Camera with object recognition/data output

• US 6,545,705 B1
• Filed: 04/10/1998
• Issued: 04/08/2003
• Est. Priority Date: 04/10/1998
• Status: Expired due to Term

• Current Assignee: Lynx System Developers Incorporated
• Original Assignee: Lynx System Developers Incorporated
• Inventors: Ciholas, Mike, Sigel, Kirk, DeAngelis, Douglas
• Primary Examiner(s): Vu, Ngoc-Yen, VU, NGOC YEN T
• Application Number:
  US09/058,542
• Time in Patent Office: 1,824 Days
• Field of Search: H04/N.5225, H04/N.718, 348/135, 348/136, 348/137, 348/139, 348/140, 348/142, 348/143, 348/157, 348/159, 348/169-172, 348/207, 348/222, 348/222.1, 386/110, 386/117, 340/540
• US Class Current: 348/157
• CPC Class Codes: G07C 1/24 Race time-recorders
• CPC Class Codes: H04N 7/188 Capturing isolated or intermittent images triggered by the occurrence of a predetermined event, e.g. an object reaching a predetermined position signal generation from motion picture films H04N5/253

Abstract

A line scan digital camera is directed at a station for recording and displaying a time-sequential scene. The digital camera takes a sequence of digital image frames representative of one or more bodies crossing a plane in space, wherein each frame represents a line image of the body, thus forming a fractional part of the scene, and the set of time-successive frames forms a recognizable image on an external display. Within the camera, frames enter a buffer and a microprocessor in the camera compares blocks from successive line images to detect changes indicative of objects entering or leaving the field of view. The changes detected by pixel or block analysis identify information-containing portions of the data stream and their time of occurrence. When the start or end of an object is detected the microprocessor flags the image stream with the detected data to produce an image data stream which can be more readily received and used by the external race management system, or the processor operates a controller in the camera which passes the active portion of the image information data stream to the output port, producing a more compact data stream with no loss of information. In a preferred embodiment, the camera is an event camera at a competition, and it images the finish line or an intermediate station to determine crossing times of contestants. Preferably, the microprocessor further detects optical patterns in the image so formed, such as bar code, numeric, or special marking features to identify contestants, or detects body features to determine estimated crossing times or other photocell determinations. This substantially automates the provision of race results, and allows relevant finish line pictures to be immediately presented to the judges from the raw image frames. The camera is also adapted to robotic vision applications for stations at irregular transport lines, and for mid-course identification and reporting along race tracks, transport lines and traffic environments.

Claims

1. An event recording camera system for forming a time sequence of images, comprising

a camera which generates a first sequence of digital line image frames of a fixed position in space, each frame of said first sequence representing a line image view that is captured by said camera at a moment in time and imaged onto an array of detector elements, said first sequence including active segments imaged at times wherein moving objects cross said fixed position, and inactive segments wherein no moving objects cross said fixed position

a buffer in said camera for storing said first sequence of frames as they are generated, and

a processor in said camera operative on said first sequence to detect an object and produce an object detection signal so as to selectively present said active segments at a camera output.

2. A system according to claim 1, wherein said processor communicates with the buffer to receive data from frames of said first sequence and compare data from successive frames to detect an object, such that said processor retroactively identifies start of an active imaging segment.

3. A system according to claim 1, wherein frames of the active imaging segment include frame time information.

4. A system according to claim 1, wherein said processor communicates with the buffer to receive data from frames of said first sequence and compare data from successive frames to detect end of an object, and sets the end of an active imaging segment.

5. A system according to claim 1, wherein the active imaging segment includes object identification information.

6. An event recording digital camera including an optical imaging element for forming a light image of a restricted visual field, and an image sensing element for generating a digital image frame from the light image, timing means in said camera for generate time signals and a processor in said camera operative on a sequence of said digital image frames for detecting movement of an object in said restricted visual field, and providing an information output in response to said detection,

wherein said image sensing element is a line sensor and said processor processes data from plural frames to detect identifier information carried by said object in said restricted visual field, and wherein said processor further provides an active segment with the object identifier information whereby image data transmitted out of the camera is suitable for automated display of identity data.

7. A digital camera according to claim 6, wherein the processor includes a memory, and said processor identifies active imaging segments in said memory in the camera.

8. A digital camera according to claim 6, wherein the processor crops said sequence by identifying start of an active segment and transmitting image frame data with time markings commencing at the start of the active segment.

9. A digital camera according to claim 8, wherein said line sensor generates frames at a rate substantially over one hundred frames per second.

10. A digital camera according to claim 9, wherein the processor detects bar code, number or color coded identifiers carried by the object.

11. A digital camera according to claim 6, wherein the processor detects object features to produce a photocell determination.

12. A digital camera including an optical imaging element for forming a visual image of a field, an image sensing element for generating a multi-pixel electrical output from the visual image, and circuit means in said camera for processing said multi-pixel electrical output to provide an image data stream including digital value image pixels, wherein said circuit means includes a processor operative on said image pixels to identify information bearing portions of said data stream and control camera output to transmit said information,

wherein said image sensing element is a line sensor and said processor processes data from plural frames to detect identifier information carried by an object in said visual field, and wherein said processor further provides an active segment with the object identifier information whereby image data transmitted out of the camera is suitable for automated display of identity data.

13. A digital camera according to claim 12, wherein the processor annotates the image data stream with data codes indicative of at least one of start of object, end of object, and identity of object.

14. A digital camera according to claim 12, wherein the processor controls output of the camera to selectively pass image frames containing moving object images.

15. An event recording video camera comprising

means for imaging a visual field

a line sensor for converting a line portion of the imaged visual field into electrical signals representative of pixels of the image of said field

circuit means for processing said electrical signals to form a digital output stream containing digitized pixel values of a sequence of frames at a high scanning rate

a buffer for storing said digital output stream before transmission, and

a processor operative on contents of the buffer for comparing sets of data from the buffer and identifying image data associated with moving objects, said processor controlling said output stream responsive to the identified data.

16. A video camera according to claim 15, wherein said processor compares block sum light values to detect beginning or end of object motion in the visual field.

17. A video camera according to claim 15, wherein said processor image-processes blocks of frames to detect an object identifier and controls said camera to transmit image data annotated with an indication of object identifier.

18. A video camera according to claim 15, wherein said processor image-processes blocks of frames to detect an object feature and controls said camera to transmit image data and estimated crossing time data.

19. A video camera according to claim 15, wherein said pixel values include color values and said processor processes values for each color separately.

20. A video camera according to claim 15, wherein the processor compares blocks of image frames over time to detect a change indicative of image frame activity and said processor applies a different threshold to detect end of image frame activity than to detect start of image frame activity.