Method and apparatus for detecting and characterizing an object

A system for detecting an object, and determining a mark count of the object, comprising:

• a conveyer, having motion relative to a two-dimensional field of view, that transports the object;
• an input device that receives an encoding signal responsive to the motion of the conveyer, from which can be obtained at desired times a corresponding encoder count indicating a relative location of the conveyer;
• an image capture device that captures a plurality of frames, each frame of the plurality of frames comprising an image of the two-dimensional field of view;
• and
• an analyzer that
• chooses, responsive to a first analysis of the plurality of frames, a plurality of active frames from the plurality of frames, such that the first analysis indicates sufficient evidence that the object is located in the field of view for each frame of the plurality of active frames;
• obtains a plurality of capture counts corresponding to the plurality of active frames, each capture count of the plurality of capture counts being responsive to the encoder count corresponding to a time at which the corresponding active frame was captured;
• computes, responsive to a second analysis of the plurality of active frames, a plurality of location values, each location value of the plurality of location values responsive to a position of the object in the field of view in an associated active frame as computed by the second analysis;
• determines the mark count of the object using the plurality of location values and the plurality of capture counts, wherein the a mark count indicates the encoder count corresponding to a time when the object was located at a fixed mark point;
• and
• an output signaler that indicates a location of the object by producing a signal at a report time that occurs when the corresponding encoder count differs from the mark count by a delay count.

A system for computing a mark count of an object transported by a transport medium, the transport medium in relative motion to a two-dimensional field of view, the object comprising a set of visible features, the set of visible features containing at least one visible feature;

• the system comprising:
• a data processing device programmed to:
• receive an encoder signal responsive to the relative motion of the transport medium, from which is obtained an encoder count indicating a relative location of the transport medium;
• receive a plurality of active frames, each frame of the plurality of active frames comprising an image of the two-dimensional field of view;
• obtain a plurality of capture counts corresponding to the plurality of active frames, each capture count of the plurality of capture counts being responsive to the encoder count corresponding to a time at which the corresponding active frame was captured;
• compute a plurality of location values based on the plurality of active frames, each location value of the plurality of location values responsive to a position of a visible feature of the set of visible features of the object in an associated active frame;
• and
• compute the mark count of the object using at least a portion of the plurality of location values and at least a portion of the plurality of capture counts, wherein the mark count indicates the encoder count corresponding to a time when the object was located at a fixed mark point;
• and
• providing a value responsive to the mark count for consumption by an i/o module, wherein the i/o module uses the value responsive to the mark count to selectively signal a location of the object at a report time that occurs when the encoder count differs from the mark count by a delay count.

A computer program product to compute a mark count of an object transported by a transport medium, the transport medium in relative motion with a two-dimensional field of view, the object comprising a set of visible features, the set of visible features containing at least one visible feature, the product tangibly embodied in a non-transitory computer readable medium, the computer program product comprising instructions being operable to cause a data processing apparatus to:

• receive, an encoder signal responsive to the relative motion of the transport medium from which is obtained an encoder count indicating a relative location of the transport medium;
• receive a plurality of active frames, each frame of the plurality of active frames comprising an image of the two-dimensional field of view;
• obtain a plurality of capture counts corresponding to the plurality of active frames, each capture count of the plurality of capture counts being responsive to the encoder count corresponding to a time at which the corresponding active frame was captured;
• compute a plurality of location values based on the plurality of active frames, each location value of the plurality of location values responsive to a position of a visible feature of the set of visible features of the object in an associated active frame;
• and
• compute the mark count of the object using at least a portion of the plurality of location values and at least a portion of the plurality of capture counts, wherein the mark count indicates the encoder count corresponding to a time when the object was located at a fixed mark point;
• and
• providing a value responsive to the mark count for consumption by an i/o module, wherein the i/o module uses the mark count to selectively signal a location of the object at a report time that occurs when the encoder count differs from the mark count by a delay count.