Imread---The difference between MATLAB and OPENCVF return values

matlab

img = Imread ('.//img01.jpg ');
Disp (IMG);

Results

disp (IMG (:,:, 1)) Columns 1 through 30 189 59 1 0 52 51 40 32 0 4 115   202 215 205 206 207 222 211 197 0 31 165 162 163 165 165 166 166 161 169 192 95 1 0 53 
  49 43 41 0 3 99 203 221 205 207 208 221 214 199 4 37 156 164 164 164 166 166 165 165 167  197 123 1 1 55 52 48 44 0 0 79 202 225 209 207 208 220 211 200 26 29 156 163 164  165 164 165 167 165 168 196 141 0 1 59 55 51 44 0 0 66 203 226 214 208 208 220 215 206 49 8 159 164 164 166 166 167 167 168 170 198 156 0 0 60 58 52 45 0 0 35 198 2 29 215 209 209 218 213 207 75 0 149 165 163 165 171 167 167 167 167 196 159 0 0 59 60 5 3 45 1 0 3 196 227 217 209 210 218 211 221 94 1 140 165 166 167 175 170 169 171 171 .... ..

disp (IMG (:,:, 2)) Columns 1 through 30 192 63 4 4 55 53 45 35 2 6 114   202 216 206 208 209 222 212 198 2 36 169 167 168 170 170 170 170 167 175 195 99 4 3 55 
  51 48 44 2 5 100 205 222 206 209 210 221 215 200 6 39 160 168 169 169 171 170 169 171 173  202 127 4 3 57 54 50 47 2 0 80 204 226 212 209 210 223 214 201 28 31 158 167 168  169 168 171 173 169 172 204 148 5 3 61 57 53 47 2 1 69 205 230 217 210 210 223 218 207 50 10 161 168 168 170 170 171 171 172 174 205 162 5 5 62 58 54 48 2 0 37 201 2 30 216 211 211 220 216 208 76 2 153 169 167 169 175 171 171 171 173 203 166 5 5 61 60 5 4 47 1 1 3 197 228 218 211 212 220 214 222 95 3 144 169 170 171 179 171 173 175 177 .... ..

Disp (IMG (:,:, 3))

  Columns 1 through
  175    0    0   47  171  254  247  224  223  221  1 216  168  171  172  174  173  173  171  167  175
  178    0    0  156  255  252  224  224  222  229  219  202    5  159  171 173 172 174  173  169  173
  182    0    0 (  253) 134  255  229  224  222  232  219  205  171 157 168  169  171  171  168  173
  183    0    0   50  124  255  255  234  225  223  232  225  211    9  169  169  171  171  171  175
  ...

OpenCV

Mat img = Imread ('.//img01.jpg ');
for (int. k=0; k<12; k++) for
    (int l=0; l<12; l++)
        std::cout << img.at<vec3b> (k, L);

Results

Print the last channel separately

for (int. k=0; k<12; k++) for
        (int l=0; l<12; l++)
            std::cout << (int) img.at<vec3b> (k, L) [2] <& Lt " ";

Results

Summary

The two channels are exactly the opposite.
MATLAB is the first to print a channel and then print a channel, OPENCV is 3 channels simultaneously printing