Solving Visibility with Epipolar Geometry TienTsin Wong Chinese

Solving Visibility with Epipolar Geometry Tien-Tsin Wong Chinese University of Hong Kong

View Interpolation z Given the reference images z Synthesize the (desired) image in between Tien-Tsin Wong (Nov. 1999)

View Interpolation (2) z Two sub-problems: y. Where should pixels be moved to? • Depth • Correspondences or optical flows y. Visibility Tien-Tsin Wong (Nov. 1999)

Visibility z Traditional solution: depth-buffering z Depths may not be available (especially in real image) z Can we solve the visibility without depth? z Epipolar geometry Tien-Tsin Wong (Nov. 1999)

Epipolar Geometry z p. Consider another p 1 two only pixel when i 2 p 1, p 2 & e are Configuration of cameras 2 will occlude coplanar, colinear and p 2 is in between Reference image Reference camera Desired image Desired camera Tien-Tsin Wong (Nov. 1999)

Epipolar Geometry (2) z If Although always we draw know i 1 before where iocclude are correct p 1 each & p 2 other, , visibility their the projection is Towe Only identify pixels ondon’t thepotentially same epipolar line may occlude each 2, the on the epipolar determines the visibility (e. g. i 1 willto epipolar other ensured plane without isline knowing intersected thewith depth the information reference image never occludes give the epipolari 2)line Epipolar plane positive epipole Tien-Tsin Wong (Nov. 1999)

Pattern of Drawing Order z By intersecting the epipolar planes with the reference image, a pattern of drawing order can be obtained Tien-Tsin Wong (Nov. 1999)

Pattern of Drawing Order z A diverging pattern is formed if the direction of the epipolar ray reverses. Tien-Tsin Wong (Nov. 1999)

Pixel-based Drawing Order z In fact, there are only three kinds of patterns Tien-Tsin Wong (Nov. 1999)

Results Reference image Desired image z Foreground To illustrate the surface ordering, should thebetriangle brightershould be drawn earlier is shaded in darker color. Tien-Tsin Wong (Nov. 1999)

The End Tien-Tsin Wong (Nov. 1999)