MATLAB: How to Draw circles from matched points of stereo camera images.

meanstereo matchingsurfvariance

Hello, I have left image and right image. I want to detect features and match the features from left and right images using SURF method. from the matched points in the left and right images, i want to calculate the midpoints(mean) and the variance. Using the mean and variance value, i want to illustrate circle in order to see how much the variance variate from its mean. Can you help me to do this task? Thanks you.

Best Answer

once you have the coordinates of the circle's center (x,y), you can draw a circle of radius r with the following:

ang = 0:0.01:2*pi; 
xp = r*cos(ang);
yp = r*sin(ang);
plot( x+xp,y+yp );

Related Solutions

MATLAB: How can you performing imwarp about the center of an image, not the top left corner

There are at least two ways to do this with IMWARP. One is to use a composite geometric transformation in which you pre and post multiply your intended transformation to shift the image to the origin (0,0), apply your affine operation, and then shift the image back to its original center.

A second, and I think easier way to do it, is to put your image into a non-default coordinate system where it is defined as being centered at the origin and then just apply your intended transformation. This approach is shown below.

A = imread('pout.tif');
Rin = imref2d(size(A))
Rin.XWorldLimits = Rin.XWorldLimits-mean(Rin.XWorldLimits);
Rin.YWorldLimits = Rin.YWorldLimits-mean(Rin.YWorldLimits);
out = imwarp(A,Rin,tform);

MATLAB: Fill area between circles

Here is one way:

% Get data for the two circles
[xp5, yp5] = circle(5,0,0,0,2*pi,0.01);
[xp10,yp10] = circle(10,0,0,0,2*pi,0.01);
% Draw the two circles
figure
hold on
plot(xp5,yp5)
plot(xp10,yp10)
% Fill in the area by defining the polygon that is defined by tracing the inner circle and then back along the outer circle
fill([xp5 flip(xp10)],[yp5 flip(yp10)],'g')
% Cover up the connecting line in the same color
h = line([xp5(1) xp10(end)],[yp5(1) yp10(end)]);
set(h,'Color','g')
% Set the axes to have equal length, so that they *look* like circles
axis equal

Best Answer

Related Solutions

MATLAB: How can you performing imwarp about the center of an image, not the top left corner

MATLAB: Fill area between circles

Related Question