Finding points above half max of peak in 2D data

Question

Guy 2013-7-23

Lets say I have a 1000 by 1000 array with each cell containing an intensity value.

The data is an image from fluorescence microscopy, so it contains a background and several peaks.

I have the coordinates of the local maxima in the picture, now i just want to find the points that are above the half maximum of each peak.

I'd appreciate a solution for both the case where the peaks aren't overlapping, and if possible, for the case they are overlapping.

Thanks,

Guy

Answer 1

kjetil87 2013-7-23

maybe this will help you on your way?

x=rand(5,5);
xMax=max(max(x));
idx=find(x> (xMax/2) );

%% or if u want row and col indx instead [m,n]=find(x>(xMax/2));

Obviously if you want it to work on a local max point, just subtract a small submatrix around the maxima.