Description
For this problem, handin Matlab .m files for the functions described by the headers below. Note that one of these is a driver which creates inputs for each function and runs the
function on those inputs to obtain the output.
Some notes:
• Indent headers correctly (5 spaces indented lines)
• Do not exceed 72 characters per source line
• CS4640 A7 driver: should show that each function works
None of the functions should write to the interpreter, draw, etc., unless explicitly required
by the function description.
function [x,y] = CS4640_ac_initial_box(r1,c1,r2,c2,gap)
% CS4640_ac_initial_box – initialize rectangular snake points
% On input:
% r1 (int): upper left corner row
% c1 (int): upper left corner col
% r2 (int): lower right corner row
% c2 (int): lower right corner col
% gap (int): gap between snake pixels
1
% On output:
% x (kx1 vector): x coordinates of snake points
% y (kx1 vector): y coordinates of snake points
% Call:
% [x0,y0] = CS4640_ac_initial_box(5,5,25,25);
% Author:
%
% UU
% Spring 2018
%
function [xs,ys] =
CS4640_ac_initial_circle(M,N,r0,c0,radius,del_theta)
% CS4640_ac_initial_circle – initialize circular snake points
% On input:
% M (int): row size of image
% N (int): col size of image
% r0 (int): row center of circle
% c0 (int): col center of circle
% radius (float): radius of circle
% del_theta (float): step in theta for circle
% On output:
% x (kx1 vector): x coordinates of snake points
% y (kx1 vector): y coordinates of snake points
% Call:
% [x0,y0] = CS4640_ac_initial_circle(31,31,16,16,9,0.1);
% Author:
%
% UU
% Spring 2018
%
function [MO,im_ac,x,y] =
CS4640_ac(im,x0,y0,alpha,beta,gamma,max_iter)
% CS4640_ac – compute active contour
% On input:
% im (MxN array): gray-level image
% x0 (Kx1 vector): x (row) locations for curve
% y0 (Kx1 vector): y (col) locations for curve
2
% alpha (float): coefficient for D2 array
% beta (float): coefficient for D4 array
% gamma (float): coefficient for external force vector
% max_iter (int): max number of iterations
% On output:
% MO (movie): movie of snake motion
% im_ac (MxN array): binary array with final curve points
% x (float): final x values of snake
% y (float): final y values of snake
% Call:
% sq = zeros(31,31);
% sq(11:20,11:20) = 100;
% [sqc,xf,yf] = CS4640_ac(sq,x0,y0,1,1,0.2,5000);
% Author:
% T. Henderson
% UU
% Spring 2018
%
function phi = CS4640_phi_circle(M,N,r0,c0,radius)
% CS4640_phi_circle – create circular phi function
% On input:
% M (int): number of rows in array
% N (int): number of cols in array
% r0 (int): center of circular function
% c0 (int): column of circular function
% radius (int): radius of circle
% On output:
% phi (MXN array): each pixel has signed distance to circle
% boundary
% Call:
% phi = CS4640_phi_circle(201,201,25,25,3);
% Author:
%
% UU
% Spring 2018
%
function [MO,phi,tr] = CS4640_level_set(im,max_iter,del_t,r0,c0)
3
% CS4640_level_set – level set of image
% On input:
% im (MxN array): gray level or binary image
% max_iter (int): maximum number of iterations
% del_t (float): time step
% r0 (int): row center of circular level set function
% c0 (int): column center of circular level set function
% On output:
% MO (movie): movie of level set propagation
% phi (MxN array): final phi array
% tr (qx1 vector): sum(sum(abs(phi_{n+1}(r,c) – phi_{n}(r,c))))
% Call:
% [MO,phi,tr] = CS4640_level_set(im,300,0.1,25,25);
% Author:
%
% UU
% Spring 2018
%
function CS4640_A7_driver
% CS4640_A7_driver – driver for A7 functions
% On input:
% N/A
% On output:
% N/A
% Call:
% CS4640_A7_driver
% Author:
%
% UU
% Spring 2018
%
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