Multi-modal object signature

A method for tracking an object in an image sequence, wherein a track associated with said image sequence is associated with a track signature, said track signature comprising a plurality of modes, said method comprising the steps of:

• detecting said object in a frame of said image sequence;
• associating said detected object with a representative signature;
• determining a spatial difference between said track and said detected object;
• determining, for each mode of said track signature, a visual difference between said mode of said track signature and said representative signature to obtain a lowest determined visual difference;
• selecting a best mode of said track signature, said best mode being associated with producing said lowest determined visual difference;
• associating said detected object with said track and updating said best mode using said representative signature of said detected object, if a sum of said spatial difference and said lowest determined visual difference is less than a combined difference threshold;
• and
• associating said detected object with said track and adding a new mode to said track signature based on said representative signature, if:
• (i) a sum of said spatial difference and said lowest determined visual difference is greater than or equal to a combined difference threshold, and
• (ii) said spatial difference is less than a spatial difference threshold.

A method for tracking an object in an image sequence, wherein a track associated with said image sequence is associated with a track signature, said track signature comprising multiple regions, each of said regions comprising multiple modes, said method comprising the steps of:

• detecting said object in a frame of said image sequence;
• associating said detected object with a representative signature comprising multiple regions, wherein each of said multiple regions of said track signature corresponds to one of said multiple regions of said representative signature of said detected object;
• determining a spatial difference between said track and said detected object;
• determining, for each mode of each of said multiple regions of said track signature, a visual difference between said mode of the track signature and a corresponding region of said representative signature to obtain a lowest determined visual difference for each of said multiple regions;
• and
• if at least one of:
• (i) said spatial difference is less than a spatial difference threshold, and
• (ii) for each of said multiple regions, a sum of said spatial difference and said lowest visual difference of said each of said multiple regions is less than a combined difference threshold,
• performing the steps of:
• associating said detected object with said track;
• for each of said multiple regions, processing each region of said multiple regions in turn, where said processing comprises:
• selecting a best mode of said region of said track signature, the best mode being associated with producing said lowest determined visual difference for the region;
• updating a best mode of said region using said representative signature of said detected object, if a sum of said spatial difference and said lowest visual difference of said region is less than a combined difference threshold;
• and
• adding a new mode to said region of said track signature based on said representative signature, if a sum of said spatial difference and said lowest visual difference of said region is greater than or equal to a combined difference threshold.

A method for tracking an object in an image sequence, wherein a track associated with said image sequence is associated with a track signature, said track signature comprising multiple regions, each of said regions comprising multiple modes, the method comprising the steps of:

• detecting said object in a frame of said image sequence, a representative signature being associated with said detected object and comprising multiple regions, wherein each of said multiple regions of said track signature corresponds to one of said multiple regions of said representative signature of said detected object;
• determining a spatial difference between said track and said detected object,
• determining, for each mode of each of said multiple regions of said track signature, a visual difference between said mode of the track signature and a corresponding region of said representative signature to obtain a lowest determined visual difference for each of said multiple regions;
• and
• utilizing said spatial difference and said lowest determined visual difference for each of the multiple regions to perform at least one of:
• (i) associating said detected object with said track;
• and (ii) adding a new mode, based on said representative signature, to selected regions of said track signature.

A system for tracking an object in an image sequence, wherein a track associated with said image sequence is associated with a track signature, said track signature comprising a plurality of modes, said system comprising:

• a storage device for storing a computer program;
• and
• a processor for executing the program, said program comprising:
• code for detecting said object in a frame of said image sequence, a representative signature being associated with said detected object, and
• code for determining a spatial difference between said track and said detected object;
• code for determining, for each mode of said track signature, a visual difference between said mode of said track signature and said representative signature to obtain a lowest determined visual difference;
• and
• code for utilizing said spatial difference and said lowest determined visual difference to perform at least one of:
• (i) associating said detected object with said track, and (ii) adding a new mode, based on said representative signature, to said track signature.

A computer readable storage medium having recorded thereon a computer program for tracking an object in an image sequence, wherein a track associated with said image sequence is associated with a track signature, said track signature comprising a plurality of modes, said computer program comprising code for performing the steps of:

• detecting said object in a frame of said image sequence;
• associating said detected object with a representative signature;
• determining a spatial difference between said track and said detected object;
• determining, for each mode of said track signature, a visual difference between said mode of said track signature and said representative signature to obtain a lowest determined visual difference;
• and
• utilizing said spatial difference and said lowest determined visual difference to perform at least one of the following steps of:
• (i) associating said detected object with said track, and (ii) adding a new mode, based on said representative signature, to said track signature.

A computer readable storage medium having recorded thereon a computer program for tracking an object in an image sequence, wherein a track associated with said image sequence is associated with a track signature, said track signature comprising a plurality of modes, said computer program comprising code for performing the steps of:

• detecting said object in a frame of said image sequence;
• associating said detected object with a representative signature;
• determining a spatial difference between said track and said detected object;
• determining, for each mode of said track signature, a visual difference between said mode of said track signature and said representative signature to obtain a lowest determined visual difference;
• selecting a best mode of said track signature, said best mode being associated with producing said lowest determined visual difference;
• associating said detected object with said track and updating said best mode using said representative signature of said detected object, if a sum of said spatial difference and said lowest determined visual difference is less than a combined difference threshold;
• and
• associating said detected object with said track and adding a new mode to said track signature based on said representative signature, if:
• (i) a sum of said spatial difference and said lowest determined visual difference is greater than or equal to a combined difference threshold, and
• (ii) said spatial difference is less than a spatial difference threshold.

A computer readable storage medium having recorded thereon a computer program for tracking an object in an image sequence, wherein a track associated with said image sequence is associated with a track signature, said track signature comprising multiple regions, each of said regions comprising multiple modes, said computer program comprising code for performing the steps of:

• detecting said object in a frame of said image sequence;
• associating said detected object with a representative signature comprising multiple regions, wherein each of said multiple regions of said track signature corresponds to one of said multiple regions of said representative signature of said detected object;
• determining a spatial difference between said track and said detected object;
• determining, for each mode of each of said multiple regions of said track signature, a visual difference between said mode of the track signature and a corresponding region of said representative signature to obtain a lowest determined visual difference for each of said multiple regions;
• and
• if at least one of:
• (i) said spatial difference is less than a spatial difference threshold, and
• (ii) for each of said multiple regions, a sum of said spatial difference and said lowest determined visual difference of said each of said multiple regions is less than a combined difference threshold,
• performing the steps of:
• associating said detected object with said track;
• for each of said multiple regions, processing each region of said multiple regions in turn, where said processing comprises:
• selecting a best mode of said region of said track signature, which is associated with producing said lowest determined visual difference for the region;
• updating a best mode of said region using said representative signature of said detected object, if a sum of said spatial difference and said lowest determined visual difference of said region is less than a combined difference threshold;
• and
• adding a new mode to said region of said track signature based on said representative signature, if a sum of said spatial difference and said lowest determined visual difference of said region is greater than or equal to a combined difference threshold.