transformation-1 A function relating coordinates in one coordinate system to coordinates in another coordinate system. Usually involving translation, rotation, and/or scale change. 2 The process of projecting a photograph (mathematically, graphically, or photographically) from its plane onto another plane by translation, rotation, and/or scale change. When a photograph is transformed to a horizontal plane, so as to remove displacement due to tilt, the process is called “rectification;” however, relief displacement cannot be removed by this process.

transformation, affine—A transformation from one set of coordinates to another, such that, in the geometric representation, straight lines remain straight and parallel lines remain parallel. Angles and scale may change.

transformation, conformal—The transformation of points from one coordinate system to another, in which the original shape is retained. At least two points in each of the two coordinate systems must be known for conformal transformation to be performed.

transformation, two-dimensional conformal coordinate—The process of converting planimetric coordinates in an arbitrary or local coordinate system into state plane coordinates, and retaining the true shape of the coordinates.

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Source: NSPS “Definitions of Surveying and Related Terms“, used with permission.

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