3D Models from Photos

Tobias Günther @elaspix

The Issue

● Create a textured 3d model based on a photo

● Without calibrating the camera or anything else

The “manual” working process

● Get photos without perspective distortion

● Step 1: Modeling

● Step 2: Texture Projection

Without orthogonal textures

● The modeler's live is much more complicated

● You need to measure

– The width, height and depth of

the object

● You need to know/guess

– camera angle

– camera position

– camera direction

● Required for projection: Match of photo and 3D-Cam

Live is easier with smart software

● Sketchup7 is made for handling perspectives

● What you have to do

– Match the green and

red axis with parallel

edges in your photo

Sketchup Step 2

● After the camera is in place

● Build the model

● The difference to my

earlier setup:

– The model is built only

AFTER the cam was

placed correctly

Insight-3D

Requires multiple images

With 2°-6° rotation diff.

The user marks key edges and facesIdentified unique pattern in all images

Texture projection and modeling

● The user models manually

● Modelling and texture projection is supported by

software

Ease of

use

Automatic pattern

matching among photos

robust Number of

images

required

Method

Sketchup ++ no +++ 1 Perspective

Geometry

Insight3D - yes - 3-4 Stereopsis

Free Software to create 3D from 2D

● Supports texture

projection and modeling

● Output: fully usable 3d-

model

● Contextual folding and

inflation

● Output: a folded Sheet

of “Paper”

Contextual folding

● calculates the depth map based on image features

● Folds the image at prominent ground lines

D. Hoim, A.A. Efros, M. Hebert, Automatic Photo Pop-up, 2005

Automatic Photo Pop-up

http://www.youtube.com/watch?v=PulpuyVx3lk

Make-3D

http://make3d.stanford.edu/images/showall

Contextual Folding

Photo-Sculpt Photo-to-3D.com

Free Software for Contextual Folding

Ease of

use

Automatic pattern

matching among

photos

robust Number of

images

required

Method

Photo-Sculpt ++++ yes - 2

(front+right)

undisclosed

Photo-to-3d + yes - many Stereopsis

Make-3D ++ Not required ? 1 Image

understanding

Automatic

Photo Pop-Up

++ Not required ? 1 Planar Plane

understanding

● Created fully automatically without calibration

● Output: planar surfaces or inflated areas

Conclusion

● (All) automatic software creates “pseudo-3D”

models by folding and inflation

● High quality can be achieved with

semi-automatic software only

● SketchUp

● The modeling of complex models

requires calibration of camera and

scene using artificial landmarks3dsom.com