how can i apply an oval mask to extract face region?

how can i apply an oval mask to extract face region?

Answer 1

[DGM]

Oh well if you want an oval, you're in luck. This is one way to generate oval masks.

inpict = imread('peppers.png');
[rows,cols,~] = size(inpict);

% generate a binary mask containing multiple ovals
[x y] = makeoval(60,[120 120],-60,'type','stadium');
mask = poly2mask(x,y,rows,cols);
[x y] = makeoval(80,[250 270],-100,'type','superegg');
mask = mask | poly2mask(x,y,rows,cols);
[x y] = makeoval(80,[400 120],-130,'type','ellipse','ratio',1.5);
mask = mask | poly2mask(x,y,rows,cols);
imshow(mask)

% apply the mask 
outpict = im2uint8(double(mask).*im2double(inpict));
imshow(outpict)

... but if all you really want is an ellipse, just use imellipse() or drawellipse()