The 2D Illusion of Attic
Tien-Tsin Wong, Chi-Wing Fu and Pheng-Ann Heng.
"The 2D Illusion of Attic",
Technical Slide,
SIGGRAPH'99.
Image
Description
McMillian proposed an image warping technique for view interpolation. It can
correctly resolve the visibility problem (several pixels mapped to the same
location) WITHOUT DEPTH BUFFERING. The problem is solved by drawing pixel in
some order. However it works for warping pixel-sized entities only. Hence it
is computationally intensive. Instead of warping image in a pixel-by-pixel
manner, we have developed an efficient warping technique which warps image
in a triangle-by-triangle manner. It is based on epipolar geometry. The
visibility is solved by drawing arbitrary-sized triangles in a specific
order while no depth-buffering is required. The drawing order is determined
by the linear-time O(n) topological sort. The technique is first applied to
warp a given perspective image. The upper left image is the reference
perspective image. The correctness can be verified by the lower left image
(warped attic scene). Note how the front trunk occludes the barrel. The
right column shows the corresponding triangulation and the drawing order.
The darker the color of the triangle is, the earlier the triangle should be
drawn. The upper right image shows a random drawing order (random darkness)
because the drawing order is irrelevant for the original image.
Hardware: Any UNIX platform.
Software: Experimental image warping prototype
