Morphing is a digital image and video manipulation technique that creates a smooth, seamless transformation between two different images by gradually blending one into the other through a series of intermediate transition frames. The term is a contraction of metamorphosing, reflecting the shape shifting transformation that the technique produces, and the results - when well executed - create the compelling visual illusion of one subject or object physically and continuously changing its form to become something entirely different.
The morphing process typically requires the user to define a set of corresponding reference points or mapped regions on both the source and destination images, identifying pairs of features in each image that correspond to one another - for example, mapping the eyes, nose, mouth, and outline of one face to the equivalent features of a second face. The morphing software analyses these user defined correspondences and calculates a series of intermediate images in which the pixel positions, shapes, and colours of the source image are progressively warped and blended towards those of the destination image, with each intermediate frame representing a slightly more advanced stage of the transformation. The smooth progression of warping and colour blending across the sequence of frames produces the characteristic fluid, organic quality of a well executed morph.
Morphing became widely available as a consumer and professional digital imaging technique during the early 1990s, when dedicated morphing software packages brought the technology - previously the exclusive domain of high end film and broadcast visual effects studios - within reach of desktop computer users. The technique was rapidly adopted by the media, advertising, and entertainment industries for a wide range of creative applications, from music videos and film special effects to television commercials and magazine features. One of its most enduring popular applications has been the creation of speculative composite portraits showing what the theoretical offspring or combination of two famous people might look like, produced by morphing between their respective facial photographs to generate a blended intermediate image that incorporates facial features from both subjects.
In the film and television industry, morphing has been used to create some of the most memorable visual effects sequences of the modern era, enabling actors to transform into other characters or creatures, objects to change shape fluidly on screen, and seamless transitions between different scenes or time periods to be achieved with a visual elegance that earlier optical effects techniques could not match. The technique remains a standard tool in the digital visual effects workflow, now implemented within sophisticated compositing and visual effects software packages that offer far greater control, precision, and integration with other effects techniques than the early dedicated morphing applications of the 1990s.