The reflection operator geometrically transforms an image such that image elements, i.e. pixel values , located at position in an original image are reflected about a user-specified image axis or image point into a new position in a corresponding output image. Reflection is mainly used as an aid to image visualization, but may be used as a preprocessing operator in much the same way as rotation .
Reflection is a special case of affine transformation .
How It Works Reflection can be performed about an image axis or a point in the image. Note that if is not in the center of the input image, part of the image will be reflected out of the visible range of the image. Most implementations fill in image areas out of which pixels have been reflected with black pixels. The simplest reflection we can define reflects an image about an axis located in the center of an image. For example, we can reflect about a vertical axis in the center of the image to produce Similarly, shows the reflection of about a horizontal axis passing through the image center.