accordance with the zooming operation, and changes the shooting angle of view in a pseudo manner. Produces the same effect. The optical zoom unit 3 and the electronic zoom control unit 4 can automatically change the focal length in the life-size mode, as will be described later, in addition to changing the focal length according to the zooming operation by the photographer. .

  The image recording unit 5 records the image data output from the photographing unit 1 after compression processing. The display unit 8 is configured by a liquid crystal monitor or the like, and performs playback display of an image recorded in the image recording unit 2 or display of live view or the like based on image data output from the imaging unit 2. The face image determination unit 6 detects a face image in the screen based on the photographed image from the photographing unit 2.

  The face image determination unit 6 includes a face size determination unit 6a. The face size determination unit 6a determines the face size of the face image determined by the face image determination unit 6. The face image determination unit 6 and the face size determination unit 6a perform detection for controlling the optical zoom 3 and the electronic zoom control unit 4 so that the size of the face becomes substantially the same as the actual size at the time of display.

The playback size and display pixel input unit 7 is connected to the camera 10 and inputs the screen size of the display device such as the television 20 (see FIG. 2) for displaying the captured image, the number of pixels, and the like. The input unit 7 may be configured by an input device that is manually operated by a user, or may be automatically transmitted from a display device such as the television 20. Further, when the camera 10 and the display device are sold as a set, they may be written in advance in the image recording unit 5 or the like in the camera 10.
In any case, the input unit 7 only needs to be able to capture such information into the camera 10.

  The resizing unit 11 changes the number of pixels of the image data recorded in the image recording unit 5 in consideration of the number of pixels on the screen of a display device such as the television 20 connected to the outside. The TV transmission unit 9 transmits image data to an external display device such as the television 20. As a transmission means, there are a wireless device using radio waves and infrared rays, wired transmission using a cable connection, and the like. Further, it may be sent to the television 20 or the like by a storage medium.

  In this way, the present embodiment is configured. The subject image formed by the zoom lens is converted into an electric signal by the photographing unit 2, subjected to image processing, compressed, and then recorded in the image recording unit 5. The image recorded in the image recording unit 5 can be reproduced and displayed on the display unit 8, but the image data is output to a display device such as a large-screen thin television 20 via the TV transmission unit 9, whereby FIG. As shown in the figure, a life-size image can be enjoyed on a large screen.

  However, whether or not life-size display is possible on an external display device such as the television 20 depends on the specifications of the television 20 such as the screen size, and therefore the specifications such as the screen size are input by the input unit 7. When transmitting to the television 20, the data is preferably larger than the number of pixels of the television 20, and if the number of pixels is small, the reproduction capability of the television 20 cannot be fully utilized and the image quality looks poor. Therefore, the number of pixels that can be displayed on the television 20 is taken into the camera 10 by the input unit 7.

  Further, the number of pixels of the captured image of the camera 10 is generally larger than that of the display device such as the television 20, and in this case, even if a part of the captured image is cut out, the number of pixels of the display device is larger. There is. In this case, if the number of pixels is larger than the number of display pixels of the television 20 or the like, it is possible to shoot without image quality deterioration. Therefore, in the present embodiment, the electronic zoom by the electronic zoom control unit 4 can be used effectively, and even if the subject is at a long distance, or even in a display device such as the television 20 with a small screen size, it is powerful and powerful. You can enjoy large shots.

  Therefore, the face image determination unit 6 detects the face image in the screen so that the face size is substantially the same as the actual size at the time of display, and the size determination unit 6a detects the face size. Then, according to the detection result, the optical zoom unit 3 and the electronic zoom unit 4 are controlled to adjust the size of the face of the subject in the acquired captured image.

  As described above, in the present embodiment, when a captured image is sent to a display device in various playback environments such as a large-screen television at home for playback, the face image is close to the size of an actual person and powerful. You can enjoy the shot images.

  Next, with reference to FIG. 3, a basic concept when taking a life-size image with the camera 10 will be described. FIG. 3A shows a state in which a person 30 as a subject is displayed on a 46-inch (inch) television 20. 46 inches indicates the diagonal of the screen of the television 20, and when the screen aspect ratio is 16: 9 of the high vision standard, the length in the vertical direction is 57 cm. When the size of the face is adjusted to be about 1/3 in the vertical direction, 57 ÷ 3≈19 (cm) is obtained, and the face size is almost life-size.

  Therefore, as shown in FIG. 3B, in order to adjust the person 30 up and down so that the person 30 is not cut in consideration of the difference in aspect ratio, the face size is 1 in the vertical direction. It is sufficient to shoot with a composition such that / 3. In accordance with this concept, in the camera 10 according to the present embodiment, when the person 30 is far away, shooting is performed so that the person 30 becomes larger by optical zooming or electronic zooming.

  Depending on the distance of the person 30, optical zooming or electronic zooming may not be able to zoom in sufficiently. In this case, an advice display 8 a such as “Please get closer” is displayed on the display unit 8. The advice display 8a is not limited to this expression, and may be a warning that the image quality of display on the TV 20 provided outside deteriorates when resizing by digital zoom, or may be a pictorial symbol. The advice display 8a is performed by the control unit 1 controlling the display unit 8 according to the determination result by the face size determination unit 6a, the focal length information of the optical zoom unit 3 and the electronic zoom unit 4, and the like.

  Next, a method for determining the focal length of the zoom lens of the camera 10 will be described with reference to FIG. 4 in consideration of the screen size of the television 20. Now, it is assumed that the person 30 as the subject is photographed by the photographing lens 2a having the focal length f. A face with a size YF of the person 30 is projected onto the image sensor 2b with a size of Yf.

  The relationship between the two is as shown in the following equation (1).

Yf = f * YF / L (1)
Here, L represents a photographing distance from the photographing lens 2a to the person 30, f represents a focal length, and * means multiplication. The focal length is a value obtained by converting the longitudinal direction of the image pickup element 2b into a 35 mm film (135 film), and Yf is also a 35 mm film converted value.

  Next, consider a case where the face image of the person 30 photographed by the camera 10 is displayed on the television 20 having the screen height Ytv. In this case, assuming that the face height is Ytvf, the following equations (2) and (3) are obtained.

24 mm: Yf = Ytv: Ytvf (2)
Yf = 24 mm * Ytvf / Ytv (3)
Here, since the person 30 is displayed on the television 20 in a life size, the face size YF of the person 30 is equal to the face size Ytvf of the person 30a displayed on the television 20, and the following equation (4) Get.

Ytvf = YF (4)
Further, the screen size of the television 20 (the length of the diagonal line is expressed in inches) and the height Ytv of the television 20 have the relationship of the following equation (5).

  As can be seen from the above equation (5), for example, in the case of a 42-inch (inch) television, the screen height Ytv is approximately 21 inches when multiplied by 0.5. To convert this to cm, What is necessary is just to multiply about 2.5 cm, and it will be about 52 cm.

  By substituting the equations (4) and (5) into Ytvf and Ytv in the above equation (3), the following equation (6) is obtained.

Yf = 48 mm * (Ytvf / screen size (inch)) (6)
Substituting equation (6) into equation (1) above to find the focal length f yields the following equation (7).

f = L * Yf / YF
= L * 48mm * Ytvf / (YF * screen size (inch))
≒ 48mm * L (mm) / (Screen size (inch) * 25 (mm))
≒ 2 * L (mm) / screen size (inch) ・ ・ ・ ・ ・ ・ ・ (7)
Therefore, when shooting a subject at a distance L (mm), if the focal length f is adjusted so as to satisfy Equation (7), the size of the subject's face becomes substantially life-size. In other words, if the camera 10 is zoomed to satisfy the expression (7), the subject can be displayed on the television 10 in a life-size manner.

  Since the relationship between the subject distance L and the focal length f can be obtained for each screen size of the television 20, if the user inputs the screen size to the camera 10, the camera 10 determines the zoom position of the zoom lens from the shooting distance. Can be determined.

In the description of FIG. 3, the shooting method is instructed from the size of the face, but as can be seen from the equation (7), life-size shooting is also possible by obtaining the shooting distance. However, since there are many cameras that cannot measure the distance, the same control is possible based on the size of the face.
The size of the face varies slightly depending on the person, but the difference due to individual differences is not large, and when displaying the life size on the TV 20, some errors are not worrisome. The shooting distance L may be obtained from the face size YF.

  Further, it may not be possible to photograph a person 30 as a long-distance subject as shown in FIG. 5 at an intended predetermined size (life size) simply by optically zooming with the optical zoom 3. In this case, the optical zoom is not enough, but only the partial image 2c is extracted (trimmed) from the image data output from the image sensor 2b as shown in FIG. It may be recorded as an image as shown.

  In this case, since only a part of the total number of pixels Nc of the image sensor 2b is used, the image quality tends to deteriorate. However, since the total number of pixels of the image sensor 2b of the camera 10 is Nc = 8M (8 million) and the number of pixels of the display unit of the television 20 is equivalent to high vision, it is 2M (2 million). Even if it is electronically enlarged twice, when it is displayed on the television 20, there is no deterioration in display.

  Enlarging the image data electronically by a factor of two corresponds to a further double in terms of focal length. If the optical zoom is 3 ×, the zoom is 6 × including the electronic zoom. If the focal length is 35 mm, the 6 × zoom enables shooting corresponding to the focal length of 210 mm.

  If the electronic zoom magnification is Zd, the number of effective pixels decreases in inverse proportion to the square thereof, but if the number of pixels Ntv of the display unit of the television 20 is equal to or larger than the number of effective pixels, transmission to the television 20 is performed. The reproduced image of the obtained image has the same image quality as the electronic zoom and the optical zoom. This is because even if an image with a large number of pixels is transmitted, it cannot be displayed unless it is resized after the display.

  When performing life-size shooting such as displaying a person in real size on the display unit of the television 20 according to the subject distance and the size of the face of the person who is the subject, the screen size of the television 20 and the life-size photography are taken. FIG. 6 shows the relationship between the subject distance and the zoom position (focal length f). In this figure, the horizontal axis is the subject distance, and the vertical axis is the focal length of the camera 10 by optical zoom or electronic (digital) zoom.

  Further, the area between the focal distances P0 to P1 is an area where the focal distance is changed by the optical zoom. A region between the focal lengths P1 and P2 is a region where there is no image degradation even if the focal length is changed by electronic zoom, considering the number of pixels of the display unit of the television 20. The focal length P2 or more is a region where image degradation appears when the number of pixels of the display unit of the television 20 is taken into account when the focal length is changed by electronic zoom.

  As can be seen from FIG. 6, the larger the screen TV, the longer the object can be photographed at a low magnification (short focal length side). The farther the subject is, the longer it is necessary to increase the focal length. However, there is no problem because there is no pixel deterioration in the optical zoom range (up to the focal length P1), and even when the focal length is extended in the electronic zoom range, as described above. Further, there is no image degradation due to the trimming effect up to the number of display pixels of the television 20 (up to the focal length P2). If this limit is exceeded, a warning such as advice display 8a (see FIG. 3) is given.

  Next, the camera control operation will be described with reference to the flowchart shown in FIG. If this flow is entered, it is first determined whether or not the shooting mode is set (S1). The camera 10 can use two modes, a playback mode and a shooting mode. If the result of determination is that the shooting mode has been set, it is determined whether or not zooming has been performed and zooming is in progress (S2).

  If the result of determination in step S <b> 2 is that zooming is not in progress, the operating state of the release button is detected and it is determined whether or not shooting is to be performed (S <b> 11). As a result of the determination, if the release operation has not been performed, the process returns as it is. On the other hand, if a release operation has been performed, shooting and recording are performed (S12). In the photographing / recording operation, the photographing unit 2 acquires image data of a subject image and records the image data in the image recording unit 5. When the photographing operation ends, the process returns and returns to step S1.

  If the result of determination in step S2 is that a zoom operation has been performed, it is determined whether or not the life-size mode has been set (S3). Since this life-size mode is set on the menu screen of the camera 10, it is determined whether or not this setting has been made. If the result of the determination is that the camera is in the life-size mode, the face size and the distance to the subject are measured (S4), the zoom is determined, and the optical zoom unit 3 performs zoom determination according to the determined focal length. Driving is performed (S5).

  That is, in the case of the life-size mode, as described with reference to FIGS. 4 to 6, using the information such as the screen size of the television 10, shooting is performed so that the person who is the subject is displayed in life-size. Adjust the focal length of the lens by optical zoom or electronic zoom. In step S4, when the distance to the subject cannot be obtained directly, the subject distance is obtained from the face size, and the focal length is determined.

  When the zoom position is determined, it is subsequently determined whether or not to perform electronic zoom (S6). The focal length of the photographic lens in the life-size mode can be determined based on the above-described equation (7). When this focal length is longer than the focal length by the optical zoom, electronic zoom is performed. If the electronic zoom is performed as a result of the determination, it is determined whether or not there is image quality degradation (S7). As described above, when the number of pixels is reduced by trimming by electronic zoom and is smaller than the number of display pixels on the screen of the television 20, it is determined that the image quality is deteriorated.

  If it is determined in step S7 that the image quality has deteriorated, a warning is given by the advice display 8a or the like as shown in FIG. 3 (S8). Further, the electronic zoom may be limited to an area where the image quality deteriorates with or without a warning. When the electronic zoom is limited, a warning may be issued to limit the resizing.

  If it is not the life-size mode in step S3, if it is not electronic zoom in step S6, or if there is no image quality deterioration in step S7, normal zoom control is performed (S9).

  If the result of determination in step S <b> 1 is not shooting mode, it is determined whether or not playback mode is set (S <b> 21). As a result of the determination, if it is not the playback mode, it is determined whether or not it is the television specification input mode (S31). As a result of the determination, if it is not the television specification input mode, the process returns. On the other hand, if it is the television specification input mode, the television specification input is performed (S32).

  For the TV specification input, the user inputs the screen size and the number of pixels of the display unit of the TV 20 by the reproduction size and display pixel input unit 7. As described above, the screen size and the number of pixels are used when performing focal length adjustment in the life-size mode, warning of image quality degradation during electronic zoom, and the like. As described above, the screen size and the like may be input manually or may be acquired by connecting the television 20 and the camera 10. Moreover, you may acquire via a net | network.

  If the result of determination in step S <b> 21 is playback mode, the selected captured image is played back and displayed on the display unit 8 such as a liquid crystal monitor as in the conventional camera (S <b> 22). Subsequently, it is determined whether or not it is a television transmission (S23). In this step, the camera 10 is provided with an operation member for transmitting a captured image on the television, and it is determined whether or not this operation member has been operated.

  If the result of determination in step S <b> 23 is that it is not television transmission, processing returns directly. On the other hand, in the case of television transmission, the image is transmitted for reproduction of the captured image on the television 20 which is a feature of the present embodiment (S24). In this step, the image data recorded in the image recording unit 5 is wirelessly transmitted from the television transmission unit 9 to the television 20 using infrared rays, a wireless LAN, or the like, and the television 20 enables reproduction of the received image. Of course, the communication is not limited to wireless, and may be wired or exchanged via a recording medium such as a card. Further, at this timing, communication may be used to acquire the television specification in the same manner as in step S32.

  As described above, in one embodiment of the present invention, in order to produce a zooming effect from image data acquired by photographing a subject, image data is generated by trimming, and the trimmed image data is externally generated. To the display device. Further, a warning is given when the image quality deteriorates when the number of pixels constituting the image data is displayed on an external display device. For this reason, in consideration of the image quality of the display device, it is possible to perform life-size and powerful reproduction display of a person or the like while effectively using the digital zoom without degrading the image quality.

  In one embodiment of the present invention, if the image quality deteriorates when displaying on an external display device because the number of pixels constituting the image data is small, a warning is given to shoot closer to the subject, Alternatively, a warning is given to limit the resizing by the electronic zoom control means, or a warning is given to the effect that the image quality of the display by the external display means deteriorates when resizing is performed by the electronic zoom control means. Therefore, when displaying on an external display device, it is possible to prevent display with degraded image quality.

  Furthermore, in one embodiment of the present invention, first, when the focal length is adjusted in the optical zoom and the processing cannot be performed by the optical zoom, the processing by the electronic zoom is performed. For this reason, when recording on a recording medium, it can record with a high pixel count.

  In the embodiment of the present invention, the resize unit 11 is provided in the camera 10, but is not limited thereto, and may be provided in the television 20, and further provided in both the camera 10 and the television 20. May be. In the present embodiment, the camera 10 is not provided with a distance measuring unit, but a distance measuring unit may be provided and the face size determining unit 6a may be omitted.

  Furthermore, in one embodiment of the present invention, an optical zoom lens is provided, and first, the focal length is adjusted to obtain a life size by the optical zoom lens. However, the present invention is not limited to this, and a fixed focus lens is provided. You may perform the process by electronic zoom so that it may become substantially life size by zooming.

  Furthermore, in one embodiment of the present invention, the focal length that is substantially life-size and can be displayed is obtained by calculation according to the formulas (1) and (7). However, the calculation is not limited to this formula, and the calculation result is also calculated. Of course, the table may be used as a table reference.

  Furthermore, in the embodiment of the present invention, the digital camera is used as the photographing device. However, the camera may be a digital single-lens reflex camera or a compact digital camera, and a mobile phone or a portable information terminal. Of course, a camera built in (PDA: Personal Digital Assist) or the like may be used.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, you may delete some components of all the components shown by embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

It is a block diagram which shows the structure of the camera concerning one Embodiment of this invention. It is a figure which shows a mode that the picked-up image is displayed on the television as an external display apparatus by the life size in the camera concerning one Embodiment of this invention. 1A and 1B are diagrams illustrating a basic concept when performing life-size shooting in a camera according to an embodiment of the present invention, in which FIG. 1A illustrates a state in which a person who is a subject is displayed on a television, and FIG. An advice display is shown when the camera is full-sized and cannot be photographed even when zooming is performed with the camera. FIG. 4 is a diagram illustrating a method of determining a focal length of a zoom lens of a camera in consideration of a screen size of a television in a camera according to an embodiment of the present invention. FIG. It is a figure which shows a relationship, (b) shows the display of the image in the display part of a television. FIG. 4 is a diagram illustrating a case where electronic zoom is performed without adjusting the focal length of the zoom lens of the camera with the optical zoom in the camera according to the embodiment of the present invention, and FIG. It is a figure which shows a relationship, (b) shows the image on an image pick-up element, (c) shows the enlarged image by electronic zoom. 5 is a graph showing the relationship between the TV screen size, subject distance, and zoom position (focal length f) when performing life-size shooting in the camera according to an embodiment of the present invention. It is a flowchart which shows the operation | movement of the camera control in the camera concerning one Embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 ... Control part, 2 ... Imaging | photography part, 2a ... Shooting lens, 2b ... Image pick-up element, 2c ... Partial image, 3 ... Optical zoom part, 4 ... Electronic zoom control , 5... Image recording unit, 6... Face image determination unit, 6a... Face size determination unit, 7... Playback size and display pixel input unit, 8. .. Advice display, 9 ... TV (TV) transmission unit, 10 ... Camera, 11 ... Resize unit, 20 ... TV, 30 ... Person

Claims (8)

An input unit for inputting the screen size of an external display device;
A control unit that calculates the zoom position according to the screen size and the distance of the subject;
A transmission unit for transmitting the captured image to the external display device;
An imaging apparatus comprising:   The imaging device according to claim 1, wherein the control unit calculates the zoom position in consideration of a difference in aspect ratio between the imaging device and the external display device.   The imaging apparatus according to claim 1, wherein the control unit determines execution of control or warning control to the zoom position in accordance with the determined focal length.   2. The imaging apparatus according to claim 1, wherein the screen size of the external display device is acquired from the external device through communication by the input unit when the captured image is transmitted to the external device. . An input step for inputting the screen size of the external display device;
A control step of calculating a converted focal length at the time of shooting according to the difference in aspect ratio between the screen size and the subject, and the imaging device and the external display device;
A transmission step of transmitting the captured image to the external display device;
An imaging method comprising: A control unit that calculates a converted focal length at the time of shooting in accordance with the screen size input by the diagonal length of the external display device screen and the distance of the subject;
A transmission unit for transmitting the captured image to the external display device;
An imaging apparatus comprising: An imaging device including a control unit that determines a converted focal length at the time of shooting according to the screen size of the external device and the distance of the subject, and a transmission unit that transmits the captured image to the external display device,
A communication device having a communication unit for inputting the screen size of the external device to the imaging device;
An imaging system comprising:   The imaging system according to claim 7, wherein the control unit of the imaging apparatus performs calculation for determining the converted focal length in consideration of a difference in aspect ratio between the imaging apparatus and the external display device.