公开(公告)号：US20230208614A1

公开(公告)日：2023-06-29

申请号：US18084905

申请日：2022-12-20

Applicant: Axis AB

Inventor： Björn VÖLCKER ,  Stefan LUNDBERG

IPC: H04L9/06 ,  H04L9/32

CPC classification number: H04L9/0643 ,  H04L9/3247

Abstract: A signed media bitstream comprises data units and signature units. Each signature unit is associated with one or more nearby data units and include at least one fingerprint derived from the associated data units and a digital signature of the at least one fingerprint. A storing method comprises: receiving a segment of the media bitstream; identifying N≥2 instances of a repeating data unit in the received segment; pruning up to N−1 of the identified instances of the repeating data unit; and storing the received segment after pruning. A validation method comprises: receiving a segment of the media bitstream stored in accordance with the storing method; and validating a signature unit using a digital signature contained therein. Despite the pruning of the repeating data unit, the received associated data units can be successfully validated, either directly or indirectly, by means of different embodiments herein.

公开(公告)号：US20220368534A1

公开(公告)日：2022-11-17

申请号：US17710151

申请日：2022-03-31

Applicant: Axis AB

Inventor： Stefan LUNDBERG ,  Viktor EDPALM

IPC: H04L9/32 ,  H04N21/835

Abstract: A device, and method of signing a video segment comprising one or more groups of pictures, GOPs, wherein each GOP comprises a header and one or more frames, are disclosed. For each of the one or more GOPs a GOP hash is produced and the GOP hash is digitally signed by means of a digital signature to produce a signed GOP hash. For each GOP except a last GOP of the one or more GOPs the respective signed GOP hash is saved in the header of a subsequent GOP. An additional GOP is added to the video segment after the last GOP of the one or more GOPs, wherein the additional GOP comprising a header and one or more frames. The signed GOP hash of the last GOP of the one or more GOPs is saved in the header of the additional GOP.

公开(公告)号：US20210097695A1

公开(公告)日：2021-04-01

申请号：US17026321

申请日：2020-09-21

Applicant: Axis AB

Inventor： Stefan LUNDBERG ,  Song YUAN

IPC: G06T7/20 ,  G06T5/20 ,  G06T7/70 ,  G06T7/194

Abstract: A method includes defining a background model of the video sequence by applying a first algorithm, the background model defining whether that spatial area belongs to a background or a foreground in the video sequence, wherein a detected significant change in image data in a spatial area in an image frame relative image data in said spatial area in a preceding image frame is indicative of said spatial area belonging to the foreground; indicating that an idle area of the defined foreground areas is to be transitioned from foreground to background; and determining whether the idle area is to be transitioned by applying a second algorithm to image data of an image frame of the video sequence, the image data at least partly corresponding to the idle area; wherein if the idle area is not to be transitioned, maintaining the idle area as a foreground area in the background model.

公开(公告)号：US20230114200A1

公开(公告)日：2023-04-13

申请号：US17957775

申请日：2022-09-30

Applicant: Axis AB

Inventor： Björn VÖLCKER ,  Stefan LUNDBERG

IPC: H04L9/40 ,  G08B13/196

Abstract: The present application relates to detecting if video images captured by a camera are depicting a live scene or a recorded video played on a monitor, display or computer screen, which is setup to hide the scene from the camera. Metadata regarding the mapping operation used to transform image data between different intensity ranges, or bit depths, is included with the video and evaluated in order to determine if a video replay attack has taken place.

公开(公告)号：US20150156423A1

公开(公告)日：2015-06-04

申请号：US14531137

申请日：2014-11-03

Applicant: AXIS AB

Inventor： Stefan LUNDBERG

IPC: H04N5/232

CPC classification number: H04N5/23296 ,  H04N5/232 ,  H04N5/23203

Abstract: There is provided a system, including a tag device and a camera arrangement, for following an object marked by the tag device with a camera. The tag device may measure a horizontal plane position and an altitude of the tag device according to different measurement principles, and transmit the measured values to a camera arrangement. The camera arrangement may measure a horizontal plane position and an altitude related to the camera according to different measurement principles. The camera arrangement may then control the pan and tilt settings of the camera based on differences in horizontal plane positions and altitudes between the camera and the tag device such that the camera is oriented in the direction of the tag device.

Abstract translation: 提供了一种包括标签装置和相机布置的系统，用于利用相机跟踪由标签装置标记的对象。 标签装置可以根据不同的测量原理测量标签装置的水平面位置和高度，并将测量值发送到相机装置。 照相机装置可以根据不同的测量原理测量与摄像机相关的水平面位置和高度。 相机配置然后可以基于相机和标签装置之间的水平面位置和高度的差异来控制相机的摇摄和倾斜设置，使得照相机朝向标签装置的方向。

公开(公告)号：US20140160308A1

公开(公告)日：2014-06-12

申请号：US14179809

申请日：2014-02-13

Applicant: AXIS AB

Inventor： Carl-Axel ALM ,  Stefan LUNDBERG ,  Willy SAGEFALK

IPC: H04N5/232

CPC classification number: H04N5/23203 ,  G02B6/3604 ,  H04N5/2251

Abstract: A pan-tilt camera is arranged to include a camera head, a stationary unit, an intermediate member arranged between the camera head and the stationary unit, a first rotary joint rotatably connecting the camera head to the intermediate member, and a second rotary joint, rotatably connecting the intermediate member to the stationary unit. A communication path is provided between the camera head and the stationary unit, including an optical waveguide arranged between the camera head and the stationary unit. The optical waveguide has a first end positioned at the first rotary joint to receive light from the camera head through the first rotary joint. The other end of the waveguide is positioned at the second rotary joint and is arranged to send light to the stationary unit through the second rotary joint.

Abstract translation: 俯仰摄像机被配置为包括相机头，固定单元，布置在相机头和固定单元之间的中间构件，将照相机头可旋转地连接到中间构件的第一旋转接头和第二旋转接头， 将中间构件可旋转地连接到固定单元。 在相机头和固定单元之间提供通信路径，包括布置在相机头和固定单元之间的光波导。 光波导具有位于第一旋转接头处的第一端，以通过第一旋转接头接收来自照相机头的光。 波导的另一端位于第二旋转接头处，并且布置成通过第二旋转接头将光发送到固定单元。

公开(公告)号：US20140152892A1

公开(公告)日：2014-06-05

申请号：US14174393

申请日：2014-02-06

Applicant: AXIS AB

Inventor： Stefan LUNDBERG

IPC: H04N7/01

CPC classification number: H04N7/0117 ,  H04N7/012

Abstract: A method for de-interlacing interlaced video includes receiving a first video field and a second video field of an interlaced video frame, generating a first video frame from the first video field and a first synthesized video field, where video data of the first synthesized video field is based exclusively on video data of the first and second video fields, generating a second video frame from the second video field and a second synthesized video field, where video data of the second synthesized video field is based exclusively on the video data of the first and second video fields, and outputting two de-interlaced video frames for every received interlaced video frame. The first (second) synthesized video field is generated by combining image data from the second (first) video field with image data from corresponding lines of an up-scaled first (second) field generated by a scaler.

Abstract translation: 一种用于去隔行隔行扫描视频的方法包括接收隔行视频帧的第一视频场和第二视频场，从第一视频场产生第一视频帧和第一合成视频场，其中第一合成视频的视频数据 字段仅基于第一和第二视频字段的视频数据，从第二视频场产生第二视频帧和第二合成视频字段，其中第二合成视频字段的视频数据完全基于视频数据 第一和第二视频场，并且为每个接收到的隔行视频帧输出两个去隔行视频帧。 第一（第二）合成视频场是通过将来自第二（第一）视频场的图像数据与由缩放器产生的高比例缩放的第一（第二）场的相应行的图像数据组合而产生的。

公开(公告)号：US20240155146A1

公开(公告)日：2024-05-09

申请号：US18490269

申请日：2023-10-19

Applicant: Axis AB

Inventor： Stefan LUNDBERG ,  Björn VÖLCKER

IPC: H04N19/46 ,  H04N19/136 ,  H04N19/184 ,  H04N19/40

CPC classification number: H04N19/46 ,  H04N19/136 ,  H04N19/184 ,  H04N19/40

Abstract: A method for providing a signed video bitstream suitable for transcoding from a first video format into a second video format, the method comprising: obtaining first video data in a lossy first video format; reconstructing a video sequence from the first video data; encoding the reconstructed video sequence as second video data in a second video format; computing first fingerprints of the first video data and second fingerprints of the second video data; deriving a first bitstring from the first fingerprints and a second bitstring from the second fingerprints; and providing a signed video bitstream, which includes the first video data and signature units, each signature unit including a first digital signature of the derived first bitstring and second digital signature of the derived second bitstring.

公开(公告)号：US20230179787A1

公开(公告)日：2023-06-08

申请号：US17980138

申请日：2022-11-03

Applicant: Axis AB

Inventor： Björn VÖLCKER ,  Stefan LUNDBERG

IPC: H04N19/46 ,  H04N19/159 ,  H04N19/169 ,  H04N19/177 ,  H04N19/172

CPC classification number: H04N19/46 ,  H04N19/159 ,  H04N19/188 ,  H04N19/177 ,  H04N19/172

Abstract: A device and a method of signing an encoded video sequence comprising: obtaining an encoded video sequence composed of encoded image frames; generating a set of one of more frame fingerprints for each encoded image frame; generating a document comprising a header of a supplemental information unit, and a representation of the generated sets of one or more frame fingerprints; generating a document signature by digitally signing the document; generating the supplemental information unit to only consist of the document, the document signature and an indication of an end of the supplemental information unit; and signing the encoded video sequence by associating the generated supplemental information unit with the encoded video sequence.

公开(公告)号：US20230112135A1

公开(公告)日：2023-04-13

申请号：US17881983

申请日：2022-08-05

Applicant: Axis AB

Inventor： Björn VÖLCKER ,  Stefan LUNDBERG

IPC: G06T1/00 ,  H04N19/50

Abstract: A method of signing prediction-coded video data, comprising: obtaining a coded video sequence including at least one I-frame (I), which contains independently decodable image data, and at least one predicted frame (P1, P2, P3, P4), which contains image data decodable by reference to at least one other frame; generating a fingerprint (HI) of each I-frame; generating a fingerprint (HP) of each predicted frame by hashing a combination of data derived from the predicted frame and data derived from an I-frame to which the predicted frame refers directly or indirectly, wherein the fingerprint of the predicted frame is independent of any further predicted frame to which the predicted frame refers directly or indirectly; and providing a signature of the video sequence including the generated fingerprints.