CN112399065A

CN112399065A - Method and equipment for adjusting focal length

Info

Publication number: CN112399065A
Application number: CN201910741234.4A
Authority: CN
Inventors: 高超; 闫三锋; 何琦
Original assignee: Hisense Mobile Communications Technology Co Ltd
Current assignee: Hisense Mobile Communications Technology Co Ltd
Priority date: 2019-08-12
Filing date: 2019-08-12
Publication date: 2021-02-23

Abstract

The invention discloses a method and equipment for adjusting focal length, which are used for solving the problem that the prior photographing technology cannot identify a specific photographing scene, so that the obtained photographing image has poor effect. According to the embodiment of the invention, the terminal can intelligently analyze the object which the user wants to shoot according to the brightness of the acquired preview picture, and automatically adjust the focal length of the camera, so that the operation that the user manually adjusts the preview picture is avoided, the shooting time is saved, and if the user is in the same position range, the shot images acquired by the terminal aiming at the same object have the same specification, for example, when shooting PPT, the occupation ratio of PPT in the shot images is the same, so that the user can conveniently browse, and the shooting effect is improved.

Description

Method and equipment for adjusting focal length

Technical Field

The present invention relates to the field of terminals, and in particular, to a method and an apparatus for adjusting a focal length.

Background

With the development of science and technology, the photographing function is integrated in various electronic devices, such as mobile phones, tablet and other electronic devices, and the photographing technology is widely applied to the aspects of people's life. Such as: the user uses the mobile phone to shoot landscape photos when traveling, and uses the mobile phone to shoot PPT photos when students attend class or lecture seats, and the like.

Currently, a user may obtain a clear picture through a photographing function of an electronic device, and then all images in the photographed picture may not be images that the user wants to obtain.

In summary, the conventional photographing technology cannot identify a specific photographing scene, so that the obtained photographing image has a poor effect.

Disclosure of Invention

The invention provides a method and equipment for adjusting a focal length, which are used for solving the problem that the specific photographing scene cannot be identified by the existing photographing technology, so that the obtained photographing image is poor in effect.

In a first aspect, a method for adjusting a focal length provided in an embodiment of the present invention includes:

acquiring a preview picture through a camera;

determining a target imaging area according to the brightness of each pixel in the preview picture;

and adjusting the focal length of the camera according to a preset specification ratio to change the ratio of the target imaging area in the preview picture.

According to the method, the terminal determines the target imaging area according to the brightness of each pixel in the preview picture acquired by the camera, and adjusts the focal length of the camera according to the preset specification proportion so as to change the ratio of the target imaging area in the preview picture. The terminal can analyze the object which the user wants to shoot according to the collected preview picture, automatically adjust the focal length of the camera, avoid the operation that the user manually adjusts the preview picture, save the shooting time, and if the user is in the same position range, the images shot aiming at the same object have the same specification, facilitate the browsing of the user, improve the shooting effect, furthermore, if the terminal has the camera with optical zoom, the terminal can change the proportion of the target imaging area in the displayed picture by adjusting the focal length of the camera, and avoid the problems of image quality reduction and the like caused by the fact that the user manually adjusts the preview picture.

In an optional implementation manner, the determining a target imaging area according to the brightness of each pixel in the preview screen includes:

determining pixels with brightness exceeding a first preset threshold value in the preview picture acquired through a camera; taking the minimum circumscribed polygon or circle containing the determined pixels in a first preset quantity proportion as a target imaging area; or

Determining a pixel with a larger brightness value, wherein the brightness difference value of any two adjacent pixels in the preview picture exceeds a second preset threshold; and determining the boundary of the target imaging area according to the determined pixels.

According to the method, the terminal determines the target imaging area according to the brightness of the pixels in the preview picture, the applicable scene is wide, and the operation is simple and convenient.

In an alternative embodiment, the determining the boundary of the target imaging area according to the determined pixels includes:

if the determined pixels form a closed graph, taking the closed graph as a target imaging area; or

If the determined pixels form a plurality of closed graphs, selecting a larger closed graph as a target imaging area according to the area; or

And if the determined pixels cannot form a closed graph, taking the minimum circumscribed polygon or circle containing the determined pixels in a second preset quantity proportion as a target imaging area.

In an optional implementation manner, the adjusting the focal length of the camera according to the preset specification ratio includes:

if the preset specification proportion is an area proportion, adjusting the focal length of the camera to enable the proportion of the area of the target imaging area to the area of the preview picture to be equal to the preset specification proportion; or

If the preset specification proportion is a longitudinal length proportion, adjusting the focal length of a camera to enable the proportion of the maximum longitudinal length of the target imaging area to the longitudinal length of the preview picture to be equal to the preset specification proportion; or

And if the preset specification proportion is a transverse length proportion, adjusting the focal length of the camera to enable the proportion of the maximum transverse length of the target imaging area to the transverse length of the preview picture to be equal to the preset specification proportion.

In an optional implementation manner, after adjusting the focal length of the camera according to a preset specification ratio to change the ratio of the target imaging area in the preview screen, the method further includes:

responding to a photographing instruction triggered by a user, and after a photographing image is acquired through a camera, carrying out image processing on an area outside the target imaging area in the image;

wherein the image processing comprises some or all of: filling, blurring and adding serial numbers.

According to the method, the obtained photographed image is tidier and more attractive through image processing, and further, the serial number is added to the photographed image, so that the method is beneficial to browsing of a user, and the photographing experience is improved.

In a second aspect, an embodiment of the present invention further provides a terminal for adjusting a focal length, where the terminal includes: a processor and a memory, wherein the memory stores program code that, when executed by the processor, causes the terminal to perform the following:

acquiring a preview picture through a camera;

In one possible implementation, the processor is specifically configured to:

In one possible implementation, the processor is further configured to:

In a third aspect, an embodiment of the present invention further provides a terminal for adjusting a focal length, where the terminal includes:

an acquisition module: the system comprises a camera, a preview screen and a display screen, wherein the camera is used for acquiring the preview screen;

a determination module: the target imaging area is determined according to the brightness of each pixel in the preview picture;

a processing module: and the camera focal length is adjusted according to a preset specification proportion so as to change the ratio of the target imaging area in the preview picture.

In a fourth aspect, the present application also provides a computer storage medium having a computer program stored thereon, which when executed by a processor, performs the steps of the method of the first aspect.

In addition, for technical effects brought by any one implementation manner of the second aspect to the fourth aspect, reference may be made to technical effects brought by different implementation manners of the first aspect, and details are not described here.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic diagram of a terminal-mounted rear camera according to an embodiment of the present invention;

fig. 2 is a schematic interface diagram of a camera application of a terminal according to an embodiment of the present invention;

fig. 3A is a schematic diagram illustrating an operation of starting a camera application according to an embodiment of the present invention;

fig. 3B is a schematic diagram of a preview page displayed by a camera application according to an embodiment of the present invention;

fig. 4 is an operation diagram of manually adjusting a preview screen according to an embodiment of the present invention;

fig. 5 is a schematic diagram of continuous frame photographed images photographed by a terminal according to an embodiment of the present invention;

fig. 6 is a schematic flowchart of a method for adjusting a focal length according to an embodiment of the present invention;

fig. 7 is an operation diagram illustrating an operation of starting an auto-scene focusing function according to an embodiment of the present invention;

fig. 8 is an operation diagram illustrating a second method for starting an auto-scene focusing function according to an embodiment of the present invention;

fig. 9 is an operation diagram illustrating a third method for starting an auto-scene focusing function according to an embodiment of the present invention;

FIG. 10 is a flowchart illustrating a method for determining an imaging region of a target according to an embodiment of the present invention;

FIG. 11 is a schematic view of a scene for determining a target imaging area according to an embodiment of the present invention;

FIG. 12 is a schematic view of another scene for determining a target imaging area according to an embodiment of the present invention;

FIG. 13 is a schematic view of a scene of an optimized target imaging region provided by an embodiment of the present invention;

FIG. 14 is a schematic view of a scene for determining a boundary of a target imaging region according to an embodiment of the present invention;

FIG. 15 is a schematic view of another example of a scene for determining the boundary of a target imaging region according to an embodiment of the present invention;

FIG. 16 is a schematic view of a third scenario for determining the boundary of a target imaging region according to an embodiment of the present invention;

FIG. 17 is a scene schematic diagram of an optimized target imaging region provided by an embodiment of the present invention;

FIG. 18 is a schematic view of a scene of another optimized target imaging region provided by an embodiment of the present invention;

fig. 19 is a scene schematic diagram for adjusting the ratio of the target imaging area according to an embodiment of the present invention;

fig. 20 is a schematic view of another scene for adjusting the ratio of the target imaging area according to the embodiment of the present invention;

fig. 21 is a schematic view of a third scene for adjusting the ratio of the target imaging area according to the embodiment of the present invention;

fig. 22 is a schematic diagram of a photographed image obtained without image processing according to an embodiment of the present invention;

FIG. 23 is a schematic diagram of a photographed image after a fill-in process according to an embodiment of the present invention;

fig. 24 is a schematic diagram of a photographed image after performing a fill-in process and a serial number adding process according to an embodiment of the present invention;

fig. 25 is a schematic diagram of photographed images added with the same serial number according to an embodiment of the present invention;

fig. 26 is a schematic diagram of a photographed image added with different serial numbers according to an embodiment of the present invention;

fig. 27 is a schematic structural diagram of a first terminal for adjusting focal length according to an embodiment of the present invention;

fig. 28 is a schematic structural diagram of a second terminal for adjusting focal length according to an embodiment of the present invention;

fig. 29 is a schematic structural diagram of a third terminal for adjusting focal length according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Some of the words that appear in the text are explained below:

1. the term "and/or" in the embodiments of the present invention describes an association relationship of associated objects, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

2. In the embodiments of the present application, the term "plurality" means two or more, and other terms are similar.

3. In the embodiment of the present application, the term "application" is simply referred to as application, and is a software program capable of implementing one or more specific functions. Such as camera applications, texting applications, mailbox applications, WeChat, WhatsApp Messenger, Link, photo sharing, Kakao Talk, nails, and the like.

The application scenario described in the embodiment of the present invention is for more clearly illustrating the technical solution of the embodiment of the present invention, and does not form a limitation on the technical solution provided in the embodiment of the present invention, and it can be known by a person skilled in the art that with the occurrence of a new application scenario, the technical solution provided in the embodiment of the present invention is also applicable to similar technical problems.

The terminal referred to herein may be a device having at least one camera, such as: mobile phones, tablet computers, and the like. Referring to fig. 1, a schematic structural diagram of an apparatus integrated with a camera provided in an embodiment of the present application is shown in fig. 1(a), which is a schematic structural diagram of an apparatus integrated with 1 rear camera, and is shown in fig. 1(b), which is a schematic structural diagram of an apparatus integrated with 4 rear cameras.

The number of cameras and the installation positions of the cameras of the terminal are not limited in the embodiments of the present application.

The foregoing is a hardware schematic diagram of a camera integrated on a terminal, and correspondingly, as shown in fig. 2, is an interface schematic diagram of a camera application of a terminal according to an embodiment of the present application. As shown in fig. 3A, the user opens the camera application by clicking the "camera" icon, and as shown in fig. 3B, the user opens the camera application and then obtains a preview image through the camera.

The preview screen shown in fig. 3B is the content of the PPT played in a large screen captured by the user in class or listening to the lecture, and when the user is far away from the screen on which the PPT is played, the occupation ratio of the PPT in the preview screen is small, and referring to the preview screen shown in fig. 4(a), the occupation ratio of the PPT in the preview screen is small, which causes an obstacle to the user to read the contents of the PPT, and for this reason, the occupation ratio of the image in the preview screen can be enlarged or reduced through the touch screen operation shown in fig. 4(B), for example: the photographed image is enlarged by sliding the screen outward with both hands, and reduced by sliding the screen inward with both hands. As shown in fig. 4(b), the ratio of PPT in the preview screen is enlarged. When the PPT is adjusted to the size desired by the user, namely after the preview picture is frozen, the user triggers a photographing instruction by clicking a touch screen or a specific button, the terminal responds to the photographing instruction, and a photographing image corresponding to the preview picture is acquired through the camera.

In the prior art, the method of changing the image proportion in the preview screen through touch screen operation still wastes time and labor for users, because users do not have too much time to carefully adjust the proportion of the images in the preview screen when in class or students are in lecture, even though users have time to adjust, the size of the images wanted by users in the continuous frame photographed images photographed after adjustment is still different in each frame photographed image, as shown in fig. 5(a), 5(b) and 5(c), the method is a method that users watch the photographed images smoothly because the proportions of PPT in the browsing page are different, and the users cannot simultaneously read PPT contents when manually adjusting the preview screen, and the method simply adopts the method of manually enlarging or reducing the proportion of PPT in the preview screen, the definition of the shot image is reduced, and for a user, the shooting function of the current terminal cannot intelligently identify the image wanted by the user, so that the user experience is poor, and the obtained shot image effect is poor.

In order to solve the technical problem, in the method for adjusting the focal length provided in this embodiment of the application, the terminal can intelligently identify a target imaging region that a user wants to photograph, for example, a PPT region in fig. 4(a), according to the brightness of each pixel in the preview screen, and after the terminal determines the target imaging region, the camera focal length is adjusted to change the ratio of the target imaging region in the preview screen, so that complicated operations and time consumption for manually adjusting the ratio of the target imaging region in the preview screen by the user are avoided, and the effect of photographing an image is improved.

The above-mentioned scenes for shooting the PPT are only illustrative, and the scenes applicable to the present application also include, for example, shooting a large screen played in a movie theater, shooting a bright outdoor scene from a dim indoor window, and the like, and all of these scenes have an obvious characteristic that an object (i.e. a target imaging area) that a user wants to shoot has a relatively high brightness value with respect to surrounding objects, and when determining the target imaging area, the terminal can determine the brightness according to the brightness of pixels in a preview screen.

Referring to fig. 6, a schematic flow chart of a method for adjusting a focal length provided by the present application is described below, where a process of determining a target imaging area in a preview screen by a terminal may include:

s601: the terminal acquires a preview picture through a camera;

s602: the terminal determines a target pixel area through the brightness of each pixel in the preview picture;

s603: and the terminal adjusts the focal length of the camera according to a preset specification ratio so as to change the ratio of the target imaging area in the preview picture.

By the method, the terminal can intelligently analyze the object which the user wants to shoot according to the brightness of the acquired preview picture, automatically adjust the focal length of the camera, avoid the operation that the user manually adjusts the preview picture, save shooting time, and if the user is in the same position range, the shot images acquired by the terminal aiming at the same object have the same specification, for example, when shooting PPT, the occupation ratio of PPT in the shot images is the same, so that the user can conveniently browse, and the shooting effect is improved.

It can be understood that the method for adjusting the focal length provided in the embodiment of the present application is a method for automatically adjusting the focal length according to a preview picture, therefore, the terminal is provided with an automatic scene focusing function, and after detecting that the automatic scene focusing is started, the terminal implements the procedure for adjusting the focal length provided in the present application, and the following introduces several ways for a user to start the automatic scene focusing function:

the method comprises the following steps: starting an automatic scene focusing function through a shortcut switch of a terminal pull-up menu;

a user can make the terminal pop-up window pull-up menu through touch screen operations such as sliding up when the terminal is in an unlocked state or an unlocked state, as shown in fig. 7, the pull-up menu has a shortcut switch with multiple applications or functions, the shortcut switch with the automatic scene focusing function is displayed at the lower right corner of the pull-up menu in fig. 7, and after the user clicks the shortcut switch, the terminal starts the automatic scene focusing function.

As another example, the terminal may further set a switch of an auto-scene focusing function on a setting interface of the camera application, and the user may also start the auto-scene focusing function on the setting interface.

And a second opening mode: starting an automatic scene focusing function through a designated switch in a camera application;

after the terminal starts the camera application, the camera application has an icon with an automatic scene focusing function, as shown in fig. 8, and after the user clicks the icon, the terminal starts the automatic scene focusing function.

And (3) opening mode three: the method comprises the steps that an automatic scene focusing function is started through touch screen operation according to characteristics in camera application;

for example, after the terminal starts the camera application, the automatic scene focusing function is started through operations such as quick double-click on the touch screen, and as shown in fig. 9, a user quickly double-clicks on a preview screen area on the touch screen to trigger the automatic scene focusing to be started. In optional operation, a user starts an automatic scene focusing function by quickly double-clicking a touch screen before shooting, and closes the automatic scene focusing function after shooting is finished; alternatively, the user may operate the auto scene focusing function only once, i.e., within a period of time or permanently, until the timing is completed or a user-triggered instruction to turn off the auto scene focusing function is received.

For S601, it should be understood that the preview screen at this time is not a photographed image but only a scene image that the user browses through the camera.

For S602, the terminal determines the target imaging area in the preview screen according to the pixel brightness, and several specific determination manners of the target imaging area are described below.

In a first determination mode, a target imaging area is determined according to a pixel in a preview picture, where the brightness of the pixel exceeds a first preset threshold, with reference to fig. 10, a specific process includes the following steps:

s1001: the terminal determines pixels with brightness exceeding a first preset threshold value in a preview picture;

s1002: the terminal selects part or all of pixels from the pixels with the brightness exceeding a first preset threshold according to a first preset quantity proportion;

s1003: and the terminal takes the area formed by the selected part or all of the pixels as a target imaging area.

For example, assuming that the first preset threshold is 50lux and the first preset number ratio is 1, referring to the preview screen shown in fig. 11(a), assuming that the minimum brightness of the pixels of the PPT region in the preview screen is not 55lux, and the maximum brightness of the pixels of the regions outside the PPT in the preview screen is 20lux, the terminal determines that the target imaging region is the PPT region in the preview screen.

Optionally, the first predetermined quantity ratio may also be other values, such as 0.9 or 0.5. If the value of the first preset quantity proportion is not 1, the terminal selects part or all of pixels from the pixels with the brightness exceeding a first preset threshold value as pixels in the target imaging area according to the first preset quantity proportion. The terminal may select the pixels in a variety of ways, such as randomly.

For example, assume that a preview screen acquired by the terminal through the camera is shown in fig. 11(a), the terminal determines that a region corresponding to a pixel with brightness exceeding a first preset threshold is shown in fig. 11(b), the terminal randomly selects pixels with a first preset number ratio from the pixels with brightness exceeding the first preset threshold, and the terminal takes a graph formed by the selected part or all of the pixels as a target imaging region. Assuming that the first preset number ratio is 0.7, referring to fig. 11(c), the ratio of the number of pixels in the target imaging region in fig. 11(c) to the number of pixels in the region shown in fig. 11(b) is equal to 0.7.

Further, for the region shown in fig. 11(c), to optimize the display effect, the terminal may further obtain a minimum circumscribed polygon or a circle of the region shown in fig. 11(c) as the target imaging region, as shown in fig. 12(a), a schematic diagram of a minimum circumscribed rectangle of the region provided in the embodiment of the present application, and as shown in fig. 12(b), a schematic diagram of a minimum circumscribed circle of the region provided in the embodiment of the present application.

In a second determination mode, the boundary of the target imaging area is determined according to the brightness difference value of the adjacent pixels, referring to fig. 13, the specific process includes the following steps:

s1301: the terminal determines that the brightness difference value of two adjacent pixels exceeds a second preset threshold value and the brighter pixel (hereinafter referred to as pixel A);

for example, optionally, the terminal may further determine that the luminance difference between two adjacent pixels exceeds a second preset threshold, and the terminal performs the following steps according to the determined pixel.

S1302: the terminal determines the boundary of a target imaging area according to a graph formed by the pixels A;

if the pixel a can constitute a closed figure, the closed figure is taken as a target imaging area, that is, the pixel a is the boundary of the target imaging area;

if the pixels A can form a plurality of closed graphs, the terminal selects the closed graph with a larger area as a target imaging area according to the area of the closed graph;

and if the pixels A cannot form a closed graph, the terminal selects pixels with a second preset quantity proportion from the pixels A to determine a target imaging area.

The following describes several possible patterns of pixels a by specific embodiments;

example 1: the pixels A can form a closed figure;

exemplarily, as shown in fig. 14(a), the terminal is a preview screen captured by a camera;

as shown in fig. 14(b), the graph composed of the pixels a is a schematic diagram, the graph is a closed graph, and the terminal uses the closed graph as the target imaging area, that is, the terminal uses the brighter pixels a whose brightness difference exceeds the second preset threshold as the boundary of the target imaging area.

As another example, the terminal may further use a darker pixel whose luminance difference value exceeds a second preset threshold as a boundary of the target imaging region, as shown in fig. 14 (c).

Example 2: the pixels A can form a plurality of closed figures;

exemplarily, as shown in fig. 15(a), a preview screen acquired by the terminal through a camera is shown;

as shown in fig. 15(b), the diagram of pixel a includes two closed graphs, wherein one closed graph is the outline of the photographed lamp tube, and the other closed graph is the outline of the photographed PPT.

The terminal selects a closed figure with a larger area as a target imaging region, and a schematic diagram of the target imaging region determined for the terminal is shown in fig. 15 (c).

Example 3: the pixels a cannot form a closed figure;

illustratively, as shown in fig. 16(a), the terminal is a schematic diagram of a pixel a determined from the preview screen, and the pixel a cannot constitute a closed figure.

The terminal selects part or all of the pixels from the pixels A according to a second preset quantity proportion; the terminal takes a selected part or all of the pixels as the boundary of the target imaging area, and exemplarily, the parts which cannot be closed are connected by a straight line. Assuming that the second preset number ratio is 0.5, a schematic diagram of the target imaging region determined for the terminal is shown in fig. 16 (b).

For embodiments 1 to 3, after the terminal determines the target imaging area, for optimal display, a minimum circumscribed polygon or circle may be made outside the target imaging area, and the minimum circumscribed polygon or circle may be used as the final target imaging area, so that the target imaging area is displayed in an elegant and regular shape.

For example, the following steps are carried out: for embodiment 3, the terminal determines the minimum bounding rectangle of fig. 16(b), see fig. 17, and the terminal takes the minimum bounding rectangle shown in fig. 17 as the target imaging region; or the terminal determines the minimum circumscribed circle of fig. 16(b), and referring to fig. 18, the terminal takes the minimum circumscribed circle shown in fig. 18 as the target imaging region.

It should be noted that, in the embodiment of the present invention, if closed graphs or unclosed graphs corresponding to multiple target imaging regions are detected, the selection may be performed according to an area or a position where the closed graphs are located, and a general user may place an object to be photographed in a center of a camera, that is, the terminal determines that an existing closed graph or unclosed graph at a center position of a preview page is a target imaging region.

The above description introduces a method for determining a target imaging area for a terminal, and after the terminal determines the target imaging area, the terminal adjusts the focal length of the camera according to a preset specification ratio to change the ratio of the target imaging area in a preview picture. The preset specification proportion comprises an area proportion and a length proportion, and the terminal adjusts the proportion of the target imaging area in the preview picture according to different preset specification proportions. The specific adjustment mode is described as follows:

the first adjustment mode is as follows: presetting the specification proportion as an area proportion;

and when the preset specification ratio is the area ratio, the terminal adjusts the area of the target imaging area in the preview picture by the preset specification ratio. For example, as shown in fig. 19(a), a target imaging region in the preview screen is shown, the area ratio of the target imaging region to the preview screen is 0.5, and assuming that the preset specification ratio is 0.9, the terminal enlarges the area of the target imaging region in the preview screen by adjusting the focal length of the camera, so that the area ratio of the target imaging region in the preview screen is 0.9, see fig. 19 (b).

The second adjustment mode is as follows: presetting the specification proportion as a length proportion;

the method comprises the steps that a preset specification proportion is a length proportion, the length proportion comprises a longitudinal length proportion and/or a transverse length proportion, if the preset specification proportion is the longitudinal length proportion, the terminal adjusts the focal length of a camera so that the proportion of the maximum longitudinal length of a target imaging area in a preview picture to the longitudinal length of the preview picture is adjusted to be the preset specification proportion; or the preset specification proportion is the transverse length proportion, and the terminal adjusts the focal length of the camera so as to adjust the proportion of the maximum transverse length of the target imaging area in the preview picture to the transverse length of the preview picture to the preset specification proportion.

For example, if the preset specification ratio is a longitudinal length ratio, as shown in fig. 20(a), it is a schematic diagram of a target imaging area in the preview screen, where a ratio of a maximum longitudinal distance of the target imaging area to a longitudinal distance of the preview screen is 0.6, and if the preset specification ratio is 1, the terminal adjusts a ratio of the maximum longitudinal distance of the target imaging area to the preview screen to be 1 by adjusting a focal length of the camera. Fig. 20(b) is a schematic view of the adjusted preview screen.

If the preset specification ratio is a transverse length ratio, as shown in fig. 21(a), the target imaging area in the preview screen is shown schematically, the ratio of the maximum transverse distance of the target imaging area to the transverse distance of the preview screen is 0.6, and if the preset specification ratio is 1, the terminal adjusts the ratio of the maximum longitudinal distance of the target imaging area to the preview screen to 1 by adjusting the focal length of the camera. Fig. 21(b) is a schematic view of the adjusted preview screen.

If the target imaging area exceeds the preview screen when the longitudinal length ratio or the transverse length ratio of the target imaging area to the preview screen is adjusted, the terminal adjusts the ratio of the target imaging area in the preview screen by using other adjustment modes, for example, when the terminal adjusts the ratio of the maximum longitudinal distance of the target imaging area to the longitudinal distance of the preview screen, the target imaging area exceeds the preview screen, and the adjustment mode is changed to adjust the ratio of the maximum transverse distance of the target imaging area to the transverse distance of the preview screen.

The modes of adjusting the focal length of the camera by the terminal to change the proportion of the target imaging area in the preview picture include multiple modes, and the following modes are listed as several modes for adjusting the focal length:

adjusting the first focal length: zooming in a digital mode;

the terminal carries out interpolation calculation on the shot scene data through an arithmetic unit in the digital camera, so that the shot object is amplified, and the zooming effect is achieved. It can also be understood that the preview image currently captured by the camera is not changed, but the originally shot image is simply locally enlarged, so that the image displayed in the camera occupies a larger proportion, and in such a focusing manner, the resolution and the image quality of the shot image are reduced along with the increase of the image enlargement factor.

Adjusting the focal length mode two: optical zooming;

when the terminal is internally provided with the zoom lens, zooming is realized through the telescopic combination of the zoom lens. The zoom lens consists of two parts, namely a fixed lens group and a variable lens group. By moving the variable lens group and changing the imaging light path, the focal length of the lens can be changed within a certain range, thereby changing the shooting angle of view. The magnification of the optical zoom is to enlarge the entire captured image by the optical zoom, so that the resolution and the image quality do not change.

The terminal implements digital focusing or optical zooming according to the equipment specification of the installed camera and the determined target imaging area in the preview picture, and can also preferentially select optical zooming according to priority.

After the terminal adjusts the ratio of the target imaging area in the preview picture to the preset ratio, after receiving the photographing instruction, the terminal obtains a photographed image corresponding to the preview picture through the camera, referring to the photographed image shown in fig. 22, and the photographed image is not subjected to image processing. Further, the embodiment of the present application further provides an operation for optimizing the effect of the photographed image, where after the terminal determines the target imaging region in the preview screen, the terminal performs image processing on the screen outside the target imaging region in the preview screen, and after receiving the photographing instruction, outputs the photographed image after the image processing. The image processing performed by the terminal includes, but is not limited to, part or all of the following: padding, blurring, and adding a serial number.

Illustratively, the terminal fills in the region other than the target imaging region in the preview page, and outputs a photographed image as shown in fig. 23 after receiving a photographing instruction.

As another example, the terminal performs the processes of padding and adding a sequence number to the region outside the target imaging region in the preview page, and when adding the sequence number, the sequence number may be added at a designated position of the padding region or one position may be randomly selected from the padding region for addition. As shown in fig. 24, the photographed image schematic diagram is obtained by the terminal after the preview screen is filled and added with serial numbers.

It should be noted that, in the shooting process, the user may repeatedly shoot the same picture, and correspondingly, before adding the serial number, the terminal determines whether the data in the current frame image is different from the previous frame image, and if so, determines the serial number of the current frame image according to the serial number of the previous frame image and a preset increasing or decreasing sequence; if the images are the same, adding the same serial number as the previous frame of image;

for example, as shown in fig. 25(a), the terminal is configured to be a schematic diagram of a previous photographed image, and fig. 25(b) is a schematic diagram of a current frame preview screen, and the terminal determines that data in the current frame preview screen is the same as data of the previous photographed image, where a sequence number added to the previous photographed image is 1, so that the terminal determines that a sequence number to be added when the current frame preview screen performs image processing is 1, and the terminal outputs the photographed image shown in fig. 25(b) after receiving a photographing instruction.

As shown in fig. 26(a), a schematic diagram of a previous photographed image is shown, a terminal acquires a current frame preview image through a camera, and the terminal determines that data in the current frame preview image is different from data of the previous photographed image, where a serial number added to the previous frame preview image is 1, if it is determined that the sequence of adding serial numbers is incremented by 1, and the terminal determines that a serial number to be added during image processing of the current frame preview image is 2, the terminal outputs the photographed image shown in fig. 26(b) after receiving a photographing instruction, and so on, and as shown in fig. 26(c), a schematic diagram of a next photographed image is shown.

Based on the same concept, as shown in fig. 27, an embodiment of the present invention provides a terminal for adjusting a focal length, the terminal including: at least one camera 2700, a processor 2701 and a memory 2702, wherein the memory 2702 stores program code that, when executed by the processor 2701, causes the terminal to perform the following process when one or more computer programs stored by the memory 2702 are executed:

acquiring a preview picture through the camera 2700;

Optionally, the processor 2701 is specifically configured to:

determining pixels with brightness exceeding a first preset threshold value in the preview image acquired through the camera 2700; taking the minimum circumscribed polygon or circle containing the determined pixels in a first preset quantity proportion as a target imaging area; or

Optionally, the processor 2701 is specifically configured to:

Optionally, the processor 2701 is further configured to:

Based on the same concept, as shown in fig. 28, an embodiment of the present invention provides another terminal for adjusting a focal length, including:

an acquisition module 2800: the system comprises a camera, a preview screen and a display screen, wherein the camera is used for acquiring the preview screen;

the determining module 2801: the target imaging area is determined according to the brightness of each pixel in the preview picture;

the processing module 2802: and the camera focal length is adjusted according to a preset specification proportion so as to change the ratio of the target imaging area in the preview picture.

Optionally, the determining module 2801 is specifically configured to:

Optionally, the processing module 2802 is specifically configured to:

Optionally, the processing module 2802 is further configured to:

As shown in fig. 29, a third focus adjustment terminal 2900 according to an embodiment of the present invention includes: radio Frequency (RF) circuit 2929, power supply 2920, processor 2930, memory 2940, input unit 2950, display unit 2960, camera 2970, communication interface 2980, Wireless Fidelity (Wi-Fi) module 2990, and the like. Those skilled in the art will appreciate that the configuration of the terminal shown in fig. 29 does not constitute a limitation of the terminal, and that the terminal provided in the embodiments of the present application may include more or less components than those shown, or may combine some components, or may be arranged in different components.

The various components of the terminal 2900 are described in detail below with reference to fig. 29:

the RF circuitry 2929 may be used for receiving and transmitting data during a communication or conversation. In particular, the RF circuit 2929 sends downlink data of the base station to the processor 2930 for processing; and in addition, sending the uplink data to be sent to the base station. Generally, the RF circuitry 2929 includes, but is not limited to, an antenna, at least one Amplifier, a transceiver, a coupler, a Low Noise Amplifier (LNA), a duplexer, and the like.

In addition, the RF circuit 2929 may communicate with networks and other terminals through wireless communication. The wireless communication may use any communication standard or protocol, including but not limited to Global System for Mobile communication (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), email, Short Message Service (SMS), and the like.

Wi-Fi technology belongs to short-distance wireless transmission technology, and the terminal 2900 can be connected with an Access Point (AP) through a Wi-Fi module 2990, so as to realize Access to a data network. The Wi-Fi module 2990 can be used for receiving and sending data in a communication process.

The terminal 2900 may be physically connected to other terminals via the communication interface 2980. Optionally, the communication interface 2980 is connected to a communication interface of the other terminal through a cable, so as to implement data transmission between the terminal 2900 and the other terminal.

In this embodiment of the application, the terminal 2900 is capable of implementing communication services and sending information to other contacts, so the terminal 2900 needs to have a data transmission function, that is, the terminal 2900 needs to include a communication module therein. Although fig. 29 illustrates communication modules such as the RF circuit 2929, the Wi-Fi module 2990, and the communication interface 2980, it is to be understood that at least one of the above components or other communication modules (e.g., bluetooth module) for enabling communication are present in the terminal 2900 for data transmission.

For example, when the terminal 2900 is a mobile phone, the terminal 2900 may include the RF circuit 2929, and may also include the Wi-Fi module 2990; when the terminal 2900 is a computer, the terminal 2900 can include the communication interface 2980, and can also include the Wi-Fi module 2990; when the terminal 2900 is a tablet, the terminal 2900 may include the Wi-Fi module.

The memory 2940 may be used to store software programs and modules. The processor 2930 executes various functional applications and data processing of the terminal 2900 by executing software programs and modules stored in the memory 2940, and when the processor 2930 executes program codes in the memory 2940, part or all of the processes in fig. 4 according to the embodiments of the present invention can be implemented.

Alternatively, the memory 2940 may mainly include a program storage area and a data storage area. The storage program area can store an operating system, various application programs (such as communication application), a face recognition module and the like; the storage data area may store data (such as various multimedia files like pictures, video files, etc., and face information templates) created according to the use of the terminal, etc.

Additionally, the memory 2940 may include high-speed random access memory and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid-state memory device.

The input unit 2950 may be used to receive numeric or character information input by a user and generate key signal inputs related to user settings and function control of the terminal 2900.

Alternatively, the input unit 2950 may include a touch panel 2951 and other input terminals 2952.

The touch panel 2951, also called a touch screen, may collect touch operations performed by a user on or near the touch panel 2951 (e.g., operations performed by the user on or near the touch panel 2951 using any suitable object or accessory such as a finger or a stylus), and drive a corresponding connection device according to a preset program. Alternatively, the touch panel 2951 may include two parts, namely, a touch detection device and a touch controller. The touch detection device detects the touch direction of a user, detects a signal brought by touch operation and transmits the signal to the touch controller; the touch controller receives touch information from the touch sensing device, converts it to touch point coordinates, and sends the touch point coordinates to the processor 2930, and can receive and execute commands sent from the processor 2930. In addition, the touch panel 2951 may be implemented in various types, such as a resistive type, a capacitive type, an infrared ray, and a surface acoustic wave.

Optionally, the other input terminals 2952 may include, but are not limited to, one or more of a physical keyboard, function keys (e.g., volume control keys, switch keys, etc.), a trackball, a mouse, a joystick, and the like.

The display unit 2960 may be used to display information input by or provided to a user and various menus of the terminal 2900. The display unit 2960 is a display system of the terminal 2900, and is used for presenting an interface and implementing human-computer interaction.

The display unit 2960 may include a display panel 2961. Alternatively, the Display panel 2961 may be configured in the form of a Liquid Crystal Display (LCD), an Organic Light-Emitting Diode (OLED), or the like.

Further, the touch panel 2951 may cover the display panel 2961, and when the touch panel 2951 detects a touch operation on or near the touch panel 2951, the touch panel is transmitted to the processor 2930 to determine the type of the touch event, and then the processor 2930 provides a corresponding visual output on the display panel 2961 according to the type of the touch event.

Although in FIG. 29 the touch panel 2951 and the display panel 2961 are shown as two separate components to implement the input and output functions of the terminal 2900, in some embodiments, the touch panel 2951 may be integrated with the display panel 2961 to implement the input and output functions of the terminal 2900.

The processor 2930 is a control center of the terminal 2900, and various interfaces and lines are used to connect various components, and by executing or executing software programs and/or modules stored in the memory 2940 and calling data stored in the memory 2940, various functions of the terminal 2900 are executed and data are processed, thereby implementing various services based on the terminal.

Optionally, the processor 2930 may include one or more processing units. Optionally, the processor 2930 may integrate an application processor and a modem processor, wherein the application processor mainly processes an operating system, a user interface, an application program, and the like, and the modem processor mainly processes wireless communication. It will be appreciated that the modem processor described above may not be integrated into the processor 2930.

The camera 2970 is configured to implement a shooting function of the terminal 2900, and shoot pictures or videos. The camera 2970 may also be used to implement a scanning function of the terminal 2900 to scan a scanned object (two-dimensional code/barcode).

The terminal 2900 also includes a power supply 2920 (such as a battery) for powering the various components. Optionally, the power supply 2920 may be logically coupled to the processor 2930 through a power management system, so that functions such as managing charging, discharging, and power consumption may be implemented through the power management system.

It is to be noted that the processor 2930 according to the embodiment of the present invention may perform the functions of the processor 2702 in fig. 27, and the memory 2940 stores the contents of the memory 2703 in fig. 27.

An embodiment of the present invention further provides a computer-readable non-volatile storage medium, which includes a program code, and when the program code runs on a computing terminal, the program code is configured to enable the computing terminal to execute the steps of the method for adjusting a focal length according to the embodiment of the present invention.

The present application is described above with reference to block diagrams and/or flowchart illustrations of methods, apparatus (systems) and/or computer program products according to embodiments of the application. It will be understood that one block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, and/or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, create means for implementing the functions/acts specified in the block diagrams and/or flowchart block or blocks.

Accordingly, the subject application may also be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.). Furthermore, the present application may take the form of a computer program product on a computer-usable or computer-readable storage medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection with an instruction execution system. In the context of this application, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A method for adjusting focal length is applied to a terminal, and the method comprises the following steps:

acquiring a preview picture through a camera;

2. The method of claim 1, wherein determining a target imaging area based on the brightness of each pixel in the preview screen comprises:

3. The method of claim 2, wherein said determining a boundary of said target imaging region based on said determined pixels comprises:

4. The method of claim 1, wherein the adjusting the focal length of the camera according to the preset specification ratio comprises:

5. The method according to any one of claims 1 to 4, wherein after adjusting the focal length of the camera according to a preset specification ratio to change the ratio of the target imaging area in the preview picture, the method further comprises:

6. A terminal for adjusting a focal length, the terminal comprising: at least one camera, a processor and a memory, wherein the memory stores program code that, when executed by the processor, causes the terminal to perform the following:

acquiring a preview picture through a camera;

7. The terminal of claim 6, wherein the processor is further specifically configured to:

8. The terminal of claim 7, wherein the processor is further configured to:

9. The terminal of claim 6, wherein the processor is further specifically configured to:

10. The terminal of any of claims 6 to 9, wherein the processor is further configured to: