National Instruments IMAQTM - Manual (Page 109)

Glossary
IMAQ Vision for Visual Basic User Manual G-12 ni.com
NI-IMAQ The driver software for National Instruments IMAQ hardware.
nonlinear filter Replaces each pixel value with a nonlinear function of its surrounding
pixels.
nonlinear
gradient filter A highpass edge-extraction filter that favors vertical edges.
nonlinear Prewitt filter A highpass, edge-extraction filter based on two-dimensional gradient
information.
nonlinear Sobel filter A highpass, edge-extraction filter based on two-dimensional gradient
information. The filter has a smoothing effect that reduces noise
enhancements caused by gradient operators.
Nth order filter Filters an image using a nonlinear filter. This filter orders (or classifies)
the pixel values surrounding the pixel being processed. The pixel being
processed is set to the Nth pixel value, where N is the order of the filter.
number of planes
(in an image) The number of arrays of pixels that compose the image. A gray-level or
pseudo-color image is composed of one plane, while an RGB image is
composed of three planes (one for the red component, one for the blue,
and one for the green).
O
OCR Optical Character Recognition. The ability of a machine to read
human-readable text.
OCV Optical Character Verification. A machine vision application that inspects
the quality of printed characters.
offset The coordinate position in an image where you want to place the origin of
another image. Setting an offset is useful when performing mask
operations.
opening An erosion followed by a dilation. An opening removes small objects and
smooths boundaries of objects in the image.
operators Allow masking, combination, and comparison of images. You can use
arithmetic and logic operators in IMAQ Vision.