Layered Texture Matting

9562631 葉展岱 9565524 范智勝

Outline

Introduction Implementation Overview Current Work Reference

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.

Texture Synthesis (without cluster)

Current Work(1)

Original Image & texture

Current Work(2)

Cut out the target image Use Matting

Current Work(3)

Normal Recovery Translate N(x,yz) to (R,G,B)

Current Work(4)

Patch Cluster Use Watershed as cluster method

Current Work(5)

Texture Synthesis Obey the normals and intensity

Reference

[1] H. Fang and JC. Hart. Texture Synthesis as Photograph Editing SIGGRAPH 2004.

[2] A. A. Efros and WT. Freeman. Image Quilting for Texture Synthesis and Transfer. SIGGRAPH 2001.

[3] A. Levin, D. Lischinski, and Y. Weiss. A Closed Form Solution to Natural Image Matting. CVPR 2006.