Patent ID: 6064760
Filing Date: 2000-05-16
Classification: G01C

Abstract:
A method for reshaping of a pair of overlapping digital images using a Digital Photogrammetric Workstation (DPW), said method comprising the steps of:importing said digital images into said DPW as an overlapping-pair of originally distorted images having an associated sensor model;triangulating said distorted images in said DPW to adjust sensor parameters within said distorted images;creating orthophotos as a pair of equivalent vertical frame images from said distorted images according to a sensor model and formula of exact projective computations onto a flat terrain matrix reference plane and rotating said distorted images for alignment during said creating step;determining interior orientation coordinates for each equivalent vertical frame image plane of said orthophotos, and finding a focal position and length of the frame-ortho image that creates a scalar similar to the scalar of the originally distorted image;importing said orthophotos as a pair of overlapping equivalent vertical frame images according to said interior orientation coordinates;generating a digital terrain matrix in said DPW using said equivalent vertical frame images; andcreating an orthophoto using said digital terrain matrix to remove measured terrain displacement, wherein said determining step comprises calculating said interior orientation coordinates according to following equationsx.sub.i =S(X.sub.I -X.sub.0)=S(FOOTPRINT(X.sub.I)-LSRCAMERA(X.sub.0)); andy.sub.i =S(Y.sub.I -Y.sub.0)=S(FOOTPRINT(Y.sub.I)-LSRCAMERA(Y.sub.0)),whereinS=f1/(LSRCAMERA(Z.sub.0)-Z)where:FOOTPRINT (X.sub.I) and FOOTPRINT (Y.sub.I) are the measured X and Y coordinates of each corner point in Cartesian coordinates of the terrain matrix reference plane of and x.sub.i and y.sub.i are the corresponding corner points derived for the equivalent vertical frame-ortho image plane, where each image plane is parallel to the flat DTM reference plane;LSRCAMERA (X.sub.o) LSRCAMERA (Y.sub.o) and LSRCAMERA (Z.sub.o) are actual determined X, Y and Z coordinates of a focal position from the originally distorted image;fl is a desired focal length of the equivalent vertical frame-ortho image that matches the actual focal length of the actual sensor marked for each originally distorted image when each was exposed; andS is an image scalar, which depends on the desired focal length and determined focal position with respect to the flat DTM elevation of Z, LSRCAMERA (Z.sub.0)-Z in the equivalent vertical frame-ortho image, where the image scalar approximates that of the originally distorted image to resolve the remaining terrain displacements left within the equivalent vertical frame-ortho image.