implementing erosion, dilation in C, C++

Question

I have theoretical understanding of how dilation in binary image is done.

AFAIK, If my SE (structuring element) is this

0 1
1 1. 

wher

Answer 1

/* structure of the image variable
 * variable n stores the order of the square matrix */

typedef struct image{
        int mat[][];
        int n;
        }image;


/* function recieves image "to dilate" and returns "dilated"*
 * structuring element predefined:
 *             0  1  0
 *             1  1  1
 *             0  1  0
 */

image* dilate(image* to_dilate)
{
       int i,j;
       int does_order_increase;
       image* dilated;

       dilated = (image*)malloc(sizeof(image));
       does_order_increase = 0;

/* checking whether there are any 1's on d border*/       

       for( i = 0 ; in ; i++ )
       {
            if( (to_dilate->a[0][i] == 1)||(to_dilate->a[i][0] == 1)||(to_dilate->a[n-1][i] == 1)||(to_dilate->a[i][n-1] == 1) )
            {
                does_order_increase = 1;
                break;
            }
       }

/* size of dilated image initialized */       

       if( does_order_increase == 1)
           dilated->n = to_dilate->n + 1;
       else
           dilated->n = to_dilate->n;

/* dilating image by checking every element of to_dilate and filling dilated *
 * does_order_increase serves to cope with adjustments if dilated 's order increase */

       for( i = 0 ; in ; i++ )
       {
            for( j = 0 ; jn ; j++ )
            {
                 if( to_dilate->a[i][j] == 1)
                 {
                     dilated->a[i + does_order_increase][j + does_order_increase] = 1;
                     dilated->a[i + does_order_increase -1][j + does_order_increase ] = 1;
                     dilated->a[i + does_order_increase ][j + does_order_increase -1] = 1;
                     dilated->a[i + does_order_increase +1][j + does_order_increase ] = 1;
                     dilated->a[i + does_order_increase ][j + does_order_increase +1] = 1;
                 }
            }
       }

/* dilated stores dilated binary image */

       return dilated;
}

/* end of dilation */