1. A rapid and high precision centroiding method for determining a centroid of each spot in an image comprising one or more spots, the method comprising: for each pixel in the image, calculating a gray value of the pixel using a Gaussian convolution; when the calculated gray value does not exceed a predetermined threshold, marking the pixel with a zero; when the calculated gray value exceeds the predetermined threshold, marking the pixel with a flag, the flag equal to the first non-zero value of a flag of a left adjacent pixel, a flag of an upper adjacent pixel, and a new flag; calculating a product of the gray value and a coordinate value of pixel, merging the flags for pixels within the one or more spots by, for each flag on each pixel, determining whether the flag is an equivalent flag to the flag of another pixel, and, for each flag determined to be an equivalent flag, changing the value of the flag to be the same as the flag of the another pixel, thereby marking the pixels of each of the one or more spots with a flag of a common value, the common flag value being different from the common flag value of each other of the one or more spots; for each of the one or more spots and each flag value after the merging step, calculating a centroid of the spot by, for each flag value after the merging step, calculating a first sum of a product of the gray value and a coordinate value of each pixel having a common flag value; calculating a second sum of the gray value of each pixel having the common flag value; and saving the results in the data buffer, when all pixels of the image have been disposed completely, for each of the one or more spots, calculating a centroid of the spot by calculating a quotient of the first sum and the second sum; and outputting the quotients as centroid coordinates of each spot image.