Surface extraction from a three-dimensional data set

A method for constructing an image of a surface from a volumetric set of signals representing data value numbers, the volumetric set described by a Cartesian coordinate system having X, Y, and Z axes such that each number has a unique location, the volumetric set comprising at least one linear set of signals representing data value numbers arranged parallel to the Z axis, the method comprising the steps of:

• generating, for each linear set of signals, a first signal representing a maximum data value number and a second signal representing a location of the maximum data value number, thereby producing a set of signals representing maximum data value numbers and a set of signals representing maximum-number locations, the step of generating comprising the steps of:
• comparing a third signal in the linear set to a fourth signal in the linear set to determine which of the third and fourth signals represents a greater data value number;
• storing the one of said third and fourth signals representing the greater data value number as said first signal representing a maximum number for the linear set and storing the location associated with the one of said third and fourth signals representing the greater data value number as said second signal representing a maximum-number location for the linear set;
• and
• for each signal in the linear set other than the third and fourth signals,
• comparing the signal to the first signal to
• determine which of the signal and the first
• signal represents a greater data value number;
• storing the one of said signal and said
• first signal as the new first signal and storing
• the signal representing the one of said signal
• and said first signal as said second signal;
• and
• creating the image using the set of signals representing maximum data value numbers and the set of signals representing maximum-number locations.