Cylindrical panoramas

1Jana Kosecka, CS 223b

Cylindrical panoramasCylindrical panoramas

Jana Kosecka, CS 223b2

Rotation Only - Calibrated Rotation Only - Calibrated CaseCase

Calibrated Two views related by rotation only

Mapping to a reference view – rotation can be estimated

Mapping to a cylindrical surface

Jana Kosecka, CS 223b3

Matching SIFT FeaturesMatching SIFT Features

[Brown 2003]

Jana Kosecka, CS 223b4

Reject Outliers using RANSACReject Outliers using RANSAC

[Brown 2003]

Jana Kosecka, CS 223b5

Stitching ImagesStitching Images

[Brown 2003]

Jana Kosecka, CS 223b6

Do we have to project on to a Do we have to project on to a plane ?plane ?

Camera Center

Jana Kosecka, CS 223b7

Cylindrical ProjectionCylindrical Projection

Camera Center

360˚ Panorama [Szeliski & Shum 97]

Jana Kosecka, CS 223b8

Map 3D point (X,Y,Z) onto cylinder

Cylindrical projectionCylindrical projection

XY

Z

unit cylinder

unwrapped cylinder

Convert to cylindrical coordinates

cylindrical image

Convert to cylindrical image coordinates

Jana Kosecka, CS 223b9

Cylindrical ProjectionCylindrical Projection

Y

X

Jana Kosecka, CS 223b10

Inverse Cylindrical projectionInverse Cylindrical projection

X

YZ

(X,Y,Z)

(sin,h,cos)

Jana Kosecka, CS 223b11

Removing SeamsRemoving Seams

Differences in exposure Vignetting Small misalignments

[Brown 2003]

Jana Kosecka, CS 223b12

Multi-band BlendingMulti-band Blending

[Burt and Adelson 1983] Multi-resolution technique using image

pyramid Hides seams but preserves sharp detail

[Brown 2003]