WO2022017261A1

WO2022017261A1 - Image synthesis method and electronic device

Info

Publication number: WO2022017261A1
Application number: PCT/CN2021/106666
Authority: WO
Inventors: 饶刚; 董辰; 卢曰万; 丁欣; 周恒�
Original assignee: 华为技术有限公司
Priority date: 2020-07-24
Filing date: 2021-07-16
Publication date: 2022-01-27
Also published as: CN113973173A; CN113973173B

Abstract

Provided are an image synthesis method and an electronic device. The method comprises: an electronic device receiving a background replacement operation of a user for a first image, and acquiring photographic angle information of the first image; acquiring a second image and photographic angle information of the second image; performing 3D viewing angle transformation on the second image according to the photographic angle information of the first image and the photographic angle information of the second image, such that a photographic angle of the second image reaches or is approximate to a photographic angle of the first image, so as to obtain a target background image; and performing image synthesis on a foreground image separated from the first image, and the target background image, so as to obtain a target image. By means of the method, the problem of a target image obtained after image synthesis having serious visual distortion can be ameliorated, thereby improving the user experience.

Description

Image synthesis method and electronic device

technical field

The present application relates to the technical field of intelligent terminals, and in particular, to an image synthesis method and an electronic device.

Background technique

At present, many image editing related applications (APPs, applications) of electronic devices provide users with the function of cutting out images and changing backgrounds. Cutout and background change is a process of separating a specified person image from a first image specified by a user, and synthesizing the separated person image into a second image to obtain a target image. The second image in the synthesized target image is used as the background image of the separated person image, thereby realizing the background replacement of the person image.

The prior art mainly focuses on how to better separate the person image from the first image, and when synthesizing the separated person image into the second image, the user often scales the person image, and then the electronic device The target image is obtained by directly synthesizing the person image and the second image. The target image synthesized in this way often has problems such as mismatch between the character image and the background image, resulting in serious visual distortion of the target image and affecting user experience.

SUMMARY OF THE INVENTION

The present application provides an image synthesis method and electronic device, which can improve the problem of serious visual distortion of a target image and improve user experience.

In a first aspect, an embodiment of the present application provides an image synthesis method, which is applied to an electronic device, including:

Receive the background replacement operation of the user for the first image, and obtain the shooting angle information of the first image;

acquiring the second image and the shooting angle information of the second image;

3D perspective transformation is performed on the second image according to the shooting angle information of the first image and the shooting angle information of the second image, so that the shooting angle of the second image reaches or is close to the shooting angle of the first image, and the target background image is obtained;

The foreground image separated from the first image is combined with the target background image to obtain the target image.

The method performs 3D perspective transformation on the second image according to the shooting angle information of the first image and the shooting angle information of the second image, so that the shooting angle of the second image reaches or is close to the shooting angle of the first image, and the target background image is obtained, thereby Compared with the second image, the shooting angle of the target background image is the same or closer to the shooting angle of the first image, that is, the shooting angle of the foreground image and the target background image is the same or closer. For the image obtained by performing image synthesis between the foreground image and the second image, the target image obtained by the method of the embodiment of the present application is more visually reasonable and coordinated, thereby improving the problem of serious visual distortion of the target image in the prior art, and improving the user experience. experience.

In a possible implementation manner, acquiring the second image includes:

obtaining preset classification information of the first image;

Obtain and display the background images to be selected that match the preset classification information of the first image; the displayed background images to be selected are sorted from small to large according to the shooting angle difference between the background images to be selected and the first image; the background images to be selected The shooting angle difference value with the first image is calculated according to the shooting angle information of the background image to be selected and the shooting angle information of the first image;

After receiving the user's selection operation on the background image to be selected, the background image to be selected indicated by the selection operation is used as the second image.

In this method, the background images to be selected displayed to the user are sorted according to the shooting angle difference between the background image to be selected and the first image from small to large, so that the shooting angles of the background images to be selected preferentially browsed by the user are closer to each other. The shooting angle of the first image, so that the fusion of the person image and the background image in the target image obtained after image synthesis according to the background image to be selected by the user is relatively more reasonable, natural and coordinated.

In a possible implementation manner, acquiring a background image to be selected that matches the preset classification information of the first image includes:

sending the shooting angle information of the first image and the preset classification information to the server;

Receive the background image to be selected that matches the preset classification information of the first image sent by the server, the background image to be selected is sorted by the server according to the difference value of the shooting angle between the background image to be selected and the first image, the background image to be selected and the first image are sorted by the server. The difference value of the shooting angle between the images is calculated by the server according to the shooting angle information of the background image to be selected and the shooting angle information of the first image.

In a possible implementation manner, image synthesis is performed on the foreground image separated from the first image and the target background image to obtain the target image, including:

Display the target background image, receive the user's position designation operation on the target background image, and obtain the position information of the user's designated position on the target background image;

determining the first distance estimation value corresponding to the location information;

Scaling the foreground image according to the first distance estimation value to obtain the target foreground image;

The target foreground image is synthesized to the position indicated by the position information in the target background image to obtain the target image.

By scaling the foreground image according to the first distance estimation value, the size of the foreground image can be made closer to the size of the image obtained by real shooting, so that the target image is visually more reasonable and coordinated.

In a possible implementation manner, before synthesizing the target foreground image to the position indicated by the position information on the target background image, before obtaining the target image, the method further includes:

Adjust the color parameters of the target foreground image and/or the target background image.

By adjusting the color parameters of the target foreground image and/or the target background image, the colors of the target foreground image and the target eyepiece image can be made closer, and the synthesized target image has high fusion at the boundary of the two images, so that the target Images are more visually plausible and coordinated.

In a possible implementation manner, the shooting angle information includes: a shooting attitude angle, and the shooting attitude angle includes: a pitch angle, an azimuth angle, and a roll angle.

In a second aspect, an embodiment of the present application provides an electronic device, including:

a display screen; one or more processors; a memory; and one or more computer programs, wherein the one or more computer programs are stored in the memory, the one or more computer programs including instructions that, when executed by the device, cause The device performs the following steps:

According to the shooting angle information of the first image and the shooting angle information of the second image, 3D perspective transformation is performed on the second image, so that the shooting angle information of the second image reaches or is close to the shooting angle information of the first image, and the target background image is obtained;

The foreground image separated from the first image is synthesized into the target background image to obtain the target image.

In a possible implementation manner, when the instruction is executed by the device, the step of acquiring the second image includes:

obtaining preset classification information of the first image;

Obtain and display the background images to be selected that match the preset classification information of the first image; the displayed background images to be selected are sorted according to the difference value of the shooting angle between the background images to be selected and the first image; The shooting angle difference value between the images is calculated according to the shooting angle information of the background image to be selected and the shooting angle information of the first image;

In a possible implementation manner, when the instruction is executed by the device, the step of obtaining a background image to be selected that matches the preset classification information of the first image includes:

In a possible implementation manner, when the instruction is executed by the device, the steps of performing image synthesis between the foreground image separated from the first image and the target background image to obtain the target image include:

In a possible implementation manner, when the instruction is executed by the device, before the step of synthesizing the target foreground image to the position indicated by the position information on the target background image, the method further includes:

In a third aspect, embodiments of the present application provide a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program runs on a computer, causes the computer to execute the method of any one of the first aspect.

In a fourth aspect, the present application provides a computer program for performing the method of the first aspect when the computer program is executed by a computer.

In a possible design, the program in the fourth aspect may be stored in whole or in part on a storage medium packaged with the processor, or may be stored in part or in part in a memory not packaged with the processor.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of an electronic device of the application;

2 is a schematic diagram of the software structure of the electronic device of the application;

3 is a GUI schematic diagram of the image synthesis method of the application;

4 is a flowchart of an embodiment of an image synthesis method of the present application;

5 is a schematic diagram of a method for establishing a mobile phone coordinate system and a first coordinate system of the present application;

6A is a schematic block diagram of some steps of the image synthesis method of the present application;

6B is a schematic block diagram of some steps of the image synthesis method of the present application;

FIG. 7 is a flowchart of another embodiment of the image synthesis method of the present application;

FIG. 8 is a structural diagram of an embodiment of an image synthesizing apparatus of the present application.

detailed description

The terms used in the embodiments of the present application are only used to explain specific embodiments of the present application, and are not intended to limit the present application.

In the prior art, after the person image is separated from the first image, the user generally automatically scales the person image to an appropriate size, and then directly combines it into the second image to obtain the target image. During image synthesis, the above-mentioned person image may also be referred to as a foreground image, and the second image may also be referred to as a background image.

From a technical point of view, factors such as the mismatch of light between the first image and the second image, and the mismatch of the shooting angle of view will cause poor coordination of the angle of view and serious visual distortion of the synthesized target image, which will affect the user experience.

From the user level, as the user's usage time for the function of cutting out the background and changing the background increases, the user's interest in the interest of this function will gradually decrease. The requirements for visual rationality and coordination of images will gradually increase.

To this end, the present application proposes an image synthesis method and electronic device, which can improve the problem of serious visual distortion of a target image obtained by synthesizing a foreground image (such as the above-mentioned person image) and a background image, and improve the quality of the target image obtained by image synthesis. Visual rationality and coordination to enhance user experience.

The image synthesis method of the present application can be applied to electronic devices, such as mobile terminals (mobile phones), tablet computers (PADs), personal computers (PCs), smart screens, in-vehicle devices and other devices.

FIG. 1 shows a schematic structural diagram of an electronic device 100 . The electronic device 100 may include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charge management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2 , mobile communication module 150, wireless communication module 160, audio module 170, speaker 170A, receiver 170B, microphone 170C, headphone jack 170D, sensor module 180, buttons 190, motor 191, indicator 192, camera 193, display screen 194, and Subscriber identification module (subscriber identification module, SIM) card interface 195 and so on. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, and ambient light. Sensor 180L, bone conduction sensor 180M, etc.

It can be understood that, the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on the electronic device 100 . In other embodiments of the present application, the electronic device 100 may include more or less components than shown, or combine some components, or separate some components, or arrange different components. The illustrated components may be implemented in hardware, software or a combination of software and hardware.

The processor 110 may include one or more processing units, for example, the processor 110 may include an application processor (application processor, AP), a modem processor, a graphics processor (graphics processing unit, GPU), an image signal processor (image signal processor, ISP), controller, video codec, digital signal processor (digital signal processor, DSP), baseband processor, and/or neural-network processing unit (neural-network processing unit, NPU), etc. Wherein, different processing units may be independent devices, or may be integrated in one or more processors.

The controller can generate an operation control signal according to the instruction operation code and timing signal, and complete the control of fetching and executing instructions.

A memory may also be provided in the processor 110 for storing instructions and data. In some embodiments, the memory in processor 110 is cache memory. This memory may hold instructions or data that have just been used or recycled by the processor 110 . If the processor 110 needs to use the instruction or data again, it can be called directly from the memory. Repeated accesses are avoided and the latency of the processor 110 is reduced, thereby increasing the efficiency of the system.

In some embodiments, the processor 110 may include one or more interfaces. The interface may include an integrated circuit (inter-integrated circuit, I2C) interface, an integrated circuit built-in audio (inter-integrated circuit sound, I2S) interface, a pulse code modulation (pulse code modulation, PCM) interface, a universal asynchronous transceiver (universal asynchronous transmitter) receiver/transmitter, UART) interface, mobile industry processor interface (MIPI), general-purpose input/output (GPIO) interface, subscriber identity module (SIM) interface, and / or universal serial bus (universal serial bus, USB) interface, etc.

The I2C interface is a bidirectional synchronous serial bus that includes a serial data line (SDA) and a serial clock line (SCL). In some embodiments, the processor 110 may contain multiple sets of I2C buses. The processor 110 can be respectively coupled to the touch sensor 180K, the charger, the flash, the camera 193 and the like through different I2C bus interfaces. For example, the processor 110 may couple the touch sensor 180K through the I2C interface, so that the processor 110 and the touch sensor 180K communicate with each other through the I2C bus interface, so as to realize the touch function of the electronic device 100 .

The I2S interface can be used for audio communication. In some embodiments, the processor 110 may contain multiple sets of I2S buses. The processor 110 may be coupled with the audio module 170 through an I2S bus to implement communication between the processor 110 and the audio module 170 . In some embodiments, the audio module 170 can transmit audio signals to the wireless communication module 160 through the I2S interface, so as to realize the function of answering calls through a Bluetooth headset.

The PCM interface can also be used for audio communications, sampling, quantizing and encoding analog signals. In some embodiments, the audio module 170 and the wireless communication module 160 may be coupled through a PCM bus interface. In some embodiments, the audio module 170 can also transmit audio signals to the wireless communication module 160 through the PCM interface, so as to realize the function of answering calls through the Bluetooth headset. Both the I2S interface and the PCM interface can be used for audio communication.

The UART interface is a universal serial data bus used for asynchronous communication. The bus may be a bidirectional communication bus. It converts the data to be transmitted between serial communication and parallel communication. In some embodiments, a UART interface is typically used to connect the processor 110 with the wireless communication module 160 . For example, the processor 110 communicates with the Bluetooth module in the wireless communication module 160 through the UART interface to implement the Bluetooth function. In some embodiments, the audio module 170 can transmit audio signals to the wireless communication module 160 through the UART interface, so as to realize the function of playing music through the Bluetooth headset.

The MIPI interface can be used to connect the processor 110 with peripheral devices such as the display screen 194 and the camera 193 . MIPI interfaces include camera serial interface (CSI), display serial interface (DSI), etc. In some embodiments, the processor 110 communicates with the camera 193 through a CSI interface, so as to realize the photographing function of the electronic device 100 . The processor 110 communicates with the display screen 194 through the DSI interface to implement the display function of the electronic device 100 .

The GPIO interface can be configured by software. The GPIO interface can be configured as a control signal or as a data signal. In some embodiments, the GPIO interface may be used to connect the processor 110 with the camera 193, the display screen 194, the wireless communication module 160, the audio module 170, the sensor module 180, and the like. The GPIO interface can also be configured as I2C interface, I2S interface, UART interface, MIPI interface, etc.

The USB interface 130 is an interface that conforms to the USB standard specification, and may specifically be a Mini USB interface, a Micro USB interface, a USB Type C interface, and the like. The USB interface 130 can be used to connect a charger to charge the electronic device 100, and can also be used to transmit data between the electronic device 100 and peripheral devices. It can also be used to connect headphones to play audio through the headphones. The interface can also be used to connect other electronic devices, such as AR devices.

It can be understood that the interface connection relationship between the modules illustrated in the embodiment of the present invention is only a schematic illustration, and does not constitute a structural limitation of the electronic device 100 . In other embodiments of the present application, the electronic device 100 may also adopt different interface connection manners in the foregoing embodiments, or a combination of multiple interface connection manners.

The charging management module 140 is used to receive charging input from the charger. The charger may be a wireless charger or a wired charger. In some wired charging embodiments, the charging management module 140 may receive charging input from the wired charger through the USB interface 130 . In some wireless charging embodiments, the charging management module 140 may receive wireless charging input through a wireless charging coil of the electronic device 100 . While the charging management module 140 charges the battery 142 , it can also supply power to the electronic device through the power management module 141 .

The power management module 141 is used for connecting the battery 142 , the charging management module 140 and the processor 110 . The power management module 141 receives input from the battery 142 and/or the charging management module 140, and supplies power to the processor 110, the internal memory 121, the display screen 194, the camera 193, and the wireless communication module 160. The power management module 141 can also be used to monitor parameters such as battery capacity, battery cycle times, battery health status (leakage, impedance). In some other embodiments, the power management module 141 may also be provided in the processor 110 . In other embodiments, the power management module 141 and the charging management module 140 may also be provided in the same device.

The wireless communication function of the electronic device 100 may be implemented by the antenna 1, the antenna 2, the mobile communication module 150, the wireless communication module 160, the modulation and demodulation processor, the baseband processor, and the like.

Antenna 1 and Antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in electronic device 100 may be used to cover a single or multiple communication frequency bands. Different antennas can also be reused to improve antenna utilization. For example, the antenna 1 can be multiplexed as a diversity antenna of the wireless local area network. In other embodiments, the antenna may be used in conjunction with a tuning switch.

The mobile communication module 150 may provide wireless communication solutions including 2G/3G/4G/5G etc. applied on the electronic device 100 . The mobile communication module 150 may include at least one filter, switch, power amplifier, low noise amplifier (LNA) and the like. The mobile communication module 150 can receive electromagnetic waves from the antenna 1, filter and amplify the received electromagnetic waves, and transmit them to the modulation and demodulation processor for demodulation. The mobile communication module 150 can also amplify the signal modulated by the modulation and demodulation processor, and then turn it into an electromagnetic wave for radiation through the antenna 1 . In some embodiments, at least part of the functional modules of the mobile communication module 150 may be provided in the processor 110 . In some embodiments, at least part of the functional modules of the mobile communication module 150 may be provided in the same device as at least part of the modules of the processor 110 .

The modem processor may include a modulator and a demodulator. Among them, the modulator is used to modulate the low-frequency baseband signal to be sent into a medium-high-frequency signal. The demodulator is used to demodulate the received electromagnetic wave signal into a low frequency baseband signal. Then the demodulator transmits the demodulated low-frequency baseband signal to the baseband processor for processing. The low frequency baseband signal is processed by the baseband processor and passed to the application processor. The application processor outputs sound signals through audio devices (not limited to the speaker 170A, the receiver 170B, etc.), or displays images or videos through the display screen 194 . In some embodiments, the modem processor may be a stand-alone device. In other embodiments, the modem processor may be independent of the processor 110, and may be provided in the same device as the mobile communication module 150 or other functional modules.

The wireless communication module 160 can provide applications on the electronic device 100 including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), bluetooth (BT), global navigation satellites Wireless communication solutions such as global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), and infrared technology (IR). The wireless communication module 160 may be one or more devices integrating at least one communication processing module. The wireless communication module 160 receives electromagnetic waves via the antenna 2 , frequency modulates and filters the electromagnetic wave signals, and sends the processed signals to the processor 110 . The wireless communication module 160 can also receive the signal to be sent from the processor 110 , perform frequency modulation on it, amplify it, and convert it into electromagnetic waves for radiation through the antenna 2 .

In some embodiments, the antenna 1 of the electronic device 100 is coupled with the mobile communication module 150, and the antenna 2 is coupled with the wireless communication module 160, so that the electronic device 100 can communicate with the network and other devices through wireless communication technology. The wireless communication technology may include global system for mobile communications (GSM), general packet radio service (GPRS), code division multiple access (CDMA), broadband Code Division Multiple Access (WCDMA), Time Division Code Division Multiple Access (TD-SCDMA), Long Term Evolution (LTE), BT, GNSS, WLAN, NFC , FM, and/or IR technology, etc. The GNSS may include a global positioning system (global positioning system, GPS), a global navigation satellite system (GLONASS), a Beidou navigation satellite system (BDS), a quasi-zenith satellite system (quasi -zenith satellite system, QZSS) and/or satellite based augmentation systems (SBAS).

The electronic device 100 implements a display function through a GPU, a display screen 194, an application processor, and the like. The GPU is a microprocessor for image processing, and is connected to the display screen 194 and the application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. Processor 110 may include one or more GPUs that execute program instructions to generate or alter display information.

Display screen 194 is used to display images, videos, and the like. Display screen 194 includes a display panel. The display panel can be a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode or an active-matrix organic light-emitting diode (active-matrix organic light). emitting diode, AMOLED), flexible light-emitting diode (flex light-emitting diode, FLED), Miniled, MicroLed, Micro-oLed, quantum dot light-emitting diode (quantum dot light emitting diodes, QLED) and so on. In some embodiments, the electronic device 100 may include one or N display screens 194 , where N is a positive integer greater than one.

The electronic device 100 may implement a shooting function through an ISP, a camera 193, a video codec, a GPU, a display screen 194, an application processor, and the like.

The ISP is used to process the data fed back by the camera 193 . For example, when taking a photo, the shutter is opened, the light is transmitted to the camera photosensitive element through the lens, the light signal is converted into an electrical signal, and the camera photosensitive element transmits the electrical signal to the ISP for processing, and converts it into an image visible to the naked eye. ISP can also perform algorithm optimization on image noise, brightness, and skin tone. ISP can also optimize the exposure, color temperature and other parameters of the shooting scene. In some embodiments, the ISP may be provided in the camera 193 .

Camera 193 is used to capture still images or video. The object is projected through the lens to generate an optical image onto the photosensitive element. The photosensitive element may be a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the optical signal into an electrical signal, and then transmits the electrical signal to the ISP to convert it into a digital image signal. The ISP outputs the digital image signal to the DSP for processing. DSP converts digital image signals into standard RGB, YUV and other formats of image signals. In some embodiments, the electronic device 100 may include 1 or N cameras 193 , where N is a positive integer greater than 1.

A digital signal processor is used to process digital signals, in addition to processing digital image signals, it can also process other digital signals. For example, when the electronic device 100 selects a frequency point, the digital signal processor is used to perform Fourier transform on the frequency point energy and so on.

Video codecs are used to compress or decompress digital video. The electronic device 100 may support one or more video codecs. In this way, the electronic device 100 can play or record videos of various encoding formats, such as: Moving Picture Experts Group (moving picture experts group, MPEG) 1, MPEG2, MPEG3, MPEG4 and so on.

The NPU is a neural-network (NN) computing processor. By drawing on the structure of biological neural networks, such as the transfer mode between neurons in the human brain, it can quickly process the input information, and can continuously learn by itself. Applications such as intelligent cognition of the electronic device 100 can be implemented through the NPU, such as image recognition, face recognition, speech recognition, text understanding, and the like.

The external memory interface 120 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the electronic device 100 . The external memory card communicates with the processor 110 through the external memory interface 120 to realize the data storage function. For example to save files like music, video etc in external memory card.

Internal memory 121 may be used to store computer executable program code, which includes instructions. The internal memory 121 may include a storage program area and a storage data area. The storage program area can store an operating system, an application program required for at least one function (such as a sound playback function, an image playback function, etc.), and the like. The storage data area may store data (such as audio data, phone book, etc.) created during the use of the electronic device 100 and the like. In addition, the internal memory 121 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, universal flash storage (UFS), and the like. The processor 110 executes various functional applications and data processing of the electronic device 100 by executing instructions stored in the internal memory 121 and/or instructions stored in a memory provided in the processor.

The electronic device 100 may implement audio functions through an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, an application processor, and the like. Such as music playback, recording, etc.

The audio module 170 is used for converting digital audio information into analog audio signal output, and also for converting analog audio input into digital audio signal. Audio module 170 may also be used to encode and decode audio signals. In some embodiments, the audio module 170 may be provided in the processor 110 , or some functional modules of the audio module 170 may be provided in the processor 110 .

Speaker 170A, also referred to as a "speaker", is used to convert audio electrical signals into sound signals. The electronic device 100 can listen to music through the speaker 170A, or listen to a hands-free call.

The receiver 170B, also referred to as "earpiece", is used to convert audio electrical signals into sound signals. When the electronic device 100 answers a call or a voice message, the voice can be answered by placing the receiver 170B close to the human ear.

The microphone 170C, also called "microphone" or "microphone", is used to convert sound signals into electrical signals. When making a call or sending a voice message, the user can make a sound by approaching the microphone 170C through a human mouth, and input the sound signal into the microphone 170C. The electronic device 100 may be provided with at least one microphone 170C. In other embodiments, the electronic device 100 may be provided with two microphones 170C, which can implement a noise reduction function in addition to collecting sound signals. In other embodiments, the electronic device 100 may further be provided with three, four or more microphones 170C to collect sound signals, reduce noise, identify sound sources, and implement directional recording functions.

The earphone jack 170D is used to connect wired earphones. The earphone interface 170D can be the USB interface 130, or can be a 3.5mm open mobile terminal platform (OMTP) standard interface, a cellular telecommunications industry association of the USA (CTIA) standard interface.

The pressure sensor 180A is used to sense pressure signals, and can convert the pressure signals into electrical signals. In some embodiments, the pressure sensor 180A may be provided on the display screen 194 . Pressure sensor 180A

There are many types, such as resistive pressure sensors, inductive pressure sensors, capacitive pressure sensors, etc. The capacitive pressure sensor may be comprised of at least two parallel plates of conductive material. When a force is applied to the pressure sensor 180A, the capacitance between the electrodes changes. The electronic device 100 determines the intensity of the pressure according to the change in capacitance. When a touch operation acts on the display screen 194, the electronic device 100 detects the intensity of the touch operation according to the pressure sensor 180A. The electronic device 100 may also calculate the touched position according to the detection signal of the pressure sensor 180A. In some embodiments, touch operations acting on the same touch position but with different touch operation intensities may correspond to different operation instructions. For example, when a touch operation whose intensity is less than the first pressure threshold acts on the short message application icon, the instruction for viewing the short message is executed. When a touch operation with a touch operation intensity greater than or equal to the first pressure threshold acts on the short message application icon, the instruction to create a new short message is executed.

The gyro sensor 180B may be used to determine the motion attitude of the electronic device 100 . In some embodiments, the angular velocity of electronic device 100 about three axes (ie, x, y, and z axes) may be determined by gyro sensor 180B. The gyro sensor 180B can be used for image stabilization. Exemplarily, when the shutter is pressed, the gyro sensor 180B detects the shaking angle of the electronic device 100, calculates the distance that the lens module needs to compensate according to the angle, and allows the lens to offset the shaking of the electronic device 100 through reverse motion to achieve anti-shake. The gyro sensor 180B can also be used for navigation and somatosensory game scenarios.

The air pressure sensor 180C is used to measure air pressure. In some embodiments, the electronic device 100 calculates the altitude through the air pressure value measured by the air pressure sensor 180C to assist in positioning and navigation.

The magnetic sensor 180D includes a Hall sensor. The electronic device 100 can detect the opening and closing of the flip holster using the magnetic sensor 180D. In some embodiments, when the electronic device 100 is a flip machine, the electronic device 100 can detect the opening and closing of the flip according to the magnetic sensor 180D. Further, according to the detected opening and closing state of the leather case or the opening and closing state of the flip cover, characteristics such as automatic unlocking of the flip cover are set.

The acceleration sensor 180E can detect the magnitude of the acceleration of the electronic device 100 in various directions (generally three axes). The magnitude and direction of gravity can be detected when the electronic device 100 is stationary. It can also be used to identify the posture of electronic devices, and can be used in applications such as horizontal and vertical screen switching, pedometers, etc.

Distance sensor 180F for measuring distance. The electronic device 100 can measure the distance through infrared or laser. In some embodiments, when shooting a scene, the electronic device 100 can use the distance sensor 180F to measure the distance to achieve fast focusing.

Proximity light sensor 180G may include, for example, light emitting diodes (LEDs) and light detectors, such as photodiodes. The light emitting diodes may be infrared light emitting diodes. The electronic device 100 emits infrared light to the outside through light emitting diodes. Electronic device 100 uses photodiodes to detect infrared reflected light from nearby objects. When sufficient reflected light is detected, it can be determined that there is an object near the electronic device 100 . When insufficient reflected light is detected, the electronic device 100 may determine that there is no object near the electronic device 100 . The electronic device 100 can use the proximity light sensor 180G to detect that the user holds the electronic device 100 close to the ear to talk, so as to automatically turn off the screen to save power. Proximity light sensor 180G can also be used in holster mode, pocket mode automatically unlocks and locks the screen.

The ambient light sensor 180L is used to sense ambient light brightness. The electronic device 100 can adaptively adjust the brightness of the display screen 194 according to the perceived ambient light brightness. The ambient light sensor 180L can also be used to automatically adjust the white balance when taking pictures. The ambient light sensor 180L can also cooperate with the proximity light sensor 180G to detect whether the electronic device 100 is in a pocket, so as to prevent accidental touch.

The fingerprint sensor 180H is used to collect fingerprints. The electronic device 100 can use the collected fingerprint characteristics to realize fingerprint unlocking, accessing application locks, taking pictures with fingerprints, answering incoming calls with fingerprints, and the like.

The temperature sensor 180J is used to detect the temperature. In some embodiments, the electronic device 100 uses the temperature detected by the temperature sensor 180J to execute a temperature processing strategy. For example, when the temperature reported by the temperature sensor 180J exceeds a threshold value, the electronic device 100 reduces the performance of the processor located near the temperature sensor 180J in order to reduce power consumption and implement thermal protection. In other embodiments, when the temperature is lower than another threshold, the electronic device 100 heats the battery 142 to avoid abnormal shutdown of the electronic device 100 caused by the low temperature. In some other embodiments, when the temperature is lower than another threshold, the electronic device 100 boosts the output voltage of the battery 142 to avoid abnormal shutdown caused by low temperature.

Touch sensor 180K, also called "touch device". The touch sensor 180K may be disposed on the display screen 194 , and the touch sensor 180K and the display screen 194 form a touch screen, also called a “touch screen”. The touch sensor 180K is used to detect a touch operation on or near it. The touch sensor can pass the detected touch operation to the application processor to determine the type of touch event. Visual output related to touch operations may be provided through display screen 194 . In other embodiments, the touch sensor 180K may also be disposed on the surface of the electronic device 100 , which is different from the location where the display screen 194 is located.

The bone conduction sensor 180M can acquire vibration signals. In some embodiments, the bone conduction sensor 180M can acquire the vibration signal of the vibrating bone mass of the human voice. The bone conduction sensor 180M can also contact the pulse of the human body and receive the blood pressure beating signal. In some embodiments, the bone conduction sensor 180M can also be disposed in the earphone, combined with the bone conduction earphone. The audio module 170 can analyze the voice signal based on the vibration signal of the vocal vibration bone block obtained by the bone conduction sensor 180M, so as to realize the voice function. The application processor can analyze the heart rate information based on the blood pressure beat signal obtained by the bone conduction sensor 180M, and realize the function of heart rate detection.

The keys 190 include a power-on key, a volume key, and the like. Keys 190 may be mechanical keys. It can also be a touch key. The electronic device 100 may receive key inputs and generate key signal inputs related to user settings and function control of the electronic device 100 .

Motor 191 can generate vibrating cues. The motor 191 can be used for vibrating alerts for incoming calls, and can also be used for touch vibration feedback. For example, touch operations acting on different applications (such as taking pictures, playing audio, etc.) can correspond to different vibration feedback effects. The motor 191 can also correspond to different vibration feedback effects for touch operations on different areas of the display screen 194 . Different application scenarios (for example: time reminder, receiving information, alarm clock, games, etc.) can also correspond to different vibration feedback effects. The touch vibration feedback effect can also support customization.

The indicator 192 can be an indicator light, which can be used to indicate the charging state, the change of the power, and can also be used to indicate a message, a missed call, a notification, and the like.

The SIM card interface 195 is used to connect a SIM card. The SIM card can be contacted and separated from the electronic device 100 by inserting into the SIM card interface 195 or pulling out from the SIM card interface 195 . The electronic device 100 may support 1 or N SIM card interfaces, where N is a positive integer greater than 1. The SIM card interface 195 can support Nano SIM card, Micro SIM card, SIM card and so on. Multiple cards can be inserted into the same SIM card interface 195 at the same time. The types of the plurality of cards may be the same or different. The SIM card interface 195 can also be compatible with different types of SIM cards. The SIM card interface 195 is also compatible with external memory cards. The electronic device 100 interacts with the network through the SIM card to implement functions such as call and data communication. In some embodiments, the electronic device 100 employs an eSIM, ie: an embedded SIM card. The eSIM card can be embedded in the electronic device 100 and cannot be separated from the electronic device 100 .

The software system of the electronic device 100 may adopt a layered architecture, an event-driven architecture, a microkernel architecture, a microservice architecture, or a cloud architecture. The embodiment of the present invention takes an Android system with a layered architecture as an example to illustrate the software structure of the electronic device 100 as an example.

FIG. 2 is a block diagram of a software structure of an electronic device 100 according to an embodiment of the present invention.

The layered architecture divides the software into several layers, and each layer has a clear role and division of labor. Layers communicate with each other through software interfaces. In some embodiments, the Android system is divided into four layers, which are, from top to bottom, an application layer, an application framework layer, an Android runtime (Android runtime) and a system library, and a kernel layer.

The application layer can include a series of application packages.

As shown in Figure 2, the application package can include applications such as camera, gallery, calendar, call, map, navigation, WLAN, Bluetooth, music, video, short message and so on.

The application framework layer provides an application programming interface (application programming interface, API) and a programming framework for applications in the application layer. The application framework layer includes some predefined functions.

As shown in Figure 2, the application framework layer may include window managers, content providers, view systems, telephony managers, resource managers, notification managers, and the like.

A window manager is used to manage window programs. The window manager can get the size of the display screen, determine whether there is a status bar, lock the screen, take screenshots, etc.

Content providers are used to store and retrieve data and make these data accessible to applications. The data may include video, images, audio, calls made and received, browsing history and bookmarks, phone book, etc.

The view system includes visual controls, such as controls for displaying text, controls for displaying pictures, and so on. View systems can be used to build applications. A display interface can consist of one or more views. For example, the display interface including the short message notification icon may include a view for displaying text and a view for displaying pictures.

The phone manager is used to provide the communication function of the electronic device 100 . For example, the management of call status (including connecting, hanging up, etc.).

The resource manager provides various resources for the application, such as localization strings, icons, pictures, layout files, video files and so on.

The notification manager enables applications to display notification information in the status bar, which can be used to convey notification-type messages, and can disappear automatically after a brief pause without user interaction. For example, the notification manager is used to notify download completion, message reminders, etc. The notification manager can also display notifications in the status bar at the top of the system in the form of graphs or scroll bar text, such as notifications of applications running in the background, and notifications on the screen in the form of dialog windows. For example, text information is prompted in the status bar, a prompt sound is issued, the electronic device vibrates, and the indicator light flashes.

Android Runtime includes core libraries and a virtual machine. Android runtime is responsible for scheduling and management of the Android system.

The core library consists of two parts: one is the function functions that the java language needs to call, and the other is the core library of Android.

The application layer and the application framework layer run in virtual machines. The virtual machine executes the java files of the application layer and the application framework layer as binary files. The virtual machine is used to perform functions such as object lifecycle management, stack management, thread management, safety and exception management, and garbage collection.

A system library can include multiple functional modules. For example: surface manager (surface manager), media library (Media Libraries), 3D graphics processing library (eg: OpenGL ES), 2D graphics engine (eg: SGL), etc.

The Surface Manager is used to manage the display subsystem and provides a fusion of 2D and 3D layers for multiple applications.

The media library supports playback and recording of a variety of commonly used audio and video formats, as well as still image files. The media library can support a variety of audio and video encoding formats, such as: MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, etc.

The 3D graphics processing library is used to implement 3D graphics drawing, image rendering, compositing, and layer processing.

2D graphics engine is a drawing engine for 2D drawing.

The kernel layer is the layer between hardware and software. The kernel layer contains at least display drivers, camera drivers, audio drivers, and sensor drivers.

For ease of understanding, the following embodiments of the present application will take the electronic device having the structure shown in FIG. 1 and FIG. 2 as an example, and combine the drawings and application scenarios to specifically describe the methods provided by the embodiments of the present application.

3 is an example diagram of a graphical user interface (graphical user interface, GUI) of the image synthesis method according to the embodiment of the present application. In FIG. 3 , the electronic device is a mobile phone as an example to illustrate the image synthesis method provided by the embodiment of the present application.

In part 31 of FIG. 3, the user selects an image as the first image whose background needs to be changed. For example, as shown in image 310 in part 31, the user clicks on the background change control. Correspondingly, the mobile phone detects the user's operation and displays the recommended image to the user. The way of displaying the background image is not limited. For example, in part 32 of FIG. 3, the background image is displayed to the user through paging. In part 32 of FIG. 3, the background image of the displayed first page is shown, the first page A total of 9 background images are displayed; the background images shown here are obtained based on the first image, and are sorted from small to large according to the difference in shooting angle between the background image and the first image. The user selects a background image from the displayed background images (in FIG. 3, the user selects the background image 1 by clicking as an example) as the second image; correspondingly, the mobile phone detects the user's selection operation and displays the user's selection to the user. The background image, as shown in part 33 in FIG. 3, presents the second image 320 to the user.

The user designates a position in the displayed second image 320 as the position where the character image separated from the first image is synthesized into the second image, and clicks the OK control. Correspondingly, the mobile phone receives the user's position designation operation, and the first image is combined. The person images separated in the image 310 are synthesized to the position designated by the user in the second image 320 to obtain the target image. The rationality and fusion of the target image obtained by using the image synthesis method of the present application are relatively higher.

Hereinafter, the implementation of the image synthesis method of the present application will be described in more detail by taking an example.

FIG. 4 is a flowchart of an embodiment of an image synthesis method of the present application. As shown in FIG. 4 , the method may include:

Step 401: Preset a material library of background images on the server side.

The images in the material library may be images captured by an electronic device such as a mobile phone, which are authorized by the user to which the electronic device belongs and uploaded to the server, or may be images shot or collected by the material library provider. The source of the image in the material library is not limited in this embodiment of the present application.

Each image in the material library can be set with: angle label and category label.

The angle tag is used to record the shooting angle information of the image, such as the shooting attitude angle; the classification tag is used to record the classification information of the image. The material library can classify and store the images in the material library according to the classification tags of the images.

The shooting attitude angle is used to describe the angle at which the electronic device rotates around the xyz axis of the first coordinate system. The method for establishing the first coordinate system is: take the origin of the mobile phone coordinate system as the origin of the first coordinate The positive direction of the axis is the due west direction of the geography, the positive direction of the y-axis is the vertical upward direction, and the positive direction of the z-axis is the due north direction of the geography.

The shooting attitude angle may include three angle parameters, namely: pitch angle α, azimuth angle β and roll angle γ. Hereinafter, three types of angle parameters will be described respectively.

Referring to FIG. 5, a method for establishing the coordinate system of a vertical screen mobile phone is shown, wherein, taking the physical center of the mobile phone as the origin, the right, top, and front three directions of the mobile phone are the positive directions of the x, y, and z axes, respectively. When the mobile phone is placed vertically and the front of the mobile phone (generally the side with the display screen) faces the geographic north direction, the mobile phone coordinate system coincides with the first coordinate system. in,

Pitch angle α: When the plane where the xz axis of the mobile phone coordinate system is located is parallel to the plane where the xz axis of the first coordinate system is located (that is, the ground or the horizontal plane), the elevation angle is 0 degrees. When the mobile phone is around the x axis of the first coordinate system Rotate, and when the top is farther and farther away from the user (assuming the user is in front of the phone), and the bottom is getting closer and closer to the transfer (at this time, it can be understood that the rear camera of the mobile phone is gradually shooting towards the ground), the pitch angle is from 0 to -90 degrees change; if the top is getting closer and closer to the user and the bottom is getting farther and farther away from the user (at this time, it can be understood that the rear camera of the mobile phone is gradually shooting towards the sky), the pitch angle changes from 0 to 90 degrees.

Azimuth β: The mobile phone rotates around the y-axis of the first coordinate system, the front of the mobile phone is 0 degrees to the true north, rotate clockwise, the azimuth changes from 0 to 360 degrees, 0 degrees true north, 90 degrees east, positive 180 degrees south, 270 degrees west.

Roll angle γ: When the plane where the yz axis of the mobile phone coordinate system is located coincides with the plane where the yz axis of the first coordinate system is located (that is, it is perpendicular to the horizontal plane), the roll angle of the mobile phone is 0 degrees, and the mobile phone surrounds the first coordinate system. If the z-axis is rotated, the roll angle changes from 0 to 90 degrees if it is rotated clockwise; if it is rotated counterclockwise, the roll angle changes from 0 to -90 degrees.

It should be noted that the vertical screen mobile phone is used as an example in Fig. 5, and it can also be extended to any electronic device, such as a horizontal screen mobile phone, etc. For a horizontal screen mobile phone, it is only necessary to change the vertical screen mobile phone in the figure to a horizontal screen. For screen phones, the definition of shooting attitude angle remains unchanged.

Classification tags of images may include, but are not limited to, tags of the following categories: scene information, and/or light information, and/or season information, and/or weather information, and the like.

The scene information is used to record the shooting scene of the image, and the parameter values may include: indoor and outdoor; the light information is used to record the brightness and darkness of the image, and the parameter values may include: bright and dark; the season information is used to record the shooting season of the image, The parameter values may include: spring, summer, autumn, and winter; the weather information is used to record the weather conditions when the image is taken, and the parameter values may include: sunny, rainy, snowy, and the like.

In the material library, images can be classified and stored according to the above-mentioned classification tags of the images, so that the images in the material library are stored in a more orderly manner.

Referring to FIG. 6A , for the process of uploading an image uploaded by the user to the material library, the user uses an electronic device to shoot an image, and after the user authorizes the electronic device, the classification information of the image and the image (with the classification label of the image in the material library) (corresponding to the recorded information), and shooting angle information (corresponding to the information recorded by the angle label of the image in the material library) are uploaded to the server where the material library is located, and the server classifies the images according to the classification information of the uploaded images and saves them to the material library. under the corresponding category.

Step 402: The electronic device acquires the user's background replacement operation for the first image.

This step may correspond to part 31 in FIG. 3 , and will not be repeated here.

Step 403: The electronic device acquires the shooting angle information and classification information of the first image, and uploads the acquired information to the server.

The shooting angle information may be the shooting attitude angle; the classification information may include: parameter values corresponding to each classification label in the material library. For example, the classification label of the image in the material library includes scene information, and the classification information of the image in this step may include: the parameter value of the scene information.

The shooting angle information and the classification information of the first image may be correspondingly determined by the electronic device when shooting the first image, and stored as parameters of the first image.

The electronic device can obtain the motion data of the electronic device based on sensors such as acceleration sensor and magnetic sensor set in itself, and use the Euler kinematic equation to calculate the Euler angle based on the electronic device coordinate system and the first coordinate system of the electronic device. The Euler angle calculated by the motion data when the electronic device captures the first image includes three components, namely the pitch angle α, the azimuth angle β and the roll angle γ corresponding to the shooting attitude angle of the first image.

The classification information of the first image may be determined by the electronic device, for example:

The scene information may be manually set by the user, or may be determined by inputting the first image into a preset scene recognition model. Optionally, a scene recognition model can be preset in the electronic device, the scene recognition model can be obtained by training a convolutional neural network, and the training principle can be: collecting a certain number of images in indoor and outdoor scenes as training. sample, and set a scene label marked indoor or outdoor for each training sample, input the training sample into the convolutional neural network for training, and obtain a scene recognition model, which is a binary classification that can recognize indoor and outdoor images. device;

The light information may be determined by the electronic device based on the brightness of the image.

The season information may be determined by the electronic device based on the time when the first image was captured and the geographic location of the electronic device. For example, when the electronic device captured the first image in January and in Beijing, the season information of the first image is: winter; The electronic device captures the first image in January in Sydney, and the season information of the first image is summer.

The weather information can be obtained by the electronic device from a weather forecast related App installed on the electronic device when the first image is taken, and then the weather information of the first image is determined as sunny, rainy, or snowy.

Step 404: The server finds the background image to be selected according to the classification information of the first image.

The material set is classified and stored according to the classification label. The classification information of the first image corresponds to the classification label of the image in the material library. According to the classification information of the first image, several pieces corresponding to the classification information of the first image can be found from the material library. Image, the image found from the material library is the background image to be selected.

For example, assuming that the material library is classified according to the two classification labels of scene information (indoor, outdoor) and light information (bright, dark) in turn, the classification information of the first image is: indoor, bright, you can find it from the material library Several images under the classification branch of scene information-indoor, light information-bright are used as background images to be selected.

Searching for the background image to be selected according to the classification information of the first image can filter out the images in the material library that do not match the classification information of the first image, so as to prevent the background image to be displayed to the user from being too complicated and unreasonable. An image is an image taken indoors and in winter, and the person in the first image is wearing thick clothes, and the information recorded in the classification tag is (indoor, summer) or (outdoor, summer) images do not need to be selected as backgrounds The image is displayed to the user as a recommended background image in the subsequent steps. Otherwise, it is obviously unreasonable to recommend an image of a summer garden to the user as a background image. Through the execution of this step, the information recorded in the classification label can be The image for (outdoor, winter) is found from the material library, and then recommended to the user as the candidate background image.

Step 405: The server calculates the difference value of the shooting angle between each background image to be selected and the first image according to the shooting angle information of the first image and the shooting angle information of the background image to be selected.

When the shooting angle information is the shooting attitude angle, calculating a shooting angle difference value between a background image to be selected and the first image may include:

Calculate the absolute difference value of the pitch angle α between the background image to be selected and the first image |Δα|, the absolute value of the difference value of the azimuth angle β |Δβ|, and the absolute value of the difference value of the roll angle γ |Δγ|;

[Omega] is calculated photographing angle difference value between the candidate image and the first background image in accordance with the following _{equation: ω = W α | Δα |} + W β | Δβ | + W γ | Δγ |; _wherein, W α is the pitch angle of the pre Set the weight, W _β is the preset weight of the azimuth angle, and W _γ is the preset weight of the roll angle, where W _β <W _γ <W _α , and the specific value of the weight is not limited in the embodiment of the present application.

Step 406: The server sorts the background images to be selected according to the angle difference values corresponding to each background image to be selected, and sends the background images to be selected to the electronic device in the sorted order.

Hereinafter, the procedures of steps 404 to 406 will be described with reference to FIG. 6B . As shown in FIG. 6B , the server finds the background image to be selected according to the classification information of the first picture, calculates the shooting angle difference value according to the shooting angle information of each background image to be selected and the shooting angle information of the first picture, and calculates the shooting angle difference value based on the shooting angle difference value. To sort the background images to be selected, the background images to be selected can be sorted in descending order of the difference value of the shooting angle.

By sorting the background images to be selected according to the shooting angle difference value from small to large, and then sending them to the electronic device and displaying them to the user by the electronic device, the shooting angle of the background image to be selected first browsed by the user can be closer to that of the first image. According to the shooting angle, the fusion of the person image and the background image in the target image obtained after image synthesis according to the background image to be selected by the user is relatively more reasonable, natural and coordinated.

Step 407: The electronic device receives the background image to be selected sent by the server, and displays the background image to be selected to the user.

The implementation of this step may correspond to part 32 in FIG. 3 , and details are not described here.

Step 408: The electronic device receives the user's selection operation for a displayed background image, and uses the background image selected by the user as the second image.

Step 409: The electronic device acquires shooting angle information of the second image.

The shooting angle information of the second image may be acquired by the electronic device from the server after the second image is determined, or carried when the server sends the background image to be selected to the electronic device for display.

Step 410: The electronic device performs three-dimensional (3D, three dimensional) perspective transformation on the second image according to the shooting angle information of the first image and the shooting angle information of the second image, so that the shooting angle of the second image reaches or is close to the first image the shooting angle to get the target background image.

Among them, the 3D perspective transformation of the second image can be realized by using the 3D Kens Burns Effect (3D Kens Burns Effect) algorithm. In this algorithm, a virtual camera is set for the second image according to the shooting attitude angle of the second image. position, and perform 3D scene geometry estimation on the image in the second image to obtain an estimated distance between each pixel in the second image and the virtual camera; rotate the shooting direction of the virtual camera to the shooting attitude angle of the first image , and then adjust the second image according to the rotation of the virtual camera.

Here, the estimated value of the distance between the pixel and the virtual camera can also be regarded as the estimated value of the actual distance between the real object corresponding to the pixel and the electronic device that captures the second image.

During the rotation of the virtual camera, in the order of priority, the pitch angle α is rotated first, then the roll angle γ is rotated, and finally the azimuth angle β is rotated.

Generally, the rotation of the shooting attitude angle of the virtual camera under this algorithm has a certain angle limit. When the angular difference between the shooting attitude angle of the second image and the shooting attitude angle of the first image is smaller than the angle limit, the processing The shooting attitude angle of the target background image can be made the same as the shooting attitude angle of the first image. When the angle difference between the shooting attitude angle of the second image and the shooting attitude angle of the first image exceeds the angle limit, it may not be possible to make the target The shooting attitude angle of the background image is the same as the shooting attitude angle of the first image, but through this process, the shooting attitude angle of the target background image can be made closer to the shooting attitude angle of the first image.

By performing 3D perspective transformation on the second image, the shooting angle of the second image can reach or be close to the shooting angle of the first image, thereby reducing the shooting angle difference between the person image and the second image, so that the difference between the person image and the second image is reduced. The shooting angles should be as close to or even consistent as possible, so that the target image obtained after image synthesis is more reasonable, natural and coordinated.

Step 411 : The electronic device displays the target background image to the user, obtains the position information of the person image in the target background image specified by the user, and determines the first estimated distance value corresponding to the position information.

The implementation of this step can correspond to part 33 in FIG. 3; or, the electronic device can also separate the person image from the first image, place the person image on the target background image, and drag the person image by the user, thereby specifying the person image in the The position in the target background image.

The location information may be information of a point or information of an area.

The estimated value of the distance between the pixel and the virtual camera can generally be obtained when performing 3D perspective transformation on the second image in step 410. If the distance between each pixel in the second image and the virtual camera is not determined during the processing in step 410 The estimated value can be calculated by, for example, the 3D Kens Burns Effect algorithm shown in step 410. According to the distance estimation value between the pixel at the location information and the virtual camera, the first distance estimation value corresponding to the location information can be obtained. Wherein, if the location information indicates a point, the estimated distance between the pixel corresponding to the point and the virtual camera may be determined as the first estimated distance corresponding to the location information. The estimated distance between one pixel or multiple pixels and the virtual camera, to determine the first estimated distance corresponding to the location information, if the estimated distance corresponding to the location information is determined according to the estimated distance between multiple pixels included in the area and the virtual camera. For the first distance estimation value, the first distance estimation value corresponding to the position information can be determined by calculating the mean value of the distance estimation values corresponding to a plurality of pixels.

Step 412: The electronic device separates the person image from the first image, and scales the person image according to the first estimated distance value corresponding to the position information to obtain the target person image.

Wherein, the step of separating the person image from the first image by the electronic device may be performed between

steps

402 and 412 of scaling the person image according to the first estimated distance value corresponding to the position information, and steps 403 to 411 The order of execution between them is not limited. The person image may be automatically separated by the electronic device, or the user may select the person image to be separated from the first image. If selected by the user, the first image can be displayed to the user, and the user can perform an area selection operation. Correspondingly, the electronic device can determine the person image to be separated based on the user's area selection operation, and then separate the person image from the first image. .

In a possible implementation, in this step, according to the principle that the distance between the human eyes is basically the same, it can be pre-determined that at different shooting distances between the person being photographed and the camera, the average distance between the human eyes in the captured images with the same resolution The number of pixels occupied, for example, if the distance between the human and the camera is 10m, the number of pixels occupied by the average distance between the human eyes in the captured image is x1, and the distance between the human and the camera is 20m. The number of pixels is x2, and so on.

In this step, the electronic device may obtain the number of pixels occupied by the distance between the human eyes of the separated person image, determine the second estimated distance value corresponding to the person image according to the number of pixels occupied by the distance between the human eyes, and determine the first distance corresponding to the position information according to the number of pixels occupied by the distance between the human eyes. The estimated value and the second estimated distance corresponding to the person image are scaled to the person image, that is, the target person image can be obtained. The second estimated distance value is also the estimated value of the distance between the person corresponding to the person image and the electronic device that photographed the first image when the first image is photographed.

In another possible implementation, in this step, for example, the 3D Kens Burns Effect algorithm can be used to calculate the estimated distance of each pixel in the first image relative to the virtual camera, so that the estimated distance corresponding to the pixels included in the person image can be obtained. , the second distance estimation value corresponding to the person image can be determined according to the distance estimation value corresponding to the pixels included in the person image, for example, taking the average value of the distance estimation values of all the pixels included in the person image, or taking a certain preset position such as the eye The distance estimate of the pixel, etc. The target person image can be obtained by scaling the person image according to the first estimated distance value corresponding to the position information and the second estimated distance value corresponding to the person image.

In this step, the image of the person is scaled according to the first estimated distance value corresponding to the position information, so that the size of the image of the person is closer to the size of the person photographed when the person actually stands at the same position in the actual scene corresponding to the second image, thereby It makes the synthesized target image more reasonable, natural and coordinated visually.

Step 413: The electronic device adjusts the color parameters of the target person image and/or the target background image, and synthesizes the adjusted target person image and the target background image to obtain the target image.

Color parameters may include color temperature, and/or contrast, among others.

By adjusting the color parameters, the color parameters of the target person image and the target background image can be made closer, thereby making the synthesized target image more natural and reasonable.

In one implementation, the color temperature of the target background image can be calculated, and the color temperature of the target person image can be adjusted accordingly, so that the color temperature of the target person image is closer to the color temperature of the target background image. The color temperature calculation method of the image will not be repeated in this embodiment of the present application. For example, the color temperature estimation method in the automatic white balance algorithm may be used to calculate the color temperature of the target background image.

In this step, by adjusting the color parameters of the target person image and/or the target background image to reduce the color difference between the two, the target image obtained after synthesis can be visually more harmonious, reasonable and natural in color.

Step 414: The electronic device presents the target image to the user.

This step may correspond to part 34 in FIG. 3 , and will not be repeated here.

In the existing process of cutting out the background and changing the background, the image of the person edited by the user is directly synthesized into the background image selected by the user according to the size of the image. , it is easy to cause problems such as poor overall coordination of the synthesized image, image distortion, scene logic errors, and light and shadow differences, resulting in distorted and unnatural synthesized images.

However, the image synthesis method of the embodiment of the present application solves the above-mentioned problems existing in the process of cutout and background replacement, reduces the difference in shooting angle between the first image and the second image, and can also reduce the difference in scene logic and color. And/or the difference in the depth of the field of view and the scene, the target image obtained after image synthesis is visually more reasonable, natural, and coordinated, and the user experience is improved.

Taking the separation of the person image in the first image and the synthesis of the second image, that is, replacing the background image of the person image in the first image as an example, the method of the embodiment of the present application can also be extended from the person image to the image of any object. , such as animal images, object images, etc., the image that is separated from the first image and needs to be synthesized with the second image is called the foreground image hereinafter.

The method in this embodiment of the present application can be extended to a method for synthesizing images in the video, so as to replace the background image of the image in the video. When processing the video, each frame of image in the video can be used as the first image in the embodiment of the present application. .

FIG. 7 is a flowchart of an embodiment of an image synthesis method of the present application, which can be applied to an electronic device. As shown in FIG. 7 , the method may include:

Step 701: receive the background replacement operation of the user for the first image, and obtain the shooting angle information of the first image;

Step 702: Acquire a second image and shooting angle information of the second image;

Step 703: Perform 3D perspective transformation on the second image according to the shooting angle information of the first image and the shooting angle information of the second image, so that the shooting angle of the second image reaches or is close to the shooting angle of the first image, and the target background image is obtained;

Step 704: Perform image synthesis on the foreground image separated from the first image and the target background image to obtain a target image.

The foreground image may be the person image in the embodiment shown in FIG. 4 , or may be an image of other existing objects, such as animal images, object images, and the like. The electronic device may display the first image to the user, and the user may perform a region selection operation. Correspondingly, the electronic device may use the region indicated by the user's region selection operation as the region of the foreground image, and then separate the foreground image from the first image.

Optionally, acquiring the second image in step 702 may include:

obtaining preset classification information of the first image;

Optionally, the electronic device can also obtain the second image locally from the electronic device, for example, the user selects an image in the album of the electronic device as the second image, and accordingly, the electronic device can obtain the first image selected by the user according to the user's operation. Second image.

Optionally, acquiring a background image to be selected that matches the preset classification information of the first image may include:

Optionally, step 704 may include:

Optionally, before synthesizing the target foreground image to the position indicated by the position information on the target background image, before obtaining the target image, it may further include:

Optionally, the shooting angle information may include: a shooting attitude angle, and the shooting attitude angle includes: a pitch angle, an azimuth angle, and a roll angle.

It can be understood that, some or all of the steps or operations in the foregoing embodiments are merely examples, and other operations or variations of various operations may also be performed in the embodiments of the present application. Furthermore, the various steps may be performed in a different order than those presented in the above-described embodiments, and it is possible that not all operations in the above-described embodiments are performed.

FIG. 8 is a structural diagram of an embodiment of an image synthesis apparatus of the present application, which can be applied to electronic equipment. As shown in FIG. 8 , the apparatus 80 may include:

The obtaining unit 81 is configured to receive the user's background replacement operation for the first image, obtain the shooting angle information of the first image; obtain the second image and the shooting angle information of the second image;

The transformation unit 82 is configured to perform 3D perspective transformation on the second image according to the shooting angle information of the first image and the shooting angle information of the second image, so that the shooting angle of the second image reaches or is close to the shooting angle of the first image, and the target is obtained. background image;

The synthesis unit 83 is configured to perform image synthesis between the foreground image separated from the first image and the target background image to obtain the target image.

Optionally, the acquiring unit may be specifically configured to: acquire preset classification information of the first image; acquire and display a background image to be selected that matches the preset classification information of the first image; the background image to be displayed is displayed according to the background image to be selected. The shooting angle difference value between the image and the first image is sorted from small to large; the shooting angle difference value between the background image to be selected and the first image is based on the shooting angle information of the background image to be selected and the shooting angle information of the first image Obtained by calculation; after receiving the user's selection operation on the background image to be selected, the background image to be selected indicated by the selection operation is used as the second image.

Optionally, the acquiring unit may be specifically configured to: send the shooting angle information of the first image and the preset classification information to the server; receive the background image to be selected that matches the preset classification information of the first image sent by the server, and the to-be-selected background image is sent to the server. The background images are sorted by the server according to the shooting angle difference value between the background image to be selected and the first image, and the shooting angle difference value between the background image to be selected and the first image is sorted by the server according to the shooting angle information of the background image to be selected, and The shooting angle information of the first image is calculated.

Optionally, the synthesizing unit can be specifically used to: display the target background image, receive the user's position specifying operation on the target background image, and obtain the position information of the user's specified position on the target background image; determine the first distance corresponding to the position information. estimated value; zoom the foreground image according to the first distance estimated value to obtain the target foreground image; synthesize the target foreground image to the position indicated by the position information in the target background image to obtain the target image.

Optionally, the synthesizing unit may also be used to: adjust the color parameters of the target foreground image and/or the target background image.

The apparatus provided by the embodiment shown in FIG. 8 can be used to implement the technical solutions of the method embodiments shown in FIG. 4 to FIG. 7 of the present application. For the implementation principle and technical effect, reference may be made to the related descriptions in the method embodiments.

It should be understood that the division of each unit of the apparatus shown in FIG. 8 above is only a division of logical functions, and in actual implementation, it may be fully or partially integrated into a physical entity, or may be physically separated. And these units can all be implemented in the form of software calling through processing elements; they can also all be implemented in hardware; some units can also be implemented in the form of software calling through processing elements, and some units can be implemented in hardware. For example, the synthesis unit may be a separately established processing element, or may be integrated in a certain chip of an electronic device. The implementation of other units is similar. In addition, all or part of these units can be integrated together, and can also be implemented independently. In the implementation process, each step of the above-mentioned method or each of the above-mentioned units may be completed by an integrated logic circuit of hardware in the processor element or an instruction in the form of software.

For example, the above units may be one or more integrated circuits configured to implement the above method, such as: one or more specific integrated circuits (Application Specific Integrated Circuit; hereinafter referred to as: ASIC), or, one or more microprocessors Digital Singnal Processor (hereinafter referred to as: DSP), or, one or more Field Programmable Gate Array (Field Programmable Gate Array; hereinafter referred to as: FPGA), etc. For another example, these units can be integrated together and implemented in the form of a system-on-a-chip (System-On-a-Chip; hereinafter referred to as: SOC).

Embodiments of the present application further provide an electronic device, which may include: a display screen; one or more processors; a memory; multiple application programs; and one or more computer programs. Wherein the above-mentioned one or more computer programs are stored in the above-mentioned memory, and the above-mentioned one or more computer programs include instructions that, when the above-mentioned instructions are executed by the above-mentioned equipment, cause the above-mentioned equipment to perform the following steps:

Optionally, the step of acquiring the second image may include:

obtaining preset classification information of the first image;

Optionally, the step of acquiring a background image to be selected that matches the preset classification information of the first image may include:

The background images to be selected that match the preset classification information of the first image sent by the server are received, the background images to be selected are sorted by the server according to the difference in shooting angle between the background images to be selected and the first image, and the background images to be selected are sorted from small to large. The difference value of the shooting angle between the image and the first image is calculated by the server according to the shooting angle information of the background image to be selected and the shooting angle information of the first image.

Optionally, the step of performing image synthesis between the foreground image separated from the first image and the target background image to obtain the target image may include:

Optionally, before the step of synthesizing the target foreground image to the position indicated by the position information on the target background image, the step of obtaining the target image may further include:

The present application also provides an electronic device, the device includes a storage medium and a central processing unit, the storage medium may be a non-volatile storage medium, and a computer-executable program is stored in the storage medium, and the central processing unit is connected to the central processing unit. The non-volatile storage medium is connected, and the computer-executable program is executed to implement the method provided by the embodiments shown in FIG. 4 to FIG. 7 of the present application.

Embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when it runs on a computer, the computer causes the computer to execute the programs provided by the embodiments shown in FIG. 4 to FIG. 7 of the present application. method.

An embodiment of the present application further provides a computer program product, where the computer program product includes a computer program that, when running on a computer, enables the computer to execute the methods provided by the embodiments shown in FIGS. 4 to 7 of the present application.

In the embodiments of the present application, "at least one" refers to one or more, and "multiple" refers to two or more. "And/or", which describes the association relationship of the associated objects, means that there can be three kinds of relationships, for example, A and/or B, which can indicate the existence of A alone, the existence of A and B at the same time, and the existence of B alone. where A and B can be singular or plural. The character "/" generally indicates that the associated objects are an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c may represent: a, b, c, a and b, a and c, b and c or a and b and c, where a, b, c may be single, or Can be multiple.

Those of ordinary skill in the art can realize that the units and algorithm steps described in the embodiments disclosed herein can be implemented by a combination of electronic hardware, computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described systems, devices and units may refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, Read-Only Memory (Read-Only Memory; hereinafter referred to as: ROM), Random Access Memory (Random Access Memory; hereinafter referred to as: RAM), magnetic disk or optical disk and other various A medium on which program code can be stored.

The above are only specific embodiments of the present application. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application. The protection scope of the present application shall be subject to the protection scope of the claims.

Claims

An image synthesis method, applied to electronic equipment, is characterized in that, comprising:

receiving the background replacement operation of the user for the first image, and acquiring the shooting angle information of the first image;

acquiring a second image and shooting angle information of the second image;

3D perspective transformation is performed on the second image according to the shooting angle information of the first image and the shooting angle information of the second image, so that the shooting angle of the second image reaches or is close to the shooting angle of the first image. Angle, get the target background image;

The foreground image separated from the first image is combined with the target background image to obtain the target image.
The method according to claim 1, wherein the acquiring the second image comprises:

acquiring preset classification information of the first image;

Acquire and display a background image to be selected that matches the preset classification information of the first image; the background image to be displayed is displayed according to the shooting angle difference between the background image to be selected and the first image. Sorting from the largest to the largest; the difference value of the shooting angle between the background image to be selected and the first image is calculated according to the shooting angle information of the background image to be selected and the shooting angle information of the first image;

After receiving the user's selection operation on the background image to be selected, the background image to be selected indicated by the selection operation is used as the second image.
The method according to claim 2, wherein the acquiring a background image to be selected that matches the preset classification information of the first image comprises:

sending the shooting angle information and preset classification information of the first image to the server;

Receive a background image to be selected that matches the preset classification information of the first image sent by the server, and the background image to be selected is sent by the server according to the relationship between the background image to be selected and the first image. The shooting angle difference value is sorted, and the shooting angle difference value between the background image to be selected and the first image is determined by the server according to the shooting angle information of the background image to be selected and the shooting angle of the first image. information is calculated.
The method according to any one of claims 1 to 3, wherein the image synthesis of the foreground image separated from the first image and the target background image to obtain the target image comprises:

Displaying the target background image, receiving a position specifying operation of the user on the target background image, and obtaining the position information of the position specified by the user on the target background image;

determining a first distance estimate corresponding to the location information;

Scaling the foreground image according to the first distance estimation value to obtain a target foreground image;

The target foreground image is synthesized to the position indicated by the position information in the target background image to obtain a target image.
The method according to claim 4, wherein before obtaining the target image by synthesizing the target foreground image to the position indicated by the position information on the target background image, the method further comprises:

Adjusting the color parameters of the target foreground image and/or the target background image.
The method according to any one of claims 1 to 3, wherein the shooting angle information includes: a shooting attitude angle, and the shooting attitude angle includes: a pitch angle, an azimuth angle, and a roll angle.
An electronic device, comprising:

a display screen; one or more processors; a memory; and one or more computer programs, wherein the one or more computer programs are stored in the memory, the one or more computer programs comprising instructions for When the instruction is executed by the device, the device is caused to perform the following steps:

receiving the background replacement operation of the user for the first image, and acquiring the shooting angle information of the first image;

acquiring a second image and shooting angle information of the second image;

3D perspective transformation is performed on the second image according to the shooting angle information of the first image and the shooting angle information of the second image, so that the shooting angle of the second image reaches or is close to the shooting angle of the first image. Angle, get the target background image;

The target image is obtained by synthesizing the foreground image separated from the first image into the target background image.
The electronic device according to claim 7, wherein when the instruction is executed by the device, the step of obtaining the second image comprises:

acquiring preset classification information of the first image;

Acquire and display a background image to be selected that matches the preset classification information of the first image; the background image to be displayed is displayed according to the shooting angle difference between the background image to be selected and the first image. Sorting from the largest to the largest; the difference value of the shooting angle between the background image to be selected and the first image is calculated according to the shooting angle information of the background image to be selected and the shooting angle information of the first image;

After receiving the user's selection operation on the background image to be selected, the background image to be selected indicated by the selection operation is used as the second image.
The electronic device according to claim 8, wherein when the instruction is executed by the device, the step of obtaining the background image to be selected that matches the preset classification information of the first image comprises:

sending the shooting angle information and preset classification information of the first image to the server;

Receive a background image to be selected that matches the preset classification information of the first image sent by the server, and the background image to be selected is sent by the server according to the relationship between the background image to be selected and the first image. The shooting angle difference value is sorted, and the shooting angle difference value between the background image to be selected and the first image is determined by the server according to the shooting angle information of the background image to be selected and the shooting angle of the first image. information is calculated.
The electronic device according to any one of claims 7 to 9, wherein when the instruction is executed by the device, the foreground image separated from the first image and the target background image are caused to The steps of performing image synthesis to obtain the target image include:

Displaying the target background image, receiving a position specifying operation of the user on the target background image, and obtaining the position information of the position specified by the user on the target background image;

determining a first distance estimate corresponding to the location information;

Scaling the foreground image according to the first distance estimation value to obtain a target foreground image;

The target foreground image is synthesized to the position indicated by the position information in the target background image to obtain a target image.
The electronic device according to claim 10, wherein when the instruction is executed by the device, the compositing of the target foreground image to the position indicated by the position information on the target background image is made. Before the steps, also include:

Adjusting the color parameters of the target foreground image and/or the target background image.
A computer-readable storage medium, characterized in that, a computer program is stored in the computer-readable storage medium, and when it is run on a computer, it causes the computer to execute the method of any one of claims 1 to 6.