IMAGE MORHING

In modern industry We want to change one image into another through a seamless transition for example suppose we want to turn one person into another through technological means or as part of a fantasy or surreal sequence so we need a special effect in motion pictures and animations which is known as morphing. Traditionally such a depiction would be achieved through cross-fading techniques on film. Since the early 1990s, this has been replaced by computer software to create more realistic transitions.

Morphing is an image processing technique used for the metamorphosis from one image to another. The idea is to get a sequence of intermediate images which when put together with the original images would represent the change from one image to the other. The simplest method of transforming one image into another is to cross-dissolve between them. In this method, the color of each pixel is interpolated over time from the first image value to the corresponding second image value.

The morph process consists of a warping stage before cross-dissolving so that the two images have the same shape. The warp is specified, in this case, by a mapping between lines in the first and second images.

There are two ways to warp an image. First is Forward Mapping where each pixel in the source image is mapped to an appropriate place in the destination image. Thus, some pixels in the destination image may not be mapped. We need interpolation to determine these pixel values. This mapping was used in our point-morphing algorithm.

Second is Reverse Mapping which goes through each pixel in the destination image and samples an appropriate source image pixel. Thus, all destination image pixels are mapped to some source image pixel. This mapping has been used in the Beier/Neely line-morphing method.

In either case, the problem is to determine the way in which the pixels in one image should be mapped to the pixels in the other image. So, we need to specify how each pixel moves between the two images. This could be done by specifying the mapping for a few important pixels. The motion of the other pixels could be obtained by appropriately extrapolating the information specified for the control pixels. These sets of control pixels can be specified as lines in one image mapping to lines in the other image or points mapping to points.

Morph target animation is a method of 3D computer animation used together with techniques such as skeletal animation. In a morph target animation, a "deformed" version of a mesh is stored as a series of vertex positions. In each key frame of an animation, the vertices are then interpolated between these stored positions.

The "morph target" is a deformed version of a shape. When applied to a human face, for example, the head is first modeled with a neutral expression and a "target deformation" is then created for each other expression. When the face is being animated, the animator can then smoothly morph (or "blend") between the base shape and one or several morph targets. Typical examples of morph targets used in facial animation is a smiling mouth, a closed eye, and a raised eyebrow.

There are a no. of movies and serials applying image morphing to get more market value.

Hey, remember bullet time? When The Matrix came out in 1999, audiences were blown away by this amazing technical achievement. This effect subsequently made its way to other forms of media: other movies (Swordfish), TV shows (Smallville), video games (Max Payne) and even Superbowl XXV. Although trademarked as "bullet time" by Warner Brothers, the effect does not have to include bullets. It is simply the rotation of a camera view around a scene as it unfolds in slow motion time. This cannot be achieved in reality as the camera would have to rotate at an incredible speed, thus special effects are employed to achieve this effect (in The Matrix some scenes approached a frame rate of around 12,000 frames per second, each at a different angle around a target character). The main technique used is a type of image morphing known as "view morphing."

For The Matrix, the Wachowski Brothers would take some still pictures at various portions of the desired camera path. They would then use computers to map out a camera trajectory using the earlier still photos as key frames. Then, they would build a track, and using a large set of sophisticated still cameras they would film the scene. Despite using many expensive cameras, this would still not be enough individual frames to create a convincing bullet time effect. This is where view morphing comes in. They would use view morphing software to interpolate between camera frames to allow the frame rate to become incredibly high. This technique also allowed the filmmakers to have complete control over the flow of the action. Certain actions of the animation could be sped up or slowed down, or a given view could be lingered upon for an extra beat for effect.

The concept of view morphing is actually an extension of the already existing image morphing technique. These techniques have been used in the special effects industry since the late 80's and 90's. Notable scenes include the 1988 film Willow in which morphing techniques pioneered by ILM were used to change animals to humans and the 1991 Michael Jackson music video Black Or White where people of different races and genders dance and sing as they are morphed into one another. Morphing first appeared in the 1986 film The Golden Child, but Willow was the first time it was used extensively. Morphing is regarded as commonplace in films with a moderate amount of special effects in modern cinema.

Sqirlz Morph is a free application I use to create stunning morphs for personal use, and on the web. In my opinion, it is the best freeware morphing software available. 

SUBHAM KHANNA

M.TECH (SOFTWARE ENGINEERING)

IIIT ALLAHABAD