Variable distribution for a parallel image acquisition

I want to parallelize my code by distributing/splitting variables among available workers, run a parallel image acquisition using a defined function 'myWatershedFun' which returns a segmented binary image, and gather the output results from each worker. Here, I have two images of the same size, a grayscale image 'img' and a corresponding binary image 'bw', and a structure array 'param'. I have split each image into vertical stripes, but how can I distribute each part to respective worker? I also want to distribute the structure 'param' to all workers in order to compute 'myWatershedFun'.

Essentially, the serial acquisition that I am trying to parallelize is

bw_seg = myWatershedFun(img, bw, param); % img, bw and bw_seg have the same size

Attempt

[n_rows n_cols] = size(img);

% Set up parallel environment 
poolobj = gcp;
n_workers = poolobj.NumWorkers;

% Split images into equal verticale stripes 
for k = 1:n_workers
    img_temp{k} = img(:, floor((k-1)*(n_cols/n_workers) + 1): ...
        floor(k*(n_cols/n_workers)));
    bw_temp{k} = bw(:, floor((k-1)*(n_cols/n_workers) + 1): ...
        floor(k*(n_cols/n_workers)));
end

spmd
    % Distribute img_temp{k} and bw_temp{k} to worker k, along with param
    ...???
    
    % Each worker segments the assigned vertical area of the image
    bw_seg_worker = myWatershedFun(img_temp{k}, bw_temp{k}, param) 
end

% Merge the 'n_workers' binary outputs bw_seg_worker into a single binary image
bw_seg = ...

% Delete pool
delete(gcp)

Could someone help me? Thanks so much in advance for any input!

Answer 1

[Matt J]

Seems like you could use a parfor loop instead:

parfor k=1:numel(img_temp)
     bw_seg_worker{k} = myWatershedFun(img_temp{k}, bw_temp{k}, param) ;
end

[De Ar]

You sir are awesome!