pic.h

#ifndef _PIC_H
#define _PIC_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stdio.h>

#ifndef ALLOC
#define ALLOC(ptr, type, n) { \
    ptr = (type *)malloc((n)*sizeof(type)); \
    if (!ptr) { \
	fprintf(stderr, "pic_alloc: Can't allocate %d bytes of memory, aborting\n", n); \
	exit(1); \
    } \
}
#endif

#ifndef TRUE
#define TRUE 1
#define FALSE 0
#endif

	typedef unsigned char Pixel1;	/* 1-byte pixel */
	typedef struct { Pixel1 r, g, b; }	Pixel1_rgb;
	typedef short                           Pixel2;
	typedef struct { Pixel2 r, g, b; }        Pixel2_rgb;
	typedef Pixel2_rgb Rgbcolor;

	typedef struct {		/* PICTURE */
		int nx, ny;			/* width & height, in pixels */
		int bpp;			/* bytes per pixel = 1, 3, or 4 */
		Pixel1* pix;		/* array of pixels */
					/* data is in row-major order,
						i.e. it has the same memory layout as:
						if 1 byte per pixel,  then array[ny][nx]
						if 3 bytes per pixel, then array[ny][nx][3]
						if 4 bytes per pixel, then array[ny][nx][4] */
	} Pic;

	/*
	 * use the following macro to access the red, green, and blue channels of
	 * a given pixel, for an image stored in a Pic structure.
	 */
#define PIC_PIXEL(pic, x, y, chan) \
    (pic)->pix[((y)*(pic)->nx+(x))*(pic)->bpp+(chan)]
	 /* returns channel chan of pixel (x,y) of picture pic */
	 /* usually chan=0 for red, 1 for green, 2 for blue */

	typedef enum { PIC_TIFF_FILE, PIC_PPM_FILE, PIC_JPEG_FILE, PIC_UNKNOWN_FILE } Pic_file_format; // only PPM is supported 

	/*----------------------Allocation routines--------------------------*/
	extern Pic* pic_alloc(int nx, int ny, int bytes_per_pixel, Pic* opic);
	extern void pic_free(Pic* p);

	/*------------------------- I/O routines ----------------------------*/
	/*
	extern int tiff_get_size(char *file, int *nx, int *ny);
	extern Pic *tiff_read(char *file, Pic *opic);
	extern int tiff_write(char *file, Pic *pic);

	extern int jpeg_get_size(char *file, int *nx, int *ny);
	extern Pic *jpeg_read(char *file, Pic *opic);
	extern int jpeg_write(char *file, Pic *pic);
	*/

	extern int ppm_get_size(char* file, int* nx, int* ny);
	extern Pic* ppm_read(char* file, Pic* opic);
	extern int ppm_write(char* file, Pic* pic);

	/*
	extern int pic_get_size(char *file, int *nx, int *ny);
	extern Pic *pic_read(char *file, Pic *opic);
	extern int pic_write(char *file, Pic *pic, Pic_file_format format);
	extern Pic_file_format pic_file_type(char *file);
	extern Pic_file_format pic_filename_type(char *file);
	*/

#ifdef __cplusplus
}
#endif
#endif