Image matching using resolution pyramids with geometric constraints

A computer program for matching a first image to a second image, said first image overlapping said second image, embodied in a computer readable medium, the computer program comprising instructions for:

• (a) generating a first set of working layers of said first image, said first set of working layers comprising a plurality of working layers having successively increasing resolutions from a first working layer having the coarsest resolution to a last working layer having the finest resolution;
• (b) generating a second set of working layers of said second image, said second set of working layers comprising a plurality of working layers having successively increasing resolutions from a first working layer having the coarsest resolution to a last working layer having the finest resolution;
• (c) determining using correlation an overlap region between said first working layer of said first image and said first working layer of said second image, said overlap region being defined by translational displacement parameters only;
• (d) selecting said first working layer of said first image;
• (e) selecting a plurality of feature points in said first working layer of said first image;
• (f) determining from within a plurality of attention areas and using the translational displacement parameters a plurality of positions in said first working layer of the second image corresponding to said plurality of feature points in said first image;
• (g) determining motion parameters based on said plurality of feature points and said plurality of positions, said motion parameters describing the positional relationship between said first working layer of said first image and said first working layer of said second image;
• (h) selecting a next working layer in said first set of working layers of said first image, the next working layer being a working layer with the next higher resolution than said first working layer;
• (i) selecting a second next working layer in said second set of working layers of said second image, the second next working layer having the same resolution as said next working layer of said first image;
• (j) selecting a plurality of feature points in said next working layer of said first image;
• (k) determining from within a plurality of attention areas and using the motion parameters a plurality of positions in said second next working layer of the second image corresponding to said plurality of feature points in said first image;
• (l) determining motion parameters based on said plurality of feature points and said plurality of positions, said motion parameters describing the positional relationship between said next working layer of said first image and said second next working layer of said second image;
• (m) selecting another next working layer in said first set of working layers of said first imaging, the next working layer being a working layer with the next higher resolution than the working layer just processed;
• and
• (n) repeating (i) to (m) using said next working layer of said first image and said second next working layer of said second image until said last working layer of said first image and said last wording layer of said second image have been processed.