EP3056012A1

EP3056012A1 - Protection of data privacy in a video stream, using a redundant slice

Info

Publication number: EP3056012A1
Application number: EP14793804.7A
Authority: EP
Inventors: Gero BÄSE; Bernhard Agthe
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2013-12-20
Filing date: 2014-10-21
Publication date: 2016-08-17
Also published as: CN105830449A; DE102013226802A1; WO2015090679A1; US20160337673A1

Abstract

In order to protect data privacy in a video stream, a video stream (30) comprising a slice structure (37) is created. A video stream slice (31) comprising content (32) that is to be protected is identified. A slice (41) which is at least partially redundant in relation to the identified slice (31) is created. The content (32) to be protected in one of the two slices (31, 41) is encrypted. At least one measure for assuring data privacy is used on the content (32) to be protected in the other (41, 31) of the two slices.

Description

description

Privacy protection in a video stream using a redundant slice

The invention relates to the technical field of privacy protection in video streams.

H.264 describes an ITU-T standard for compressing video data, and is the same wording as in ISO / IEC 14496-10 (AVC) be ^¬ wrote.

HEVC describes another standard for compressing video data and is described in ISO / IEC 23008-2.

AVC is the name at ISO and stands for Advanced Video Coding. HEVC is also the name at ISO and stands for High Efficiency Video Coding. It is known that a video stream can comprise a slice structure, this is the case, for example, in AVC and HEVC. A slice is usually used to structure the video stream data. A slice is typically a section of an image.

There are numerous situations in which the privacy of video streams is desirable. It may be indicated when monitoring a site or building by means of a video camera to protect image sections showing public space from unauthorized surveillance. Likewise there is

Situations in which faces of people walking in an area monitored by a video camera are to be blurred. On the one hand, decoder-side solutions are known. This stel len ^¬ but is usually not sufficient to protect, since at least present protected at the input of the decoder, the content of the video stream un ^¬. As part of this decoder-side process original streams are, for example, the decoder decodes and blended to Schütting ^¬ collapsing areas, for example by GE blackens ^¬ or distorted, so that they show no privacy relevant content more at the display on a screen. The resulting video streams are encoded in turn complicated by an additional encoder and abgespei ^¬ chert. In this way, measures for the protection of privacy in the image area are inserted on the decoder side and passed the decoder side, again encoded streams in the video management system ^¬ the monitoring system. By curtailing ^¬ kung access rights the presentation of the video streams is no privacy, he ^¬ enables only certain users while other users to view the video streams is possible with-applied privacy. A disadvantage of decoder-side solutions is that several, largely identical video streams must be stored, and that the videos without the use of ^measures for the protection of privacy require special, the content to be protected worth appropriate handling.

On the other hand, other known measures are based on selective encryption in the encoder. These methods usually require a deep integration into the video encoder. One main application is to reduce the overall quality of the video to include paid content. However, the benefits of privacy protection are questionable. To obtain standard conformity, also very few syntax elements remain on the encryption below applies, which is particularly problematic when context-adaptive binary arithmetic coding (CABAC) ver ^¬ applies is. Also, with selective encryption in the encoder, restrictions on the encoding modes used must be accepted, or the availability of special features in the encoder, such as flexible macroblock ordering (FMO), is required. However, these known methods have the disadvantage that measures to protect the Private Sphere an adjustment of the encoder and decoder bedin ^¬ conditions.

Both decoder-side, as well as encoder-side process HA usually ben the disadvantage that measures to protect privacy on the entire contents of the video stream at ^¬ be turned, since so far no signaling on the limitation of standardized measures is well known in certain areas of the image.

The present invention therefore has for its object to simplify the implementation of protection of privacy in ei ^¬ nem video stream. This object is achieved by the solutions described in the independent claims. Advantageous embodiments are described in the further claims.

In one aspect, a method for protecting privacy is proposed. This creates a video stream. The video stream includes a slice structure. A slice of the video stream comprising content to be protected is identified. A slice which is at least partially redundant with respect to the identified slice is generated so that there are at least two partially redundant slices. The protect ^¬ the content in one of two slices is encrypted. In the other slice at least one measure to secure ^¬ position of privacy on the content to be protected is ^¬ spent.

In another aspect, an apparatus for protecting privacy in a video stream is presented. The video stream includes a slice structure. The device comprises an identification means, a generating means, an encryption means and a privacy means. The identi ^¬ fizierungsmittel adapted to identify a comprehensive content to be protected slice of the video stream. The ^{generating means} is adapted, one to the identified Slice at least partially redundant slice to produce so ^¬ that two at least partially redundant slices are present. The encryption means is adapted to encrypt the content to be protected in one of the two slices. The private sphere funds are adapted, at least one measure for

Ensuring privacy applies to the content to be protected in the other of the two slices.

The invention is explained in more detail below with reference to the figures, for example:

FIG. 1 shows a block diagram of a system that has a

Device for protecting privacy in a video stream according to an embodiment of the invention comprises;

FIG. 2 shows a flow chart of a method according to an ^exemplary embodiment of the invention; FIG. 3 shows a schematic of an exemplary video stream comprising an exemplary slice structure that may be implemented in preferred embodiments of the invention, for example in the embodiments described with reference to FIG. 1 and / or FIG. 2;

Figure 4 shows a schematic of two slices slice structure of

FIG. 3 in a method step of a method according to preferred embodiments of the invention;

FIG. 5 shows another scheme of the two slices of FIG

4 in another process step.

FIG. 1 shows a network-based system 100 for transmitting and protecting a video stream 30. The system 100 comprises a video camera 11, a device 1 for the

Privacy protection and a display means 20, example ^¬ a personal computer. The video camera 11 comprises an The encoder 20 comprises a screen 21 and a decoder 22. The encoder 12 and the decoder 22 may also be designed as separate, ie not integrated into the video camera 11 or not in the display means 20. The video stream 30 flows from the encoder 12 via the device 1 to the decoder 22, and is preferably compressed on this route.

The privacy protection device 1 comprises an identification means 2, a generation means 3, an ^{encryption means} 4 and a privacy means 5. The identification means 2 is adapted to identify a slice 31 of a video stream 30 comprising content 32 to be protected. The generating means 3 is adapted to generate a slice 31 to the identified at least partially redundant slice 41, so that two at least partially Redun ^¬ Dante slices 31 are present 41st The encryption means 4 is adapted to encrypt the content 32 to be protected in one of the two slices 31, 41. The privacy means 5 is adapted to apply at least one measure for ensuring privacy to the content 32 to be protected in the other 41, 31 of the two slices 31, 41.

FIG. 2 shows a flow chart of a method 24 according to an exemplary embodiment of the invention. The system 100 is preferably adapted to perform the method 24. The exemplary method 24 is used to protect a Privatsphä ^¬ re. As part of the method, a video stream 30 is generated in method step 25. The video stream 30 comprises a slice structure 37. In method step 26, a slice 31 of the video stream 30, which comprises content 32 to be protected, is identified. Content to be protected is, for example, content relevant to the private sphere. In process step 27 ei ^¬ ne to the identified slice 31 at least partially redundant slice 41 is produced, so that two at least partially re ^¬ dant Slices 31 are present 41st In method step 28, the content 32 to be protected is encrypted in one of the two slices 31, 41. In method step 29, at least one a measure to ensure privacy on the content 32 to be protected is applied in the other 41, 31 of the two slices. For the invention it does not matter whether the method step 28 is carried out before, after or simultaneously with the method step 29. Also, it does not matter which of the two redundant slices 31, ver down ^¬ 41, and to which the measure to ensure privacy is applied. Preferably, the method is performed for multiple slices comprising contents to be protected. For example, according to a preferred embodiment, each slice of the video stream 30 which comprises a content to be protected is identified as part of a method step 26. To JE of these identified Slices an at least partially redundant slice is created in each case, so that slice pairs, each having two at least partially redundant slices vorlie ^¬ gene. For each of the slice pairs are respectively performed ^¬ method steps 27-29.

Preferably, the method is performed only for slices comprising contents to be protected. In the ^¬ sem case, there is in the video stream 30 so at least one slice, which includes no content to be protected, and for which no redundant slice is created.

FIG. 3 shows, by way of example, the video stream 30 shown in FIG. 1, from the video camera 11 via the device 1 connected therebetween to the display device 20, in an increased degree of detail. The video stream ^¬ 30 may for example comprise multiple images 39, 39a. The video stream 30 comprises a slice structure 37, as can be seen in FIG. The slice structure 37 comprises a plurality of slices 31, 31a, 31b, 41. The slices 31 and 41 are, according to preferred embodiments, at least partially redundant and comprise the content 32 to be protected as well as content 34 which is not to be protected. Figure 4 shows the two slices 31, 41 of the slice structure 37 of Figure 3 in an increased level of detail immediately after step 27, but before the process ^¬ steps were carried out 28 and / or 29th According to the on hand of Figure 4 illustrated preferred embodiment, the at least partially redundant slice 41 is generated by the generating means 3 is completely redundant with the identifier ^¬ th slice 31, so that two fully redundant Sli ^¬ ces 31, 41 are present.

In addition, the two slices are identifiable 31,41 respectively by means of a marking 33, 43 in the video stream 30, wherein the markings 33, 43 later in preference ^¬ not, be encrypted, so that the two slices 31, 41, even after the encryption or without increased effort are identifiable. The markings 33, 43 also allow direct access to the slices which, inter alia, is advantageous for the packaging in corresponding transmission methods or the organization of the memory space in the decoding.

FIG. 5 shows the two slices 31, 41 after the method steps 28 and 29 have been carried out according to preferred embodiments. In the example illustrated in Figure 5 embodiment, the slice is completely encrypted by the fasteners ^¬ 4 averaging means 31, thereby, is formed with the exception of the marking 33, completely encrypted slice 31z. Moreover, it was blackened as the basis of FIG 5 il ^¬ lustrierten embodiment in the slice 41 of the content to be protected collapsing 32 through the privacy of means 5 and thus obscured. This results in the slice 41z with the blackened content 32z and the unchanged content 34. The blackening of the content to be protected is an example of a measure to ensure the privacy of the content 32 to be protected. Further examples are ver ^{¬ different} types of distortion of the content means Filtering eg lowpass filter or clouding. Preferably, the at least partially redundant slice 41 is generated in the video stream 30, so that two at least partially redundant slices 31, 41 are present in the video stream 30. According to preferred embodiments, the encoding of the video is included. For example, according to one exemplary embodiment, the slice structure is designed in such a way that the content to be protected is covered by the identified slice. In other words, the structuring of the content into slices can be done in such a way that the area to be protected (eg the visible part of the road) is summarized in a slice. Thus, the protection of Pri vacy ^¬ easier because only one slice is to duplicate.

Preferably, the video stream 30 is a compressed video stream and / or the at least partially redundant slice 41 is generated in the compressed video stream 30. In other words: First, a compressed video stream is generated, for example, by the encoder 12 of the video camera 11, and at ^some later time, the encryption means 4 encrypts the content 32 to be protected in one of the two slices 31, 41. Since encrypted data is usually less compressible, it can increase the compression rate.

Preferably, the compressed video stream into which privacy protection is performed is an AVC video stream.

According to preferred embodiments of the invention is produced in the compressed video, an at least partially redundant slice 41 for the slice 31 in the original image, in which the degree ^¬ acceptance to be applied to the protected content. The original contents in slice 31 are rendered unreadable by encryption. This causes the decoder 22 to decode the redundant slice 41. In the redundant slice 41, the areas to be protected 32 are blackened or rendered unrecognizable. The regions 32 to be protected are changed in the redundant slice according to the chosen method. The original slice 31 is encrypted, for example. This procedural ^¬ ren operates independently from the video encoder 12 and decoder 22nd

At the end of the process 24 an encoded video is present, in which both portions 32, 34 are included, each verfüg ^¬ bare decoder 22 would only display the video in which the measures are applied.

By encrypting the original slice 31 does not know ^¬ tere special treatment of the protected content is required. It can only be displayed again if the key is known.

By the method according to the claims of this invention, only the areas to be protected are transferred and stored twice, as original slice 31 and redundant slice 41.

Preferred embodiments of the invention solve the following problems: Privacy Protection in AVC video streaming;

• Privacy Protection without the intervention of the encoder;

• Privacy Protection without the involvement of

Decoder / display device;

• Preservation of the genuine AVC original stream for preservation of evidence;

• Using commercially available decoders to watch the video including privacy protection;

• Use of commercially available decoders to display the original video;

· Use of commercially available encoders for the compression of the video stream. Preferred embodiments of the invention are characterized by the following advantages:

• An AVC decoder 22 automatically uses the unencrypted slice according to the AVC standard. For example, an AVC decoder 22 uses the redundant slice 41 if the original slice 31 is not decodable due to encryption. The redundant slice includes the areas protected by privacy protection.

• An AVC decoder 22 used according AVC standard automatic ^¬ table 31 when it decrypts is present ^¬, the redundant slice is ignored in the case, the original slice. Preferred embodiments of the method 24 and the device 1 operate in the compressed domain area and can be used independently of an AVC encoder.

• The procedure can be used independently of an AVC decoder.

• Only authorized with access to the corresponding keys are able to be looking content to be protected 32 ^¬ s.

• No two versions of the video stream are generated, resulting in a memory reduction.

Claims

claims

1. A process for privacy protection, comprising the procedural steps:

- generating a video stream (30) comprising a slice structure (37);

Identifying a slice (31) of the video stream comprising content (32) to be protected;

Generating a slice (31) which is at least partially redundant with respect to the identified slice (31), so that there are two at least partially redundant slices (31, 41);

Encrypting the content (32) to be protected in one of the two slices (31, 41), and applying at least one measure to ensure privacy to the content (32) to be protected in the other (41, 31) of the two slices.

2. The method of claim 1, wherein the content to be protected (32) in one of the two slices is encrypted by the fact that the entire one of the two slices (31, 41) ver ^¬ is encrypted.

3. The method according to any one of the preceding claims, wherein the two slices (31, 41) each by means of a label (33, 43) are identifiable in the video stream, wherein the labels (33, 43) are not encrypted.

The method of any one of the preceding claims, wherein the video stream (30) is a compressed video stream.

5. The method according to any one of the preceding claims, wherein the at least partially redundant slice (41) is generated in the komprimier ^¬ th video stream (30).

6. The method according to any one of the preceding claims, wherein the at least partially redundant slice (41) is completely re ^¬ dundant to the identified slice (31).

7. The method according to any one of the preceding claims, wherein the at least one measure to ensure the Pri ^¬ vatsphäre a make unrecognizable the content to be protected (32), preferably a blackening of the content to be protected (32) comprises.

8. The method according to any one of the preceding claims, wherein the at least partially redundant slice (41) in the video stream ^¬ (30) is generated, so that two at least partially redundant slices (31, 41) in the video stream (30).

9. The method according to any one of the preceding claims, wherein the slice structure is designed so that the ^¬ de content to be protected by the identified slice is included.

10. A device (1) for protecting privacy in a video stream (30) comprising a slice structure (37), the device (1) comprising:

An identification means (2) adapted to identify a slice (31) of the video stream (30) comprising content (32) to be protected;

A generating means (3) which is adapted to generate a slice (41) which is at least partially redundant with respect to the identified slice (31) so that there are two at least partially redundant slices (31, 41);

An encryption means (4) adapted to encrypt the content (32) to be protected in one of the two slices (31, 41);

Privacy means (5) adapted to apply at least one measure of privacy to the content (32) to be protected in the other (41, 31) of the two slices (31, 41).

11. Device (1) according to claim 10, wherein said encryption means (4) is adapted to encrypt the entire one of the two Sli ^¬ ces (31, 41).

12. Device (1) according to any one of claims 10 or 11, wherein the two slices (31,41) in each case by means of a signing ^¬ voltage (33, 43) in the video stream (30) are identifiable, wherein the markings (33, 43 ) are not encrypted.

The apparatus (1) of any one of claims 10 to 12, wherein the video stream (30) is a compressed video stream.

14. Device (1) according to claim 13, wherein the device (1) is adapted, the at least partially redundant slice

(41) in the compressed video stream (30).

15. Device (1) according to one of claims 10 to 14, wherein the generating means (3) is adapted to generate the at least partially redundant slice (41) completely redundant to the identified slice (31).

16. Device (1) according to any one of claims 10 to 15, wherein the privacy means (5) is adapted to make the contents to be protected (32) unrecognizable, preferably by blackening out the content (32) to be protected.

The apparatus (1) of any of claims 10 to 16, wherein the apparatus is adapted to generate the at least partially redundant slice (41) in the video stream (30) such that two at least partially redundant slices (31, 41) in the video stream Video stream (30) are present.

18. Device (1) according to any one of claims 10 to 17, wherein the slice structure is designed such that the content to be protected is covered by the identified slice.