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/*
* jwrppm.c
*
* Copyright (C) 1991, 1992, 1993, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains routines to write output images in PPM/PGM format.
*
* These routines may need modification for non-Unix environments or
* specialized applications. As they stand, they assume output to
* an ordinary stdio stream.
*
* These routines are invoked via the methods put_pixel_rows, put_color_map,
* and output_init/term.
*/
#include "jinclude.h"
#ifdef PPM_SUPPORTED
/*
* Haven't yet got around to making this work with text-format output,
* hence cannot handle pixels wider than 8 bits.
*/
#ifndef EIGHT_BIT_SAMPLES
Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
#endif
/*
* On most systems, writing individual bytes with putc() is drastically less
* efficient than buffering a row at a time for fwrite(). But we must
* allocate the row buffer in near data space on PCs, because we are assuming
* small-data memory model, wherein fwrite() can't reach far memory. If you
* need to process very wide images on a PC, you may have to use the putc()
* approach. Also, there are still a few systems around wherein fwrite() is
* actually implemented as a putc() loop, in which case this buffer is a waste
* of space. So the putc() method can be used by defining USE_PUTC_OUTPUT.
*/
#ifndef USE_PUTC_OUTPUT
static char * row_buffer; /* holds 1 pixel row's worth of output */
#endif
/*
* Write the file header.
*/
METHODDEF void
output_init (decompress_info_ptr cinfo)
{
if (cinfo->out_color_space == CS_GRAYSCALE) {
/* emit header for raw PGM format */
fprintf(cinfo->output_file, "P5\n%ld %ld\n%d\n",
cinfo->image_width, cinfo->image_height, 255);
#ifndef USE_PUTC_OUTPUT
/* allocate space for row buffer: 1 byte/pixel */
row_buffer = (char *) (*cinfo->emethods->alloc_small)
((size_t) (SIZEOF(char) * cinfo->image_width));
#endif
} else if (cinfo->out_color_space == CS_RGB) {
/* emit header for raw PPM format */
fprintf(cinfo->output_file, "P6\n%ld %ld\n%d\n",
cinfo->image_width, cinfo->image_height, 255);
#ifndef USE_PUTC_OUTPUT
/* allocate space for row buffer: 3 bytes/pixel */
row_buffer = (char *) (*cinfo->emethods->alloc_small)
((size_t) (3 * SIZEOF(char) * cinfo->image_width));
#endif
} else {
ERREXIT(cinfo->emethods, "PPM output must be grayscale or RGB");
}
}
/*
* Write some pixel data.
*/
#ifdef USE_PUTC_OUTPUT
METHODDEF void
put_pixel_rows (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
{
register FILE * outfile = cinfo->output_file;
register JSAMPROW ptr0, ptr1, ptr2;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr0 = pixel_data[0][row];
ptr1 = pixel_data[1][row];
ptr2 = pixel_data[2][row];
for (col = width; col > 0; col--) {
putc(GETJSAMPLE(*ptr0), outfile);
ptr0++;
putc(GETJSAMPLE(*ptr1), outfile);
ptr1++;
putc(GETJSAMPLE(*ptr2), outfile);
ptr2++;
}
}
}
METHODDEF void
put_gray_rows (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
{
register FILE * outfile = cinfo->output_file;
register JSAMPROW ptr0;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr0 = pixel_data[0][row];
for (col = width; col > 0; col--) {
putc(GETJSAMPLE(*ptr0), outfile);
ptr0++;
}
}
}
#else /* use row buffering */
METHODDEF void
put_pixel_rows (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
{
FILE * outfile = cinfo->output_file;
register JSAMPROW ptr0, ptr1, ptr2;
register char * row_bufferptr;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr0 = pixel_data[0][row];
ptr1 = pixel_data[1][row];
ptr2 = pixel_data[2][row];
row_bufferptr = row_buffer;
for (col = width; col > 0; col--) {
*row_bufferptr++ = (char) GETJSAMPLE(*ptr0++);
*row_bufferptr++ = (char) GETJSAMPLE(*ptr1++);
*row_bufferptr++ = (char) GETJSAMPLE(*ptr2++);
}
(void) JFWRITE(outfile, row_buffer, 3*width);
}
}
METHODDEF void
put_gray_rows (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
{
FILE * outfile = cinfo->output_file;
register JSAMPROW ptr0;
register char * row_bufferptr;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr0 = pixel_data[0][row];
row_bufferptr = row_buffer;
for (col = width; col > 0; col--) {
*row_bufferptr++ = (char) GETJSAMPLE(*ptr0++);
}
(void) JFWRITE(outfile, row_buffer, width);
}
}
#endif /* USE_PUTC_OUTPUT */
/*
* Write some pixel data when color quantization is in effect.
*/
#ifdef USE_PUTC_OUTPUT
METHODDEF void
put_demapped_rgb (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
{
register FILE * outfile = cinfo->output_file;
register JSAMPROW ptr;
register JSAMPROW color_map0 = cinfo->colormap[0];
register JSAMPROW color_map1 = cinfo->colormap[1];
register JSAMPROW color_map2 = cinfo->colormap[2];
register int pixval;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr = pixel_data[0][row];
for (col = width; col > 0; col--) {
pixval = GETJSAMPLE(*ptr++);
putc(GETJSAMPLE(color_map0[pixval]), outfile);
putc(GETJSAMPLE(color_map1[pixval]), outfile);
putc(GETJSAMPLE(color_map2[pixval]), outfile);
}
}
}
METHODDEF void
put_demapped_gray (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
{
register FILE * outfile = cinfo->output_file;
register JSAMPROW ptr;
register JSAMPROW color_map0 = cinfo->colormap[0];
register int pixval;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr = pixel_data[0][row];
for (col = width; col > 0; col--) {
pixval = GETJSAMPLE(*ptr++);
putc(GETJSAMPLE(color_map0[pixval]), outfile);
}
}
}
#else /* use row buffering */
METHODDEF void
put_demapped_rgb (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
{
FILE * outfile = cinfo->output_file;
register JSAMPROW ptr;
register char * row_bufferptr;
register JSAMPROW color_map0 = cinfo->colormap[0];
register JSAMPROW color_map1 = cinfo->colormap[1];
register JSAMPROW color_map2 = cinfo->colormap[2];
register int pixval;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr = pixel_data[0][row];
row_bufferptr = row_buffer;
for (col = width; col > 0; col--) {
pixval = GETJSAMPLE(*ptr++);
*row_bufferptr++ = (char) GETJSAMPLE(color_map0[pixval]);
*row_bufferptr++ = (char) GETJSAMPLE(color_map1[pixval]);
*row_bufferptr++ = (char) GETJSAMPLE(color_map2[pixval]);
}
(void) JFWRITE(outfile, row_buffer, 3*width);
}
}
METHODDEF void
put_demapped_gray (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
{
FILE * outfile = cinfo->output_file;
register JSAMPROW ptr;
register char * row_bufferptr;
register JSAMPROW color_map0 = cinfo->colormap[0];
register int pixval;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr = pixel_data[0][row];
row_bufferptr = row_buffer;
for (col = width; col > 0; col--) {
pixval = GETJSAMPLE(*ptr++);
*row_bufferptr++ = (char) GETJSAMPLE(color_map0[pixval]);
}
(void) JFWRITE(outfile, row_buffer, width);
}
}
#endif /* USE_PUTC_OUTPUT */
/*
* Write the color map.
* For PPM output, we just remember to demap the output data!
*/
METHODDEF void
put_color_map (decompress_info_ptr cinfo, int num_colors, JSAMPARRAY colormap)
{
if (cinfo->out_color_space == CS_RGB)
cinfo->methods->put_pixel_rows = put_demapped_rgb;
else
cinfo->methods->put_pixel_rows = put_demapped_gray;
}
/*
* Finish up at the end of the file.
*/
METHODDEF void
output_term (decompress_info_ptr cinfo)
{
/* No work except to make sure we wrote the output file OK; */
/* we let free_all release any workspace */
fflush(cinfo->output_file);
if (ferror(cinfo->output_file))
ERREXIT(cinfo->emethods, "Output file write error --- out of disk space?");
}
/*
* The method selection routine for PPM format output.
* This should be called from d_ui_method_selection if PPM output is wanted.
*/
GLOBAL void
jselwppm (decompress_info_ptr cinfo)
{
cinfo->methods->output_init = output_init;
cinfo->methods->put_color_map = put_color_map;
if (cinfo->out_color_space == CS_RGB)
cinfo->methods->put_pixel_rows = put_pixel_rows;
else
cinfo->methods->put_pixel_rows = put_gray_rows;
cinfo->methods->output_term = output_term;
}
#endif /* PPM_SUPPORTED */
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.