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img2pnm.c

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#include "sadie.h"

#define UCHAR(c) ((unsigned char) (c))

/*
 * The maximum amount of memory to allocate for data read from the
 * file.  If we need more than this, we do it in pieces.
 */

#define MAX_MEMORY      10000           /* don't allocate > 10KB */

/*
 * Define PGM and PNM, i.e. gray images and color images.
 */

#define PGM 1
#define PPM 2


/*-Copyright Information------------------------------------------------------*/
/* Copyright (c) 1988 by the University of Arizona Digital Image Analysis Lab */
/*----------------------------------------------------------------------------*/
/*-General Information--------------------------------------------------------*/
/*                                                                            */
/*   This function writes a SADIE image from main memory to a PNM file.       */
/*                                                                            */
/*----------------------------------------------------------------------------*/
/*-Interface Information------------------------------------------------------*/
void IMG2PNM (in,name)
IMAGE *in;          /*  I   Pointer to the image.                                 */
char *name;         /*  I   String, containing the name of the disk file.         */
/*----------------------------------------------------------------------------*/
{
    int i,j,k;
    char msg[SLEN];
    FILE *fp=NULL;
    int nBytes,nbit=8;
    unsigned char *pixelPtr=NULL, *data=NULL;
    char header[30];
    int count;
    PIXEL factor;
    char type[5];
    int nbnd;
    

    /* open image file */
    if (!(fp=fopen(name,"w"))) {
        sprintf(msg," Can't open file %s.",name);
        MESSAGE('E',msg);
        goto the_end;
    }

    if (!CHECKIMG(in)) {
        MESSAGE('E'," Can't identify image.");
        goto the_end;
    }

    if (NAMES) {
        MESSAGE('I',"");
        MESSAGE('I',"IMG2PNM");
        MESSAGE('I',"");
        sprintf(msg," Input image:               %s",in->text);
        MESSAGE('I',msg);
        sprintf(msg," Output disk file:          %s",name);
        MESSAGE('I',msg);
        sprintf(msg," Output format:             %d-bit PNM",nbit);
        MESSAGE('I',msg);
        MESSAGE('I'," ...............");
    }

    RANGE(in);
    if (in->gmax > in->gmin) {
        factor = (PIXEL) 255.0 / (in->gmax - in->gmin);
    }

    if (in->nbnd == 3) {
        nbnd = 3;
        sprintf(type,"P6");
    } else {
        nbnd = 1;
        sprintf(type,"P5");
    }
        
    sprintf(header, "%s\n%d %d\n255\n", type, in->npix, in->nlin);
    nBytes = strlen(header);
    count = fwrite(header, 1, nBytes, fp);
    if (count != nBytes) {
        MESSAGE('E',"Can't write header to file.");
        goto the_end;
    }

    nBytes = in->npix * nbnd;
    pixelPtr = (unsigned char *) malloc((unsigned) nBytes);
    if (!pixelPtr) {
        MESSAGE('E',"Could not allocate memory to write image.");
        goto the_end;
    }

    for (j=0; j<in->nlin; j++) {
        data = pixelPtr;

        for (k=0; k<in->npix; k++) {
            for (i=0; i<nbnd; i++) {
                *data++ = (unsigned char) rnd(in->data[i][j][k] * factor);
            }
        }

        count = fwrite(pixelPtr, 1, nBytes, fp);
        if (count != nBytes) {
            sprintf(msg, "Error writing PNM image data to file");
            MESSAGE('E',msg);
            goto the_end;
        }
    }

 the_end:

    if (pixelPtr) free(pixelPtr);
    
    if (fp) {
        if (fclose(fp)) {
            sprintf(msg," Can't close file %s.",name);
            MESSAGE('W',msg);
        }
    }

}

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