John Drake

I wrote this Matlab code for my CIS399 class.

It takes two images and morphs between them when given user input describing where corresponding points are on the two images.

Here I combined two morphs of a friend's face into one video:

Code:

function morphed_im = morph(im1, im2, im1_pts, im2_pts, tri, warp_frac, dissolve_frac);

[ysize,xsize] = size(im1);

morphed_im = im1*0;

trisize = size(tri);
trisize = trisize(1);

abcmatrixarray = cell(2,trisize+1);  %makes extra cell for comparison later

interp_pts = (warp_frac * im2_pts) + ((1 - warp_frac) * im1_pts);

for x=1:1:xsize
    for y=1:1:ysize
        tindex = tsearch(interp_pts(:,1),interp_pts(:,2),tri,x,y);
        if (isnan(tindex))
            tindex = 1;
        end
        triangle = tri(tindex,:);

if (size(abcmatrixarray{2,tindex}) == size(abcmatrixarray{2,trisize+1})) %uses the extra cell here for size comparison
            %calculate abcmatrix for tindex triangle
            a = interp_pts(triangle(1),:);
            b = interp_pts(triangle(2),:);
            c = interp_pts(triangle(3),:);
            temp = [a(1),b(1),c(1);a(2),b(2),c(2);1,1,1];
            abcmatrixarray{1,tindex} = temp;
            abcmatrixarray{2,tindex} = inv(temp);
        end

barycoord = abcmatrixarray{2,tindex} * [x;y;1];
        
        a = im1_pts(triangle(1),:);
        b = im1_pts(triangle(2),:);
        c = im1_pts(triangle(3),:);
        temp = [a(1),b(1),c(1);a(2),b(2),c(2);1,1,1];
        xyzcoord = temp * barycoord;
        xx = floor(xyzcoord(1)/xyzcoord(3)) + 1;
        yy = floor(xyzcoord(2)/xyzcoord(3)) + 1;
        
        value1 = im1(max(1,min(yy,ysize)),max(1,min(xx,xsize)));
        
        a = im2_pts(triangle(1),:);
        b = im2_pts(triangle(2),:);
        c = im2_pts(triangle(3),:);
        temp = [a(1),b(1),c(1);a(2),b(2),c(2);1,1,1];
        xyzcoord = temp * barycoord;
        xx = floor(xyzcoord(1)/xyzcoord(3)) + 1;
        yy = floor(xyzcoord(2)/xyzcoord(3)) + 1;

value2 = im2(max(1,min(yy,ysize)),max(1,min(xx,xsize)));
        
        morphed_im(y,x) = (value2 * dissolve_frac) + ((1 - dissolve_frac) * value1);
    end
end

maxv = 0;
minv = 1000;
for x=1:1:xsize
    for y=1:1:ysize
        if (morphed_im(y,x) < minv)
            minv = morphed_im(y,x);
        end
        if (morphed_im(y,x) > maxv)
            maxv = morphed_im(y,x);
        end
    end
end
for x=1:1:xsize
    for y=1:1:ysize
        morphed_im(y,x) = morphed_im(y,x) - minv;
        morphed_im(y,x) = morphed_im(y,x) * (255 / (maxv - minv));
    end
end