# Some Useful Definitions

Term | Definition
--- | ---
affine rectangle | A quadrilateral where the opposite sides are parallel to each other
edge mode | Feature detection based on locating edges or edge peaks within the run-time image.
edge model | Template for the edge pattern that you are searching for with the Caliper tool.
edge pattern candidate | Edge pattern within the run-time image that is being evaluated for its similarity to the edge pattern described by the edge model.
interpolation | Method of estimating the grey-level value of a sub-pixel location in an image based on the pixel values surrounding the location
peak | Maximum or minimum in the value of a function or a plot of values; a maximum is a positive peak; a minimum is a negative peak.
projection | Reduction of a two-dimensional array of pixels to a one-dimensional array of pixels. A projection is formed by summing the pixel values along a ray within the projection region.
ray | Line drawn in the direction of a projection along which pixel values are summed.
rotation | The turning of a rectangle about an axis point
score | Measure of the similarity between an edge pattern candidate found by the Caliper tool and an edge model.
scoring function | Function that maps input values to output values within a fixed range.
scoring method | Procedure for evaluating the degree of similarity between an edge pattern candidate and an edge model.
skew | The distortion of a rectangle into a parallelogram