Difference between revisions of "Glossary"
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Revision as of 09:30, 16 December 2005
Aliasing - less than optimal resampling that causes "jaggies" and Moire effects.
Alpha channel - an image channel containing a mask or selection.
Angle of View The angle in degrees that a projection covers.
Aspect Ratio - the ratio (proportion) between height and width of an image.
Banding Visible steps in smooth gradients.
Barrel distortion A distortion produced by the lens itself which causes straight lines to be bent outwards.
CCD A type of image sensor used in digital cameras.
Contrast Blending A technique to blend several exposure bracketed images in one image
Cylindrical Projection A projection capable of mapping 360 degrees horizontally by roughly 120 degrees vertically with acceptable distortion.
Depth of Field The distance in front of and behind the focus distance where the image blur is not recognizable.
Dynamic range The ratio in brightness of the brightest highlight to the darkest shadow that are accurately captured in a scene.
Entrance Pupil The special point that you have to rotate your camera around, to avoid parallax errors. Commonly referred to as the Nodal Point, which see for more information.
Equirectangular Projection A projection capable of mapping the entire sphere to a rectangle with 2:1 aspect ratio.
EXIF Exchangeable Image File Format. EXIF data allows camera, lens, exposure information, image description, copyright, etc. to be embedded in an image file.
Field of View The angle in degrees that a projection covers.
Fisheye Projection A projection where the distance from the centre of the image to a point is proportional to the equivalent spatial angle.
Gamma The relation between pixel values and visible brightness.
Halo Bright or dark areas along hard contrast edges introduced by certain image manipulations.
Interpolation A mathematical way to estimate a value in beetween two values. In image processing: The pixel color and brightness in between two pixels.
Landscape Image orientation with the longer side in horizontal direction.
Lens distortion A distortion produced by the lens itself which causes straight lines to be bent in some way.
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.
Nadir The point directly below
Pincushion distortion A distortion produced by the lens itself which causes straight lines to be bent inwards.
Portrait Image orientation with the longer side in vertical direction.
Projections Different possibilities to get a two-dimensional image of the three-dimensional world around us.
PTOptimizer Panorama tools image position and correction parameters optimizer. Script driven.
PTStitcher Main panorama tools stitcher application. Script driven.
Rectilinear Projection A projection in which every straight line in the world stays straight in the image.
Spherical is a panorama format that can contain the whole sphere around the viewer.
Vignetting Light fall-off in the corners of images
Wavy distortion A distortion produced by the lens itself which causes straight lines to be bent in waves.
Zenith The point directly above.