Patent ID: 7916830

Claim:
A method for compressing projection data in a computed tomography system that includes a plurality of sensors providing a plurality of sensor measurements to form one or more sets of projection data for an object, wherein each set includes an array of samples of the projection data, the array having at least one line of samples, wherein each sample has a position in the array indicated by a sample coordinate, the method comprising: detecting a first edge sample and a second edge sample in the line of the array; determining a first boundary coordinate in the line based on the first edge sample and a second boundary coordinate in the line based on the second edge sample; compressing samples having sample coordinates between the first boundary coordinate and the second boundary coordinate to form compressed samples; and encoding the first and second boundary coordinates to form encoded boundaries included with the compressed samples, wherein the step of detecting comprises: calculating differences between consecutive samples in the line of the array to form difference samples, each difference sample having a positive value or a negative value; and comparing the positive difference samples to a positive threshold and the negative difference samples to a negative threshold to determine the first edge sample and the second edge sample, wherein the step of detecting further comprises determining the positive threshold and the negative threshold, further comprising: setting the positive threshold to an initial positive value and the negative threshold to an initial negative value; applying the step of comparing to determine a number of positive difference samples greater than the positive threshold and a number of negative difference samples less than the negative threshold; reducing respective magnitudes of the positive threshold and the negative threshold, if the respective number of difference samples is zero; and repeating the steps of comparing and reducing until the respective number of difference samples is greater than zero to produce the positive threshold and the negative threshold.