An affine transformation is a mathematical concept commonly used in computer graphics and image processing. The word "affine" is pronounced /əˈfaɪn/ and spelled with two "f"s and one "i". The first syllable is pronounced as a schwa sound, followed by "fai" which is pronounced like "fie" with an "a" sound. The word "affine" derives from the Latin word "affinis" meaning "related". In mathematics, an affine transformation preserves collinearity, parallelism, ratios of lengths, and barycentric coordinates, making it a useful tool in various fields.
An affine transformation is a mathematical transformation that preserves parallelism and ratios of distances between collinear points while allowing for modifications of position, rotation, scaling, shearing, and reflection of objects in a plane or space. It is a type of geometric transformation commonly used in computer graphics, computer vision, and linear algebra.
In a more precise definition, an affine transformation is a function that maps one set of geometric points onto another set of points, typically in a coordinate space. It is composed of a linear transformation followed by a translation. The linear transformation preserves the structure of objects, such as straight lines or parallel lines, without altering their lengths or angles. The translation shifts the entire coordinate system.
Mathematically, an affine transformation can be represented using a matrix multiplication and vector addition. The transformation matrix contains the scaling, shearing, and rotation components, while the translation vector defines the displacement of the object. By applying different values to the transformation parameters, various modifications can be achieved, enabling the transformation to rotate, scale, or translate an object in different ways.
Overall, affine transformations provide a fundamental tool for altering the position and orientation of geometric objects, preserving their relative shapes and proportions. They play a vital role in various fields, including computer graphics, image processing, robotics, and physics simulations.
The word "affine" comes from the Latin word "affinis", which means "related" or "connected". It entered English in the mid-16th century, deriving from the French word "affiner", which means "to refine".
In mathematics, the term "affine transformation" was first used by the French mathematician Arthur Cayley in the late 19th century. It refers to a transformation that preserves collinearity (the property of lying on the same line) and ratios of distances between points. The term "affine" conveys the idea of a logical connection between points or an association between related elements, illustrating the relationship preserved by this transformation.