/***********************************************
*
* file d:\cips\edge3.c
*
* Functions: This file contains
* gaussian_edge
* enhance_edges
*
* Purpose:
* These functions implement several
* types of advanced edge detection.
*
* External Calls:
* wtiff.c - does_not_exist
* round_off_image_size
* create_allocate_tiff_file
* write_array_into_tiff_image
* tiff.c-read tiff header
* rtiff.c-read_tiff_image
* numcvrt.c-get_integer
* edge.c-fix_edges
*
* Modifications:
* 26 March 1991 - created
*
***********************************************/
#include "d:\cips\cips.h"
short enhance_mask[3][3] = {
{-1, 0, -1},
{ 0, 4, 0},
{-1, 0, -1} };
short g7[7][7] = {
{ 0, 0, -1, -1, -1, 0, 0},
{ 0, -2, -3, -3, -3, -2, 0},
{ -1, -3, 5, 5, 5, -3, -1},
{ -1, -3, 5, 16, 5, -3, -1},
{ -1, -3, 5, 5, 5, -3, -1},
{ 0, -2, -3, -3, -3, -2, 0},
{ 0, 0, -1, -1, -1, 0, 0}};
short g9[9] [9] = {
{ 0, 0, 0, -1, -1, -1, 0, 0, 0},
{ 0, -2, -3, -3, -3, -3, -3, -2, 0},
{ 0, -3, -2, -1, -1, -1, -2, -3, 0},
{ -1, -3, -1, 9, 9, 9, -1, -3, -1},
{ -1, -3, -1, 9, 19, 9, -1, -3, -1},
{ -1, -3, -1, 9, 9, 9, -1, -3, -1},
{ 0, -3, -2, -1, -1, -1, -2, -3, 0},
{ 0, -2, -3, -3, -3, -3, -3, -2, 0},
{ 0, 0, 0, -1, -1, -1, 0, 0, 0}};
/******************************************************************
*
* gaussian_edge(...
*
*
*******************************************************************/
gaussian_edge(in_name, out_name, the_image, out_image,
il, ie, ll, le, size, threshold, high)
char in_name[], out_name[];
int high, il, ie, ll, le, size, threshold;
short the_image[ROWS] [COLS], out_image[ROWS] [COLS];
{
char response[80];
long sum;
int a, b, absdiff, absmax, diff, i, j,
length, lower, max, new_hi, new_low,
scale, start, stop, upper, width;
struct tiff_header_struct image_header;
if(does_not_exist(out_name)){
printf("\n\nGAUSSIAN> output file does not exist %s",
out_name);
read_tiff_header(in_name,&image_header);
round_off_image_size(&image_header,
&length, &width);
image_header.image_length = length*ROWS;
image_header.image_width = width*COLS;
create_allocate_tiff_file(out_name, &image_header,
out_image);
} /* ends if does_not_exist */
read_tiff_header(in_name, &image_header);
new_hi = 250;
new_low = 16;
if(image_header.bits_perpixel == 4){
new_hi = 10;
new_low = 3;
}
max = 255;
if(image_header.bits_per_pixel == 4)
max = 16;
if(size == 7){
lower = -3;
upper = 4;
start = 3;
stop = ROWS-3;
scale = 2;
}
if(size == 9){
lower = -4;
upper = 5;
start = 4;
stop = ROWS-4;
scale = 2;
}
read_tiff_image(in_name, the_image, il, ie, ll, le);
for(i=0; i<ROWS; i++)
for(j=0; j<COLS; j++)
out_image[i] [j] = 0;
for(i=start; i<stop; i++){
if ((i%10) == 0) printf(" i=%d", i);
for(j=start; j<stop; j++){
sum = 0;
for(a=lower; a<upper; a++){
for(b=lower; b<upper; b++){
if(size == 7)
sum = sum + the_image[i+a] [j+b] * g7 [a+3] [b+3];
if(size == 9)
sum = sum + the_image[i+a] [j+b] * g9 [a+4] [b+4];
} /* ends loop over a */
} /* ends loop over b */
if(sum < 0) sum = 0;
if(sum > max) sum = max;
out_image[i] [j] = sum;
} /* ends loop over j */
} /* ends loop over i */
/* if desired, threshold the output image */
if(threshold == 1){
for(i=0; i<ROWS; i++){
for(j=0; j<COLS; j++){
if(out_image[i] [j] > high){
out_image[i][j] = new_hi;
}
else{
out_image[i] [j] = new_low;
}
}
}
} /* ends if threshold == 1 */
fix_edges(out_image, size/2);
write_array_into_tiff_image(out_name, out_image,
il, ie, ll, le);
} /* ends gaussian_edge */
/*********************************************
*
* enhance_edges(...
*
* This function enhances the edges in an
* input image and writes the enhanced
* result to an output image. It operates
* much the same way as detect_edges
* except it uses only one type of mask.
*
* The threshold and high parameters perform
* a different role in this function. The
* threshold parameter does not exist. The
* high parameter determines if the edge is
* strong enough to enhance or change the
* input image.
*
*******************************************/
enhance_edges(in_name, out_name, the_image, out_image,
il, ie, ll, le, high)
char in_name[], out_name[];
int high, il, ie, ll, le;
short the_image[ROWS][COLS], out_image[ROWS][COLS];
{
int a, b, i, j, k,
length, max, new_hi,
new_lo, sum, width;
struct tiff_header_struct image_header;
if(does_not_exist(out_name)){
printf("\n\nEE> output file does not exist %s",
out_name);
read_tiff_header(in_name, &image_header);
round_off_image_size(&image_header,
&length, &width);
image_header.image_length = length*ROWS;
image_header.image_width = width*COLS;
create_allocate_tiff_file(out_name, &image_header,
out_image);
} /* ends if does_not_exist */
read_tiff_header(in_name, &image_header);
max = 255;
if(image_header.bits_per_pixel == 4)
max = 16;
read_tiff_image(in_name, the_image, il, ie, ll, le);
/* Do convolution over image array */
for(i=1; i<ROWS-1; i++){
if((i%10) == 0) printf("%d ", i);
for(j=1; j<COLS-1; j++){
sum = 0;
for(a=-1; a<2; a++){
for(b=-1; b<2; b++){
sum = sum + the_image[i+a] [j+b] * enhance_mask [a+1] [b+1];
}
}
if(sum < 0) sum = 0;
if(sum > max) sum = max;
if(sum > high)
out_image[i] [j] = max;
else
out_image[i][j] = the_image[i][j];
} /* ends loop over j */
} /* ends loop over i */
fix_edges(out_image, 1);
write_array_into_tiff_image(out_name, out_image,
il, ie, ll, le);
} /* ends enhance_edges */
/* End of File */