CN104125387A - Photography guidance method and electronic device - Google Patents

Abstract

The present invention provides a photography guidance method and an electronic device, wherein the electronic device has a photography unit to capture a photography picture, and the photography guidance method includes: determining a designated area in the photography picture, wherein the size of the designated area is smaller than the size of the photography picture; determining a target object in the photography picture; when the target object is not located in the designated area, generating a guidance signal according to a relative position between the target object and the designated area, so as to guide the target object to move into the designated area by the guidance signal. The present invention can improve the problems that are easily encountered in the photography process, such as the user's body being cut off in the photos taken in the past, blocking a specific scenery, or the photography angle being not good.

Description

Photography guidance method and electronic device

technical field

The invention relates to image analysis technology, in particular to a photography guidance method and an electronic device.

Background technique

Generally speaking, users may use cameras or photographic devices such as smartphones to take selfies under certain circumstances (for example, when there is no one nearby). For example, using the lenses of various photographic devices or the front lens of a smart phone to take selfies and the like.

However, for users who use a camera device without a front lens, who are unwilling to use a front lens to take a selfie (the performance of the front lens is usually poor), or use the remote control camera function, they often encounter problems It is impossible to take an ideal picture smoothly. For example, when it is impossible to know whether the user is currently at an ideal position in the photographing frame, it often leads to problems such as the user's body part being cut off, blocking a specific scenery, or the photographing angle in the captured photograph is not good.

Contents of the invention

In view of this, the present invention provides a photography guidance method and an electronic device, which can effectively improve problems such as cut off user's body parts, blocked specific scenery, or poor photography angles in the captured photos.

The present invention provides a photography guidance method, which is suitable for an electronic device, and the electronic device has a photography unit to capture a photography picture. The photography guidance method includes: setting a designated area in the photography picture, wherein the designated area The size is smaller than the size of the photographing screen; set a target in the photographing screen; when the target is not located in the designated area, generate a guide signal according to a relative position between the target and the designated area, so as to pass the guide signal Guide the target to move within the designated area.

The present invention further provides an electronic device, including a photographing unit and a processing unit. The photographing unit is used for capturing a photographing frame. The processing unit is coupled to the photographing unit, and is used for setting a designated area in the photographing frame and setting a target in the photographing frame, wherein the size of the designated area is smaller than the size of the photographing frame. When the target object is not located in the designated area, the processing unit generates a guide signal according to a relative position between the target object and the designated area, so as to guide the target object to move into the designated area by the guide signal.

Based on the above, the present invention proposes a photography guidance method and an electronic device, which can set one or more designated areas in the photography screen. When the captured target exceeds the specified area, a guidance signal is sent out by voice or other means to guide the target to move into the specified area, thereby improving the user's body parts that were cut off and blocked in the photos taken in the past Problems that are easy to encounter during photography such as specific scenery or poor camera angles.

Description of drawings

FIG. 1 is a schematic diagram of an electronic device according to an embodiment of the invention.

FIG. 2A , FIG. 2B , FIG. 2C and FIG. 2D are schematic diagrams of guiding an object to move into a designated area according to an embodiment of the present invention.

FIG. 3A , FIG. 3B and FIG. 3C are schematic diagrams of guiding an object to move into a designated area according to another embodiment of the present invention.

FIG. 4A , FIG. 4B and FIG. 4C are schematic diagrams illustrating how to guide a user to move the electronic device to capture the same photographing frame as the background image according to an embodiment of the present invention.

FIG. 5 is a flowchart of a photography guidance method according to an embodiment of the present invention.

FIG. 6 is a flowchart of a photography guidance method according to another embodiment of the present invention.

Symbol Description:

10—electronic device; 11—photographic unit;

12—processing unit; 13—display unit;

14—input unit; 15—voice output unit;

16—storage unit; 21, 31, 41—photographing screen;

22, 32, 45—designated area; 23, 33—user;

44—background image; 412, 414, 442, 444—reference point;

S510, S520, S530—the steps of the photography guidance method according to an embodiment of the present invention;

S602, S604, S606, S608, S610, S612, S614—the steps of the photography guidance method in another embodiment of the present invention.

Detailed ways

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of an electronic device according to an embodiment of the invention. Please refer to FIG. 1 , the electronic device 10 may be various electronic devices with a camera function such as a camera, a digital video recorder (digital video) or a smart phone (smart phone). The electronic device 10 at least includes a camera unit 11 and a processing unit 12 . The camera unit 11 is a camera module, and is used to capture a camera frame. For example, the camera unit 11 may include main components in a general camera module such as a lens and a photosensitive element. It is worth mentioning that the photographing picture mentioned here refers to the picture captured by the photographing unit 11 when the user focuses or searches for a target before pressing the shutter, not after the user presses the shutter. A picture actually taken by the photographing unit 11.

The processing unit 12 is coupled to the camera unit 11 , and the processing unit 12 is, for example, various processors or controllers. The processing unit 12 can set a specified area in the photographing frame from the photographing unit 11 . In this embodiment, the size of the specified area will be smaller than (or equal to) the size of the photographing frame, depending on the needs of the user. In particular, the present invention can also adaptively adjust setting information such as the number, size, and shape of designated regions in each photographing frame, and the position of each designated region in the photographing frame. For example, the electronic device 10 may further include a display unit 13 and an input unit 14 . The processing unit 12 can display the photographed frame and the designated area captured by the photographing unit 11 on the screen of the display unit 13, wherein the designated area can be surrounded by visible or invisible lines. The input unit 14 can be a variety of signal input devices such as physical or virtual keys, a remote controller and/or a voice input device, and is used to receive user input operations. After the input unit 14 receives the user's input operation, the processing unit 14 can set the above-mentioned setting information of the designated area according to the input operation, that is, set the number, size, shape and position of the designated area in the photographing screen, etc. . Alternatively, the display unit 13 and the input unit 14 can also be combined into a touch screen, depending on practical requirements.

In addition, the processing unit 12 can set the target object in the photographing frame. The target in the photographing frame is, for example, an object that the user of the electronic device 10 or various users want to make appear in a specific position in the photographing frame, and the number of the target can be one or more. Furthermore, the target can be locked on a certain part of the body (for example, the face or upper body) or the whole body, depending on the needs. For example, the user can set the configuration of the target through the input unit 14 , and use the configuration as a basis for the processing unit 12 to identify or search for the target from the photographed images. For example, suppose the user defines the target as face or upper body, when the processing unit 12 sets the target in the photographing frame, it can recognize the person's face or upper body from the photographing frame as the target. Alternatively, assuming that the user sets the definition of the target as the whole body, the processing unit 12 can recognize the whole body of the person as a whole target from the shooting frame when setting the target in the shooting frame. The above-mentioned method of setting the target object from the photographic image can be realized by various image processing methods such as face recognition technology and human body recognition technology, and the present invention is not limited to specific implementation methods.

Next, the processing unit 12 can determine whether the target object in the shooting frame is located in the specified area. For example, the processing unit 12 may determine whether the user's face, upper body or whole body in the photographing frame is located in the designated area, depending on the above definition of the target object. In this embodiment, as long as the target object in the shooting screen is not completely within the specified area, for example, some parts of the target object (such as face, hands, feet and other body parts) exceed the specified area, the processing unit 12 will determine that the target object The object is not located in the designated area. Or, in one embodiment, the processing unit 12 can also pre-set a threshold value. When the area of the target object beyond the specified area is greater than the threshold value, the processing unit 12 determines that the target object is not located in the specified area, thereby improving practical operation. operational flexibility.

When the processing unit 12 judges that the target object in the photographing frame is not located in the designated area, the processing unit 12 can generate a guide signal according to the relative position of the target object and the designated area, so as to guide the target object to move to the designated area by the guide signal. within the area. In this embodiment, the guide signal is, for example, a voice guide signal. For example, the electronic device 10 may include a voice output unit 15 . The voice output unit 15 is, for example, various audio output devices such as speakers and earphones. The processing unit 12 can control the voice output unit 15 to output the voice guidance signal, so as to guide the user (that is, the target object) beyond the specified area in the photographing frame to move into the specified area. Alternatively, the processing unit 12 may also wirelessly transmit the guidance signal to a remote device held by the user, so that guidance information is displayed on the screen of the remote device to guide the user to move to a designated area, etc. Etc., the present invention does not limit the embodiment of the pilot signal, as long as the embodiment of the pilot signal can be used as the above purpose, it all belongs to the category of the embodiment of the present invention.

Taking the user taking pictures of himself/herself by remotely controlling the electronic device 10 in a non-handheld manner as an example, FIG. 2A , FIG. 2B , FIG. 2C and FIG. Schematic diagram of the area. Referring to FIG. 2A , the user 23 can set the designated area 22 in the photographing screen 21 through the input unit 14 . In this embodiment, although the designated area 22 is a rectangle as an example, it may also be various geometric figures such as a circle or a shape defined by the user. Taking the touch screen combined with the display unit 13 and the input unit 14 as an example, the user can draw on the touch screen with input tools such as fingers and other human body postures such as standing, sitting, squatting and/or lying. The designated area corresponding to the pose.

Please continue to refer to FIG. 2B , assuming that the object in the shooting frame 21 is defined as the whole body of the user 23 . Since the initial position of the user 23 in the photographing frame 21 is much beyond the right border of the specified area 22, the processing unit 12 judges that the object in the photographing frame 21 (that is, the user 23) is not located in the specified area 22, and according to The relative position of the target object (ie, the user 23 ) and the designated area 22 generates a guide signal, so as to guide the target object (ie, the user 23 ) to move into the designated area 22 by the guide signal. In particular, in this embodiment, since the user 23 places the electronic device 10 in front of him and controls the electronic device 10 to take a selfie by remote control, the processing unit 12 can control the voice output unit 15 to output "please Move to your right" and similar voice guidance signals to allow the user 23 to move to his right.

Please continue to refer to FIG. 2C. After the user 23 follows the guidance signal and moves his body to the right, if the user 23 still exceeds the scope of the designated area 22, the processing unit 12 can continue to output the corresponding guidance signal to guide The user 23 completely enters the designated area 22 . Referring to FIG. 2D , after the user 23 completely enters the designated area 22 , the processing unit 12 can automatically send a shutter signal to the photographing unit 11 to execute the photographing function of the photographing unit 11 . Alternatively, the processing unit 12 can also send out a notification signal (for example, through the voice output unit 15 to send out a voice notification signal such as "the target is already in the designated area") to inform the user 23 that there is no need to move any more, and within a preset After a certain time (for example, 3 seconds), the above-mentioned shutter signal and the like are sent, which can be flexibly adjusted according to practical requirements.

In addition, taking the user holding the electronic device 10 and pointing the lens of the electronic device 10 at himself to take a selfie as an example, FIG. 3A , FIG. 3B and FIG. 3C illustrate the movement of the guided object according to another embodiment of the present invention. to the map in the specified area. Referring to FIG. 3A , the user 33 can set the designated area 32 in the photographing screen 31 through the input unit 14 . Similar to the previous embodiment, although the designated area 32 is exemplified by a rectangle, it may also be various geometric figures such as a circle or a shape defined by the user. In particular, in this embodiment, the target is defined as the face of the user 33 .

Please continue to refer to FIG. 3B. When the processing unit 12 judges that the target object (ie, the face of the user 33) in the photographing screen 31 is not located in the designated area 32, the processing unit 12 may The relative position of the face) and the designated area 32 generates a guide signal, so as to guide the target (ie, the face of the user 33 ) to move into the designated area 32 by the guide signal. In this embodiment, since the user takes a selfie by pointing the lens of the electronic device 10 at himself in a hand-held manner, the processing unit 12 can control the voice output unit 15 to output "please turn the lens of the electronic device 10 to your left." Turn" or "please move your head to your right" and other similar voice guidance signals to allow the user to turn the lens of the electronic device 10 to the left or to move the user's head to the right. Please continue to refer to FIG. 3C, after the target object (that is, the head of the user 33) is completely within the designated area 33, the processing unit 12 can automatically send a shutter signal to the camera unit 11 to perform the camera function of the camera unit 11, or send a The above-mentioned notification signal informs the user 23 that there is no need to move any more, and the above-mentioned shutter signal is sent after a preset time (for example, 3 seconds), which can also be flexibly adjusted according to practical requirements.

Furthermore, the electronic device 10 may further include a storage unit 16 . The storage unit 16 is, for example, the internal memory of the electronic device 10 or an external storage medium (eg, a memory card or a USB flash drive), etc., and can be used to store various identification information such as one or more specified facial features. Wherein, the identification information can be used to identify the specified target object in the photographing frame from the photographing unit 11 . For example, the processing unit 12 may know that there are more than one candidate target (for example, one or more persons including the user) in the currently captured photographic frame through facial recognition technology, and obtain the information of each candidate target. Candidate facial features. Then, the processing unit 12 can compare the obtained candidate facial features with a specified facial feature stored in the storage unit 16 , wherein the specified facial feature is, for example, the facial feature of the user currently using the electronic device 10 to take pictures. Next, the processing unit 12 may use the candidate target object having the same facial features as the specified facial feature among the candidate target objects recognized in the photographing frame as the selected target object, and compare the selected target object with the previously set associated with the designated area. After the association between the target object and the designated area is generated, the processing unit 12 can perform subsequent guidance operations such as determining whether the target object is located in the designated area based on the association.

In addition, the present invention does not limit the number of associations between objects and designated areas. For example, when taking a group photo of multiple people, the processing unit 12 can set a plurality of designated areas (for example, according to the user's input operation), and recognize a plurality of designated targets ( For example, each object is a person). Wherein, the method of identifying the specified target object can be achieved by using facial recognition technology to compare the multiple candidate facial features with the multiple specified facial features in the storage unit 16 . Then, the processing unit 12 can associate each obtained target object with a designated area, and then perform subsequent guidance operations such as determining whether each target object is located in its corresponding designated area, etc. for these objects.

In particular, in one embodiment, the user can pre-set the designated area and/or the number of objects. Then, the processing unit 12 may determine whether the number of objects set from the photographing frame is equal to a preset number. If the number of targets is not equal to the preset number, it means that someone may be blocked or not in the mirror due to other factors, so the processing unit 12 can control the voice output unit 15 to output "Please pay attention to whether you are in the mirror" or similar voices pilot signal. Alternatively, the processing unit 12 may also determine whether the number of objects is equal to the number of designated areas. If the number of target objects is not equal to the number of specified areas (for example, the number of target objects is small), the processing unit 12 can find out from the storage unit 16 whether it appears on the photographing screen according to the association between each specified area and the target object. The name or nickname of the target object, and control the voice output unit 15 to output "Please Wang Xiaoming (that is, the user's name or nickname that does not appear on the photographing screen) to adjust your position" and similar voice guidance signals to inform Users who do not appear on the photographing screen adjust their photographing positions.

Or, in one embodiment, in order to recognize a specified target object from the photographic image (for example, to identify a specified target object from a plurality of candidate targets), the processing unit 12 can also output a recognition voice through the voice output unit 16 , taking the candidate target that performs the behavior corresponding to the recognized voice among the candidate targets as the specified target, and associating the specified target with the specified area. For example, the processing unit 12 can output through the voice output unit 16 recognition voices with motion information such as "please shake your head left and right" or "please wave your hands". Then, the processing unit 12 can use the candidate target object that has the action of "shaking the head left and right" or "waving the hands" in the photographing screen as the specified target object, and compare the specified target object with the previously set specified area. to associate. After the association between the target object and the designated area is generated, the processing unit 12 can perform subsequent guidance operations such as determining whether the target object is located in the designated area based on the association.

In addition, in an embodiment, in addition to making the user taking the selfie appear in an ideal position in the photo, the present invention can also make the background in the photo meet the user's requirements. For example, before setting the designated area on the photographing screen, the processing unit 12 can also obtain a background image (background image) from the storage unit 16, wherein the background image is an image previously captured by the user, and it can include using Or the preset information of the designated area, for example, the number, size, shape of the designated area, the position of the designated area in the background image, and so on. Next, after the photographing unit 16 captures the current photographing frame, the processing unit 12 can determine whether the photographing frame is the same as the background image. When the photographing frame is different from the background image, the processing unit 12 can generate a guide signal according to the relative position of the photographing frame and the background image, so as to use the guide signal to guide the user to move the electronic device 10 to capture the image identical to the background image. photography screen.

For example, FIG. 4A and FIG. 4B are schematic diagrams of guiding the user to move the electronic device to capture the same photographing frame as the background image according to an embodiment of the present invention. Referring to FIG. 4A , the user uses the electronic device 10 to capture a background image 44 in advance, sets a designated area 45 on the background image 44 , and stores the background image 44 in the storage unit 16 . After reading out the background image 44 from the storage unit 16, the processing unit 12 can set more than one first reference point on the background image 44, and record the first position of the first reference point on the background image 44 and its corresponding to the first image feature. In this embodiment, the first reference point is, for example, reference point 442 and reference point 444, and as shown in FIG. Characterized by "House".

Please continue to refer to FIG. 4B. After setting the first position of the first reference point on the background image 44 and its corresponding first image feature, the processing unit 12 can search for the first reference point on the photographing screen 41 from the photographing unit 11. A second image feature with the same or similar image features (for example, searching for the “tree” corresponding to the reference point 442 and the “house” corresponding to the reference point 444 ). After searching for the second image feature, the processing unit 12 may set a second reference point on the shooting frame 41 according to a second position of the second image feature on the shooting frame 41 . In this embodiment, the second reference point is, for example, the reference point 412 and the reference point 414 , which correspond to the “tree” and the “house” corresponding to the reference point 412 and the reference point 414 respectively.

After setting the second reference point on the photographing frame 41, the processing unit 12 can set the relative position between the photographing frame 41 and the background image 44 by comparing the relative positions of the first reference point and the second reference point, and according to the The relative position of the frame 41 and the background image 44 generates a guide signal. For example, the processing unit 12 can control the voice output unit 15 to output a voice guidance signal such as "please turn the lens of the electronic device 10 to your left" to guide the user to turn the lens of the electronic device 10 to the left, Thus, the photographing screen 41 from the photographing unit 11 is adjusted to be the same as the background image 44 .

When the processing unit 12 judges that the first reference point and the second reference point are at the same position or overlap, it means that the user has adjusted the photographing frame 41 from the photographing unit 11 to be the same as the background image 44 according to the guide signal, and the processing unit 12 The specified area can be set in the photographing screen according to the information of the designated area 45 included in the background image, and the above-mentioned subsequent guidance operations such as setting the target object in the photographing screen and judging whether the target object is located in the designated area can be performed. Efficiently capture photos with your favorite background and with the user in an ideal position in the photo (eg, without blocking a particular view, etc.) without the assistance of outsiders.

In addition, in an embodiment, the above implementation manner is also applicable to a usage scenario where one person helps another person to take a photo. Also taking FIG. 4A and FIG. 4B as an example, it is assumed that user A is the photographer and user B is the subject. The user B can use the electronic device 10 to take a picture of his favorite background image 44 in advance, and set a designated area 45 on the background image 44 . Next, please refer to FIG. 4C , the processing unit 12 can simultaneously display the background image 44 and the photographing frame 41 on the screen of the display unit 13 . For example, the background image 44 and the photographing screen 41 are displayed on the left and right sides of the screen, respectively. Alternatively, the processing unit 12 can also overlap and display the background image 44 and the photographing screen 41, for example, display the background image 44 with a higher transparency, and display the photographing screen 41 with a lower transparency, etc., so that user A can compare For the background image 44 and the photographing screen 41 . In addition, the processing unit 12 can also simultaneously display the first reference point on the background image 44 and the second reference point on the photographing frame 41 , or output a voice guidance signal based on the relative positions of the photographing frame 41 and the background image 44 .

Then, the user A can adjust the shooting angle and/or direction of the electronic device 10 by comparing the background image 44 with the shooting frame 41 or according to the voice guidance signal, so as to capture the same shooting frame 41 as the background image 44 . Next, when the processing unit 12 determines that the photographing frame 41 is the same as the background image 44, the processing unit 12 may switch the screen of the display unit 13 to only display the current photographing frame, so that user A can conveniently select according to user B's preset designation. area 45 to instruct the user B (i.e., the target) to move to the designated area 45, or the processing unit 12 controls the voice output unit 15 to output a voice guidance signal to guide the user B (i.e., the target) to move to the designated area Inside and so on.

FIG. 5 is a flowchart of a photography guidance method according to an embodiment of the present invention. Please refer to FIG. 1 and FIG. 5 at the same time. In step S510, the processing unit 12 sets a designated area in the photographing frame from the photographing unit 11, wherein the size of the designated region is smaller than the size of the photographing frame. In step S520, the processing unit 12 sets the target object in the shooting frame. The present invention does not limit the execution sequence of step S510 and step S520. Next, in step S530, when the target object is not located in the designated area, the processing unit 12 can generate a guidance signal according to a relative position between the target object and the designated area, so as to guide the target object to move to the designated area by the guidance signal. within the area.

Furthermore, FIG. 6 is a flowchart of a photography guidance method according to another embodiment of the present invention. Please refer to FIG. 1 and FIG. 6 at the same time. In step S602, the processing unit 12 may obtain a background image. Next, in step S604 , the processing unit 12 can determine whether the background image is the same as the photographing frame from the photographing unit 11 . If the background image is different from the photographed picture from the photographing unit 11, in step S606, the processing unit 12 can generate a first guide signal according to the relative position of the photographed picture and the background image, so as to guide the Guide the user to move the electronic device to capture the same photographing frame as the background image, and repeat step S604 after step S606. In addition, if the background image is the same as the photographing frame from the photographing unit 11, then in step S608, the processing unit 12 may set a specified area in the photographing frame according to the information of the specified area in the background image, and in step S610, The processing unit 12 can set the target object in the photographing frame. Next, in step S612, the processing unit 12 may determine whether the target is located within the designated area. If the target object is not located in the designated area, the processing unit 12 can generate a second guidance signal according to the relative position of the target object and the designated area, so as to guide the target object to move into the designated area by the second guidance signal, and Step S612 is repeatedly executed after step S614. In addition, if the target object is already located in the designated area, the processing unit 12 may perform functions such as automatic photographing after step S612, and the guided photographing method of this embodiment ends here.

The detailed implementation of each step of the photography guidance method in the embodiment of the present invention has been described in detail in the above-mentioned embodiments, so it will not be repeated here.

To sum up, the present invention proposes a photography guidance method and an electronic device, which can set one or more designated areas in the photography frame. When the photographed target exceeds the designated area, a guiding signal is sent out by means of voice or the like to guide the target to move into the designated area. In addition, the present invention can also guide the user to obtain a photographing screen with the same background image according to a background image that the user likes, and guide the user to move to a preset position, thereby greatly improving the self-portrait of the user. The convenience of the time, and effectively improve the problems that are easily encountered in the shooting process such as the user's body part being cut off, blocking a specific scenery, or a poor shooting angle in the photos taken in the past.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention. Any skilled person in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection should be based on the claims.

Claims (10)

1. A photography guidance method, applicable to an electronic device, the electronic device has a photography unit to capture a photography frame, the method comprising: setting a specified area in the photographing frame, wherein the size of the designated area is smaller than the size of the photographing frame; setting a target object in the photographing frame; When the target object is not located in the designated area, a first guide signal is generated according to a first relative position between the target object and the designated area, so as to guide the target object to move to by the first guide signal within the designated area. 2. The photography guidance method according to claim 1, wherein the step of setting the designated area in the photography frame comprises: receiving an input operation through an input unit of the electronic device; and According to the input operation, one or a combination of the number, size, shape, and position of the designated area in the photographing frame is set. 3. The photography guidance method according to claim 1, wherein the step of setting the target object in the photography frame comprises: Obtaining at least one candidate facial feature of at least one candidate target in the photographing frame; comparing the at least one candidate facial feature with a specified facial feature stored in a storage unit of the electronic device; and A candidate object having the same facial feature as the specified facial feature among the at least one candidate target object is used as the target object, and the target object is associated with the specified area. 4. The photography guidance method according to claim 1, wherein the step of setting the target object in the photography frame comprises: setting at least one candidate object in the photographing frame; Outputting a recognized voice through a voice output unit of the electronic device; and A candidate target that performs the behavior corresponding to the recognized voice among the at least one candidate target is used as the target, and the target is associated with the designated area. 5. The photography guidance method according to claim 1, further comprising: obtaining a background image from a storage unit of the electronic device, wherein the background image includes information of the designated area; judging whether the photography frame is the same as the background image; and When the photographing frame is different from the background image, a second guide signal is generated according to a second relative position between the photographing frame and the background image, so as to guide a user to move the electronic device by the second guide signal device to capture the photographic frame identical to the background image, The steps of setting the designated area in the photographing frame include: The designated area is set in the photographing frame according to the information of the designated area. 6. An electronic device comprising: a photographing unit for capturing a photographic frame; A processing unit, coupled to the photographing unit, the processing unit is used to set a designated area in the photographing frame and set a target in the photographing frame, wherein the size of the designated area is smaller than the size of the photographing frame , Wherein when the target object is not located in the specified area, the processing unit generates a first guidance signal according to a relative position between the target object and the specified area, so as to guide the target object by the first guidance signal Move into the designated area. 7. The electronic device as claimed in claim 6, further comprising: an input unit for receiving an input operation, Wherein the processing unit sets one or a combination of the number, size, shape, and position of the designated area in the photographing frame according to the input operation. 8. The electronic device as claimed in claim 6, further comprising: a storage unit, coupled to the processing unit, for storing a specified facial feature, Wherein the processing unit obtains at least one candidate facial feature of at least one candidate target in the photographing frame, compares the at least one candidate facial feature with the specified facial feature, and the at least one candidate target has the same feature as the specified facial feature The candidate target object with facial features is used as the target object, and the target object is associated with the designated area. 9. The electronic device as claimed in claim 6, further comprising: a voice output unit, coupled to the processing unit, for outputting a preset voice, Wherein the processing unit sets at least one candidate target object in the photographing frame, uses the candidate target object that executes the behavior corresponding to the preset voice among the at least one candidate target object as the target object, and combines the target object with the specified Regions are associated. 10. The electronic device as claimed in claim 6, further comprising: a storage unit, coupled to the processing unit, for storing a background image, wherein the background image includes information of the designated area; and Wherein the processing unit further obtains the background image from the storage unit, and judges whether the photographed frame is the same as the background image, Wherein when the photographing frame is the same as the background image, the processing unit generates a second pilot signal according to a second relative position between the photographing frame and the background image, so as to guide a user by the second pilot signal or move the electronic device to capture the photographic frame identical to the background image, Wherein the processing unit sets the specified area in the photographing frame according to the information of the specified area.