cntrd: calculates the centroid of bright spots to sub-pixel accuracy.

Inspired by Grier & Crocker s feature for IDL, but greatly simplified and optimized

for matlab

INPUTS:

im: image to process, particle should be bright spots on dark background with little noise

ofen an bandpass filtered brightfield image or a nice fluorescent image



mx: locations of local maxima to pixel-level accuracy from pkfnd.m



sz: diamter of the window over which to average to calculate the centroid.

should be big enough

to capture the whole particle but not so big that it captures others.

if initial guess of center (from pkfnd) is far from the centroid, the

window will need to be larger than the particle size. RECCOMMENDED

size is the long lengthscale used in bpass plus 2.





interactive: OPTIONAL INPUT set this variable to one and it will show you the image used to calculate

each centroid, the pixel-level peak and the centroid-

cntrd:　calculates the centroid of bright spots to sub-pixel accuracy.

　 Inspired by Grier & Crocker s feature for IDL, but greatly simplified and optimized

　 for matlab

　INPUTS:

　im: image to process, particle should be bright spots on dark background with little noise

　　ofen an bandpass filtered brightfield image or a nice fluorescent image



　mx: locations of local maxima to pixel-level accuracy from pkfnd.m



　sz: diamter of the window over which to average to calculate the centroid.

　　　should be big enough

　　　to capture the whole particle but not so big that it captures others.

　　　if initial guess of center (from pkfnd) is far from the centroid, the

　　　window will need to be larger than the particle size.　RECCOMMENDED

　　　size is the long lengthscale used in bpass plus 2.





　interactive:　OPTIONAL INPUT set this variable to one and it will show you the image used to calculate

　　 each centroid, the pixel-level peak and the centroid