DefinitionMorphing is a special technique that creates a smooth, controlled transformation of one image into another.
Warping vs MorphingWarping
•Single object
•Specification of original and deformed states
Morphing
•Two objects
•Specification of initial and final states
Warping and Morphing
Warping• Source object• No target object
Morphing• Source object• Target object
Specification
DefinitionsCorrespondence
association between two regions defines original and final states
Specification set of correspondences
Warping x MorphingWarping
Single objectSpecification of original and deformed states
Morphing (metamorphosis)Two objectsSpecification of initial and final states
Specification by PartitionRegions cover the entire objectRegular x Irregular partitionsSame topology: original and final sets
Specification by FeaturesRegions do not cover the objectDimension of features £ object dimensionExamples: points, vectors, planes, boxes,...
Linear BlendingA and B objects in a vector space
c(t) = (1 - t) A + t B
c(0) = A, c(1) = B
Functions (attributes)
Subsets of space (shape)
Also Bilinear, Trilinear and Affine Blending
Some Guidelines for a good morphing
Feature preservation
Smoothness preservation
Avoid linearitiesuse adaptive methods
Warping Techniques
Barycentric mappingField-based mappingRadial basis functions - RBFFree-form deformation - FFDMulti-pass spline meshPhysically-based warping
Bilinear Coordinate TransformationTransformation Equations are:
xT = axs + bys + cxsys + dyT = exs + fys + gxsys + h
Which are solved simultaneouslyFrom a minimum of 4 points whoseCoordinates are known in both systems.
Forward warpingSend each pixel f(x,y) to its corresponding location
(x’,y’) = T(x,y) in the second imageif pixel lands “between” two pixels distribute color among neighboring pixels (x’,y’), known as “splatting”
f(x,y) g(x’,y’)x x’
T(x,y)y y’
Origin Target
Inverse WarpingGet each pixel g(x’,y’) from its corresponding location
(x,y) = T-1(x’,y’) in the first imageif pixel comes from “between” two pixels, Interpolate color value from neighbors
nearest neighbor, bilinear, Gaussian, bicubic
Inverse warping usually better because it eliminates holes, but it is not always possible.
f(x,y) g(x’,y’)x
y
x x’
T-1(x,y)y’
Origin Target
ApplicationsGenesis in the graphic arts, moviesYet, Morphing is not just a special effect:Lens distortion correctionGraphical objects modelingMotion capture data interpolationAccelerated Rendering
ApplicationsMapping “significance”
Area = the relative significance of states based on electoral college votes
Applications: Interpolation of AnimationExample: Glacial Metamorphosis
Considerations: Frame time resolutionSpeed of motionRealistic shapes
Georegister Maps: Example Rubber Sheeting in ArcGIS
For two raster maps in separate layers in ArcGIS. Look up procedure in Help under “georeferencing.”
Work with tools in georeferencing menu bar
httpChina Historical GIS: georeferencing
Applications: PhotorectificationExample: Leica Photogrammetry SuiteCorrects for camera, camera angle, and relief distortions.
Applications: Showing ChangeNot just areal change, but also warping of a surface to show change in mapped parameters, such as population density or temperature.
Software used in different types of morphingImage morphing software
Morpheous Photo Morpher www.morpheoussoftware.net
Winmorph http://debugmode.com/winmorph
Abrosoft Fantatmorph www.fantamorph.com
Terrain imaging softwareTerragen http://www.planetside.co.uk
Bryrce 5.5 http://bryce.daz3d.com/55index.php
Other software capable of morphingAutodesk Map 3D 2007 www.autodesk.com
Esri Arcview 9.1 www.esri.com
Flash 8 www.macromedia.com
Landscape created in terragen
By: Giancarolo http://www.timster.net/terragenasart/site/giancarlo-flight2.html