Method for unambiguous range estimation

A method of unambiguous range estimation for use with a range imaging system that generates phase images corresponding to range information derived from image pixels of a digital image, said method comprising the steps of:

• (a) generating a first phase image having one or more ambiguous phase intervals, wherein image pixels of the first phase image include a phase term that is derived from an algorithm operating on one or more images captured by the range imaging system;
• (b) generating at least one additional phase image by including a phase shift in the algorithm that perturbs the phase intervals of the first phase image;
• (c) identifying at least one region of intersection between at least one phase interval in the first phase image and at least one perturbed phase interval in the additional phase image;
• and
• (d) adjusting the phase of at least one of the ambiguous phase intervals in the first phase image based on values of the phase of the image pixels that belong to the region of intersection, whereby the phase adjustment unwraps the phase ambiguity in one or more of the ambiguous phase intervals of the first phase image.

A method for unambiguous range estimation for use with a range imaging system that generates an original ambiguous phase image having ambiguous phase intervals corresponding to range information derived from image pixels of a digital image, said method comprising the steps of:

• (a) generating first and second phase images from the original ambiguous phase image by respectively shifting the ambiguous phase intervals by first and a second phase shifts, wherein the first phase shift in the first phase image is less than the second phase shift in the second phase image;
• (b) identifying ambiguity regions in the first and second phase images, wherein each phase image is represented as a union of mutually exclusive ambiguity regions;
• (c) selecting a first ambiguity region in the first image that contains unwrapped phase values;
• (d) selecting an ambiguity region in the second phase image that overlaps both the first and a second ambiguity region in the first phase image;
• and
• (e) adjusting the phase of the second ambiguity region in the first phase image based on the values of the pixels that belong to a region of intersection between the ambiguity region in the second phase image and the second ambiguity region in the first phase image, whereby the phase values are unwrapped in the second ambiguity region in the first phase image.

A computer program product for unambiguous range estimation in a range imaging system that generates phase images corresponding to range information derived from image pixels of a digital image, said computer program product comprising a computer readable storage medium having a computer program stored thereon for performing the steps of:

• (a) generating a first phase image having one or more ambiguous phase intervals;
• (b) generating at least one additional phase image by shifting the phase intervals of the first phase image;
• (c) identifying at least one region of intersection between phase intervals in the two phase images;
• and
• (d) adjusting the phase of at least one of the ambiguous phase intervals in the first phase image based on values of the phase of the image pixels that belong to the region of intersection, whereby the phase adjustment unwraps the phase ambiguity in one or more of the ambiguous phase intervals of the first phase image.

A range imaging system capable of unambiguous range estimation, said system comprising:

• (a) a range imaging apparatus that generates phase images corresponding to range information derived from image pixels of a digital image;
• (b) means for generating a first phase image having one or more ambiguous phase intervals;
• (c) means for generating at least one additional phase image by shifting the phase intervals of the first phase image;
• (d) means for identifying at least one region of intersection between phase intervals in the two phase images;
• and
• (e) means for adjusting the phase of at least one of the ambiguous phase intervals in the first phase image based on values of the phase of the image pixels that belong to the region of intersection, whereby the phase adjustment unwraps the phase ambiguity in one or more of the ambiguous phase intervals of the first phase image.