Generate convex hull image from binary image
Read a grayscale image into the workspace. Convert it into a binary image and calculate the union binary convex hull. Finally, calculate the objects convex hull and display all the images in one figure window.
subplot(2,2,1); I = imread('coins.png'); imshow(I); title('Original'); subplot(2,2,2); BW = I > 100; imshow(BW); title('Binary'); subplot(2,2,3); CH = bwconvhull(BW); imshow(CH); title('Union Convex Hull'); subplot(2,2,4); CH_objects = bwconvhull(BW,'objects'); imshow(CH_objects); title('Objects Convex Hull');
BW— Input binary image
Input binary image, specified as a 2-D logical matrix.
method— Method used to compute the convex hull
Method used to compute the convex hull, specified as one of the following:
|Compute the convex hull of all foreground objects, treating them as a single object|
|Compute the convex hull of each connected component of |
conn— Pixel connectivity
4| 3-by-3 matrix of
Pixel connectivity, specified as one of these values The
conn parameter is only valid when the
Pixels are connected if their edges touch. Two adjoining pixels are part of the same object if they are both on and are connected along the horizontal or vertical direction.
Pixels are connected if their edges or corners touch. Two adjoining pixels are part of the same object if they are both on and are connected along the horizontal, vertical, or diagonal direction.
Connectivity can also be defined in a more general way by specifying a
3-by-3 matrix of
1-valued elements define neighborhood locations
relative to the center element of
conn. The matrix must
be symmetric about its center element.
CH— Binary mask of the convex hull of all foreground objects in the input image
Binary mask of the convex hull of all foreground objects in the input image, returned as a 2-D logical matrix.