how to write code for given algorithm

to write code for this given algorithm if my image is pic.jpg

my image is gray image.

FOR all rows in image:
FOR i from 1 to (row length-1):
IF gray value(pixeli) -
gray value(pixeli+1) > edge Threshold THEN
set pixeli=WHITE
ELSE
set pixeli=BLACK
END IF
END
END

this is for only rows but i hv to do it both horizontally and vertically

Answer 1

[nug]

Are you trying to get someone to do your homework? Anyways you would first need to read the image using 'imread'. Use 'size' to figure out the number of rows and columns. If I represents your image, size(I,1) gives you number of rows and size(I,2) number of columns. Then based on your threshold you can set the pixel value to either 255(white) or 0(black).

Here is the sample code

 I = imread('pic.jpg');
 imshow(I);
 for i= 1:size(I,1)
    for j = 1:size(I,2)
        if I(i,j) > threshold
           I(i,j) = 255;
        else
           I(i,j) = 0;
        end
    end
 end
 figure, imshow(I)

or as an alternative you could use 'graythresh' from matlab to do the same.