MATLAB: Find the coordinates nearest to the center coordinate of a patch in an image

image processing

i have an image of size [512 512], and xy coordinates values, which have been found on the whole image. (I have attached an example xy coordinate which i'm working on)

Now i wanted to divide the image into blocks of size [128 128], and

I need to find the center most xy coordinate that falls on each patch

Best Answer

See this simple example

x = rand(100,1);                    % random data
y = rand(100,1);
[x1,y1] = meshgrid(0.05:.3:1);      % mesh
D = pdist2([x y],[x1(:) y1(:)]);    % combinations of distances
[~,ix] = min(D);                    % closest distances (indices)
plot(x,y,'.r')
hold on
plot(x1,y1,'.-b','markersize',25)
plot(x1',y1','.-b')
plot(x(ix),y(ix),'om','markersize',20)
hold off

Related Solutions

MATLAB: Putting two circles on the same image

Try the following

function [outimg] = CircleIm(radius)
SizeX = 256;
SizeY = 256;
[C, R] = meshgrid(1:SizeX, 1:SizeY);
centerX = 64;
centerY = 64;
centerX1 = 192;
centerY1 = 192;
circle = (R - centerY).^2 + (C - centerX).^2 <= radius.^2;
circle1 = (R - centerY1).^2 + (C - centerX1).^2 <= radius.^2;
circles = circle|circle1;
outimg=image(circle|circle1);
colormap([0 0 0.4; 1 1 1]);
end

your method of hold on will make draw the new image on top of the last image. You need to or both images together to retain both circles. The following are drawn with a radius of 20.

MATLAB: Converting Cartesian Coordinates to Binary image

Something like this

x = randn(1, 5000); % generate random points
y = randn(1, 5000);
img_dimension = [500 500]; % [width height]
img = zeros(img_dimension);
xt = floor(rescale(x, 1, img_dimension(2))); % convert x-y in range of image coordinates
yt = floor(rescale(y, 1, img_dimension(1)));
idx = sub2ind(img_dimension, yt, xt);
img(idx) = 1;
imshow(img)

Best Answer

Related Solutions

MATLAB: Putting two circles on the same image

MATLAB: Converting Cartesian Coordinates to Binary image

Related Question