Glossary
Please add the entry alphabetically to the list.
A
B
Banding Visible steps in smooth gradients. Early versions of Panorama Tools software could introduce obvious banding, for example during radial luminance correction as discussed here. This problem is largely corrected in current versions of the software.
C
Cylindrical Projection A projection capable of mapping 360 degrees horizontally by roughly 120 degrees vertically with acceptable distortion. The horizon becomes a straight line across the middle of the image. Vertical lines in the world become vertical (straight) lines in the image; all other straight lines except the horizon become curved. Areas near the poles get stretched both horizontally and vertically, worse vertically. (The poles would map to plus and minus infinity.) See Mathworld for formulas.
D
E
Entrance Pupil The special point that you have to rotate your camera around, to avoid parallax. See Nodal Point for more information.
Equirectangular Projection A projection capable of mapping the entire sphere to a rectangle with 2:1 aspect ratio. The horizon becomes a straight line across the middle of the image; the north pole maps to the top row; the south pole to the bottom row. Vertical lines in the world become vertical (straight) lines in the image; all other straight lines except the horizon become curved. Areas near the poles get stretched horizontally and squashed vertically. Equirectangular projection is excellent for panorama viewers, which "undo" all of these transformations so that the user sees an undistorted image. See Mathworld for formulas.
F
G
H
I
J
K
L
M
N
Nodal Point The special point that you have to rotate your camera around, to avoid parallax. Also called "entrance pupil". Click the term for more info.
O
P
Pitch Angle up-and-down (above and below horizon). See also "roll" and "yaw".
Q
R
Rectilinear Projection A projection in which every straight line in the world stays straight in the image. Stretches both horizontally and vertically away from the center. Limited to roughly 120 degrees field-of-view with acceptable distortion. Geographers call this projection "gnomonic"; see Mathworld for the formulas.
Roll Rotation angle around the lens axis. See also "pitch" and "yaw".
S
T
U
V
W
X
Y
Yaw Panning angle, left-and-right. See also "pitch" and "roll".