how to save all pixel co-ordinate locations as a vector ??

Whether it is possible to save the pixel locations of an image in a vector ? which comment to save the pixel locations ..could any one help me out ...

[Image Analyst]

Locations means (row, columns) or (y, x). If you want both of those separately you'll need an array or two vectors. If you want one you'll have to use linear indexing as Dishant showed you.

[Abhishek sadasivan]

i mean x,y..thanks

Answer 1

[Dishant Arora]

% Use Linear Indexing/Vector Indexing
ind = 1:M*N;  % For an image of dimension MxN

Answer 2

[Image Analyst]

[rows, columns, numberOfColorChannels] = size(yourImage);
[X, Y] = meshgrid(1:columns, 1:rows);
xy = [X(:), Y(:)];

I really highly doubt you'd ever need this. Explain to me why you think you need this and I'll explain why you probably don't.

[Abhishek sadasivan]

I want to extract 15% data radially from the attached image.so I thinking to prepare a radial mask to extract the data from the image ..

[Image Analyst]

Yeah, like I thought, you don't want what you asked for. Even if you did you'd use

elementsToTake = randperm(numel(grayImage), 0.15*numel(grayImage));

But that's going to take random pixels, not random rays from your ultrasound image.