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Morphing,. and. Warping. Blending. Cartographic Applications. Definition . Morphing is a special technique that creates a smooth, controlled transformation of one image into another. Transforming Shape. Warping vs Morphing Warping Single object
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Morphing, and Warping Blending Cartographic Applications
Definition • Morphing is a special technique that creates a smooth, controlled transformation of one image into another.
Warping vs Morphing • Warping • 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 of Transformations • Global Transformations • Affine Maps • Projective Maps • Non-Linear Maps
Specification • Definitions • Correspondence • association between two regions • defines original and final states • Specification • set of correspondences
Warping x Morphing • Warping • Single object • Specification of original and deformed states • Morphing (metamorphosis) • Two objects • Specification of initial and final states
Types of Specification • Parametric • Partition-based • Feature-based • Automatic or semi-automatic
Specification by Partition • Regions cover the entire object • Regular x Irregular partitions • Same topology: original and final sets
Specification by Features • Regions do not cover the object • Dimension of features £ object dimension • Examples: points, vectors, planes, boxes,...
Transforming Attributes Texture, Color
Linear Blending • A 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 linearities • use adaptive methods
Avoid leakage Select and warp foreground only
Example of Morphing and Attribute Transformation form Fantamorph
Geometry Deformation • Change of Coordinate Systems
Animation • Emphasis • Stretch • Squash • Distortion plus Motion
Animation • Keyframes • Tweens • Motion • Shape
Warping Techniques • Barycentric mapping • Field-based mapping • Radial basis functions - RBF • Free-form deformation - FFD • Multi-pass spline mesh • Physically-based warping
Parametric (global) warping Examples aspect rotation translation perspective cylindrical affine
Rotation xT = xs (cos(q)) + ys (sin(q)) yT = ys (cos(q)) - xs (sin(q))
Scale Change xT = mxs yT = nys Scaling coefficient m usually is the same as n
Translation xs = xs + Dx ys = ys + Dy
Bilinear Coordinate Transformation • Transformation Equations are: xT = axs + bys + cxsys + d yT = exs + fys + gxsys + h • Which are solved simultaneously • From a minimum of 4 points whose • Coordinates are known in both systems.
Forward warping • Send each pixel f(x,y) to its corresponding location (x’,y’)=T(x,y) in the second image • if pixel lands “between” two pixels distribute color among neighboring pixels (x’,y’), known as “splatting” Origin Target T(x,y) y y’ x x’ f(x,y) g(x’,y’)
T-1(x,y) Inverse Warping • Get each pixel g(x’,y’) from its corresponding location (x,y)=T-1(x’,y’) in the first image • if 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. Origin Target y y’ x x x’ f(x,y) g(x’,y’)
Applications • Genesis in the graphic arts, movies • Yet, Morphing is not just a special effect: • Lens distortion correction • Graphical objects modeling • Motion capture data interpolation • Accelerated Rendering
Mapping “significance” Applications Area = the relative significance of states based on electoral college votes
Applications: Interpolation of Animation Example: Glacial Metamorphosis Considerations: Frame time resolution Speed of motion Realistic 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: Photorectification • Example: Leica Photogrammetry Suite • Corrects for camera, camera angle, and relief distortions.
Applications: Showing Change • Not just areal change, but also warping of a surface to show change in mapped parameters, such as population density or temperature.
Terragen: Mount St. Helens Morph Is this morph realistic?
Software used in different types of morphing Image morphing software • Morpheous Photo Morpher www.morpheoussoftware.net • Winmorph http://debugmode.com/winmorph • Abrosoft Fantatmorph www.fantamorph.com Terrain imaging software • Terragenhttp://www.planetside.co.uk • Bryrce 5.5http://bryce.daz3d.com/55index.php Other software capable of morphing • Autodesk Map 3D 2007 www.autodesk.com • Esri Arcview 9.1 www.esri.com • Flash 8www.macromedia.com
Landscapes done in Bryce ‘Canyon Walls’ by Burpee ‘Hidden Valley‘ by Andy Simmons
Landscape created in terragen By: Giancarolo http://www.timster.net/terragenasart/site/giancarlo-flight2.html