#include "header.h"

/* ReadImageFile() takes as an argument a pointer to a file stream.  It 
 * allocates space for and reads the image into a two dimetional array and
 * returns a pointer to the array (**I).  It assumes that the file is already
 * open and that the size parameters have already been read.
 */

/* Written by Justin Romberg, Waqas Akram, & Charles Gamiz, May 1997 */

int **ReadStartFile(FILE *sfile, int *sizef)
{
  int **image;
  int i;

  /* allocate space for the image */
  image = (int **)calloc(sizef[0], sizeof(int*));
  for (i=0; i < sizef[0]; i++) {
    image[i] = (int*)calloc(sizef[1], sizeof(int));
  }

  /* read in the image (the image is written in row order) */
  for (i=0; i < sizef[0]; i++) {
    fread(image[i], sizeof(int), sizef[1], sfile);
  }

  return(image);

}


int **ReadImageFile(FILE *imagefile, int *sizeI)
{
  int **Image;
  int i;

  /* allocate space for the image */
  Image = (int **)calloc(sizeI[0], sizeof(int*));
  for (i=0; i < sizeI[0]; i++) {
    Image[i] = (int*)calloc(sizeI[1], sizeof(int));
  }

  /* read in the image (the image is written in row order) */
  for (i=0; i < sizeI[0]; i++) {
    fread(Image[i], sizeof(int), sizeI[1], imagefile);
  }

  return(Image);

}


/* ReadGradientFile() takes a pointer to a 2D array of doubles. Assumes that
   the file is already open, but the size HAS NOT BEEN READ YET */
double **ReadGradientFile(FILE *gradfile)
{
  double **Gradient;
  int dummy;
  int i;

  /* kill the size from the file */
  fread(&dummy, sizeof(int), 1, gradfile);
  fread(&dummy, sizeof(int), 1, gradfile);

  /* allocate space for the image */
  Gradient = (double **)calloc(sizeI[0], sizeof(double*));
  for (i=0; i < sizeI[0]; i++) {
    Gradient[i] = (double*)calloc(sizeI[1], sizeof(double));
  }

  /* read in the image (the image is written in row order) */
  for (i=0; i < sizeI[0]; i++) {
    fread(Gradient[i], sizeof(double), sizeI[1], gradfile);
  }

  return(Gradient);

}



/* WriteImageFile() takes a 2D array and writes it out row wise to a file.  It
 * also writes out the size of the image (first the number of rows and then the
 * number of columns.
 */
void WriteImageFile(char *filename, int **Image, int *sizeI)
{
  int i;
  FILE *resultfile;

  resultfile = fopen(filename, "w");

  /* write the number of rows and columns out */
  fwrite(&sizeI[0], sizeof(int), 2, resultfile);

  /* write the image to the file row-wise */
  for (i=0; i < sizeI[0]; i++) {
    fwrite(Image[i], sizeof(int), sizeI[1], resultfile);
  }

  fclose(resultfile);

}