updateConnection

Update connection between views in a view set

Syntax

vSet = updateConnection(vSet,viewId1,viewId2,relPose)

vSet = updateConnection(vSet,viewId1,viewId2,relPose,infoMat)

vSet = updateConnection(___,'Matches',featureMatches)

Description

vSet = updateConnection(vSet,viewId1,viewId2,relPose) updates the connection between views viewId1 and viewId2 with the relative pose specified by relPose.

vSet = updateConnection(vSet,viewId1,viewId2,relPose,infoMat) specifies the information matrix associated with the connection.

vSet = updateConnection(___,'Matches',featureMatches) specifies the indices of matched points between two views in addition to any of the input argument combinations in previous syntaxes.

Examples

Update Connection in Image View Set

Create an empty image view set.

vSet = imageviewset;

Read two images into the workspace.

imageDir= fullfile(toolboxdir("vision"),"visiondata","structureFromMotion");
I1 = im2gray(imread(fullfile(imageDir,"image1.jpg")));
I2 = im2gray(imread(fullfile(imageDir,"image2.jpg")));

Detect interest points in each image.

points1 = detectSURFFeatures(I1);
points2 = detectSURFFeatures(I2);

Extract feature descriptors from the interest points.

[features1,validPoints1] = extractFeatures(I1,points1);
[features2,validPoints2] = extractFeatures(I2,points2);

Add features and the points for the two images to the image view set.

vSet = addView(vSet,1,Features=features1,Points=validPoints1);
vSet = addView(vSet,2,Features=features2,Points=validPoints2);

Match the features between the two images. Then, store the matched features as a connection in the image view set.

indexPairs = matchFeatures(features1,features2);
vSet = addConnection(vSet,1,2,Matches=indexPairs);

Create a relative pose between the views. Then,update the connection in the image view set.

theta = 30; % degrees
rot = [ cosd(theta) -sind(theta) 0; ...
        sind(theta) cosd(theta) 0; ...
        0           0  1];

trans = [2 3 4];
tform = rigidtform3d(rot,trans);
vSet = updateConnection(vSet,1,2,tform);

Input Arguments

vSet — Image view set

imageviewset object

Image view set, specified as an imageviewset object.

viewId1 — View identifier 1

positive integer

View identifier 1, specified as an integer. View identifiers are unique to a specific view.

viewId2 — View identifier 2

positive integer

View identifier 2, specified as an integer. View identifiers are unique to a specific view.

relPose — Relative pose

rigidtform3d object | simtform3d object

Relative pose of viewId2 with respect to viewId1, specified as a rigidtform3d or an simtform3d object.

infoMat — Information matrix

6-by-6 numeric matrix

Information matrix associated with the connection, specified as a 6-by-6 numeric matrix.

featureMatches — Indices of matched points between two views

M-b-2 matrix

Indices of matched points between two views, specified as an M-b-2 matrix.

Output Arguments

vSet — View set with updated connections

imageviewset object

View set with updated connections, returned as an imageviewset object.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2020a

R2022b: Supports premultiply geometric transformation convention

Starting in R2022b, most Computer Vision Toolbox™ functions create and perform geometric transformations using the premultiply convention. Accordingly, you can now specify the relPose argument as a rigidtform3d or simtform3d object, which use the premultiply convention.

Although you can still specify relPose as a rigid3d or affine3d object, these objects are not recommended because they use the postmultiply convention. The updateConnection function automatically converts the relative pose to the premultiply convention and returns an imageviewset object that represents the pose as a rigidtform3d object.

For more information, see Migrate Geometric Transformations to Premultiply Convention.