Image-sensing server and control method and storage medium therefor

• US 6,469,737 B1
• Filed: 07/22/1997
• Issued: 10/22/2002
• Est. Priority Date: 07/23/1996
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Igarashi, Masaru, Yamakawa, Tadashi, Sato, Mamoru
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): MOE, AUNG SOE
• Application Number:
  US08/898,268
• Time in Patent Office: 1,918 Days
• Field of Search: 348/13, 348/15, 348/17, 348/18, 348/19, 348/384.1, 348/387.1, 348/390.1, 348/12, 348/7, 348/14.1, 348/14.12, 348/211, 348/212, 348/213, 348/552, 348/220, 348/222, 709/219, 709/217, 709/218, 709/299, 709/233, 709/223, 709/224, 709/232, 709/204, 455/4.2, 455/5.1, 370/229, 370/230, 370/235, 370/236, 370/260, 370/261, 370/263, 725/96
• US Class Current: 348/211.3
• CPC Class Codes: H04N 21/234354 by altering signal-to-noise ratio parameters, e.g. requantization
• CPC Class Codes: H04N 21/234381 by altering the temporal resolution, e.g. decreasing the frame rate by frame skipping
• CPC Class Codes: H04N 21/238 Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams hybrid fiber coaxial [HFC] networks for downstream channel allocation for video distribution H04L12/2801; flow control in packet networks H04L47/10; real-time communication protocols in data switching networks H04L65/00; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/2402 Monitoring of the downstream path of the transmission network, e.g. bandwidth available traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876
• CPC Class Codes: H04N 21/25808 Management of client data terminal profiles in network data switching protocols H04L67/303
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/4621 Controlling the complexity of the content stream or additional data, e.g. lowering the resolution or bit-rate of the video stream for a mobile client with a small screen arrangements for using the results of monitoring on user's side in broadcast systems H04H60/65; flow control in packet networks H04L47/10
• CPC Class Codes: H04N 21/4622 Retrieving content or additional data from different sources, e.g. from a broadcast channel and the Internet web site content organization and management for information retrieval from the Internet G06F16/958; transmission by internet of broadcast information H04H60/82; stock exchange data over packet-switching network H04L12/1804; push services including data channel over packet-switching network H04L12/1859
• CPC Class Codes: H04N 21/4782 Web browsing , e.g. WebTV
• CPC Class Codes: H04N 21/643 Communication protocols network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP], H04L65/65
• CPC Class Codes: H04N 21/6583 Acknowledgement
• CPC Class Codes: H04N 23/66 Remote control of cameras or camera parts, e.g. by remote control devices
• CPC Class Codes: H04N 23/661 Transmitting camera control signals through networks, e.g. control via the Internet

Abstract

An image-sensing server performs moving-image transfer service by sequentially transferring live video images obtained by a video camera via a general network such as the Internet. When live video images are requested from an external device as a client on the network, a system controller controls data-transfer amount per unit time of an image obtained by image sensing by the video camera, in accordance with traffic status on the network, and transfers the image data to the external device.

Claims

1. An image-sensing server, connected to a general network, capable of controlling image-sensing means, comprising:

transfer means for transferring a series of video images, obtained by said image-sensing means, to a client device on the network, as a moving image;

detection means for detecting the degree of traffic congestion on the network; and

control means for controlling a data amount of video images transferred by said transfer means, in accordance with the result of detection by said detection means;

wherein said detection means detects the degree of traffic congestion on the network by measuring time from a point where data transfer has been started to a point where an acknowledgment signal is received from a transfer destination, and

wherein said control means controls the video images from said image-sensing means by controlling operation response of said image-sensing means, in accordance with the degree of traffic congestion on the network detected by said detection means.

2. The image-sensing server according to claim 1, wherein said transfer means compresses the video images into motion JPEG format data.

3. The image-sensing server according to claim 2, wherein if it is determined by the result of detection by said detection means that the degree of traffic congestion on the network is high, said control means lowers the operation response of said image-sensing means.

4. The image-sensing server according to claim 1, wherein said control means controls a thinning amount of the video images by selecting a frame to be skipped.

5. The image-sensing server according to claim 1, wherein said transfer means compresses the video images into MPEG format data and transfers the data,

and wherein said control means controls the data amount by controlling a mask area of high-frequency component obtained by orthogonal conversion performed in MPEG compression.

6. The image-sensing server according to claim 1, further comprising:

determination means for determining whether or not a still-image transfer request has been received from the client device;

second transfer means for, if said determination means determines that the still-image transfer request has been received while the moving image is transferred, temporarily saving control status of said image sensing means, setting said image sensing means for still-image sensing and controlling said image sensing means to perform image sensing, encoding obtained still image by a predetermined coding processing, and transferring the coded still image to said client device; and

restoring means for, when transfer of the still image has been completed, restoring the control status saved by said second transfer means and continuing transfer of the moving image.

7. The image-sensing server according to claim 6, further comprising notification means for notifying the client device, which has received the moving image, that control right has been temporarily lost when the still image is transferred by said second transfer means.

8. A control method for an image-sensing server, connected to a general network, capable of controlling image-sensing means, comprising:

a transfer step of transferring a series of video images, obtained by said image-sensing means, to a client device on the network, as a moving image;

a detection step of detecting the degree of traffic congestion on the network; and

a control step of controlling a data amount of video images transferred at said transfer step, in accordance with the result of detection at said detection step;

wherein at said detection step, the degree of traffic congestion is detected on the network by measuring time from a point where data transfer has been started to a point where an acknowledgment signal is received from a transfer destination, and

wherein at said control step, the video images from said image-sensing means are controlled by controlling operation response of said image-sensing means, in accordance with the degree of traffic congestion on the network detected at said detection step.

9. The control method according to claim 8, wherein at said transfer step, the video images are compressed into motion JPEG format data.

10. The control method according to claim 9, wherein if it is determined at said detection step that the degree of traffic congestion on the network is high, the operation response of said image-sensing means is lowered at said control step.

11. The control method according to claim 8, wherein at said control step, a thinning amount of the video images is controlled by selecting a frame to be skipped.

12. The control method according to claim 8, wherein at said transfer step, the video images are compressed into MPEG format data and transferred,

and wherein at said control step, the data amount is controlled by controlling a mask area of high-frequency component obtained by orthogonal conversion performed in MPEG compression.

13. The control method according to claim 8, further comprising:

a determination step of determining whether or not a still-image transfer request has been received from the client device;

a second transfer step of, if it is determined at said determination step that the still-image transfer request has been received while the moving image is transferred, temporarily saving control status of said image sensing means, setting said image sensing means for still-image sensing and controlling said image sensing means to perform image sensing, encoding obtained still image by a predetermined coding processing, and transferring the coded still image to said client device; and

a restoring step of, when transfer of the still image has been completed, restoring the control status saved at said second transfer step and continuing transfer of the moving image.

14. The control method according to claim 13, further comprising a notification step of notifying the client device, which has received the moving image, that control right has temporarily lost when the still image is transferred at said second transfer step.

15. A computer-readable storage medium containing program codes for executing processing by a computer connected to image sensing means, comprising:

transfer-process program codes for executing processing for transferring a series of video images obtained by said image sensing means to a client device on a network, as a moving image;

detection-process program codes for executing processing for detecting the degree of traffic congestion on the network; and

control-process program codes for executing processing for controlling a data amount of video images transferred by said transfer means, in accordance with the result of detection by said detection means;

wherein at said detection-process program codes, the degree of traffic congestion is detected on the network by measuring time from a point where data transfer has been started to a point where an acknowledgment signal is received from a transfer destination, and

wherein at said control-process program codes, the video images from said image-sensing means are controlled by controlling operation response of said image-sensing means, in accordance with the degree of traffic congestion on the network detected at said detection step.

16. The computer-readable storage medium according to claim 15, wherein said transfer-process program codes compress the video images into motion JPEG format data.

17. The computer-readable storage medium according to claim 16, wherein if it is determined by the result of detection by said detection-process program codes that the degree of traffic congestion on the network is high, said control process program codes lowers the operation response of said image-sensing means.

18. The computer-readable storage medium according to claim 15, wherein said control-process program codes control a thinning amount of the video images by selecting a frame to be skipped.

19. The computer-readable storage medium according to claim 15, wherein said transfer-process program codes compress the video images into MPEG format data and transfers the data,

and wherein said control-process program codes control the data amount by controlling a mask area of high-frequency component obtained by orthogonal conversion performed in MPEG compression.

20. The computer-readable storage medium according to claim 15, further comprising:

determination-process program codes for determining whether or not a still-image transfer request has been received from the client device;

second transfer-process program codes for, if said determination-process program codes determine that the still-image transfer request has been received while the moving image is transferred, temporarily saving control status of said image sensing means, setting said image sensing means for still-image sensing and controlling said image sensing means to perform image sensing, encoding obtained still image by a predetermined coding processing, and transferring the coded still image to said client device; and

restoring-process program codes for, when transfer of the still image has been completed, restoring the control status saved by said second transfer-process program codes and continuing transfer of the moving image.

21. The computer-readable storage medium according to claim 20, further comprising notification-process program codes for notifying the client device, which has received the moving image, that control right has been temporarily lost when the still image is transferred by said second transfer-process program codes.