Image Processing Toolbox

Passing an M-File Function to a Function Function

Create an M-file containing your block-processing function. Using the example function above, your M-file might contain the following lines.

function y = myblkfun(x,P1)
% For an input block of x, divide the pixel values by P1.
% Temporarily make x double so you can perform arithmetic on it.
y = uint8(double(x)*P1);

To use your M-file with blkproc, create a function handle (function_handle) to it, and pass in the handle and any desired value for P1. For example,

I = imread('cameraman.tif');
f = @myblkfun; % Create a function handle.
I2 = blkproc(I, [10 10], f, 2);
imshow(I);
figure, imshow(I2);

Figure A-1: Original Image (left) and Brightened Image (right)

Working with Function Functions

Passing an Inline Object to a Function Function