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A method and apparatus for accurately auto focusing a lens of an imaging device. In an exemplary embodiment, an imaged scene is split into an array of zones. The minimum and maximum sharpness score for each zone is determined over a plurality of lens positions. A histogram of the lens positions of t

A method and apparatus for accurately auto focusing a lens of an imaging device. In an exemplary embodiment, an imaged scene is split into an array of zones. The minimum and maximum sharpness score for each zone is determined over a plurality of lens positions. A histogram of the lens positions of the corresponding maximum sharpness score for each zone is created. The peak of the histogram is determined to be the best focus position for a given scene.

대표청구항 ▼

What is claimed as new and desired to be protected by Letters Patent of the United States is: 1. A method of determining a focus position of a lens structure relative to an imaging sensor, comprising the steps of: dividing a scene imaged by said sensor into zones; reading sharpness values for every

What is claimed as new and desired to be protected by Letters Patent of the United States is: 1. A method of determining a focus position of a lens structure relative to an imaging sensor, comprising the steps of: dividing a scene imaged by said sensor into zones; reading sharpness values for every zone for each of a predetermined number of lens positions; determining a minimum sharpness value for each zone; determining a maximum sharpness value for each zone; determining a focus position giving the maximum sharpness score for each zone; building a histogram based on the positions providing the maximum sharpness values, wherein the step of building the histogram further comprises the steps of: setting a predetermined threshold value; and incorporating the peak zone sharpness value into the histogram if the difference between the minimum and maximum sharpness value is greater than the threshold value; and determining a focus position in accordance with the contents of said histogram. 2. A method of determining a focus position of a lens structure relative to an imaging sensor, comprising: dividing a scene imaged by said sensor into zones; reading sharpness values for every zone for each of a predetermined number of lens positions; determining a minimum sharpness value for each zone; determining a maximum sharpness value for each zone; determining a focus position giving the maximum sharpness score for each zone; building a histogram based on the positions providing the maximum sharpness values; determining a focus position in accordance with the contents of said histogram; setting the lens structure relative to the sensor to the position corresponding to the position of the histogram with the peak sharpness value; and moving the position of the sensor relative to the lens structure. 3. A method of determining a focus position of a lens structure relative to an imaging sensor comprising: dividing a scene imaged by said sensor into zones; assigning a predetermining weight for each of said zones; determining a minimum sharpness value for each zone; determining a maximum sharpness value for each zone; determining a focus position giving the maximum sharpness score for each zone; generating a histogram based on the positions providing the maximum sharpness values, further comprising the steps of: calculating the difference between each minimum and maximum sharpness values for each zone and comparing the difference to a predetermined threshold; if the calculated difference is larger than the predetermined threshold, adding to the histogram the predetermined weight for the zone; and determining the position in the histogram with the largest value, wherein the lens structure relative to the sensor corresponding to the largest value is the best focus position for the lens structure. 4. The method according to claim 3, further comprising the step of automatically focusing said imaging device by setting the lens structure relative to the sensor corresponding to said best focus position. 5. A method of determining a focus position of a camera lens structure relative to an image sensor location comprising: dividing an image scene into a plurality of zones, each zone comprising a plurality of pixels; determining the best focus position for each of said plurality of zones; and identifying a best focus position satisfying a maximum number of zones. 6. The method according to claim 5, further comprising the step of auto focusing the lens by setting the lens structure relative to the sensor to the best focus position. 7. The method according to claim 4, further comprising the steps of: setting predetermined weights for each zone; and incorporating the predetermined zone weights into the histogram. 8. An apparatus for determining the best relative focus position of a lens structure and image sensor, said apparatus comprising: a sensor for sensing an image through said lens structure; and a controller system coupled to said sensor for receiving an image and determining said best focus position, said controller system operating to: divide an image scene into a plurality of zones, each zone comprising a plurality of pixels; determine a best focus position for each of said plurality of zones; and identify the best focus position satisfying a maximum number of zones. 9. The apparatus of claim 8, wherein the controller system further operates to set the lens to the best focus position. 10. The apparatus of claim 9, wherein the controller system further operates to: set predetermined weights for each of said plurality of zones; and incorporate the predetermined zone weights into the identification of the zone with the best focus position. 11. The apparatus of claim 9, wherein the controller system further operates to move the position of at least one lens of the lens structure relative to the sensor. 12. The apparatus of claim 9, wherein the controller system further operates to move the position of the sensor relative to the lens structure. 13. An apparatus comprising: a processor; and a program for operating said processor to: divide a scene imaged by a sensor into a plurality of zones, each zone comprising a plurality of pixels; determine a best focus position for each of said plurality of zones; and identify the best focus position satisfying a maximum number of zones. 14. The apparatus of claim 13, wherein the program further operates to set the lens to the best focus position. 15. The apparatus of claim 14, wherein the program further operates to: set predetermined weights for each of said plurality of zones; and incorporate the predetermined zone weights into the identification of the best focus position. 16. The apparatus of claim 14, wherein the program further operates to move the position of at least one lens of the lens structure relative to the sensor. 17. The apparatus of claim 14, wherein the program further operates to move the position of the sensor relative to the lens structure. 18. A storage medium comprising: a program for operating a processor to determine a relative focus position of a lens structure and image sensor, said program causing said processor to: divide an image scene into a plurality of zones, each zone comprising a plurality of pixels; determine a best focus position for each of said plurality of zones; and identify the best focus position satisfying a maximum number of zones. 19. The storage medium of claim 18, wherein the program further operates to set the lens to the best focus position. 20. The storage medium of claim 19, wherein the program further operates to: set predetermined weights for each of said plurality of zones; and incorporate the predetermined zone weights into the identification of the best focus position. 21. The storage medium of claim 19, wherein the program further operates to move the position of at least one lens of the lens structure relative to the sensor. 22. The storage medium of claim 19, wherein the program further operates to move the position of the sensor relative to the lens structure.