Calling function for blockproc

I want to create a calling function for blockproc, where I obtain the number of connected objects inside each block of the image. B1 is my image, a logical returned after converting my image to black and white based on a threshold. The relevant code is here:

    func = @blockfun 
    blockSize = [16 16];
    blockyImage8 = blockproc(B1, blockSize, func);

And the function is here:

    function x = blockfun(a)
    CC = bwconncomp(a,8);
    x = CC.NumObjects;
    end

I get the error message:

Error using bwconncomp
Expected input number 1, BW, to be one of these types:

logical, double, single, uint8, uint16, uint32, uint64, int8, int16, int32, int64

Instead its type was struct.

Any advice?

Answer 1

[Stephen23]

As its help explains, blockproc supplies a structure to the called function. The fields of the structure are listed in the help. Possibly you want the data field:

CC = bwconncomp(a.data,8);

[Pa342]

thanks, I understand now.