Content deleted Content added
Added an image showing how the suggested shape is conformed to the shape model |
m →top: Remove blank line(s) between list items per WP:LISTGAP to fix an accessibility issue for users of screen readers. Do WP:GENFIXES and cleanup if needed. Discuss this at Wikipedia talk:WikiProject Accessibility#LISTGAP |
||
Line 1:
'''Active shape models (ASMs)''' are [[statistical model]]s of the [[shape]] of objects which iteratively deform to fit to an example of the object in a new image, developed by Tim Cootes and Chris Taylor in 1995.<ref name=Cootes>{{cite journal| author=T.F. Cootes and C.J. Taylor and D.H. Cooper and J. Graham| title=Active shape models - their training and application| journal=Computer Vision and Image Understanding| pages=38–59| year=1995| issue=61}} [http://www.cs.ualberta.ca/~nray1/CMPUT615/Snake/cootes_cviu95.pdf]</ref> The shapes are constrained by the PDM ([[point distribution model]]) [[Statistical Shape Model]] to vary only in ways seen in a training set of labelled examples.
The shape of an object is represented by a set of points (controlled by the shape model). The ASM algorithm aims to match the model to a new image.
[[File:Operation Of Shape Model In Active Shape Model.jpg|frame|right|Operation of the shape model]]
Line 6:
The ASM works by alternating the following steps:
* Generate a suggested shape by looking in the image around each point for a better position for the point. This is commonly done using what is called a "profile model", which looks for strong edges or uses the [[Mahalanobis distance]] to match a model template for the point.<ref name=Cootes/>
* Conform the suggested shape to the point distribution model, commonly called a "shape model" in this context. The figure to the right shows an example.
| |||