PNMImage* readPNM(char* filename) {
FILE* fp;
char buffer[16];
int c;
// Open PNM file for reading
fp = fopen(filename, "rb");
if (!fp) {
fprintf(stderr, "Unable to open file '%s'\n", filename);
return NULL;
}
// Read image format
if (!fgets(buffer, sizeof(buffer), fp)) {
return NULL;
}
if (buffer[0] != 'P' || buffer[1] != '6') {
fprintf(stderr, "Invalid image format (must be 'P6')\n");
return NULL;
}
// Check for comments
c = getc(fp);
while (c == '#') {
while (getc(fp) != '\n');
c = getc(fp);
}
ungetc(c, fp);
// Read image size
size_t width;
size_t height;
if (fscanf(fp, "%zu %zu", &width, &height) != 2) {
fprintf(stderr, "Invalid image size (error loading '%s')\n", filename);
return NULL;
}
// Read RGB depth
if (fscanf(fp, "%d", &c) != 1) {
fprintf(stderr, "Invalid RGB depth (error loading '%s')\n", filename);
return NULL;
}
if (c != 255) {
fprintf(stderr, "'%s' does not have 8-bits components\n", filename);
return NULL;
}
while (fgetc(fp) != '\n') ;
// Allocate memory
PNMImage* image = createPNM(width, height);
if (!image) {
return NULL;
}
// Read pixels
if (fread(image->data, 3 * image->width,
image->height, fp) != image->height) {
fprintf(stderr, "Error loading image '%s'\n", filename);
freePNM(image);
return NULL;
}
fclose(fp);
return image;
}
/*----------------------------converte----------------------------*/
PNM *converte(PNM *pnm, char*tipoDes)
{
char tipoOrig = pnm->tipo[1], tipoDest;
PNM *temp = (PNM *)malloc(sizeof(PNM));
if(strlen(tipoDes) == 2) tipoDest = tipoDes[1];
else return NULL;
switch(tipoDest)
{
case '1':
switch(tipoOrig)
{
case '1': temp = copia(pnm);
break;
case '2': temp = p2_2_p1(pnm);
break;
case '3': temp = p3_2_p1(pnm);
break;
case '4': temp = p4_2_p1(pnm);
break;
case '5': temp = p5_2_p1(pnm);
break;
case '6': temp = p6_2_p1(pnm);
break;
default: return NULL;
}
break;
case '2':
switch(tipoOrig)
{
case '1': temp = p1_2_p2(pnm);
break;
case '2': temp = copia(pnm);
break;
case '3': temp = p3_2_p2(pnm);
break;
case '4': temp = p4_2_p2(pnm);
break;
case '5': temp = p5_2_p2(pnm);
break;
case '6': temp = p6_2_p2(pnm);
break;
default: return NULL;
}
break;
case '3':
switch(tipoOrig)
{
case '1': temp = p1_2_p3(pnm);
break;
case '2': temp = p2_2_p3(pnm);
break;
case '3': temp = copia(pnm);
break;
case '4': temp = p4_2_p3(pnm);
break;
case '5': temp = p5_2_p3(pnm);
break;
case '6': temp = p6_2_p3(pnm);
break;
default: return NULL;
}
break;
case '4':
switch(tipoOrig)
{
case '1': temp = p1_2_p4(pnm);
break;
case '2': temp = p2_2_p4(pnm);
break;
case '3': temp = p3_2_p4(pnm);
break;
case '4': temp = copia(pnm);
break;
case '5': temp = p5_2_p4(pnm);
break;
case '6': temp = p6_2_p4(pnm);
break;
default: return NULL;
}
break;
case '5':
switch(tipoOrig)
{
case '1': temp = p1_2_p5(pnm);
break;
case '2': temp = p2_2_p5(pnm);
break;
case '3': temp = p3_2_p5(pnm);
break;
case '4': temp = p4_2_p5(pnm);
break;
case '5': temp = copia(pnm);
break;
case '6': temp = p6_2_p5(pnm);
break;
default: return NULL;
}
break;
case '6':
switch(tipoOrig)
{
case '1': temp = p1_2_p6(pnm);
break;
case '2': temp = p2_2_p6(pnm);
break;
case '3': temp = p3_2_p6(pnm);
break;
case '4': temp = p4_2_p6(pnm);
break;
case '5': temp = p5_2_p6(pnm);
break;
case '6': temp = copia(pnm);
break;
default: return NULL;
}
break;
default: return NULL;
}
if(pnm != NULL)
{
freePNM(pnm);
pnm = NULL;
}
return temp;
}
