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Other projections are possible

  • You can stitch on the plane and then warp the resulting panorama

    • What’s the limitation here?

  • Or, you can use these as stitching surfaces

    • But there is a catch…

What s your focal length, buddy?

  • Focal length is (highly!) camera dependant

  • Can get a rough estimate by measuring FOV:

    • Can use the EXIF data tag (might not give the right thing)

    • Can use several images together and try to find f that would make them match

    • Can use a known 3D object and its projection to solve for f

    • Etc.

  • There are other camera parameters too:

    • Optical center, non-square pixels, lens distortion, etc.

Radial distortion

  • Correct for “bending” in wide field of view lenses

Use this instead of normal projection

Cylindrical reprojection

top-down view

Focal length – the dirty secret…

Image 384x300

f = 180 (pixels)

f = 280

f = 380

Distortion

No distortion

Pin cushion

Barrel

  • Radial distortion of the image

    • Caused by imperfect lenses

    • Deviations are most noticeable for rays that pass through the edge of the lens

Blending the mosaic

An example of image compositing: the art (and sometime science) of combining images together…

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