| Image Processing Toolbox | |
Get block values in quadtree decomposition
Syntax
[vals,r,c] = qtgetblk(I,S,dim)[vals,idx] = qtgetblk(I,S,dim)
Description
[vals,r,c] = qtgetblk(I,S,dim) returns in vals an array containing the dim-by-dim blocks in the quadtree decomposition of I. S is the sparse matrix returned by qtdecomp; it contains the quadtree structure. vals is a dim-by-dim-by-k array, where k is the number of dim-by-dim blocks in the quadtree decomposition; if there are no blocks of the specified size, all outputs are returned as empty matrices. r and c are vectors containing the row and column coordinates of the upper-left corners of the blocks.
[vals,idx] = qtgetblk(I,S,dim) returns in idx a vector containing the linear indices of the upper-left corners of the blocks.
Class Support
I can be of class uint8, uint16, or double. S is of class sparse.
Remarks
The ordering of the blocks in vals matches the columnwise order of the blocks in I. For example, if vals is 4-by-4-by-2, vals(:,:,1) contains the values from the first 4-by-4 block in I, and vals(:,:,2) contains the values from the second 4-by-4 block.
Example
This example continues the qtdecomp example.
[vals,r,c] = qtgetblk(I,S,4)
vals(:,:,1) =
1 1 1 1
1 1 2 1
1 1 1 1
1 1 1 1
vals(:,:,2) =
20 22 20 22
20 22 22 20
20 22 20 20
22 22 20 20
r =
1
5
c =
1
1
See Also
| | qtdecomp | qtsetblk | |