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* Copyright (C) 1991-1996, Thomas G. Lane.
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* This file is part of the Independent JPEG Group's software.
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* For conditions of distribution and use, see the accompanying README file.
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* This file contains routines to write output images in Targa format.
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* These routines may need modification for non-Unix environments or
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* specialized applications. As they stand, they assume output to
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* an ordinary stdio stream.
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* Based on code contributed by Lee Daniel Crocker.
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#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
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#ifdef TARGA_SUPPORTED
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* To support 12-bit JPEG data, we'd have to scale output down to 8 bits.
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* This is not yet implemented.
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#if BITS_IN_JSAMPLE != 8
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Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
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* The output buffer needs to be writable by fwrite(). On PCs, we must
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* allocate the buffer in near data space, because we are assuming small-data
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* memory model, wherein fwrite() can't reach far memory. If you need to
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* process very wide images on a PC, you might have to compile in large-memory
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* model, or else replace fwrite() with a putc() loop --- which will be much
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/* Private version of data destination object */
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struct djpeg_dest_struct pub; /* public fields */
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char *iobuffer; /* physical I/O buffer */
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JDIMENSION buffer_width; /* width of one row */
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typedef tga_dest_struct * tga_dest_ptr;
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write_header (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, int num_colors)
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/* Create and write a Targa header */
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/* Set unused fields of header to 0 */
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MEMZERO(targaheader, SIZEOF(targaheader));
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targaheader[1] = 1; /* color map type 1 */
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targaheader[5] = (char) (num_colors & 0xFF);
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targaheader[6] = (char) (num_colors >> 8);
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targaheader[7] = 24; /* 24 bits per cmap entry */
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targaheader[12] = (char) (cinfo->output_width & 0xFF);
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targaheader[13] = (char) (cinfo->output_width >> 8);
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targaheader[14] = (char) (cinfo->output_height & 0xFF);
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targaheader[15] = (char) (cinfo->output_height >> 8);
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targaheader[17] = 0x20; /* Top-down, non-interlaced */
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if (cinfo->out_color_space == JCS_GRAYSCALE) {
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targaheader[2] = 3; /* image type = uncompressed gray-scale */
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targaheader[16] = 8; /* bits per pixel */
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} else { /* must be RGB */
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targaheader[2] = 1; /* image type = colormapped RGB */
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targaheader[2] = 2; /* image type = uncompressed RGB */
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if (JFWRITE(dinfo->output_file, targaheader, 18) != (size_t) 18)
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ERREXIT(cinfo, JERR_FILE_WRITE);
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* Write some pixel data.
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* In this module rows_supplied will always be 1.
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put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
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JDIMENSION rows_supplied)
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/* used for unquantized full-color output */
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tga_dest_ptr dest = (tga_dest_ptr) dinfo;
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register JSAMPROW inptr;
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register char * outptr;
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register JDIMENSION col;
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inptr = dest->pub.buffer[0];
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outptr = dest->iobuffer;
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for (col = cinfo->output_width; col > 0; col--) {
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outptr[0] = (char) GETJSAMPLE(inptr[2]); /* RGB to BGR order */
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outptr[1] = (char) GETJSAMPLE(inptr[1]);
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outptr[2] = (char) GETJSAMPLE(inptr[0]);
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inptr += 3, outptr += 3;
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(void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
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put_gray_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
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JDIMENSION rows_supplied)
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/* used for grayscale OR quantized color output */
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tga_dest_ptr dest = (tga_dest_ptr) dinfo;
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register JSAMPROW inptr;
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register char * outptr;
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register JDIMENSION col;
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inptr = dest->pub.buffer[0];
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outptr = dest->iobuffer;
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for (col = cinfo->output_width; col > 0; col--) {
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*outptr++ = (char) GETJSAMPLE(*inptr++);
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(void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
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* Write some demapped pixel data when color quantization is in effect.
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* For Targa, this is only applied to grayscale data.
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put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
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JDIMENSION rows_supplied)
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tga_dest_ptr dest = (tga_dest_ptr) dinfo;
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register JSAMPROW inptr;
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register char * outptr;
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register JSAMPROW color_map0 = cinfo->colormap[0];
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register JDIMENSION col;
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inptr = dest->pub.buffer[0];
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outptr = dest->iobuffer;
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for (col = cinfo->output_width; col > 0; col--) {
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*outptr++ = (char) GETJSAMPLE(color_map0[GETJSAMPLE(*inptr++)]);
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(void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
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* Startup: write the file header.
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start_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
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tga_dest_ptr dest = (tga_dest_ptr) dinfo;
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if (cinfo->out_color_space == JCS_GRAYSCALE) {
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/* Targa doesn't have a mapped grayscale format, so we will */
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/* demap quantized gray output. Never emit a colormap. */
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write_header(cinfo, dinfo, 0);
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if (cinfo->quantize_colors)
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dest->pub.put_pixel_rows = put_demapped_gray;
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dest->pub.put_pixel_rows = put_gray_rows;
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} else if (cinfo->out_color_space == JCS_RGB) {
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if (cinfo->quantize_colors) {
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/* We only support 8-bit colormap indexes, so only 256 colors */
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num_colors = cinfo->actual_number_of_colors;
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if (num_colors > 256)
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ERREXIT1(cinfo, JERR_TOO_MANY_COLORS, num_colors);
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write_header(cinfo, dinfo, num_colors);
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/* Write the colormap. Note Targa uses BGR byte order */
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outfile = dest->pub.output_file;
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for (i = 0; i < num_colors; i++) {
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putc(GETJSAMPLE(cinfo->colormap[2][i]), outfile);
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putc(GETJSAMPLE(cinfo->colormap[1][i]), outfile);
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putc(GETJSAMPLE(cinfo->colormap[0][i]), outfile);
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dest->pub.put_pixel_rows = put_gray_rows;
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write_header(cinfo, dinfo, 0);
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dest->pub.put_pixel_rows = put_pixel_rows;
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ERREXIT(cinfo, JERR_TGA_COLORSPACE);
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* Finish up at the end of the file.
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finish_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
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/* Make sure we wrote the output file OK */
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fflush(dinfo->output_file);
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if (ferror(dinfo->output_file))
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ERREXIT(cinfo, JERR_FILE_WRITE);
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* The module selection routine for Targa format output.
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GLOBAL(djpeg_dest_ptr)
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jinit_write_targa (j_decompress_ptr cinfo)
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/* Create module interface object, fill in method pointers */
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dest = (tga_dest_ptr)
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(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
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SIZEOF(tga_dest_struct));
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dest->pub.start_output = start_output_tga;
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dest->pub.finish_output = finish_output_tga;
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/* Calculate output image dimensions so we can allocate space */
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jpeg_calc_output_dimensions(cinfo);
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/* Create I/O buffer. Note we make this near on a PC. */
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dest->buffer_width = cinfo->output_width * cinfo->output_components;
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dest->iobuffer = (char *)
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(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
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(size_t) (dest->buffer_width * SIZEOF(char)));
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/* Create decompressor output buffer. */
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dest->pub.buffer = (*cinfo->mem->alloc_sarray)
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((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width, (JDIMENSION) 1);
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dest->pub.buffer_height = 1;
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return (djpeg_dest_ptr) dest;
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#endif /* TARGA_SUPPORTED */
added
removed
wrtarga.c
