MATLAB: Not enough input arguments for read an immage

error

Hi, I'm new to MATLAB and am having some trouble. I want read an immage form a function. this is my code:
function [j]=readimmage(img_gray);
p=im2bw(img_gray);
imshow(p);
The error is:
Not enough input arguments.
Error in readimmage (line 2) p=im2bw(img_gray);
i know that i can use imread function but… how can I read an image file using a function unless imread ?

Best Answer

Check out the documentation. The function im2bw needs two arguments:
BW = im2bw(I, level)
Where level is a number between 0 and 1, and is the cutoff for a pixel being classified as white or black. So this should work:
function [j]=readimmage(img_gray)
p=im2bw(img_gray,0.5);
imshow(p);
end