## Copyright (C) 2020 Jens
## 
## This program is free software: you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
## 
## This program is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
## 
## You should have received a copy of the GNU General Public License
## along with this program.  If not, see
## <https://www.gnu.org/licenses/>.

## -*- texinfo -*- 
## @deftypefn {} {@var{retval} =} bluescreen (@var{input1}, @var{input2})
##
## @seealso{}
## @end deftypefn

## Author: Jens <jens@orion>
## Created: 2020-10-03

function chromakey (img_name)
im = im2double(imread(img_name));
im_rgb = imresize(im, 1);
se = strel('square',3)

#ref = [0.3 0.4 0.65];	# cineon_before 
ref = [0.2 0.6 0.95];	# adventure_rose 

ref_rgb = toRef(ref, size(im_rgb));	

k_ds_matte = 1.0;
k_e_matte = 20.0
k_e_edge = 10.0

close all;

figure;
matte = supermatte(im_rgb, ref_rgb, k_e_matte);
imshow(matte); title("matte")

figure;
intermediate = im_rgb.*matte;
imshow(intermediate); title("intermediate")

figure;
edges = 1-supermatte(intermediate, ref_rgb, k_e_edge);
imshow(edges); title("edges")

figure;
final = max(0, intermediate - k_ds_matte.*edges.*ref_rgb);
imshow(final); title("final")

imwrite(intermediate, 'intermediate.png','png','alpha', matte);
imwrite(final, 'final.png','png','alpha', matte);
imwrite(matte, 'alpha.png','png');

function r = toRef(ref, d)
	r = repmat(reshape(ref,1, 1, 3), d(1), d(2));
endfunction

function mask = mask_clip_above(mask_in, thresh)
		k = mask_in < thresh;
		mask = k .* mask_in + kn;
endfunction

function mask = mask_clip_below(mask_in, thresh)
		k = mask_in > thresh;
		mask = k .* mask_in  + 0;
endfunction

endfunction