Is http://www.mathworks.com/matlabcentral/fileexchange/29518-freeman-chain-code what you are looking for?

thanks mr.Daniel that what i mean

but the input for it is "b" since the b is a np by 2 matrix that represent the boundary of the object ... so i need first to extract the outer boundry and make it an input to chain code .... how can i ?

For example http://www.mathworks.se/help/images/ref/bwtraceboundary.html

big thanks mr.Daniel

its so helpful and i used another technique to extract the outer boundary and it works good.

and i saved the coordination of the edge in N*2 matrix

but when used chaincode function in matlab i have error that the input was not 8-connected.

any suggestions ,please ??

regards

Are you sure that the data you're using as input is 8-connected?

Should you possibly transpose the data you're using as input?

Ok i have an image that contains a hand gun, i enhanced this image to get just the outer boundary of the gun then i get the coordinates by for loop and check the pixel value if it is a white or not if it is a white i store the coordinates in matrix... Sure the matrix values will not be in 8-connected. But how can i make it in 8-connected with keeping the arrangement of x and y coordinates?

The image like an attachment

big thanks to you mr.Daniel

i solve it .. :)

Abdullah Alzaqebah Sir

I am implementing chain code but getting problem in that. Can you provide some help? I can share my code with you if you want.

you are welcome Ekta Shharma

i am ready to any help you want.

regards

Hi sir Abdullah Alzaqebah

can you send me the code ,i need it ,please ?

I am also trying to implement this code for segmenting out the boundary of a Mammographic image , so can anyone please help me ....??