Method and system for transferring live video pictures from a video camera to a remote video displayer via a conventional telephone line

• US 6,738,087 B2
• Filed: 11/22/2002
• Issued: 05/18/2004
• Est. Priority Date: 03/09/2000
• Status: Expired due to Fees

• Current Assignee: OZ Vision Limited
• Original Assignee: OZ Vision Limited
• Inventors: Belkin, Shahar, Ovnat, Zev, Groswirth, Dan, Shdema, Orly
• Primary Examiner(s): CHAN, WING F
• Application Number:
  US10/220,850
• Publication Number:
  US 20030169331A1
• Time in Patent Office: 543 Days
• Field of Search: 348/14.01, 348/14.12, 348/14.13, 348/384.1, 348/420.1, 348/143, 358/426.01, 358/426.02, 709/228, 375/240.24, 379/93.08, 379/93.17
• US Class Current: 348/14.13
• CPC Class Codes: H04N 19/503 involving temporal prediction adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A method for transferring live video signals from a video camera of a local system to a remote video-display system via low-bandwidth communication lines is disclosed. The method is especially useful for a fixed camera located at a predetermined location, such as a security camera, for monitoring a picture of a substantially constant background. A live video system for implementation of the method is also disclosed that includes a video camera and a video displayer interconnected by a conventional telephone line.

Claims

1. Method for transferring live video signals from a video camera of a local system to a remote video-display system via low-bandwidth communication lines, comprising the steps of;

(a) acquiring the analog data of an initial-picture by a video camera of a local system;

digitizing the said analog data into digital values each presents visual information of one definite picture pixel;

grouping the pixels'"'"' digital values data into a plurality of data-blocks each contains data of one particular picture-region associated to its respective location in the picture by a particular address code wherein each picture-region consists of a few neighboring video-pixels taken from at least four neighboring video rows;

storing each data-block in a memory means of the local system and successively transferring it with its address code information to a remote video-display system;

(b) storing the transferred data of the initial-picture in memory means of the remote video-display system and converting the said data to a video-picture displayed on a screen of the video-display system;

(c) acquiring successive video pictures by the video camera, digitizing the analog data of each picture into digital values each presents visual information of one definite picture pixel;

grouping the pixels'"'"' digital values data into a plurality of similar data-blocks having the same structure and the same respective addresses as the analogous data-blocks of the initial-picture, subtracting each pixel'"'"'s value of a successive picture from the analogous pixel'"'"'s value of the initial picture, summing the pixels subtraction results of each block into a single value representing the significance-weight of the respective block, compressing data of blocks having significance-weight greater than a predetermined threshold-value and transferring this compressed data followed by the respective block addresses to the remote video-display system;

(d) decompressing the said transferred data received by the remote video-display system and refreshing the relevant picture regions of the displayed video picture according to the newly received data.

2. Method for transferring live video signals according to claim 1, wherein the threshold-value is dynamic and determined automatically relatively to previous amount of transferred data.

3. Method for transferring live video signals according to claim 1, wherein the threshold value is dynamic and determined automatically considering the actual data transfer rate allowed by the communication line in use.

4. Method for transferring live video signals according to claim 1, wherein the threshold value is determined considering a preferred picture-refresh rate electrically pointed-out through the communication line by a user of the remote video-display system.

5. Method for transferring live video signals according to claim 1, wherein data of blocks neighboring to data-blocks having significance-weight greater than the threshold value is also compressed and transferred to the remote video-display system.

6. Method for transferring live video signals according to claim 1, wherein data of blocks neighboring to data-blocks having significance-weight greater than the threshold value is also compressed and transferred to the remote video-display system, conditionally to having a significance-weight value greater than a lenient secondary threshold value.

7. Method for transferring live video signals according to claim 1, wherein the data compressed and transferred to the remote video-display system is the original digitized picture data.

8. Method for transferring live video signals according to claim 1, wherein each data-block include data of a square picture region holding 64 pixels.

9. Live-video system especially useful for transferring live video data through low-bandwidth communication lines according to the method defined in claim 1, comprising a video-camera system and a video-display system, wherein the video camera system is comprised of a video camera, a variable micro-processor-controlled low-pass filter, an analog-to-digital video-data converter, a digital signal processor, a logical unit, memory means, a programmable address-manager counter, and a communication buffering unit, wherein video analog data flows from the camera to the variable low-pass filter, converted by the digital-to-analog converter into successively flowing digital values each presents visual information of one definite picture pixel, and the successive digital values are distributed by an addressing sequence of the programmable address-manager counter to a fixed-interval storage addresses of the memory means, thus performing data-blocks respective to picture regions, and wherein in the said logical unit pixels'"'"' visual information digital values of an initial picture stored in the memory and pixels'"'"' visual information digital values of successive pictures are subtracted respectively from each other, the subtraction results of each data-block are summed into a significance-weight value, compared with a predetermined threshold-value, and data of blocks having significance-weight value greater than the threshold value is being compressed by the signal processor and transferred followed by respective address codes through the telephone line to the remote video-display system, de-compressed and displayed.

10. Live-video system especially useful for transferring live video data through low-bandwidth communication lines according to the method defined in claim 1, comprising a video-camera system and a video-display system, wherein the video camera system is comprised of a video camera, a variable micro-processor-controlled low-pass filter, an analog-to-digital video-data converter, a digital signal processor, a logical unit, memory means, a programmable address-manager counter, and a communication buffering unit, wherein video analog data flows from the camera to the variable low-pass filter, converted by the digital-to-analog converter into successively flowing digital values each presents visual information of one definite picture pixel, and the successive digital values are being stored successively in the memory means, than being collected from a fixed-interval storage addresses of the memory means by an addressing sequence of the programmable address-manager counter, thus reading the data in blocks respective to picture regions, and wherein in the said logical unit pixels'"'"' visual information digital values of an initial picture read-out from the memory-means are subtracted respectively from pixels'"'"' visual information digital-values of successive pictures, the subtraction results of each data-block are summed into a significance-weight value, compared with a predetermined threshold-value, and data of blocks having significance-weight value greater than the threshold value is being compressed by the signal processor and transferred followed by respective address codes through the telephone line to the remote video-display system, de-compressed and displayed.

11. Live-video system especially useful for transferring live video data through low-bandwidth communication lines according to claim 9, wherein each data-block includes data of a square picture region holding 64 pixels.