output of fun is not a matrix the same size as the block in block proc

1 次查看（过去 30 天）
Kasra Sadatsharifi
Kasra Sadatsharifi 2020-12-16
评论： Ameer Hamza 2020-12-18
Hello,
I am trying to divid my image into distinct block and perform a function on each one of them. The output of my function would be two column matrices of coordinates and with each iteration the number of coordinates will not be the same(different number of points with specific features in each block). What should I do to be able to stack the coordinates into a two column matrix at each iteration so at the end I have a bunch of XY coordinates?
Thank you

请先登录，再回答此问题。

回答（1 个）

Ameer Hamza
Ameer Hamza 2020-12-16
编辑：Ameer Hamza 2020-12-16
You can create a cell array for saving data in each iteration and then stack them together at the end
xy_cell = cell(1,N); % it assumes you have N blocks
for i = 1:N
% calculate x and y coordinates
xy_cell{i} = [x y];
end
xy = vertcat(xy_cell{:})
  2 个评论
Kasra Sadatsharifi
Kasra Sadatsharifi 2020-12-17
thank you ameer for your answer but blockproc stack the output of each patch as anumeric array and returns a matrix at the end. I have tried using cells but it did not work since you cannot have any other outputs other thatn the one the function stacks up together.
Ameer Hamza
Ameer Hamza 2020-12-18
In that case, blockproc() is not an appropriate function for you. You either need to use for loops or something like this
img = rand(100); % example matrix
C = mat2cell(img, 20*ones(1,size(img,1)/20), 20*ones(1,size(img,2)/20)); % divide image in blocks of 20x20
C_processed = cellfun(@fun, C, 'uni', 0); % fun the function you want to call on each block. It should return an nx2 matrix
xy = vertcat(C_processed{:});

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Neighborhood and Block Processing 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by