#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#define mx(a,i,j) (i)*(a)->cols+(j)
/*--------------------------------------------------------------------------*/
typedef struct {
int rows;
int cols;
double *val;
} MATRIX;
MATRIX *r[2], *g[2], *b[2], *kernel, *counter;
/*--------------------------------------------------------------------------*/
void clrscr(void)
{
printf("\033[2J"); /* Clear the entire screen.
*/
printf("\033[0;0f"); /* Move cursor to the top left hand
corner */
}
/*-------------------------------------------------------------------------*/
MATRIX *matrix_new(int nrows, int ncols)
{
double *temp;
MATRIX *m = NULL;
if ((temp = malloc(nrows * ncols * sizeof(double))) == NULL)
{ printf("allocation failed"); return NULL; }
if ((m = malloc(sizeof(MATRIX))) == NULL)
{ printf("allocation failed"); free(temp); return NULL; }
m->rows = nrows;
m->cols = ncols;
m->val = temp;
return m;
}
/*-------------------------------------------------------------------------*/
void matrix_free(MATRIX * m)
{
if ( m == NULL) return;
free(m->val);
free(m);
}
/*--------------------------------------------------------------------------*/
int ask_for_image()
{
char filename[128], *c;
int i=0;
system("ls -l");
printf("Enter image filename: ");
i = 0;
do {
c = fgetc(stdin);
filename[i++] = c;
fputc(c, stdout);
fflush(stdout);
} while (c != '\n');
filename[i] = '\0';
i = strlen(filename);
if(i < 5) { printf("No filename selected!\n"); return 1; }
else { filename[i-1] = '\0'; load_image(filename); return 0; }
}
/*--------------------------------------------------------------------------*/
void load_image(char *filename)
{
char sType[8], cmd[512], temp[4];
int ROW, COL, SIZE, c, i, j, pnm=0;
FILE *fp;
clrscr(); printf("Loading %s\n", filename);
i = strlen(filename);
c = &filename[i-3];
system("rm -f temp.* ");
if((strcmp(c, "jpg")) == NULL)
{ sprintf(cmd, "/usr/bin/jpegtopnm %s > temp.pnm", filename); pnm=1;
}
else if((strcmp(c, "tif")) == NULL)
{ sprintf(cmd, "/usr/bin/tifftopnm %s > temp.pnm", filename); pnm=1;
}
else if((strcmp(c, "png")) == NULL)
{ sprintf(cmd, "/usr/bin/pngtopnm %s > temp.pnm", filename); pnm=1;
}
else if((strcmp(c, "gif")) == NULL)
{ sprintf(cmd, "/usr/bin/giftopnm %s > temp.pnm", filename); pnm=1;
}
else if((strcmp(c, "pnm")) == NULL)
{ sprintf(cmd, "cp %s temp.pnm", filename); pnm=1;
}
else if((strcmp(c, "bmp")) == NULL)
{ sprintf(cmd, "/usr/bin/bmptoppm %s > temp.ppm", filename);
}
else if((strcmp(c, "tga")) == NULL)
{ sprintf(cmd, "/usr/bin/tgatoppm %s > temp.ppm", filename);
}
else
{ printf("%s is no valid filename ext[jpg, tif, png, gif, tga]\n",
c); return; }
system(cmd);
if(pnm) { if((fp = fopen("temp.pnm","rb")) == NULL)
{ fprintf(stderr, "Enable to open file"); exit(1); } }
else { if((fp = fopen("temp.ppm","rb")) == NULL)
{ fprintf(stderr, "Enable to open file"); exit(1); } }
fscanf(fp, "%s %d %d %d", sType, &COL, &ROW, &SIZE);
printf("Image Type: %s\n", sType);
printf("COL: %d\tROW: %d\tMAX SIZE: %d", COL, ROW, SIZE);
/* read 1 space */
c = fgetc(fp); printf("%c", c);
r[0] = matrix_new( ROW, COL );
g[0] = matrix_new( ROW, COL );
b[0] = matrix_new( ROW, COL );
r[1] = matrix_new( ROW, COL );
g[1] = matrix_new( ROW, COL );
b[1] = matrix_new( ROW, COL );
counter= matrix_new( ROW, COL );
for(i=0; i<ROW; i++)
{
for(j=0; j<COL; j++)
{
c = fgetc(fp); r[0]->val[mx(r[0],i,j)] = c;
c = fgetc(fp); g[0]->val[mx(g[0],i,j)] = c;
c = fgetc(fp); b[0]->val[mx(b[0],i,j)] = c;
}
}
fclose(fp);
}
/*--------------------------------------------------------------------------*/
void compute_kernel(int radius)
{
int x, y, i, j, size;
double tval, coefficient;
size = (radius*2) + 1;
kernel = matrix_new(size,size);
coefficient = -2 / pow(radius,2);
i=0;
for(y=-radius; y<=radius; y++)
{
j=0;
for(x=-radius; x<=radius; x++)
{
kernel->val[mx(kernel,i,j)] = exp(coefficient * (pow(x,2) +
pow(y,2)));
j++;
} i++;
}
}
/*--------------------------------------------------------------------------*/
void write_new_pnm( int size, MATRIX *r, MATRIX *g, MATRIX *b )
{
int SIZE, c, i, j;
FILE *fp;
if((fp = fopen("new.pnm","wb")) == NULL)
{ fprintf(stderr, "Enable to open file"); exit(1); }
fprintf(fp, "P6\n%d %d\n%d\n", r->cols, r->rows, size);
printf("Writting COL: %d\tROW: %d\tMAX SIZE: %d\n", r->cols,
r->rows, size);
fflush(stdout);
for (i=0; i < r->rows; i++)
{
for (j = 0; j < r->cols; j++)
{
c = r->val[mx(r,i,j)]; fputc(c, fp);
c = g->val[mx(g,i,j)]; fputc(c, fp);
c = b->val[mx(b,i,j)]; fputc(c, fp);
}
}
fclose(fp);
fflush(stdout);
system("gqview new.pnm &");
}
/*-------------------------------------------------------------------------*/
/* Gaussian Blur
*/
/*-------------------------------------------------------------------------*/
static GaussianBlur(MATRIX *a, MATRIX *b, int radius)
{
int crow, ccol, i, j, ki, kj;
unsigned long index=0;
double convolution, coefficient=0.0;
compute_kernel(radius);
/*--- adding all the value of kernel ---*/
for(i=0; i<5; i++)
for(j=0; j<5; j++)
coefficient += kernel->val[mx(kernel,i,j)];
/* initialize counter matrix to 0.0 */
index=0;
for (i=0; i < counter->rows; i++)
{
for (j=0; j < counter->cols; j++)
{
counter->val[index] = 0.0;
index++;
}
}
index=0;
/******************* Source Matrix Loop **************************/
for(crow=0; crow < a->rows; crow++)
{
for(ccol=0; ccol < a->cols; ccol++)
{
/*=================== Kernel Matrix Loop =====================*/
ki=0;
for (i=crow-radius; i<crow+radius+1; i++)
{
kj=0;
for (j=ccol-radius; j<ccol+radius+1; j++)
{
index++;
if((i >= 0) && (j >=0) && (i < a->rows) && (j < a->cols))
{
if(a->val[mx(a,i,j)] != 0)
{
index++;
b->val[mx(b,crow,ccol)] += a->val[mx(a,i,j)] *
kernel->val[mx(kernel,ki,kj)];
counter->val[mx(counter,crow,ccol)] +=
kernel->val[mx(kernel,ki,kj)];
fflush(stdout);
}
}
kj++;
}
ki++;
}
/*================= End of Kernel Loop ===================*/
if(counter->val[mx(counter,crow,ccol)] == 0)
b->val[mx(b,crow,ccol)] = 0;
else b->val[mx(b,crow,ccol)] = b->val[mx(b,crow,ccol)] /
counter->val[mx(counter,crow,ccol)];
}
}
/********************** End of Source Loop ********************/
printf("Coefficient : %3.0f\n", coefficient);
printf("Total calculations: %d\n", index);
}
/*-------------------------------------------------------------------------*/
int main(int argc, char *argv[])
{
char str[80];
if(ask_for_image()) { printf("Exiting\n"); return EXIT_FAILURE;}
printf("Input Radius: ");
fgets(str, 80, stdin);
printf("Computing Radius is: %s ", str);
GaussianBlur(r[0], r[1], atoi(str));
GaussianBlur(g[0], g[1], atoi(str));
GaussianBlur(b[0], b[1], atoi(str));
write_new_pnm( 255, r[1], g[1], b[1] );
matrix_free(r[0]); matrix_free(b[0]); matrix_free(g[0]);
matrix_free(r[1]); matrix_free(b[1]); matrix_free(g[1]);
matrix_free(kernel);
matrix_free(counter);
return EXIT_SUCCESS;
}
результирующего изображения записывайте среднее арифметическое цветов пикселей (точнее говоря, интенсивностей в каждом RGB-канале) исходного изображения, взятых из прямоугольника 
, левый-верхний угол которого имеет координаты 
.