ImageStich/mymosaic.m at master · visionbang/ImageStich · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
function img_mosaic = mymosaic(img_input)
% img_input is a cell array of input images
verbose = 1;
Imgs = img_input;
num_imgs = length(img_input);
ref_im = 2;
non_ref_inds = [1:ref_im-1,ref_im+1:num_imgs];
%% convert to grayscale
Imgs_Gray = cell(1,num_imgs);
for i=1:num_imgs
    Imgs_Gray{i} = rgb2gray(Imgs{i});
end

%% Corner Detection (per image)
Corners = cell(1,num_imgs);
for i=1:num_imgs
    Corners{i} = cornermetric(Imgs_Gray{i}, 'Harris');
end

%% Adaptive Non-Maximum Supression (per image)
num_corners = 100;
corner_x = cell(1,num_imgs);
corner_y = cell(1,num_imgs);
for i=1:num_imgs
    [corner_y{i}, corner_x{i}, rmax] = anms(Corners{i}, num_corners);
    if verbose
        figure();
        imagesc(Imgs{i});
        hold on;
        plot(corner_x{i},corner_y{i},'xr');
    end
end

%% Extract Feature Descriptors (per image)
ps = cell(1,num_imgs);
for i=1:num_imgs
    ps{i} = feat_desc(Imgs_Gray{i}, corner_y{i}, corner_x{i});
end

%% Matching Descriptors (per match)
% assuming imaages come in order.
ms = cell(1, num_imgs-1);
n = cell(1, num_imgs-1);
x_im = cell(1, num_imgs-1);
y_im = cell(1, num_imgs-1);
x_ref = cell(1, num_imgs-1);
y_ref = cell(1, num_imgs-1);


for i=1:num_imgs-1
    ms{i} = feat_match(ps{non_ref_inds(i)}, ps{ref_im});
    n{i} = ms{i} ~= -1;
    x_im{i} = corner_x{non_ref_inds(i)}(n{i});
    y_im{i} = corner_y{non_ref_inds(i)}(n{i});
    x_ref{i} = corner_x{ref_im}(ms{i}(n{i}));
    y_ref{i} = corner_y{ref_im}(ms{i}(n{i}));

    if verbose
        figure();
        showMatchedFeatures(Imgs_Gray{non_ref_inds(i)},Imgs_Gray{ref_im}, [x_im{i},y_im{i}], [x_ref{i}, y_ref{i}], 'montage');
    end

end


% ms{1} = feat_match(ps{1}, ps{2});
% n1 = ms{1} ~= -1;
% x1 = corner_x{1}(n1);
% y1 = corner_y{1}(n1);
% x21 = corner_x{2}(ms{1}(n1));
% y21 = corner_y{2}(ms{1}(n1));
%
%     if verbose
%         figure();
%         showMatchedFeatures(Imgs_Gray{1},Imgs_Gray{ref_im}, [x1,y1], [x21, y21], 'montage');
%     end
%ms{2} = feat_match(ps{3}, ps{2});
% n2 = ms{2} ~= -1;
% x3 = corner_x{3}(n2);
% y3 = corner_y{3}(n2);
% x22 = corner_x{2}(ms{2}(n2));
% y22 = corner_y{2}(ms{2}(n2));

% % code to check individual matches
% if verbose
%     for ii = 1:size(ms{1},1)
%         %plot both features
%         if(ms{1}(ii) ~= -1)
%             figure(1);
%             subplot(1,2,1);
%             imshow(reshape(ps{1}(:, ii), [8,8]));
%             axis equal
%             subplot(1,2,2);
%             imshow(reshape(ps{2}(:, ms{1}(ii)), [8,8]));
%             colormap(gray);
%             axis equal
%             figure(2)
%             showMatchedFeatures(Imgs_Gray{1},Imgs_Gray{2}, [corner_x{1}(ii), corner_y{1}(ii)], [corner_x{2}(ms{1}(ii)), corner_y{2}(ms{1}(ii))], 'montage');
%             waitforbuttonpress
%         end
%     end
% end


%% Estimate Homography with RANSAC
verbose=1;debug=1;
ransac_thres = 5;
H = cell(1, num_imgs-1);
inlier_ind = cell(1, num_imgs-1);

for i=1:num_imgs-1
    i
    [H{i}, inlier_ind{i}] = ransac_est_homography(y_im{i},x_im{i}, y_ref{i}, x_ref{i}, ransac_thres);
    %[H23, inlier_ind23] = ransac_est_homography(y3,x3, y22, x22, ransac_thres);
    if verbose
        figure();
        showMatchedFeatures(Imgs_Gray{non_ref_inds(i)},Imgs_Gray{ref_im}, [x_im{i}(inlier_ind{i}),y_im{i}(inlier_ind{i})], [x_ref{i}(inlier_ind{i}), y_ref{i}(inlier_ind{i})], 'montage');
    end
end
%%
% if debug
%     x = 300;
%     y = 300;
%     H=est_homography(x21,y21,x1,y1);
%     [X,Y] = apply_homography(H12,x1,y1);
%     figure(30);
%     subplot(1,2,1);
%     imshow(Imgs{1});
%     hold on;
%     plot(x1,y1, '+r');
%     subplot(1,2,2);
%     imshow(Imgs{2});
%     hold on;
%     plot(X,Y,'+r');
% end
%%


%% Stitch Images Together
tform = cell(1, num_imgs-1);
im_trans = cell(1, num_imgs-1);
R_im = cell(1, num_imgs-1);
R_ref = cell(1, num_imgs-1);
im_warp = cell(1, num_imgs-1);

for i=1:num_imgs-1
    if i==1
        img_mosaic = Imgs{ref_im};
        Rm = imref2d(size(Imgs{ref_im}));
    end
    tform{i} = projective2d(H{i}');
    %tform23 = projective2d(H23');
    [im_trans{i}, R_im{i}] = imwarp(Imgs{non_ref_inds(i)}, imref2d(size(Imgs{non_ref_inds(i)})), tform{i});
    %[im3_t, R3] = imwarp(Imgs{3}, imref2d(size(Imgs{3})), tform23);
    %[im_warp{i}, R_ref{i}]= imfuse(im_trans{i}, R_im{i}, Imgs{ref_im}, imref2d(size(Imgs{ref_im})), 'blend');
    %[warp23, R23]= imfuse(im3_t, R3, Imgs{2}, imref2d(size(Imgs{2})), 'blend');
    [img_mosaic, Rm] = imfuse(im_trans{i}, R_im{i}, img_mosaic, Rm, 'blend');
    if verbose
        figure();
        imshow(im_warp{i});
    end
end

imwrite(img_mosaic, 'mymosaic.jpg', 'jpg');