Keratograph autoscanner system

• US 4,685,140 A
• Filed: 06/26/1984
• Issued: 08/04/1987
• Est. Priority Date: 06/26/1984
• Status: Expired due to Fees

• Current Assignee: KERA
• Original Assignee: KERA
• Inventors: Mount, Houston B. II
• Primary Examiner(s): Boudreau, Leo H.
• Assistant Examiner(s): Mancuso, Joseph
• Application Number:
  US06/624,650
• Time in Patent Office: 1,134 Days
• Field of Search: 354/62, 351/212, 351/206, 351/211, 382/6, 382/65, 382/1, 382/2, 382/57, 364/413, 340/709, 340/710, 356/376, 356/377, 356/395, 356/397
• US Class Current: 382/128
• CPC Class Codes: G06T 7/00 Image analysis

Abstract

A computer-controlled system for displaying an image of a keratograph taken by a video camera on a video monitor and determining the position/dimensions of the Placido rings on the keratograph, then selectively correcting the measured data. An interface circuit is provided which digitizes and stores in the computer memory one video scan line at a time, and contains ring data storage and logic for superimposing ring data on the keratograph image.

Claims

1. A system for analyzing an image of an object which includes superimposed contour lines, comprising video means for generating electronic signals representative of the image by line scanning;

means for digitizing the video signals a scan line at a time;

computer means responsive to the digitized video signals for storing the image in the form of the digitized scan line data, and being adapted for detecting and storing intersection address locations of the contour lines along selected reference lines;

a monitor controlled by the video means and stored addresses for displaying the image and intersection locations;

the computer means being further adapted to detect the intersection addresses based upon highest-magnitude peak values of the digitized video signals along the selected reference lines, and to correct intersection addresses by selectively writing in high or low values; and

adjustable correction control means interfacing with the computer means for selectively positioning correction cursors on the monitor image to thereby generate the address of the intersection correction.

2. The system of claim 1, the adjustable correction control means including a game paddle interface circuit for selectively positioning said correction cursors on the monitor image.

3. The system of claim 1, further comprising a printer responsive to the computer for printing the intersection locations.

4. The system of claim 1 wherein the video means comprises a microscope and a video camera adapted for receiving optical images from the microscope.

5. A system for analyzing an image of an object which includes superimposed contour lines, comprising video means for generating electronic signals representative of the image;

means for digitizing the electronic signals;

computer means responsive to the digitized electronic signals for detecting and storing the intersection address locations of the contour lines along selected reference lines based upon the highest-magnitude peak values of the digitized electronic signals along the selected reference lines;

a monitor controlled by the video means and stored addresses for displaying the image and intersection locations;

correction control means interfacing with the computer means for selectively positioning correction cursors on the monitor image at selected locations corresponding to missing or incorrectly positioned intersection locations; and

wherein the computer means is adapted for correcting intersection addresses by selectively writing in high or low values at the addresses of said selected locations.

6. The system of claim 5, the computer means including a game paddle interface circuit and the system further comprising adjustable correction control means interfacing with the computer means game paddle interface circuit for selectively positioning correction cursors on the monitor image to thereby generate the address of the intersection correction.

7. The system of claim 5, further comprising a printer responsive to the computer for printing the intersection locations.

8. The system of claim 5 wherein the video means is a video camera adapted for line scanning and wherein the digitizing means is adapted for digitizing a scan line at a time and transferring the digitized scan line data to the computer memory.

9. The system of claim 5 wherein the video means comprises a video camera adapted for line scanning and a microscope adapted for transferring images having contour rings superimposed thereon to the video camera;

and wherein the digitizing means is adapted for digitizing a scan line at a time for transferring the digitized scan line data to the computer memory.

10. A system for analyzing an image of an object which includes superimposed contour lines, comprising a video camera for generating electronic video signals representative of the image by line scanning;

means for digitizing the video signals a scan line at a time;

computer means including a memory responsive to the digitized video signals for storing the image in the form of the digitized scan line data, and being adapted for detecting and storing the intersection addresses of the contour lines along selected reference lines based upon the highest-magnitude peak values of the digitized video along the selected reference lines;

a monitor controlled by the video camera and stored addresses for displaying the image locations;

adjustable correction control means interfacing with the computer means for selectively positioning correction cursors on the monitor image to thereby generate the address of the intersection corrections; and

an interface circuit comprising the signal digitizing means;

buffer storage for transferring the digitized scan line data to the computer memory;

intersection address storage means for storing the intersection addresses of the contour lines along the selected reference lines and for storing the corrected intersection addresses;

a logic circuit adapted for selectively receiving the video signals and the intersection addresses to responsively superimpose the address locations on the monitor image; and

a multiplex circuit responsive to field signals and horizontal and vertical sync signals inherent to the video image for controlling transfer of the digitized scan line data to the computer means and transfer of the intersection address data to the intersection address storage means.

11. The system of claim 10, further comprising a printer responsive to the computer for printing the intersection locations.

12. The system of claim 10 wherein the video camera further comprises a microscope and the video camera is adapted for receiving optical images from the microscope.

13. The system of claim 10 wherein the video camera further comprises a microscope having contour rings superimposed therein and being adapted for transferring images to the video camera.

14. A method of using a video camera and a computer to determine the topography of a corneal surface, comprising using the camera to provide a video corneal image comprising a matrix of scan lines and superimposed reference curves such a Placido rings or mires;

digitizing the image matrix one scan line at a time;

determining the intersectional position of the reference curves along at least one selected axis;

checking the accuracy of the detected reference curve positions by displaying the reference curve positions on the video image;

selectively positioning correction cursors at the correct reference curve positions on the image for controlling correctional movement of the detected reference curve positions;

storing the address of the correction cursors in the computer as the corrected reference curve address; and

displaying the corrected video corneal image.

15. The method of claim 14 wherein the video corneal image is of a keratograph.

16. The method of claim 14 wherein the corneal image is a real time image provided by optically reflecting the reference curves from a cornea.