CN112087582A

CN112087582A - Special effect video generation method, mobile terminal and computer readable storage medium

Info

Publication number: CN112087582A
Application number: CN202010961859.4A
Authority: CN
Inventors: 里强; 王汇; 陈国庭
Original assignee: Nubia Technology Co Ltd
Current assignee: Nubia Technology Co Ltd
Priority date: 2020-09-14
Filing date: 2020-09-14
Publication date: 2020-12-15

Abstract

The application provides a special effect video generation method, which is applied to a mobile terminal, wherein the mobile terminal comprises a camera, and the special effect video generation method comprises the following steps: acquiring a plurality of image frames through the camera and storing the image frames to an image buffer queue; reading at least two image frames which are adjacent at will from the image cache queue to carry out image registration to obtain a corresponding transformation matrix; sequentially overlapping the last synthesized frame obtained by overlapping with the current image frame according to the current image frame and a transformation matrix corresponding to the last image frame adjacent to the current image frame until each image frame in the image cache queue is overlapped; and selecting a preset number of image frames at intervals from the image frames obtained by superposition to construct a special effect video. The application also provides a mobile terminal and a computer readable storage medium. In the method, the special effect video can be constructed by selecting the preset number of image frames at intervals, so that the effect of instant movement of the object is achieved.

Description

Special effect video generation method, mobile terminal and computer readable storage medium

Technical Field

The present application relates to the field of communications technologies, and in particular, to a special effect video generation method, a mobile terminal, and a computer-readable storage medium.

Background

The existing image shooting methods of a plurality of 'multi-frame special effects' continuously shoot a plurality of frames of images, synthesize the plurality of frames of images into one image through certain algorithms, and present special effects such as optical flow, smear and the like of moving objects on the synthesized image; the end result of the special effect on the composite image is static, if a video with the special effect is to be obtained, many composite images are required to be continuously shot and then the images are combined into the video, which requires a long time, and auxiliary shooting using a tripod is required in shooting for the video effect.

Meanwhile, the video shooting cannot achieve the effect of instantaneous movement of an object due to more synthesized images.

Disclosure of Invention

The application mainly aims to provide a special effect video generation method, a mobile terminal and a computer readable storage medium, and aims to solve the problems that shooting time is long and an object does not have an instant moving effect.

In order to achieve the above object, the present application provides a special effect video generating method, where the special effect video generating method is applied to a mobile terminal, the mobile terminal includes a camera, and the special effect video generating method includes:

acquiring a plurality of image frames through the camera and storing the image frames to an image buffer queue;

reading at least two image frames which are adjacent at will from the image cache queue to carry out image registration to obtain a corresponding transformation matrix, and storing the transformation matrix to a transformation matrix cache queue;

sequentially overlapping a last composite frame obtained by overlapping with the current image frame according to the current image frame and a transformation matrix corresponding to a last image frame adjacent to the current image frame until each image frame in the image cache queue is overlapped;

and selecting a preset number of image frames at intervals from the image frames obtained by superposition to construct a special effect video.

Optionally, the step of acquiring a plurality of image frames by the camera includes:

acquiring a plurality of image frames at a preset speed through the camera;

the preset speed is 30fps, and the maximum length of the image buffer queue is 200.

Optionally, before the step of sequentially superimposing, according to the current image frame and the transformation matrix corresponding to the previous image frame adjacent to the current image frame, the previous composite frame obtained by superimposing and the current image frame, the first image frame is a previous image frame adjacent to the current image frame, and the second image frame is a previous image frame adjacent to the first image frame, the method includes:

superposing the second image frame and the first image frame according to the first image frame and a transformation matrix corresponding to the second image frame adjacent to the first image frame to obtain the last synthesized frame;

the second image frame is a starting image frame or a certain image frame determined according to a preset image determination instruction.

Optionally, the step of sequentially overlapping a previous synthesized frame obtained by overlapping with the current image frame according to the current image frame and a transformation matrix corresponding to a previous image frame adjacent to the current image frame until each image frame in the image buffer queue is overlapped includes:

superposing the previous synthesized frame and the current image frame according to the current image frame and a transformation matrix corresponding to the first image frame adjacent to the current image frame to obtain a new synthesized frame;

and sequentially overlapping the new synthesized frames until each image frame in the image buffer queue is overlapped.

Optionally, the mobile terminal further includes a video encoder, and the step of selecting a preset number of image frames at intervals from the image frames obtained by superimposing to construct a special effect video includes:

and selecting the preset number of image frames at intervals from the image frames obtained by superposition and transmitting the image frames to the video encoder to obtain the special effect video.

Optionally, the step of selecting a preset number of image frames at intervals from the image frames obtained by the superposition to construct the special effect video includes:

and taking one image frame at every ten image frames obtained by superposition to construct the special effect video.

Optionally, the image buffer queue has a preset length, and the special effect video generation method further includes:

and when the number of the image frames in the image buffer queue exceeds the preset length, releasing the image frames stored in the image frame buffer queue.

Optionally, the special effect video generation method further includes:

and performing multi-frame noise reduction on the special-effect video and then previewing in real time.

The present application further provides a mobile terminal, the mobile terminal including: a touch screen; a processor; and the memory is connected with the processor and comprises a control instruction, and when the processor reads the control instruction, the memory controls the mobile terminal to realize the special effect video generation method.

The present application also provides a computer readable storage medium having one or more programs executed by one or more processors to implement the special effects video generation method described above.

According to the special effect video generation method, the mobile terminal and the computer readable storage medium, a plurality of image frames are obtained through the camera and stored in the image cache queue; reading at least two image frames which are adjacent at will from the image cache queue to carry out image registration to obtain a corresponding transformation matrix, and storing the transformation matrix to a transformation matrix cache queue; sequentially overlapping a last composite frame obtained by overlapping with the current image frame according to the current image frame and a transformation matrix corresponding to a last image frame adjacent to the current image frame until each image frame in the image cache queue is overlapped; the method comprises the steps of selecting a preset number of image frames at intervals from image frames obtained by superposition to construct a special effect video, repeatedly using an original data frame of a last synthesized frame when the image frames are superposed, thereby reducing shooting time, shooting a video with a multi-frame special effect in each frame only within the same time as a common video, and simultaneously selecting the preset number of image frames at intervals to construct the special effect video to achieve the effect of instant movement of an object. Further, the image buffer queue has a preset length, and when the number of the image frames in the image buffer queue exceeds the preset length, the image frames previously stored in the image frame buffer queue are released, so that a buffer space is ensured, and the shooting efficiency is improved.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Fig. 1 is a schematic diagram of a hardware structure of an optional mobile terminal for implementing various embodiments of the present application;

FIG. 2 is a schematic diagram of a communication network system of the mobile terminal shown in FIG. 1;

fig. 3 is a flowchart of a special effect video generation method according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a mobile terminal according to an embodiment of the present application.

The implementation, functional features and advantages of the objectives of the present application will be further explained with reference to the accompanying drawings.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the following description, suffixes such as "module", "component", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no specific meaning in itself. Thus, "module", "component" or "unit" may be used mixedly.

The terminal may be implemented in various forms. For example, the terminal described in the present invention may include a mobile terminal such as a mobile phone, a tablet computer, a notebook computer, a palmtop computer, a Personal Digital Assistant (PDA), a Portable Media Player (PMP), a navigation device, a wearable device, a smart band, a pedometer, and the like, and a fixed terminal such as a Digital TV, a desktop computer, and the like.

The following description will be given by way of example of a mobile terminal, and it will be understood by those skilled in the art that the construction according to the embodiment of the present invention can be applied to a fixed type terminal, in addition to elements particularly used for mobile purposes.

Referring to fig. 1, which is a schematic diagram of a hardware structure of a mobile terminal for implementing various embodiments of the present invention, the mobile terminal 100 may include: RF (Radio Frequency) unit 101, WiFi module 102, audio output unit 103, a/V (audio/video) input unit 104, sensor 105, display unit 106, user input unit 107, interface unit 108, memory 109, processor 110, and power supply 111. Those skilled in the art will appreciate that the mobile terminal architecture shown in fig. 1 is not intended to be limiting of mobile terminals, which may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components.

The various components of the mobile terminal 100 are described in detail below with reference to fig. 1:

the radio frequency unit 101 may be configured to receive and transmit signals during information transmission and reception or during a call, and specifically, receive downlink information of a base station and then process the downlink information to the processor 110; in addition, the uplink data is transmitted to the base station. Typically, radio frequency unit 101 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, and the like. In addition, the radio frequency unit 101 can also communicate with a network and other devices through wireless communication. The wireless communication may use any communication standard or protocol, including but not limited to GSM (Global System for Mobile communications), GPRS (General Packet Radio Service), CDMA2000(Code Division Multiple Access 2000), WCDMA (Wideband Code Division Multiple Access), TD-SCDMA (Time Division-Synchronous Code Division Multiple Access), FDD-LTE (Frequency Division duplex Long Term Evolution), and TDD-LTE (Time Division duplex Long Term Evolution).

WiFi belongs to short-distance wireless transmission technology, and the mobile terminal can help a user to receive and send e-mails, browse webpages, access streaming media and the like through the WiFi module 102, and provides wireless broadband internet access for the user. Although fig. 1 shows the WiFi module 102, it is understood that it does not belong to the essential constitution of the mobile terminal, and may be omitted entirely as needed within the scope not changing the essence of the invention.

The audio output unit 103 may convert audio data received by the radio frequency unit 101 or the WiFi module 102 or stored in the memory 109 into an audio signal and output as sound when the mobile terminal 100 is in a call signal reception mode, a call mode, a recording mode, a voice recognition mode, a broadcast reception mode, or the like. Also, the audio output unit 103 may also provide audio output related to a specific function performed by the mobile terminal 100 (e.g., a call signal reception sound, a message reception sound, etc.). The audio output unit 103 may include a speaker, a buzzer, and the like.

The a/V input unit 104 is used to receive audio or video signals. The a/V input Unit 104 may include a Graphics Processing Unit (GPU) 1041 and a microphone 1042, the Graphics processor 1041 Processing image data of still pictures or video obtained by an image capturing device (e.g., a camera) in a video capturing mode or an image capturing mode. The processed image frames may be displayed on the display unit 106. The image frames processed by the graphic processor 1041 may be stored in the memory 109 (or other storage medium) or transmitted via the radio frequency unit 101 or the WiFi module 102. The microphone 1042 may receive sounds (audio data) via the microphone 1042 in a phone call mode, a recording mode, a voice recognition mode, or the like, and may be capable of processing such sounds into audio data. The processed audio (voice) data may be converted into a format output transmittable to a mobile communication base station via the radio frequency unit 101 in case of a phone call mode. The microphone 1042 may implement various types of noise cancellation (or suppression) algorithms to cancel (or suppress) noise or interference generated in the course of receiving and transmitting audio signals.

The mobile terminal 100 also includes at least one sensor 105, such as a light sensor, a motion sensor, and other sensors. Specifically, the light sensor includes an ambient light sensor that can adjust the brightness of the display panel 1061 according to the brightness of ambient light, and a proximity sensor that can turn off the display panel 1061 and/or a backlight when the mobile terminal 100 is moved to the ear. As one of the motion sensors, the accelerometer sensor can detect the magnitude of acceleration in each direction (generally, three axes), can detect the magnitude and direction of gravity when stationary, and can be used for applications of recognizing the posture of a mobile phone (such as horizontal and vertical screen switching, related games, magnetometer posture calibration), vibration recognition related functions (such as pedometer and tapping), and the like; as for other sensors such as a fingerprint sensor, a pressure sensor, an iris sensor, a molecular sensor, a gyroscope, a barometer, a hygrometer, a thermometer, and an infrared sensor, which can be configured on the mobile phone, further description is omitted here.

The display unit 106 is used to display information input by a user or information provided to the user. The Display unit 106 may include a Display panel 1061, and the Display panel 1061 may be configured in the form of a Liquid Crystal Display (LCD), an Organic Light-Emitting Diode (OLED), or the like.

The user input unit 107 may be used to receive input numeric or character information and generate key signal inputs related to user settings and function control of the mobile terminal. Specifically, the user input unit 107 may include a touch panel 1071 and other input devices 1072. The touch panel 1071, also referred to as a touch screen, may collect a touch operation performed by a user on or near the touch panel 1071 (e.g., an operation performed by the user on or near the touch panel 1071 using a finger, a stylus, or any other suitable object or accessory), and drive a corresponding connection device according to a predetermined program. The touch panel 1071 may include two parts of 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 the touch information into touch point coordinates, sends the touch point coordinates to the processor 110, and can receive and execute commands sent by the processor 110. In addition, the touch panel 1071 may be implemented in various types, such as a resistive type, a capacitive type, an infrared ray, and a surface acoustic wave. In addition to the touch panel 1071, the user input unit 107 may include other input devices 1072. In particular, other input devices 1072 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, and are not limited to these specific examples.

Further, the touch panel 1071 may cover the display panel 1061, and when the touch panel 1071 detects a touch operation thereon or nearby, the touch panel 1071 transmits the touch operation to the processor 110 to determine the type of the touch event, and then the processor 110 provides a corresponding visual output on the display panel 1061 according to the type of the touch event. Although the touch panel 1071 and the display panel 1061 are shown in fig. 1 as two separate components to implement the input and output functions of the mobile terminal, in some embodiments, the touch panel 1071 and the display panel 1061 may be integrated to implement the input and output functions of the mobile terminal, and is not limited herein.

The interface unit 108 serves as an interface through which at least one external device is connected to the mobile terminal 100. For example, the external device may include a wired or wireless headset port, an external power supply (or battery charger) port, a wired or wireless data port, a memory card port, a port for connecting a device having an identification module, an audio input/output (I/O) port, a video I/O port, an earphone port, and the like. The interface unit 108 may be used to receive input (e.g., data information, power, etc.) from external devices and transmit the received input to one or more elements within the mobile terminal 100 or may be used to transmit data between the mobile terminal 100 and external devices.

The memory 109 may be used to store software programs as well as various data. The memory 109 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, a phonebook, etc.) created according to the use of the cellular phone, and the like. Further, the memory 109 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 storage device.

The processor 110 is a control center of the mobile terminal, connects various parts of the entire mobile terminal using various interfaces and lines, and performs various functions of the mobile terminal and processes data by operating or executing software programs and/or modules stored in the memory 109 and calling data stored in the memory 109, thereby performing overall monitoring of the mobile terminal. Processor 110 may include one or more processing units; preferably, the processor 110 may integrate an application processor, which mainly handles operating systems, user interfaces, application programs, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 110.

The mobile terminal 100 may further include a power supply 111 (e.g., a battery) for supplying power to various components, and preferably, the power supply 111 may be logically connected to the processor 110 via a power management system, so as to manage charging, discharging, and power consumption management functions via the power management system.

Although not shown in fig. 1, the mobile terminal 100 may further include a bluetooth module or the like, which is not described in detail herein.

In order to facilitate understanding of the embodiments of the present invention, a communication network system on which the mobile terminal of the present invention is based is described below.

Referring to fig. 2, fig. 2 is an architecture diagram of a communication Network system according to an embodiment of the present invention, where the communication Network system is an LTE system of a universal mobile telecommunications technology, and the LTE system includes a UE (User Equipment) 201, an E-UTRAN (Evolved UMTS Terrestrial Radio Access Network) 202, an EPC (Evolved Packet Core) 203, and an IP service 204 of an operator, which are in communication connection in sequence.

Specifically, the UE201 may be the terminal 100 described above, and is not described herein again.

The E-UTRAN202 includes eNodeB2021 and other eNodeBs 2022, among others. Among them, the eNodeB2021 may be connected with other eNodeB2022 through backhaul (e.g., X2 interface), the eNodeB2021 is connected to the EPC203, and the eNodeB2021 may provide the UE201 access to the EPC 203.

The EPC203 may include an MME (Mobility Management Entity) 2031, an HSS (Home Subscriber Server) 2032, other MMEs 2033, an SGW (Serving gateway) 2034, a PGW (PDN gateway) 2035, and a PCRF (Policy and Charging Rules Function) 2036, and the like. The MME2031 is a control node that handles signaling between the UE201 and the EPC203, and provides bearer and connection management. HSS2032 is used to provide registers to manage functions such as home location register (not shown) and holds subscriber specific information about service characteristics, data rates, etc. All user data may be sent through SGW2034, PGW2035 may provide IP address assignment for UE201 and other functions, and PCRF2036 is a policy and charging control policy decision point for traffic data flow and IP bearer resources, which selects and provides available policy and charging control decisions for a policy and charging enforcement function (not shown).

The IP services 204 may include the internet, intranets, IMS (IP Multimedia Subsystem), or other IP services, among others.

Although the LTE system is described as an example, it should be understood by those skilled in the art that the present invention is not limited to the LTE system, but may also be applied to other wireless communication systems, such as GSM, CDMA2000, WCDMA, TD-SCDMA, and future new network systems.

Based on the above mobile terminal hardware structure and communication network system, the present invention provides various embodiments of the method.

Fig. 3 is a flowchart of an embodiment of a special effect video generation method provided in the present application. Once the method of this embodiment is triggered by the user, the process in this embodiment is automatically executed by the mobile terminal 100, where each step may be executed sequentially according to the sequence in the flowchart, or may be executed simultaneously according to a plurality of steps in an actual situation, which is not limited herein. The mobile terminal 100 includes a camera. The special effect video generation method provided by the application comprises the following steps:

step S310, acquiring a plurality of image frames through the camera and storing the image frames to an image buffer queue;

step S330, reading at least two image frames which are adjacent at will from the image cache queue to carry out image registration to obtain a corresponding transformation matrix, and storing the transformation matrix to a transformation matrix cache queue;

step S350, sequentially overlapping a last composite frame obtained by overlapping with a current image frame according to the current image frame and a transformation matrix corresponding to a last image frame adjacent to the current image frame until each image frame in the image buffer queue is overlapped;

step S370, selecting a preset number of image frames at intervals from the image frames obtained by the superposition to construct a special effect video.

According to the embodiment, image registration is carried out according to read image frames to obtain corresponding transformation matrixes, next, the last composite frame obtained by superposition is superposed with the current image frame according to the current image frame and the transformation matrix corresponding to the last image frame adjacent to the current image frame in sequence, finally, a preset number of image frames are selected at intervals from the superposed image frames to construct a special effect video, when the image frames are superposed, the original data frame of the last composite frame is repeatedly used to reduce shooting time, the video with the multi-frame special effect on each frame can be shot only in the same time as that of a common video, and meanwhile, the effect of instant movement of an object is achieved by selecting the preset number of image frames at intervals to construct the special effect video.

The above steps will be specifically described with reference to specific examples.

In step S310, a plurality of image frames are acquired by the camera and stored in an image buffer queue.

In this embodiment, the step of acquiring a plurality of image frames by the camera includes:

step S3101, acquiring a plurality of image frames at a preset speed by the camera;

the preset speed is 30fps, the maximum length of the image buffer queue is far greater than the value of the preset speed, and the maximum length of the image buffer queue is far greater than the value of the preset speed may be a value of the preset speed, which is greater than 5 times the maximum length of the image buffer queue, for example, the maximum length of the image buffer queue is 200.

In this embodiment, when it is necessary to take a picture through the camera to obtain an image frame, the mobile terminal 100 may click the APP application related to the camera, start the camera and initiate a shooting request, and obtain a plurality of image frames within a shooting range in real time through the camera of the mobile terminal 100. In particular, a plurality of the image frames may be acquired by the camera at a speed of 30 fps.

It is understood that in other embodiments, the mobile terminal 100 may receive a plurality of image frames sent by other mobile terminals instead of acquiring the plurality of image frames through the camera of the mobile terminal 100, and sequentially store the plurality of acquired image frames in the image buffer queue. The maximum length of the image buffer queue can be any other positive integer larger than zero.

In this embodiment, the image buffer queue has a preset length, and the method for generating a special effect video further includes:

step S3102, when the number of image frames in the image buffer queue exceeds the preset length, releasing the image frames previously stored in the image buffer queue.

Specifically, after the image frames are acquired by the camera, it may be determined whether the number of the image frames in the image buffer queue reaches the preset length, and when the determination result is yes, the image frames previously stored in the image buffer queue are released, that is, the image frame with the earliest acquisition time in the image buffer queue is deleted, and the acquired image frames are stored in the image buffer queue; and when the judgment result is negative, the acquired image frame can be directly stored in an image buffer queue. The preset length may be a maximum length of the image buffer queue.

For example, the image frames are collected by the camera at the speed of 30fps, when the number of the image frames in the image buffer queue is determined to exceed 200, the image frame with the earliest acquisition time in the image buffer queue is deleted, and the image frame acquired last is stored in the image buffer queue; and when the number of the image frames in the image buffer queue is determined not to exceed 200, storing the acquired image frames in the image buffer queue.

In step S330, at least two adjacent image frames are read from the image buffer queue for image registration to obtain a corresponding transformation matrix, and the transformation matrix is stored in the transformation matrix buffer queue.

In the present embodiment, Image registration (Image registration) is a process of matching and superimposing two or more images acquired at different times, different sensors (imaging devices), or under different conditions (weather, illuminance, imaging position, angle, and the like) (a process of converting different images of the same scene into the same coordinate system). The images may also be taken from different perspectives. The spatial relationship between these images may be rigid (translational and rotational), affine (e.g. miscut), or homography, or complex large deformation models. The flow of the image registration technique is as follows: firstly, extracting the characteristics of two images to obtain characteristic points; finding matched characteristic point pairs by carrying out similarity measurement; then obtaining image space coordinate transformation parameters through the matched feature point pairs; and finally, carrying out image registration by the coordinate transformation parameters, so that the two images are aligned.

Specifically, the step of reading at least two image frames adjacent to each other from the image buffer queue to perform image registration to obtain a corresponding transformation matrix includes: after a plurality of image frames are acquired through the camera, the image frames are sequentially sequenced according to the acquisition time of the image frames, and at least two adjacent image frames are subjected to image registration to obtain a corresponding transformation matrix; and establishing a corresponding relation between at least two arbitrary adjacent image frames and the transformation matrix.

For example, sequentially acquiring 1 st to 200 th image frames, and performing image registration on the 1 st image frame and the 2 nd image frame to obtain corresponding transformation matrixes 1 to 2; carrying out image registration on the 2 nd image frame and the 3 rd image frame to obtain a corresponding transformation matrix 2-3; carrying out image registration on the 3 rd image frame and the 4 th image frame to obtain a corresponding transformation matrix 3-4; carrying out image registration on the 5 th image frame and the 6 th image frame to obtain a corresponding transformation matrix 5-6; carrying out image registration on the 7 th image frame and the 8 th image frame to obtain a corresponding transformation matrix 7-8; … …, respectively; and performing image registration on the 199 th image frame and the 200 th image frame to obtain a corresponding transformation matrix 199-200. The transformation matrix of the 1 st image frame is an identity matrix, that is, the transformation matrix of the starting image frame is an identity matrix.

It is understood that any three adjacent image frames may also be subjected to image registration to obtain corresponding transformation matrices, for example, the image registration is performed on the 3 rd image frame, the 4 th image frame and the 5 th image frame to obtain corresponding transformation matrices 3-4-5.

In other embodiments, the step of reading at least two image frames adjacent to each other from the image buffer queue to perform image registration to obtain the corresponding transformation matrix may further be: finding out one-to-one corresponding matching point pairs (characteristic point extraction, description and point pair matching) in the two images, and then obtaining the transformation matrix through the matching point pairs, for example, obtaining the transformation matrix by using a centrosymmetric local binary pattern descriptor based on similarity; specifically, two image frames may be obtained in real time by the camera, for example, a current image frame and a previous image frame are used for image registration to obtain the transformation matrix; and then acquiring two image frames from the camera in real time to obtain another transformation matrix.

In step S350, according to the current image frame and the transformation matrix corresponding to the previous image frame adjacent to the current image frame, sequentially overlapping the previous synthesized frame obtained by overlapping with the current image frame until each image frame in the image buffer queue is overlapped.

In this embodiment, the first image frame is a previous image frame adjacent to the current image frame, and the second image frame is a previous image frame adjacent to the first image frame. The method comprises the following steps of sequentially overlapping a last composite frame obtained by overlapping with a current image frame according to the current image frame and a transformation matrix corresponding to the last image frame adjacent to the current image frame, wherein the steps comprise:

step S3501, superimposing the second image frame and the first image frame according to the first image frame and a transformation matrix corresponding to the second image frame adjacent to the first image frame to obtain the previous composite frame;

Specifically, the second image frame and the first image frame may be subjected to rigid body transformation or radial transformation by using the transformation matrix, so as to obtain the previous synthesized frame. When the second image frame is a starting image frame (namely, a 1 st image frame), the starting image frame and the adjacent first image frame (namely, a2 nd image frame) are superposed according to a transformation matrix 1-2 of the 1 st image frame and the 2 nd image frame to obtain the last synthesized frame. When the second image frame is determined to be the 6 th image frame according to the preset image determining instruction, the preset image determining instruction further determines that the adjacent first image frame is the 7 th image frame, and then the 6 th image frame and the 7 th image frame are superposed according to a transformation matrix 6-7 of the 6 th image frame and the 7 th image frame to obtain the previous composite frame.

In other embodiments, the second image frame may also be a certain image frame determined by the mobile terminal 100 according to a preset image determination instruction, and the adjacent first image frame is not limited herein.

In this embodiment, the step of sequentially overlapping a previous synthesized frame obtained by overlapping with the current image frame according to the current image frame and a transformation matrix corresponding to a previous image frame adjacent to the current image frame until each image frame in the image buffer queue is overlapped includes:

step S3502, according to the current image frame and the transformation matrix corresponding to the first image frame adjacent to the current image frame, overlapping the previous synthesized frame and the current image frame to obtain a new synthesized frame;

step S3503, sequentially overlapping the new synthesized frames until each image frame in the image buffer queue is overlapped.

Specifically, according to a transformation matrix of the second image frame and the first image frame, the second image frame and the first image frame are superimposed to obtain the previous synthesized frame, and the previous synthesized frame and the current image frame are superimposed to obtain a new synthesized frame; according to the new synthesized frame and the transformation matrix corresponding to the current image frame, overlapping the new synthesized frame and the current image frame to obtain a new synthesized frame again; according to the transformation matrix of the newly obtained new synthesized frame and the next image frame, overlapping the newly obtained new synthesized frame and the next image frame to obtain a new synthesized frame again, wherein the next image frame is a next image frame of the current image frame; and repeating the overlapping of the new synthesized frames in sequence until each image frame in the image buffer queue is overlapped, namely until the total number of the overlapped image frames reaches a threshold value, namely, repeatedly using the original data frame of the previous synthesized frame, and realizing the accumulative overlapping of the image frames according to a transformation matrix with continuity so that the image after the overlapping is finished has a multi-frame special effect. The threshold, including but not limited to the last frame, may be set by the user.

For example, according to a transformation matrix 1-2 of a 1 st frame image and a2 nd frame image, the 1 st frame image and an adjacent 2 nd frame image are superimposed to obtain the previous synthesized frame, and the previous synthesized frame can be used as a new 2 nd frame image; at the moment, the current image frame is a 3 rd image frame, and the new 2 nd image frame and the 3 rd image frame are superposed according to a transformation matrix 2-3 corresponding to the new 2 nd image frame and the 3 rd image frame to obtain a new composite frame which can be used as the new 3 rd image frame; and then, according to a transformation matrix of a new 3 rd image frame and a next image frame (a 4 th image frame), overlapping the new 3 rd image frame and the new 4 th image frame to obtain a new composite frame again, and repeating the steps to sequentially overlap the new composite frame until each image frame in the image buffer queue is overlapped.

In other embodiments, a certain image frame may be determined as the current image frame according to a preset image determination instruction, and the first image frame and the second image frame may be subjected to image registration to obtain a transformation matrix; according to the transformation matrix of the first image frame and the second image frame, overlapping the second image frame and the first image frame to obtain the previous composite frame, and overlapping the previous composite frame and the current image frame to obtain a new composite frame; and then, according to the transformation matrix, overlapping the obtained new synthesized frame with the next image frame until each image frame in the image buffer queue is overlapped.

For example, the 5 th image frame determined according to the preset image determination instruction is the current image frame, and the 1 st image frame and the adjacent 2 nd image frame are superimposed according to the transformation matrix 1-2 of the 1 st image frame and the 2 nd image frame to obtain the previous synthesized frame, which can be used as a new 2 nd image frame; arranging the current image frame as a 3 rd image frame according to the sequence of the image frames, performing image registration on the last synthesized frame and the 5 th image frame to obtain a transformation matrix 2-5 if the current image frame is a 5 th image frame according to an image determination instruction, and overlapping the last synthesized frame and the 5 th image frame according to the transformation matrix 2-5 to obtain a new synthesized frame; and then, according to the transformation matrix, overlapping the obtained new synthesized frame with the next image frame until each image frame in the image buffer queue is overlapped.

In another embodiment, the second image frame and the first image frame are superimposed to obtain the previous composite frame according to the first image frame and a transformation matrix corresponding to the second image frame adjacent to the first image frame. The first image frame is a next image frame adjacent to the current image frame. The second image frame is the next image frame adjacent to the first image frame, and the second image frame is a last image frame (i.e. 200 th image frame) or a certain image frame determined according to a preset image determination instruction. The previous synthesized frame and the current image frame may be superimposed according to the current image frame and a transformation matrix corresponding to a next image frame adjacent to the current image frame to obtain a new synthesized frame, and the new synthesized frame may be sequentially superimposed until each of the image frames in the image buffer queue is superimposed.

For example, the second image frame is a200 th image frame, the first image frame is a 199 th image frame, and the current image frame is a 198 th image frame. According to the 199-th image frame and the 200-th image frame, the 199-th image frame and the 200-th image frame are overlapped to obtain a previous composite frame (namely, a new 199-th image frame), according to the 198-th image frame and a new 199-th image frame, a new composite frame is obtained, and the new composite frames are sequentially overlapped until each image frame in the image buffer queue is overlapped.

In this embodiment, when an object passes in front of the camera, the object may appear at different positions of the image frames at different times, and for the same position, 200 image frames at different times have only a few shadows of the object and most background pictures, so that the average superposition result is only background pictures. When the moving object stays at a certain position, more and more image frames with the figure of the object are stored in the image buffer queue, and the figure of the object gradually emerges in the superposition result. When the moving object leaves from a certain position, images with the shadow of the object at the position where the object stays in the image buffer queue are fewer and fewer, and the shadow of the object is gradually hidden in the superposition result. In this way, the effect of completely hiding the moving object can be realized by superposing each image frame in the image buffer queue.

In step S370, a preset number of image frames are selected at intervals from the superimposed image frames to construct a special effect video.

In this embodiment, the mobile terminal 100 further includes a video encoder, and the step of selecting a preset number of image frames at intervals from the image frames obtained by superimposing to construct a special effect video includes:

and step 3701, selecting the preset number of image frames at intervals from the image frames obtained by superposition and transmitting the selected image frames to the video encoder to obtain the special effect video.

In this embodiment, the step of selecting a preset number of image frames at intervals from the image frames obtained by superimposing to construct a special effect video includes:

step 37011, taking one image frame at every ten image frames obtained by superposition to construct the special effect video.

In this embodiment, the image frames obtained by the superposition are at least two different superposed image frames obtained by steps S310 to S350. The special effect video is constructed by a plurality of superposed image frames. Specifically, a preset number of image frames are selected from the image frames obtained through superposition and transmitted to the video encoder, if one image frame is obtained at every ten intervals, the video encoder encodes the image frames to generate the special effect video, and the image frames obtained through superposition at every ten intervals are subjected to frame dropping processing to record a video with the speed of 10 times, so that the object has an instant moving effect.

In this embodiment, the special effect video generation method further includes:

and step 3702, performing multi-frame noise reduction on the special effect video and then previewing in real time.

Specifically, the superimposed image frames and the special effect video subjected to the multi-frame noise reduction processing can be previewed on the display screen of the mobile terminal 100 in real time. The generated special effect video has better effect by carrying out multi-frame noise reduction processing on the special effect video.

According to the embodiment, a plurality of image frames are obtained through the camera and stored in the image buffer queue; reading at least two image frames which are adjacent at will from the image cache queue to carry out image registration to obtain a corresponding transformation matrix, and storing the transformation matrix to a transformation matrix cache queue; sequentially overlapping a last composite frame obtained by overlapping with the current image frame according to the current image frame and a transformation matrix corresponding to a last image frame adjacent to the current image frame until each image frame in the image cache queue is overlapped; the method comprises the steps of selecting a preset number of image frames at intervals from image frames obtained by superposition to construct a special effect video, repeatedly using an original data frame of a last synthesized frame when the image frames are superposed, thereby reducing shooting time, shooting a video with a multi-frame special effect in each frame only within the same time as a common video, and simultaneously selecting the preset number of image frames at intervals to construct the special effect video to achieve the effect of instant movement of an object. Further, the image buffer queue has a preset length, and when the number of the image frames in the image buffer queue exceeds the preset length, the image frames previously stored in the image frame buffer queue are released, so that a buffer space is ensured, and the shooting efficiency is improved.

Fig. 4 is a schematic structural component diagram of a mobile terminal 100 provided in an embodiment of the present application, where the mobile terminal 100 includes a camera, and the mobile terminal 100 further includes: a touch panel 1071; a processor 110; the memory 109 is connected to the processor 110, the memory 109 contains a control instruction, and when the processor 110 reads the control instruction, the mobile terminal 100 is controlled to implement the following steps:

acquiring a plurality of image frames at a preset speed through the camera;

Optionally, the image buffer queue has a preset length, and further includes:

Optionally, the method further comprises:

Acquiring a plurality of image frames through the camera and storing the image frames in an image buffer queue through the mobile terminal 100; reading at least two image frames which are adjacent at will from the image cache queue to carry out image registration to obtain a corresponding transformation matrix, and storing the transformation matrix to a transformation matrix cache queue; sequentially overlapping a last composite frame obtained by overlapping with the current image frame according to the current image frame and a transformation matrix corresponding to a last image frame adjacent to the current image frame until each image frame in the image cache queue is overlapped; the method comprises the steps of selecting a preset number of image frames at intervals from image frames obtained by superposition to construct a special effect video, repeatedly using an original data frame of a last synthesized frame when the image frames are superposed, thereby reducing shooting time, shooting a video with a multi-frame special effect in each frame only within the same time as a common video, and simultaneously selecting the preset number of image frames at intervals to construct the special effect video to achieve the effect of instant movement of an object. Further, the image buffer queue has a preset length, and when the number of the image frames in the image buffer queue exceeds the preset length, the image frames previously stored in the image frame buffer queue are released, so that a buffer space is ensured, and the shooting efficiency is improved.

Embodiments of the present application also provide a computer-readable storage medium having one or more programs, where the one or more programs are executed by one or more processors to implement the following steps:

acquiring a plurality of image frames at a preset speed through the camera;

Optionally, the image buffer queue has a preset length, and further includes:

Optionally, the method further comprises:

Acquiring a plurality of image frames through the camera and storing the image frames to an image buffer queue through the computer readable storage medium; reading at least two image frames which are adjacent at will from the image cache queue to carry out image registration to obtain a corresponding transformation matrix, and storing the transformation matrix to a transformation matrix cache queue; sequentially overlapping a last composite frame obtained by overlapping with the current image frame according to the current image frame and a transformation matrix corresponding to a last image frame adjacent to the current image frame until each image frame in the image cache queue is overlapped; the method comprises the steps of selecting a preset number of image frames at intervals from image frames obtained by superposition to construct a special effect video, and repeatedly using an original data frame of a previous synthesized frame when the image frames are superposed, so that the shooting time is reduced, the video with multi-frame special effects on each frame can be shot only in the same time as the common video, and meanwhile, the special effect video is constructed by selecting the preset number of image frames at intervals to achieve the effect of instantaneous movement of an object. Further, the image buffer queue has a preset length, and when the number of the image frames in the image buffer queue exceeds the preset length, the image frames previously stored in the image frame buffer queue are released, so that a buffer space is ensured, and the shooting efficiency is improved.

The embodiment of the application also provides a computer readable storage medium. The computer-readable storage medium herein stores one or more programs. Among other things, computer-readable storage media may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as read-only memory, flash memory, a hard disk, or a solid state disk; the memory may also comprise a combination of memories of the kind described above.

The corresponding technical features in the above embodiments may be used with each other without causing contradiction in the schemes or without being implementable.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.

Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present application may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present application.

While the present embodiments have been described with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments described above, which are meant to be illustrative and not restrictive, and that various changes may be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A special effect video generation method is applied to a mobile terminal, and is characterized in that the mobile terminal comprises a camera, and the special effect video generation method comprises the following steps:

2. The special effect video generation method of claim 1, wherein the step of acquiring a plurality of image frames by the camera comprises:

acquiring a plurality of image frames at a preset speed through the camera;

3. The special effect video generation method according to claim 1, wherein a first image frame is a previous image frame adjacent to the current image frame, a second image frame is a previous image frame adjacent to the first image frame, and the step of sequentially superimposing a previous superimposed composite frame on the current image frame based on the current image frame and a transformation matrix corresponding to the previous image frame adjacent to the current image frame comprises:

4. The special effect video generation method according to claim 3, wherein the step of sequentially overlapping a previous composite frame obtained by overlapping with the current image frame according to a transformation matrix corresponding to the current image frame and a previous image frame adjacent to the current image frame until each image frame in the image buffer queue is overlapped comprises:

5. The special effect video generation method according to claim 1, wherein the mobile terminal further includes a video encoder, and the step of selecting a preset number of image frames at intervals from the image frames obtained by the superimposition to construct the special effect video includes:

6. The special effect video generation method according to claim 1, wherein the step of selecting a preset number of image frames at intervals from the image frames obtained by the superimposition to construct the special effect video includes:

7. The special effect video generation method of claim 1, wherein the image buffer queue has a preset length, the special effect video generation method further comprising:

8. The special effect video generation method of claim 1, further comprising:

9. A mobile terminal, characterized in that the mobile terminal comprises:

a touch screen;

a processor; and

a memory connected to the processor, the memory containing control instructions, and when the processor reads the control instructions, the memory controlling the mobile terminal to implement the special effect video generation method according to any one of claims 1 to 8.

10. A computer-readable storage medium having one or more programs thereon for execution by one or more processors to implement the special effects video generation method of any of claims 1-8.