Method for generating a model of a flat object from views of the object

Patent metadata

Field	Value
Publication number	US-9380293-B2
Application number	US-201113819564-A
Country	US
Kind code	B2
Filing date	Jul 11, 2011
Priority date	Aug 27, 2010
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A method for generating a model of a flat object from views taken by at least two calibrated cameras, which is capable of generating two-dimensional and volumetric representations of the object, where the representations can be a depth map, a volumetric representation or a mesh representation, method including the following basic steps: calibrating at least two cameras, calculating several 3D coordinates of at least three points belonging to the same plane of the flat object, calculating the equation of the plane of the flat object, selecting at least one region representing the surface of the flat object, in at least one view provided by at least one camera, and calculating the intersection between the selected region representing the surface of the object and the equation of the plane.

First claim

The invention claimed is:

1. Method for generating a model of a flat object from views of the flat object, wherein it generates a representation selected from among a depth map of the flat object, a volumetric representation of the flat object and a mesh representation of the flat object, by means of at least the following steps:
i) calibrating at least a first camera and a second camera;
ii) calculating the 3D coordinates of at least three points belonging to a plane of the flat object;
iii) calculating a equation of the plane comprised in the flat object;
iv) selecting at least one region representing the surface of the flat object, in at least one image plane provided by at least one camera; and,
v) calculating an intersection between the selected region representing the surface of the object and the equation of the plane, wherein step ii) additionally comprises: selecting a point and a first image point, in which the first image point represents the selected point in the image plane provided by the first camera, and in which said selected point is comprised in the flat object; calculating a first ray joining the center of the first camera with the first image point, and also with the selected point; calculating the projection of the selected point on the image plane provided by the second camera; calculating at least one second ray by means of at least the image plane of the second camera, connecting the center of the second camera with the second image point and also with the selected point; determining the 3D coordinates of the selected point by means of calculating the point of intersection between the first ray and at least one second ray; repeating the previous steps for at least two more points, obtaining at least the 3D coordinates of three points belonging to the plane of the flat object.

2. Method for generating a model of a flat object from views of the object according to claim 1 , wherein step i) additionally comprises calculating the extrinsic and intrinsic parameters of at least the first camera and second camera by solving the equations for as many points in 2D/3D as degrees of freedom the cameras comprise.

3. Method for generating a model of a flat object from views of the object according to claim 1 , wherein the projection of the selected point on the image plane of the second camera is calculated by means of a calculation option selected from manual and semiautomatic.

4. Method for generating a model of a flat object from views of the object according to claim 3 , wherein the manual calculation option comprises a user, by means of a graphical user interface showing at least the image plane provided by the second camera, selecting the image point which best represents the point previously selected by means of the image plane provided by the first camera.

5. Method for generating a model of a flat object from views of the object according to claim 3 , wherein the semiautomatic calculation option is selected from semiautomatic levels as a set comprised by a low level, a medium level and a high level.

6. Method for generating a model of an object from views of the object according to claim 5 , wherein the low level comprises the following steps:
calculating an epipolar line in at least the image plane provided by the second camera, wherein said epipolar line is the line drawn on the image plane of the second camera representing the first ray by means of the calibration of the cameras;
representing the epipolar line by means of the graphical user interface;
and,
selecting a second image point on the graphical user interface, wherein the second image point is a selected point along the epipolar line which best represents the selected point by means of the image plane provided by the first camera.

7. Method for generating a model of a flat object from views of the object according to claim 5 , wherein the medium level comprises the following steps:
a) determining a first image area containing at least the first image point and storing at least one information value of the image point selected from among the color, the color intensity and a combination thereof, of at least the first image point and each of the image points surrounding the first image point;
b) calculating an epipolar line in at least the image plane provided by the second camera, wherein said epipolar line is the line drawn on the image plane of the second camera representing the first ray by means of the calibration of the cameras;
c) determining a second area containing at least one image point comprised in the epipolar line, and storing at least one information value of the image point selected from among the color, the color intensity and a combination thereof, of at least said first image point comprised in the epipolar line and each of the image points surrounding the image point comprised in the epipolar line;
d) comparing the information value of the image point of the first image area with the information value of the image point of the second image area;
e) repeating steps c) and d) for each of the image points forming the epipolar line; and,
f) selecting a second image point from among a group of image points formed by the image points obtained in each repetition by means of an option selected from manual and automatic; the automatic option comprises selecting the second image point as the image point from the total image points comprised by the epipolar line, for which the second image area of the image point comprises a reproduction index of the first image area greater than a threshold; the manual form comprises highlighting with a predetermined color the second image point, which is selected as the image point from the total image points comprised by the epipolar line, for which the second image area of the second image point comprises a reproduction index of the first image area greater than a threshold, and selecting a point from among those highlighted by the graphical user interface.

8. Method for generating a model of a flat object from views of the object according to claim 5 , wherein the high level comprises the following steps:
a) determining a set of characteristic points in at least the image planes provided by the first camera and the second camera, said characteristic points being those located in corners and edges of the object, and in the surfaces of objects with texture, the points obtained by a corner detection algorithm;
b) comparing the first image point with a previously determined characteristic point;
c) determining a first image area containing at least the first image point and storing at least one information value of the image point selected from among the color, the color intensity and a combination thereof for at least the first image point and each of the image points surrounding the first image point;
d) calculating an epipolar line in at least the image plane provided by the second camera, wherein the epipolar line is the line drawn on the image plane of the second camera representing the first ray by means of the calibration of the cameras;
e) determining a second image area comprising at least one image point contained in the epipolar line, and storing at least one information value of the image point selected from among the color, the color intensity and a combination thereof, of at least the image point contained in the epipolar line and each image point surrounding the image point contained in the epipolar line;
f) comparing the information value of the image point of the first image area with the information value of the image point of the second image area;
g) repeating steps e) and f) for each of the image points forming the epipolar line; and,
h) selecting a second image point from among a group of image poi

Assignees

• Marimon Sanjuan David
• Landabaso Diaz José Luis
• Divorra Escoda Oscar
• Pujol Alcolado José Carlos
• Telefonica Sa

Inventors

• Marimon Sanjuan David
• Landabaso Diaz José Luis
• Divorra Escoda Oscar
• Pujol Alcolado José Carlos

Classifications

• G06T2207/10012

  Stereo images · CPC title

• G06T7/0075

  Physics · mapped topic

• H04N13/0239 Primary

  Electricity · mapped topic

• G06T2200/24

  involving graphical user interfaces [GUIs] · CPC title

• G06T2207/20101

  Interactive definition of point of interest, landmark or seed · CPC title