Patent ID: 11915435
Assignee: RAYTHEON COMPANY
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 14:
15. A method of image cross correlation to detect moving vehicles, comprising:
receiving a single multi-band image including a first set of band images and a second set of band images collected with a time lag relative to the first set;
forming first and second pseudo-pan images as a weighted average of one or more band images in the first set and a weighted average of one or more band images in the second set, respectively,
segmenting the first pseudo-pan image into a plurality of local template windows; for each local template window,
a) correlating each local template window to a larger search window in the second pseudo-pan image to produce a correlation surface;
b) extracting at least one pair of correlation offsets X and Y from the correlation surface for each template window, said correlation offsets X and Y being real numbers including fractional portions capable of representing fractional offsets;
c) rejecting correlations where the correlation offsets X and Y are less than a first threshold;
d) resampling the pixel values within the local template window of the first pseudo-pan image or the search window of the second pseudo-pan image using the fractional portions of the X and Y correlation offsets;
e) using the resampled pixel values to correlate the local template window in the first pseudo-pan image to the search window in the second pseudo-pan image to produce a resampled correlation surface; and
f) computing a Figure of Merit (EOM) for a peak in the resampled correlation surface; and
g) removing those correlations whose FOM is less than a second threshold with the remaining correlations detecting moving vehicles in the single multi-band image.