#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <ctype.h>
#include "proto.h"
void SavePNMImage(Image *, char *);
Image *SwapImage(Image *);
Image *ReadPNMImage(char *);
Image *CreateNewImage(Image *, char *comment);
int TestReadImage(char *, char *);
int main(int argc, char **argv)
{
TestReadImage(argv[1],argv[2]);
return(0);
}
int TestReadImage(char *filename, char *outfilename)
{
Image *image;
Image *outimage;
image=ReadPNMImage(filename);
outimage=SwapImage(image);
SavePNMImage(outimage, outfilename);
return(0);
}
Image *SwapImage(Image *image)
{
unsigned char *tempin, *tempout;
int i, size;
Image *outimage;
outimage=CreateNewImage(image,"#testing Swap");
tempin=image->data;
tempout=outimage->data;
if(image->Type==GRAY) size = image->Width * image->Height;
else if(image->Type==COLOR) size = image->Width * image->Height * 3;
for(i=0;i<size;i++)
{
*tempout=*tempin;
tempin++;
tempout++;
}
return(outimage);
}
/*******************************************************************************/
//Read PPM image and return an image pointer
**************************************************************************/
Image *ReadPNMImage(char *filename)
{
char ch;
int maxval, Width, Height;
int size, num,j;
FILE *fp;
Image *image;
int num_comment_lines=0;
image=(Image *)malloc(sizeof(Image));
if((fp=fopen(filename,"r"))==NULL){
printf("Cannot open %s\n", filename);
exit(0);
}
printf("Loading %s ...",filename);
if (fscanf(fp, "P%c\n", &ch) != 1) {
printf("File is not in ppm/pgm raw format; cannot read\n");
exit(0);
}
if( ch != '6' && ch !='5') {
printf("File is not in ppm/pgm raw format; cannot read\n");
exit(0);
}
if(ch == '5')image->Type=GRAY; // Gray (pgm)
else if(ch=='6')image->Type=COLOR; //Color (ppm)
/* skip comments */
ch = getc(fp);
j=0;
while (ch == '#')
{
image->comments[num_comment_lines][j]=ch;
j++;
do {
ch = getc(fp);
image->comments[num_comment_lines][j]=ch;
j++;
} while (ch != '\n'); /* read to the end of the line */
image->comments[num_comment_lines][j-1]='\0';
j=0;
num_comment_lines++;
ch = getc(fp); /* thanks, Elliot */
}
if (!isdigit((int)ch)){
printf("Cannot read header information from ppm file");
exit(0);
}
ungetc(ch, fp); /* put that digit back */
/* read the width, height, and maximum value for a pixel */
fscanf(fp, "%d%d%d\n", &Width, &Height, &maxval);
/*
if (maxval != 255){
printf("image is not true-color (24 bit); read failed");
exit(0);
}
*/
if(image->Type==GRAY)
size = Width * Height;
else if(image->Type==COLOR)
size = Width * Height *3;
image->data = (unsigned char *) malloc(size);
image->Width = Width;
image->Height = Height;
image->num_comment_lines= num_comment_lines;
if (!image->data){
printf("cannot allocate memory for new image");
exit(0);
}
num = fread((void *) image->data, 1, (size_t) size, fp);
//printf("Complete reading of %d bytes \n", num);
if (num != size){
printf("cannot read image data from file");
exit(0);
}
//for(j=0;j<image->num_comment_lines;j++){
// printf("%s\n",image->comments[j]);
// }
fclose(fp);
/*----- Debug ------*/
if(image->Type==GRAY)printf("..Image Type PGM\n");
else printf("..Image Type PPM Color\n");
/*
printf("Width %d\n", Width);
printf("Height %d\n",Height);
printf("Size of image %d bytes\n",size);
printf("maxvalue %d\n", maxval);
*/
return(image);
}
void SavePNMImage(Image *temp_image, char *filename)
{
int num,j;
int size ;
FILE *fp;
//char comment[100];
printf("Saving Image %s\n", filename);
fp=fopen(filename, "w");
if (!fp){
printf("cannot open file for writing");
exit(0);
}
//strcpy(comment,"#Created by Dr Mohamed N. Ahmed");
if(temp_image->Type==GRAY){ // Gray (pgm)
fprintf(fp,"P5\n");
size = temp_image->Width * temp_image->Height;
}
else if(temp_image->Type==COLOR){ // Color (ppm)
fprintf(fp,"P6\n");
size = temp_image->Width * temp_image->Height*3;
}
for(j=0;j<temp_image->num_comment_lines;j++)
fprintf(fp,"%s\n",temp_image->comments[j]);
fprintf(fp, "%d %d\n%d\n", temp_image->Width, temp_image->Height, 255);
num = fwrite((void *) temp_image->data, 1, (size_t) size, fp);
if (num != size){
printf("cannot write image data to file");
exit(0);
}
fclose(fp);
}
/*************************************************************************/
/*Create a New Image with same dimensions as input image */
/*************************************************************************/
Image *CreateNewImage(Image * image, char *comment)
{
Image *outimage;
int size,j;
outimage=(Image *)malloc(sizeof(Image));
outimage->Type =image->Type;
if(outimage->Type==GRAY) size = image->Width * image->Height;
else if(outimage->Type==COLOR) size = image->Width * image->Height * 3;
outimage->Width =image->Width;
outimage->Height=image->Height;
outimage->num_comment_lines=image->num_comment_lines;
/*--------------------------------------------------------*/
/* Copy Comments for Original Image */
for(j=0;j<outimage->num_comment_lines;j++)
strcpy(outimage->comments[j],image->comments[j]);
/*----------- Add New Comment ---------------------------*/
strcpy(outimage->comments[outimage->num_comment_lines],comment);
outimage->num_comment_lines++;
outimage->data = (unsigned char *) malloc(size);
if (!outimage->data){
printf("cannot allocate memory for new image");
exit(0);
}
return(outimage);
}
/////////////////////
//proto.h
#define GRAY 1
#define COLOR 2
typedef struct Image
{
int Width;
int Height;
int Type; // Gray=1, Color=2;
unsigned char *data;
char comments[15][100];
int num_comment_lines;
}Image;
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