## 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

# chromakey('adventure_rose', 20, 10)
# chromakey('cineon_before', 200, 100)

function eval_matte (prj_name, k_e_matte)

clip_white_thresh = 0.80;
clip_white_amp = 3;

clip_black_thresh = 0.20;
clip_black_amp = 3;

[im_rgb, ref_rgb] = prj_load(prj_name);

close all;

pre_filtered = im_rgb - ref_rgb;
pre_filtered_p = max(0,pre_filtered);
pre_filtered_n = -min(0,pre_filtered);

figure;
imshow(abs(pre_filtered)); title("pre_filtered")

figure;
filtered_var = var(pre_filtered, 0, 3);

kn = 1/max(max(filtered_var(:)))
var_n = k_e_matte*kn*filtered_var;
matte = min(1, var_n);
imshow(matte); title("var")

figure;
filtered_norm = vecnorm(pre_filtered, 2, 3);
imshow(filtered_norm); title("norm")

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

figure;
edges = exp(-1.7*k_e_matte*var(intermediate - ref_rgb, 0, 3));
imshow(edges); title("edges")

figure;
final = intermediate - edges.*ref_rgb;
imshow(final); title("final")

imwrite(intermediate, sprintf('%s.intermediate.png',prj_name),'png','alpha', matte);
imwrite(edges, sprintf('%s.edges.png',prj_name),'png');
imwrite(final, sprintf('%s.final.png',prj_name),'png','alpha', matte);