Patent Publication Number: US-2022215071-A1

Title: Privacy protection method for transmitting end and receiving end, electronic device and computer readable storage medium

Description:
TECHNICAL FIELD 
     The present disclosure relates to the technical field of privacy protection and, in particular, to a privacy protection method for a transmitting end and a receiving end, an electronic device, and a computer-readable storage medium. 
     BACKGROUND 
     With the popularity of technologies including monitoring technology and video chat, videos and images may be intercepted in transmission, making user privacy easily invaded. Accordingly, how to establish a protection scheme for videos and images with limited resources to prevent user privacy from being invaded is particularly important. 
     SUMMARY 
     The present disclosure provides a privacy protection method for a transmitting end and a receiving end, an electronic device, and a computer-readable storage medium so as to protect user privacy in the image and video transmission process. 
     The present disclosure provides a privacy protection method for a transmitting end. The method includes the steps below. 
     An initial image is acquired. 
     An area to be scrambled in the initial image is acquired. 
     Backup and scrambling are performed for the initial image based on the area to be scrambled to obtain a scrambled image and backup information. 
     The backup information is encrypted to obtain an encrypted result. 
     The scrambled image and the encrypted result are transmitted. 
     The present disclosure provides a privacy protection method for a receiving end. The method includes the steps below. 
     A scrambled image and an encrypted result are received. 
     Decryption is performed for the encrypted result to obtain backup information. 
     An initial image is generated based on the scrambled image and the backup information. 
     The present disclosure further provides an electronic device. The electronic device includes at least one processor and a memory configured to store at least one program. 
     When executed by the at least one processor, the at least one program enables the at least one processor to perform a preceding method. 
     The present disclosure further provides a computer-readable storage medium storing computer-executable instructions for executing the preceding methods. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a flowchart of the privacy protection method for a transmitting end according to the first embodiment of the present disclosure. 
         FIG. 2  is a flowchart of the privacy protection method for a transmitting end according to the second embodiment of the present disclosure. 
         FIG. 3  is a flowchart of the privacy protection method for a transmitting end according to a variation of the second embodiment of the present disclosure. 
         FIG. 4  is a flowchart of the privacy protection method for a transmitting end according to the third embodiment of the present disclosure. 
         FIG. 5  is a flowchart of the privacy protection method for a transmitting end according to the fourth embodiment of the present disclosure. 
         FIG. 6  is a flowchart of the privacy protection method for a transmitting end according to the fifth embodiment of the present disclosure. 
         FIG. 7  is a flowchart of the privacy protection method for a transmitting end according to the sixth embodiment of the present disclosure. 
         FIG. 8  is a flowchart of the privacy protection method for a receiving end according to the first embodiment of the present disclosure. 
         FIG. 9  is an overall flowchart of a privacy protection method for a transmitting end and a receiving end according to an embodiment of the present disclosure. 
         FIG. 10  is a diagram showing the structure of an electronic device according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure provide a privacy protection method for a transmitting end. The privacy protection method for a transmitting end is executed by a transmitting end. The transmitting end may be a transmitting end of, for example, a monitoring video or a monitoring image. Referring to  FIG. 1 ,  FIG. 1  is a flowchart of the privacy protection method for a transmitting end according to the first embodiment of the present disclosure. 
     In this embodiment, the privacy protection method for a transmitting end includes the steps below. 
     In step S 1 , an initial image is acquired. 
     It is to be noted that the initial image is an image requiring privacy protection and may be captured by a device like a monitoring device. The initial image may also be acquired by intercepting one frame in a video (for example, a monitoring video) requiring privacy protection. That is, step S 1  may include a step in which one frame in an initial video is extracted to serve as the initial image. The initial video is a video requiring privacy protection. 
     In step S 2 , an area to be scrambled in the initial image is acquired. 
     It is to be noted that the area to be scrambled refers to an area that needs to be scrambled to protect user privacy. In a specific implementation, the area to be scrambled may be any area specified by a user. The area to be scrambled may also be a feature area (for example, a face area) or a motion area (for example, an area with a moving object in an image). In this embodiment, step S 2  may include the following steps: in step S 21 , an area to be selected in the initial image is extracted based on a preset rule; in step S 22 , a user selection area is selected, based on the area selection setting performed by a user, from the extracted area to be selected so as to take the user selection area as the area to be scrambled. The preset rule may take a motion area, a feature area, or any area set by the user as the area to be selected. 
     In step S 3 : backup and scrambling are performed for the initial image based on the area to be scrambled to obtain a scrambled image and backup information. 
     It is to be noted that in this step, the area to be scrambled may be first backed up and then scrambled so as to obtain the scrambled image and the backup information. In this step, the area to be scrambled may also be backed up and scrambled first; then the backup information is generated based on the result of scrambling the area to be scrambled (refer to the second embodiment hereinafter). In this step, after scrambling is performed for the initial image, the scrambled image may be re-processed as a new initial image so that a new scrambled image and new backup information are acquired. Accordingly, this step may also include processes of multiple backup and multiple scrambling that are arranged alternately. The arrangement in which backup and scrambling are performed for the initial image multiple times increases the difficulty for an interceptor restoring the initial image based on the scrambled image and the backup information in the case where the scrambled image and the backup information are intercepted. This helps protect user privacy in the image and video transmission process. 
     In this step, backup may be performed for the entire initial image. In this step, backup may also be performed only for the area to be scrambled in the initial image. That is, specifically, this step may be that backup and scrambling are performed for the area to be scrambled in the initial image to obtain the scrambled image and the backup information. In this case, backup is performed only for the area to be scrambled, helping reduce the data size of the backup information. 
     In a specific implementation, this step may include the following steps: in step S 34 , data to be scrambled in the initial image is extracted based on the area to be scrambled; in step S 35 , the backup information is generated based on the data to be scrambled; in step  36 , tampering is performed for the data to be scrambled in the initial image to generate the scrambled image. The data to be scrambled is the data corresponding to the area to be scrambled in the initial image. 
     In one embodiment, the data to be scrambled may be a quantizer parameter (QP) matrix of the area to be scrambled. The quantizer parameter matrix is composed of a plurality of quantizer parameter values (that is, QP values). The area to be scrambled is tampered with and becomes a mosaic by performing the processing of random virtual values for the quantizer parameter values in the quantizer parameter matrix (that is, randomly changing the quantizer parameter values in the quantizer parameter matrix into integers from 0 to 51). Accordingly, the area to be scrambled is scrambled. In one embodiment, when the differences between the tampered quantizer parameter values and the quantizer parameter values before tampering are relatively small, the processing of radon virtual values may be re-performed for the quantizer parameter values in the quantizer parameter matrix in a certain range so as to guarantee the scrambling effect on the initial image. 
     In one embodiment, the initial image is one frame in the initial video. The frame before the initial image in the initial video may be used for tampering with the area to be scrambled in the initial image. Specifically, pixels of a standstill area in the frame before the initial image may be replaced with pixels in the area to be scrambled. Accordingly, the technical effect that an object in the area to be scrambled in the initial image disappears is implemented. It is to be noted that a motion area and a standstill area that are in each frame of the initial video may be distinguished by performing motion detection for each frame in the initial video. In a specific implementation for this embodiment, as for a key frame (which may be an I frame in a related video standard), the previously backed-up data of the standstill area of another frame is used directly for replacement. As for a predictive frame (which may be a P frame in a related video standard), a P-SKIP operation is taken directly for performing data replacement for the area to be scrambled. 
     In step S 4 , the backup information is encrypted to obtain an encrypted result. 
     It is to be noted that in this embodiment, the backup information is encrypted by using the Advanced Encryption Standard (AES) and/or the Data Encryption Standard (DES). 
     In step S 5 , the scrambled image and the encrypted result are transmitted. 
     It is to be noted that the encrypted result may be transmitted along with the scrambled image. Alternatively, the encrypted result and the scrambled image may be transmitted separately. In this embodiment, the encrypted result is transmitted through a private data path of a user. 
     In this embodiment, an initial image is acquired; an area to be scrambled in the initial image is acquired; backup and scrambling are performed for the initial image based on the area to be scrambled to obtain a scrambled image and backup information; the backup information is encrypted to obtain an encrypted result; the scrambled image and the encrypted result are transmitted. In this case, even if an image or a video is intercepted in the transmission process, the interceptor fails to obtain the entire content of the original image. Accordingly, user privacy is protected. Moreover, the initial image is restored and acquired through decryption based on the scrambled image and the encrypted result. Thus the transmission of the initial image is performed under the premise of protecting user privacy. 
     It is to be understood that this embodiment mainly describes the privacy protection process for the initial image. In the case where privacy protection needs to be performed for a video file (that is, the initial video), each frame in the initial video may be processed by using the preceding privacy protection method for a transmitting end so as to implement privacy protection for the initial video. 
     Referring to  FIG. 2 ,  FIG. 2  is a flowchart of the privacy protection method for a transmitting end according to the second embodiment of the present disclosure. 
     Based on the preceding first embodiment, in this embodiment, step S 3  includes the steps below. 
     In step S 31 , a backup area image is generated based on the area to be scrambled in the initial image. 
     It is to be noted that the backup area image may be consistent with the pixel value of each corresponding pixel of the area to be scrambled and may also be generated by processing the area to be scrambled based on a specific procedure (refer to the third embodiment). 
     In step S 32 , scrambling is performed for the area to be scrambled in the initial image to obtain the scrambled image. 
     It is to be noted that this step may be performed based on the following process: the area to be scrambled is divided into N×N areas (where N&gt;8 and N/8&gt;4; if the conditions that N&gt;8 and N/8&gt;4 cannot be satisfied, the value of N may be 4); the mid-value of all the pixels in each divided area (that is, the value in the middle of the arrangement result after all the pixels are arranged in sequence based on pixel values) is acquired, or the mean value of all the pixels in each divided area is calculated; in each divided area, the pixel value of each pixel in the area is replaced with the mid-value or the mean value. 
     In step S 33 , the backup information is generated based on the backup area image. 
     In a specific implementation, the backup area image may be taken as the backup information directly. Alternatively, the backup area image may be processed to generate the backup information.  FIG. 3  is a variation of this embodiment. In the embodiment illustrated in  FIG. 3 , step S 33  includes the following steps: in step S 331 , the difference between the scrambled image and the backup area image is analyzed to obtain a difference analysis result; in step S 332 , the difference analysis result is taken as the backup information. The difference analysis result may be acquired by calculating the difference between each pixel in the scrambled image and each pixel at the same position in the backup area image. 
     It is to be noted that the backup information may include the position information of the area to be scrambled. The position information of the area to be scrambled refers to the information for recording the position of the area to be scrambled in the initial image. The position information of the area to be scrambled may be acquired when the area to be scrambled in the initial image is acquired. Alternatively, the backup information may not include the position information of the area to be scrambled. Without encryption or after encryption, the position information of the area to be scrambled may be transmitted independently of the backup information. 
     In this embodiment, the area to be scrambled in the initial image is first backed up and then scrambled. In this case, the initial image can be restored based on the backup information and the scrambled image. Thus the restorable scrambling is performed. 
     Referring to  FIG. 4 ,  FIG. 4  is a flowchart of the privacy protection method for a transmitting end according to the third embodiment of the present disclosure. 
     Based on the preceding variation of the second embodiment as shown in  FIG. 3 , in this embodiment, step S 331  includes the steps below. 
     In step S 3311 , a comparison analyzation is performed for the scrambled image and the backup area image to obtain a comparison result image. 
     It is to be noted that the comparison result image refers to an image that can reflect the difference between the scrambled image and the backup area image. The backup area image can be obtained based on the comparison result image and the scrambled image. 
     In a specific implementation, the difference between each pixel in the scrambled image and each pixel at the same position in the backup area image may be calculated. Values acquired from difference calculation are taken as pixel values of pixels at corresponding positions in the comparison result image. In this case, the backup area image can be acquired based on the comparison result image and the scrambled image. 
     In step S 3312 , the comparison result image is compressed and encoded to obtain compressed comparison result data. 
     It is to be noted that in this step, the comparison result image may be compressed in the format of, for example, JPEG, H264, or H265. 
     It is to be understood that in this step, the arrangement in which the comparison result image is compressed and encoded enables the data size of the comparison result image to be compressed. Accordingly, the data size of the backup information needing to be transmitted is decreased and thus the pressure of network transmission is reduced. 
     In step S 3313 , the difference analysis result is generated based on the compressed comparison result data. 
     In a specific implementation, in this embodiment, the compressed comparison result data is taken as the difference analysis result directly. 
     In this embodiment, the comparison result image is compressed and encoded to obtain compressed comparison result data; the difference analysis result is generated based on the compressed comparison result data; the difference analysis result is taken as the backup information. Accordingly, the data size of the backup information needing to be transmitted is decreased and thus the pressure of network transmission is reduced. 
     As a variation of the third embodiment, the initial image is one frame in the initial video. Step S 3313  may include the following steps: in step S 33131 , motion area data in the compressed comparison result data is extracted based on a pre-detected motion area range in the initial image; in step S 33132 , the motion area data in the compressed comparison result data is taken as the difference analysis result. The pre-detected motion area range in the initial image may be acquired by performing motion detection for the initial image. It is to be noted that in the video file, an image in a non-motion area may be restored based on the frame before the initial image in the initial video. Accordingly, the non-motion area in the compressed comparison result data can be restored after being discarded. In the compressed comparison result data, a motion area and a non-motion area may be recorded specifically in a manner of, for example, a private code table so that the motion area data in the compressed comparison result data can be extracted. The private code table may be in the form shown in Table 1 below. 
     
       
         
           
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 One embodiment of the private code table 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 1 
                 1 
                 0 
                 0 
               
               
                   
                 1 
                 1 
                 0 
                 0 
               
               
                   
                 1 
                 1 
                 0 
                 0 
               
               
                   
                 1 
                 1 
                 0 
                 0 
               
               
                   
                   
               
            
           
         
       
     
     In Table 1, an area corresponding to 1 is a motion area and an area corresponding to 0 is a non-motion area. 
     The arrangement of step S 33131  and step S 33132  enables the non-motion area data in the compressed comparison result data to be discarded so that only the motion area data in the compressed comparison result data is transmitted. Accordingly, the data size of the backup information needing to be transmitted is decreased and thus the pressure of network transmission is reduced. 
     As another variation of the third embodiment, the initial image may be one frame in the initial video. Step S 3313  may include the following steps: in step S 33133 , it is determined whether the initial image is a key frame (that is, it is determined whether the initial image is a key frame in the initial video); in step S 33134 , real quantization data in the compressed comparison result data is taken as the difference analysis result based on a determination result that the initial image is not the key frame; in step S 33135 , both a code stream head and the real quantization data that are in the compressed comparison result data are taken as the difference analysis result based on a determination result that the initial image is the key frame. The code stream head refers to the data for storing a standardized quantization table (which is usually used for recording the loss status of image compression) in an image in a format of, for example, JPEG. The real quantization data includes private information and encoded data information. The private information is used for storing, for example, the position information of a feature area, the position information of a motion area, and a private code table. 
     The arrangement of step S 33133 , step S 33134  and step S 33135  enables that the code stream head of the key frame is retained in the difference analysis result and that the code stream head of a non-key frame is not retained. Accordingly, the data size of the backup information needing to be transmitted is decreased and thus the pressure of network transmission is reduced. 
     Referring to  FIG. 5 ,  FIG. 5  is a flowchart of the privacy protection method for a transmitting end according to the fourth embodiment of the present disclosure. 
     Based on the preceding third embodiment, in this embodiment, before step S 5 , the method further includes the step below. 
     In step S 45 , compressing and encoding is performed for the scrambled image to obtain scrambled and encoded data. 
     It is to be noted that the scrambled image may be compressed in the format of, for example, JPEG, H264, or H265. 
     It is to be understood that in this step, the arrangement in which the scrambled image is compressed and encoded enables the data size of the scrambled image to be compressed. Accordingly, the pressure of network transmission is reduced in the process of transmitting the scrambled image. 
     Moreover, step S 5  includes the steps below. 
     In step S 51 , scrambled and encoded information is generated based on the scrambled and encoded data and the encrypted result. 
     It is to be noted that the scrambled and encoded information may be acquired by merging the scrambled and encoded data with the data in the encrypted result. 
     In a variation of the fourth embodiment, the initial image is one frame in the initial video. Step  51  may include step S 511  in which the encrypted result is stored in the supplemental enhancement information (SEI) of the scrambled and encoded data to generate the scrambled and encoded information. In other embodiments, the encrypted result may be taken as additional information. Moreover, the additional information is transmitted in another manner. 
     In step S 52 , the scrambled and encoded information is transmitted. 
     In this embodiment, compressing and encoding is performed for the scrambled image to obtain scrambled and encoded data; scrambled and encoded information is generated based on the scrambled and encoded data and the encrypted result; the scrambled and encoded information is transmitted. In this case, the data size of the scrambled and encoded information needing to be transmitted is compressed and decreased, and thus the pressure of network transmission is reduced in the process of transmitting the scrambled image. 
     Referring to  FIG. 6 ,  FIG. 6  is a flowchart of the privacy protection method for a transmitting end according to the fifth embodiment of the present disclosure. 
     Based on the preceding fourth embodiment, in this embodiment, step S 45  includes the steps below. 
     In step S 451 , the scrambled image is taken as an image to be scrambled repeatedly. 
     It is to be noted that the difference between this embodiment and the fourth embodiment lies in that in this embodiment, the scrambled image is scrambled repeatedly in the processing of compressing and encoding the scrambled image. Before this step is performed, it may be determined whether step S 451  can be performed based on the capability of at least one of the CPU of the transmitting end, the coprocessor of the transmitting end, or the encoder of the transmitting end or based on whether the chip in the transmitting end supports pre-data processing for entropy decoding. Specifically, it may be determined whether step S 451  can be performed in the following process: The capability of at least one of the CPU of the transmitting end, the coprocessor of the transmitting end, or the encoder of the transmitting end is acquired so as to distinguish whether the encoder has the capability of processing quantized data (that is, the compressed and encoded data) or determine whether the CPU/coprocessor can support a related service; a scrambling effect of repeated scrambling that may be selected by a user is provided based on the capability of at least one of the CPU of the transmitting end, the coprocessor of the transmitting end, or the encoder of the transmitting end (for example, the area to be scrambled is displayed in a mosaic or an object in the area to be scrambled disappears). 
     In step S 452 , data to be tampered with in the image to be scrambled repeatedly is extracted based on the area to be scrambled. 
     It is to be noted that the data to be tampered with are the data corresponding to the area to be scrambled in the image to be scrambled repeatedly. 
     In step S 453 , backup data is generated based on the data to be tampered with. 
     In a specific implementation, the data to be tampered with may be copied to obtain the backup data. 
     In step S 454 , a new encrypted result is generated based on the backup data and the encrypted result. 
     In a specific implementation, the backup data may be encrypted. Moreover, the encrypted backup data and the encrypted result acquired in step S 4  are jointly taken as the new encrypted result. 
     In step S 455 , tampering is performed for the data to be tampered with in the image to be scrambled repeatedly to generate a repeatedly scrambled image. 
     In one embodiment, the data to be tampered with may be a quantizer parameter (QP) matrix of an area corresponding to the area to be scrambled in the image to be scrambled repeatedly. The quantizer parameter matrix is composed of a plurality of quantizer parameter values (that is, QP values). In the image to be scrambled repeatedly, the area corresponding to the area to be scrambled is tampered with and becomes a mosaic by performing the processing of random virtual values for the quantizer parameter values in the quantizer parameter matrix (that is, randomly changing the quantizer parameter values in the quantizer parameter matrix into integers from 0 to 51). Accordingly, the image to be scrambled repeatedly is scrambled. In one embodiment, when the differences between the tampered quantizer parameter values and the quantizer parameter values before tampering are relatively small, the processing of radon virtual values may be re-performed on the quantizer parameter values in the quantizer parameter matrix in a certain range so as to guarantee the repeated scrambling effect on the image to be scrambled repeatedly. 
     In one embodiment, the initial image is one frame in the initial video. The frame before the initial image in the initial video may be used for tampering with the area corresponding to the area to be scrambled in the image in the image to be scrambled repeatedly. Specifically, pixels of a standstill area in the frame before the initial image may be replaced with pixels in the area to be scrambled. Accordingly, the technical effect that one or more moving objects in the initial image disappear is implemented. It is to be noted that a motion area and a standstill area that are in each frame of the initial video may be distinguished by performing motion detection for each frame in the initial video. 
     In step S 456 , the repeatedly scrambled image is taken as the scrambled and encoded data. 
     It is to be noted that this step enables the image that has been scrambled repeatedly (that is, the repeatedly scrambled image) to be taken as the scrambled and encoded data. 
     In this embodiment, the scrambled image is scrambled repeatedly in the process of compression and encoding. Accordingly, the scrambling effect on the initial image is strengthened and user privacy security is further enhanced. 
     Referring to  FIG. 7 ,  FIG. 7  is a flowchart of the privacy protection method for a transmitting end according to the sixth embodiment of the present disclosure. 
     Based on the preceding fifth embodiment, in this embodiment, before step S 456 , the method further includes the steps below. 
     In step S 4551 , a current number of repeated scrambling is acquired. 
     It is to be noted that the current number of repeated scrambling is used for counting the number of repeated scrambling. In a specific implementation, the current number of repeated scrambling may be stored in the transmitting end and is increased each time repeated scrambling is completed. 
     In step S 4552 , the current number of repeated scrambling is compared with a preset number of repeated scrambling. 
     It is to be noted that the preset number of repeated scrambling may be set by the user or may be set based on the capability of at least one of the CPU of the transmitting end, the coprocessor of the transmitting end, or the encoder of the transmitting end. In a specific implementation, a recommended number of repeated scrambling may be acquired based on the capability of at least one of the CPU of the transmitting end, the coprocessor of the transmitting end, or the encoder of the transmitting end. Then the user sets a number not larger than the recommended number of repeated scrambling as the preset number of repeated scrambling. In one embodiment, the preset number of repeated scrambling may be set to 1. Moreover, each time repeated scrambling is completed, the user is allowed to select whether repeated scrambling is performed again based on the capability of at least one of the CPU of the transmitting end, the coprocessor of the transmitting end, or the encoder of the transmitting end. 
     In step S 4553 , the repeatedly scrambled image is taken as a new image to be scrambled repeatedly based on a determination result that the current number of repeated scrambling is not larger than the preset number of repeated scrambling; moreover, the step in which the data to be tampered with in the image to be scrambled repeatedly is extracted based on the area to be scrambled is returned to (that is, returning to step S 452 ). 
     It is to be noted that in this step, the process of repeated scrambling is performed again by returning to step S 452 . In this case, through repeated scrambling multiple times, the scrambling effect on the initial image is strengthened and user privacy security is further enhanced. It is to be understood that in the case where the scrambled image and the backup information are intercepted, the difficulty for the interceptor restoring the initial image based on the scrambled image and the backup information. This helps protect user privacy in the image and video transmission process. 
     Embodiments of the present disclosure further provide a privacy protection method for a receiving end. Referring to  FIG. 8 ,  FIG. 8  is a flowchart of the privacy protection method for a receiving end according to the first embodiment of the present disclosure. The privacy protection method for a receiving end is executed by a receiving end. The receiving end may be a transmitting end of, for example, a monitoring video or a monitoring image. 
     In this embodiment, the privacy protection method for a receiving end includes the steps below. 
     In step S 6 , a scrambled image and an encrypted result are received. 
     It is to be noted that the scrambled image and the encrypted result are transmitted based on a privacy protection method for a transmitting end in any one of the preceding embodiments. The encrypted result may be received along with the scrambled image. Alternatively, the encrypted result and the scrambled image may be received separately. In this embodiment, the encrypted result is transmitted through a private data path of a user. 
     In step S 7 : decryption is performed for the encrypted result to obtain backup information. 
     It is to be noted that the decryption algorithm used in this step is ought to be an algorithm corresponding to the encryption algorithm used in step S 4 . It is to be noted that in this embodiment, the encrypted result is decrypted by using the Advanced Encryption Standard (AES) and/or the Data Encryption Standard (DES). 
     In step S 8 , an initial image is generated based on the scrambled image and the backup information. 
     It is to be noted that the scrambled image and the backup information are acquired by performing backup and scrambling for the initial image. Accordingly, the initial image may be generated from the scrambled image and the backup information by using a process inverse to backup and scrambling in step S 3 . 
     In the technical solutions of this embodiment, a scrambled image and an encrypted result are received; decryption is performed for the encrypted result to obtain backup information; an initial image is generated based on the scrambled image and the backup information. In this case, the restoring of the initial image based on the scrambled image and the encrypted result is performed. Even if an image or a video is intercepted in the transmission process, the interceptor fails to obtain the entire content of the original image. Accordingly, user privacy is protected. Moreover, the initial image is restored and acquired through decryption based on the scrambled image and the encrypted result. Thus the transmission of the initial image is performed under the premise of protecting user privacy. 
       FIG. 9  is an overall flowchart of a privacy protection method for a transmitting end and a receiving end according to an embodiment of the present disclosure. The flow includes the steps below. 
     In step S 100 , an option of performing scrambling on an initial video is provided for a user so that the user specifies an area to be scrambled in each frame in the initial video by making a selection for the option. 
     In a specific implementation, the user may specify a specific area of each frame in the initial video as an area to be selected by making a selection for the option. A specific area may be, for example, an area satisfying any condition, a motion area acquired by motion detection, or a feature area acquired by feature area detection. 
     In step S 200 , one frame in the initial video is acquired as an initial image; and motion detection and feature area detection are performed for the initial image to obtain a motion area and a feature area that are in the initial area. 
     It is to be noted that motion detection may be performed by comparing the initial image with a frame adjacent to the initial image in the initial video. A feature area may be a face area. Specifically, the feature area detection may be face area detection. The face region detection may be performed specifically in the manner of, for example, comparing a pixel color with a face skin color. 
     In step S 300 , backup is performed for an area to be scrambled to obtain a backup area image; and strong filtering processing is performed for the area to be scrambled based on N×N macroblocks to obtain a scrambled image. 
     Strong filtering processing may be performed according to the following process: The area to be scrambled is divided into N×N areas (where N&gt;8 and N/8&gt;4; if the conditions that N&gt;8 and N/8&gt;4 cannot be satisfied, the value of N may be 4); the mid-value of all the pixels in each divided area (that is, the value in the middle of the arrangement result after all the pixels are arranged in sequence based on pixel values) is acquired, or the mean value of all the pixels in each divided area is calculated; in each divided area, the pixel value of each pixel in the area is replaced with the mid-value or the mean value. 
     In step S 400 , difference calculation (that is, comparison analysis) is performed for the area to be scrambled in the backup area image and the area to be scrambled in the initial image to obtain a difference value image (that is, a comparison result image); the difference value image is compressed and encoded according to the format of JPEG to obtain compressed difference value data (that is, compressed comparison result data); and motion area data in the compressed comparison result data is extracted as a difference analysis result. 
     It is to be noted that in step S 400 , the difference value image is compressed and encoded first to obtain the compressed difference value data. Then the motion area data in the compressed difference value data is extracted to obtain the difference analysis result. In other embodiments, the motion area in the difference value image may be extracted first. Then the extracted motion area in the difference value image is compressed and encoded to obtain the difference analysis result. 
     In step S 500 , the scrambled image is transmitted to a video encoder in the transmitting end for encoding so as to obtain a scrambled video. 
     It is to be understood that each frame in the initial video is taken as an initial image sequentially to perform scrambling so as to obtain a plurality of scrambled images. Then the acquired scrambled images are transmitted to the video encoder for encoding so as to obtain the initial video that has been scrambled (that is, the scrambled video). 
     In a specific implementation, in the processing of encoding a scrambled image, the processing of repeated scrambling may be performed for the scrambled image. The processing of repeated scrambling may include the following steps: the capabilities of the CPU, the coprocessor, and the encoder are acquired so as to distinguish whether the encoder has the capability of processing quantized data or determine whether the CPU/coprocessor can support a related service; an option is provided for the user based on the acquired capabilities of the CPU, the coprocessor, and the encoder to enable the user to select a scrambling effect with a mosaic or a scrambling effect that an object disappears; a scrambled user area before compression and encoding is acquired, which is the area corresponding to the area to be scrambled in the scrambled image; the area corresponding to the area to be scrambled in the scrambled area is backed up; data acquired by backing up the area corresponding to the area to be scrambled in the scrambled image is packaged and transmitted to the receiving end. 
     In step S 600 , the difference analysis result is encrypted; and the encrypted difference analysis result is stored in the supplemental enhancement information of the scrambled image in the scrambled video. 
     It is to be noted that in this step, the backup information may be encrypted by using the Advanced Encryption Standard (AES) and/or the Data Encryption Standard (DES). 
     In step S 700 , the received video data is decoded; the supplemental enhancement information is decrypted to obtain the difference analysis result; the difference analysis result is decoded to obtain the motion area in the difference value image; and the initial image is generated based on the motion area in the difference value image. 
     It is to be noted that the received video data in this step includes the supplemental enhancement information. In this step, the difference analysis result is ought to be decoded using a manner corresponding to the compression and encoding of the difference analysis result. 
     In the preceding flow, steps S 100  to S 600  are performed by the transmitting end. Step S 700  is performed by the receiving end. The transmitting end and the receiving end may be different electronic devices or the same electronic device. 
     The scrambling transmission of the initial image is performed through the preceding flow. Even if an image or a video is intercepted in the transmission process, the interceptor fails to obtain the entire content of the original image. Accordingly, user privacy is protected. Moreover, the initial image is restored and acquired through decryption based on the scrambled image and the encrypted result. Thus the transmission of the initial image is performed under the premise of protecting user privacy. 
     The present disclosure further provides an electronic device.  FIG. 10  is a diagram showing the structure of an electronic device according to an embodiment of the present disclosure. As shown in  FIG. 10 , the electronic device includes one or more processors  110  and a memory  120 .  FIG. 10  illustrates an example in which one processor  110  is provided. 
     The electronic device may further include an input apparatus  130  and an output apparatus  140 . 
     The processor  110 , the memory  120 , the input apparatus  130 , and the output apparatus  440  that are in the electronic device may be connected through a bus or in other manners.  FIG. 10  illustrates an example of the connection through a bus. 
     As a computer-readable storage medium, the memory  120  may be configured to store software programs, computer-executable programs, and modules. The processor  110  runs the software programs, instructions, and modules stored in the memory  120  to execute multiple function applications and data processing so as to perform any method in the preceding embodiments. 
     The memory  120  may include a program storage region and a data storage region. The program storage region may store an operating system and an application program required by at least one function. The data storage region may store the data created according to the use of the electronic device. Additionally, the memory may include a volatile memory, for example, a random access memory (RAM), and may also include a non-volatile memory, for example, at least one magnetic disk memory element, a flash memory element, or another non-volatile solid-state memory element. 
     The memory  120  may be a non-transitory computer storage medium or a transitory computer storage medium. The non-transitory computer storage medium includes, for example, a magnetic disk memory element, a flash memory element, or another non-volatile solid-state memory element. In some embodiments, the memory  120  optionally includes memories that are disposed remotely relative to the processor  110 . These remote memories may be connected to the electronic device via a network. The examples of the preceding network may include the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof 
     The input apparatus  130  may be configured to receive the input digital or character information and generate key signal input related to user settings and function control of the electronic device. The output apparatus  140  may include a display device, for example, a display screen. 
     This embodiment further provides a computer-readable storage medium storing computer-executable instructions for executing the preceding methods. 
     All or part of the procedure processes in a method of the preceding embodiments may be performed by related hardware executed by computer programs. The programs may be stored in a non-transitory computer-readable storage medium. During the execution of the programs, the processes in a method according to the preceding embodiments may be included. The non-transitory computer-readable storage medium may be, for example, a magnetic disk, an optical disk, a read-only memory (ROM), or a RAM.