How do I create a minimum bounding box from locations in cornerPoints object?

I am trying to create a minimum bounding box(rectangle) from the corner locations obtained by selecting 75 strongest points after using detectMinEigenFeatures(the example given in the documentation). Here is my code:

I = imread('F:\8th sem\programs\proc_8\001.jpg'); corners = detectMinEigenFeatures(I); strong = corners.selectStrongest(70); figure, imshow(I); hold on plot(strong);

I want to know how to create a rectangle that encloses my region on interest with these corner point locations. Can someone help me in writing the code?

Answer 1

[KSSV]

Are you expecting rectangle like below?

I = imread('F:\8th sem\programs\proc_8\001.jpg'); 
corners = detectMinEigenFeatures(I); 
strong = corners.selectStrongest(70); 
figure, 
imshow(I); 
hold on 
plot(strong);
coor = strong.Location ;
xmin = min(coor(:,1)) ; xmax = max(coor(:,1));
ymin = min(coor(:,2)) ; ymax = max(coor(:,2));
% Rectangle coordinates
O = [xmin,ymin ; xmax ymin ; xmax ymax ; xmin ymax ; xmin ymin] ;
plot(O(:,1),O(:,2),'k')

[Chica_chic]

This is what I was looking for. Thank you for your help :)

[Chica_chic]

What if I wanted a polygon out of the coordinates, in such a way that the points get connected clockwise? I've posted a separate question regarding it. It would be great if you could check it.

Answer 2

[Nut]

Hi,

I think this code should be ok for you:

 x_coordinates = strong.Location(:,1);
 y_coordinates = strong.Location(:,2);

 left_edge = floor(min(x_coordinates));
 right_edge = ceil(max(x_coordinates));

 up_edge = floor(min(y_coordinates));
 down_edge = ceil(max(y_coordinates));

 new_I = I(up_edge:down_edge,left_edge:right_edge);

 imshow(new_I)

[Chica_chic]

Although this code is working well, it wasn't what I was looking for. But thank you for your help :)

Answer 3

[Amir Barkhordary]

I am trying to create a rectangular bounding box of coordinates (latitude and longitude) to find out about the SST in Great Barrier Reef. For example the coordinates of Lizard Island in Queensland are: -14.667997328 145.455664844. In order to create a SST file using seaDAS Program I would would at least to have more coordinates (such left right top bottom) for this region but I do not know how create such a box containing the region's geographical characteristics in Matlab. I appreciate any help :)

Answer 4

[karim botros]

you can plot a rectangle or anyshape around the matched feature points using the following code:

minx = min(matchedPoints.Location(:,1));

miny = min(matchedPoints.Location(:,2));

maxx = max(matchedPoints.Location(:,1));

maxy = max(matchedPoints.Location(:,2));

rectangle('Position', [minx, miny, (maxx-minx),(maxy-miny)],...

'EdgeColor','g', 'LineWidth', 2)