High-speed video instrumentation system

• US 5,301,240 A
• Filed: 09/08/1992
• Issued: 04/05/1994
• Est. Priority Date: 12/14/1990
• Status: Expired due to Fees

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Stockum, Larry A., Gorenflo, Ronald L.
• Primary Examiner(s): Razavi, Michael T.
• Assistant Examiner(s): Fox, David
• Application Number:
  US07/941,852
• Time in Patent Office: 574 Days
• Field of Search: 382/1, 382/48, 358/93, 358/105, 358/108, 358/135, 358/136, 340/541
• US Class Current: 382/100
• CPC Class Codes: G06V 20/00 Scenes; Scene-specific elements control of digital cameras H04N23/60
• CPC Class Codes: H04N 5/76 Television signal recording

Abstract

An imager and an analog to digital converter yield a series of digital signals from successive frames of images of scenes in which selected types of high-speed events may take place. The signals are sampled, and changes in the sampled signals typically indicative of such events are detected. Random access memory temporarily stores a sequence of the signals including each such changed signal. Analytic circuitry determines whether the sequence contains a record of such an event, and, if it does, provides a videotape record of the event.

Claims

1. Video apparatus for providing records of selected types of images of high-speed events comprising:

A. solid state imager means for receiving and converting focused images and providing an ordered series of digital signals representing sequential frames of images of scenes in which high-speed events may take place;

B. solid state memory means for storing, at least temporarily, a portion of the digital signals;

C. first comparative means responsive to the digital signals, for comparing values of individual pixels, in the digital signals being stored, with average preceding values of the individual pixels for a predetermined number of prior frames, and for incrementing an average event counter each time a comparison exceeds a predetermined threshold value, wherein the first comparative means operates on the digital signals from (A) in real time simultaneously with the solid state memory means (B);

D. second comparative means responsive to the digital signals, for comparing values of individual pixels, in the digital signals being stored, with values of the individual pixels in a preceding frame, and for incrementing a frame-to-frame event counter each time a comparison exceeds a predetermined threshold value, wherein the second comparative means operates on the digital signals from (A) in real time simultaneously with the solid state memory means (B) and the first comparative means (C);

E. average event counter means for providing a first output signal indicating when an average pixel threshold within a frame is exceeded a predetermined number of times;

F. frame-to-frame event counter means for providing a second output signal indicating when a frame-to-frame pixel threshold is exceeded a predetermined number of times; and

G. means responsive to the detection of an event by the counter means (E) and (F) when both counter means provide first and second output signals to indicate that their respective thresholds have been exceeded a predetermined number of times within the same frame, providing for retaining a portion or none of pre-event digital signals in solid state memory means (B) and storing additional and post-event digital signals that contain a record of the selected types of images.

2. The apparatus of claim 1, comprising programmable means for selecting frame rates from between about 200 to about 22,000 frames per second.

3. The apparatus of claim 1, comprising programmable means for selecting frame rates from between 10,000 to about 22,000 frames per second.

7. The apparatus of claim 1, comprising means for retrieving the stored digital signals for video display or recording of the images.

8. The apparatus of claim 1, comprising

a. solid state imager means for receiving focused images and providing an ordered series of analog signals;

b. conversion means for converting the analog signals to an ordered series of digital signals representing sequential frames of images of scenes in which high-speed events may take place.

9. The apparatus of claim 1, comprising means for video display and/or recording the stored digital signals representing the image scene at a slower frame rate than they were stored.

10. The apparatus of claim 1, wherein the solid state imager means comprises:

a. photodiode means having an image plane and an amplifier for converting an image focused on the image plane to analog signals;

b. converter means for converting the analog signals to digital signals.

11. The apparatus of claim 10, comprising optical means for focusing images on the image plane.

4. A method for providing records of selected types of images of high-speed events comprising:

A. focusing an image on an image plane of a solid state imager;

B. converting the focused image into an ordered series of digital signals representing sequential frames of images of scenes in which high-speed events may take place;

C. storing, at least temporarily, a portion of the digital signals in a solid state memory;

D. comparing the value of individual pixels, in the digital signals being stored, with average preceding values for the individual pixels for a predetermined number of prior frames, and incrementing an average event counter means each time a comparison exceeds a predetermined threshold value, whereby the comparison is made with the digital signals from (B) in real time simultaneously with the storing of the digital signals in (C);

E. comparing the values of individual pixels, in the digital signal being stored, with values for individual pixels in a preceding frame, and incrementing a frame-to-frame event counter means each time a comparison exceeds a predetermined threshold value, whereby the comparison is made with the digital signals form B. in real time simultaneously with the storing in (C) and the comparing in (D);

F. providing an output signal from the average event counter means when an average pixel threshold within a frame is exceeded a predetermined number of times;

G. providing an output signal from the frame-to-frame event counter means when a frame-to-frame pixel threshold is exceeded a predetermined number of times; and

H. detecting an event when both the average event counter means and the frame-to-frame event counter means have provided an output signal during the same frame and retaining a portion or none of pre-event digital signals in memory and storing additional event and post-event digital signals that contain a record of the selected types of images.

5. The method of claim 4, comprising programming and selecting a frame rate from between about 200 to about 22,000 frames per second.

6. The method of claim 4, comprising programming and selecting a frame rate from between about 10,000 to about 22,000 frames per second.

12. The method of claim 4, comprising retrieving the stored digital signals for video displaying or recording of the images.

13. The method of claim 4, comprising:

a. converting focused images to an ordered series of analog signals; and

b. converting the analog signals to an ordered series of digital signals representing sequential frames of images of scenes in which high-speed events may take place.

14. The method of claim 4, comprising video displaying and/or recording the stored digital signals representing the image scene at a lower frame rate than they were stored.

15. The method of claim 4, comprising:

a. converting an image focused on the image plane of a photodiode array to analog signals; and

b. converting the analog signals to digital signals.

16. The method of claim 15, comprising focusing images on the image plane with a lens.