Layered Texture Matting 9562631 葉展岱 9565524 范智勝. Outline Introduction Implementation...
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Transcript of Layered Texture Matting 9562631 葉展岱 9565524 范智勝. Outline Introduction Implementation...
Introduction
Our goal Doing texture synthesis on
various objects with an irregular shape.
Without losing the 3D property in vision.
( differ from texture transfer)
Preserving the property of texture by using the layered texture synthesis.
E.g., leaves, hair
Implementation Overview
Shape from Shading - 葉展岱 (Patch Orientation) Texture Synthesis - 范智勝 (Layered Texture Synthesis)
Shape from Shading(1)
Normal Recovery Related parameters
S : a unit vector toward a sufficiently distant point light source
I(x,y) : intensity of pixel at (x,y). Imin : minimum intensity
ambient light in the scene Imax : maximum intensity
faces the light source
Shape from Shading(2)
c(x,y) = (I(x,y)−Imin)/(Imax −Imin) cosine of the angle of incidence at (x,y).
s(x,y) = sqrt(1−c(x,y)^2) sine of the angle of incidence at (x,y).
G(x,y) = ▽I(x,y)−(▽I(x,y) ·S)S ▽I(x,y) is the image gradient.
N(x,y) = c(x,y)*S+s(x,y)*G(x,y)/||G(x,y)||
So, what we need is ‘S’.
Shape from Shading(3)
How to estimate S ?
N(xi,yi) . S = (I(xi,yi) – Imin)/(Imax - Imin)
(xi,yi): on the boundary of the object’s projection N(xi,yi): the gradient of (xi,yi) The source vector S is the least-squares solution to th
e over constrained linear system
Shape from Shading(2)
Surface Segmentation Cluster with the pixels with similar normals. Use Watershed as cluster method.
Texture Synthesis
Image Quilting Procedure Define similarity using L2-norm applied to
every pixel/color in block. Optimize overlap region using minimum er
ror boundary cut.