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Working on G4 encoding.

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This commit is contained in:
Eric Smith 2003-03-10 13:08:25 +00:00
parent 94dc23e0a9
commit 7377a4de00
5 changed files with 71 additions and 49 deletions
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7
bitblt.h
View File

@ -4,7 +4,7 @@
* will be compressed using ITU-T T.6 (G4) fax encoding.
*
* bitblt routines
* $Id: bitblt.h,v 1.13 2003/03/10 01:49:50 eric Exp $
* $Id: bitblt.h,v 1.14 2003/03/10 05:08:25 eric Exp $
* Copyright 2001, 2002, 2003 Eric Smith <eric@brouhaha.com>
*
* This program is free software; you can redistribute it and/or modify
@ -47,9 +47,12 @@ static inline int32_t rect_height (Rect *r)
}
/* word_type should be the largest native type that can be handled
efficiently, so it shouldn't be a 64-bit type on a processor that
doesn't have native 64-bit operations. */
typedef uint32_t word_type;
#define BITS_PER_WORD (8 * sizeof (word_type))
#define ALL_ONES (~ 0U)
#define ALL_ONES (~ 0UL)
typedef struct Bitmap

84
bitblt_g4.c
View File

@ -4,7 +4,7 @@
* will be compressed using ITU-T T.6 (G4) fax encoding.
*
* G4 compression
* $Id: bitblt_g4.c,v 1.9 2003/03/10 01:49:50 eric Exp $
* $Id: bitblt_g4.c,v 1.10 2003/03/10 05:08:25 eric Exp $
* Copyright 2003 Eric Smith <eric@brouhaha.com>
*
* This program is free software; you can redistribute it and/or modify
@ -32,6 +32,7 @@
#include "bitblt.h"
#include "pdf_util.h"
#include "g4_tables.h"
@ -134,13 +135,24 @@ static void g4_encode_horizontal_run (struct bit_buffer *buf,
}
static uint32_t find_transition (uint8_t *data,
uint32_t pos,
uint32_t width)
static inline int g4_get_pixel (uint8_t *buf, uint32_t x)
{
if (! data)
return (width);
return (0); /* $$$ */
return ((buf [x >> 3] >> (x & 7)) & 1);
}
static uint32_t g4_find_pixel (uint8_t *buf,
uint32_t pos,
uint32_t width,
bool color)
{
while (pos < width)
{
if (g4_get_pixel (buf, pos) == color)
return (pos);
pos++;
}
return (width);
}
@ -149,22 +161,19 @@ static void g4_encode_row (struct bit_buffer *buf,
uint8_t *ref,
uint8_t *row)
{
int a0, a1, a2;
int b1, b2;
uint32_t a0, a1, a2;
uint32_t b1, b2;
bool a0_c;
a0 = -1;
a0 = 0;
a0_c = 0;
a1 = g4_find_pixel (row, 0, width, 1);
b1 = g4_find_pixel (ref, 0, width, 1);
while (a0 < width)
{
/* find a1, a2 */
a1 = find_transition (row, a0, width);
a2 = find_transition (row, a1, width);
/* find b1, b2 */
b1 = find_transition (ref, a0, width);
if (0) /* $$$ b1 color = a0 color */
b1 = find_transition (ref, b1, width);
b2 = find_transition (ref, b2, width);
b2 = g4_find_pixel (ref, b1 + 1, width, g4_get_pixel (ref, b1));
if (b2 < a1)
{
@ -183,22 +192,41 @@ static void g4_encode_row (struct bit_buffer *buf,
else
{
/* horizontal mode - 001 */
a2 = g4_find_pixel (row, a1, width, a0_c);
write_bits (buf, 3, 0x1);
g4_encode_horizontal_run (buf, 0 /* $$$ color (a0) */, a1 - a0);
g4_encode_horizontal_run (buf, 1 /* $$$ color (a1) */, a2 - a1);
g4_encode_horizontal_run (buf, a0_c, a1 - a0);
g4_encode_horizontal_run (buf, ! a0_c, a2 - a1);
a0 = a2;
}
if (a0 >= width)
break;;
a0_c = g4_get_pixel (row, a0);
a1 = g4_find_pixel (row, a0 + 1, width, ! a0_c);
b1 = g4_find_pixel (ref, a0 + 1, width, a0_c);
b1 = g4_find_pixel (ref, b1 + 1, width, ! a0_c);
}
}
void bitblt_write_g4 (Bitmap *bitmap, FILE *f)
{
uint32_t width = (bitmap->rect.max.x - bitmap->rect.min.x) + 1;
uint32_t row;
struct bit_buffer bb;
word_type *ref_line = NULL; /* reference (previous) row */
word_type *line = bitmap->bits;
word_type *temp_buffer;
word_type *cur_line;
word_type *ref_line; /* reference (previous) row */
temp_buffer = pdf_calloc ((width + BITS_PER_WORD - 1) / BITS_PER_WORD,
sizeof (word_type));
cur_line = bitmap->bits;
ref_line = temp_buffer;
memset (& bb, 0, sizeof (bb));
@ -209,11 +237,11 @@ void bitblt_write_g4 (Bitmap *bitmap, FILE *f)
row++)
{
g4_encode_row (& bb,
(bitmap->rect.max.x - bitmap->rect.min.x) + 1,
width,
(uint8_t *) ref_line,
(uint8_t *) line);
ref_line = line;
line += bitmap->row_words;
(uint8_t *) cur_line);
ref_line = cur_line;
cur_line += bitmap->row_words;
}
@ -221,6 +249,8 @@ void bitblt_write_g4 (Bitmap *bitmap, FILE *f)
write_bits (& bb, 24, 0x001001);
flush_bits (& bb);
free (temp_buffer);
}

3
pdf_util.c
View File

@ -4,7 +4,7 @@
* will be compressed using ITU-T T.6 (G4) fax encoding.
*
* PDF routines
* $Id: pdf_util.c,v 1.4 2003/02/21 02:49:11 eric Exp $
* $Id: pdf_util.c,v 1.5 2003/03/10 05:08:25 eric Exp $
* Copyright 2001, 2002, 2003 Eric Smith <eric@brouhaha.com>
*
* This program is free software; you can redistribute it and/or modify
@ -32,7 +32,6 @@
#include <string.h>
#include "bitblt.h"
#include "pdf.h"
#include "pdf_util.h"

13
t2p.c
View File

@ -4,7 +4,7 @@
* will be compressed using ITU-T T.6 (G4) fax encoding.
*
* Main program
* $Id: t2p.c,v 1.27 2003/03/10 01:58:09 eric Exp $
* $Id: t2p.c,v 1.28 2003/03/10 05:08:25 eric Exp $
* Copyright 2001, 2002, 2003 Eric Smith <eric@brouhaha.com>
*
* This program is free software; you can redistribute it and/or modify
@ -304,7 +304,7 @@ bool process_page (int image, /* range 1 .. n */
uint16_t planar_config;
uint16_t resolution_unit;
double x_resolution, y_resolution;
float x_resolution, y_resolution;
double dest_x_resolution, dest_y_resolution;
double width_points, height_points; /* really 1/72 inch units rather than
@ -439,20 +439,17 @@ bool process_page (int image, /* range 1 .. n */
image_length * bitmap->row_words * sizeof (word_type));
#endif /* TIFF_REVERSE_BITS */
#if 0
if (input_attributes.has_page_size)
bitmap = resize_bitmap (bitmap,
x_resolution,
y_resolution,
input_attributes);
#endif
rotate_bitmap (bitmap,
input_attributes);
#ifdef TIFF_REVERSE_BITS
reverse_bits ((uint8_t *) bitmap->bits,
image_length * bitmap->row_words * sizeof (word_type));
#endif /* TIFF_REVERSE_BITS */
width_points = (rect_width (& bitmap->rect) / dest_x_resolution) * POINTS_PER_INCH;
height_points = (rect_height (& bitmap->rect) / dest_y_resolution) * POINTS_PER_INCH;
@ -464,7 +461,6 @@ bool process_page (int image, /* range 1 .. n */
page = pdf_new_page (out->pdf, width_points, height_points);
#if 0
pdf_write_g4_fax_image (page,
0, 0, /* x, y */
width_points, height_points,
@ -472,7 +468,6 @@ bool process_page (int image, /* range 1 .. n */
0, /* ImageMask */
0, 0, 0, /* r, g, b */
0); /* BlackIs1 */
#endif
while (bookmarks)
{

13
tumble.c
View File

@ -4,7 +4,7 @@
* will be compressed using ITU-T T.6 (G4) fax encoding.
*
* Main program
* $Id: tumble.c,v 1.27 2003/03/10 01:58:09 eric Exp $
* $Id: tumble.c,v 1.28 2003/03/10 05:08:25 eric Exp $
* Copyright 2001, 2002, 2003 Eric Smith <eric@brouhaha.com>
*
* This program is free software; you can redistribute it and/or modify
@ -304,7 +304,7 @@ bool process_page (int image, /* range 1 .. n */
uint16_t planar_config;
uint16_t resolution_unit;
double x_resolution, y_resolution;
float x_resolution, y_resolution;
double dest_x_resolution, dest_y_resolution;
double width_points, height_points; /* really 1/72 inch units rather than
@ -439,20 +439,17 @@ bool process_page (int image, /* range 1 .. n */
image_length * bitmap->row_words * sizeof (word_type));
#endif /* TIFF_REVERSE_BITS */
#if 0
if (input_attributes.has_page_size)
bitmap = resize_bitmap (bitmap,
x_resolution,
y_resolution,
input_attributes);
#endif
rotate_bitmap (bitmap,
input_attributes);
#ifdef TIFF_REVERSE_BITS
reverse_bits ((uint8_t *) bitmap->bits,
image_length * bitmap->row_words * sizeof (word_type));
#endif /* TIFF_REVERSE_BITS */
width_points = (rect_width (& bitmap->rect) / dest_x_resolution) * POINTS_PER_INCH;
height_points = (rect_height (& bitmap->rect) / dest_y_resolution) * POINTS_PER_INCH;
@ -464,7 +461,6 @@ bool process_page (int image, /* range 1 .. n */
page = pdf_new_page (out->pdf, width_points, height_points);
#if 0
pdf_write_g4_fax_image (page,
0, 0, /* x, y */
width_points, height_points,
@ -472,7 +468,6 @@ bool process_page (int image, /* range 1 .. n */
0, /* ImageMask */
0, 0, 0, /* r, g, b */
0); /* BlackIs1 */
#endif
while (bookmarks)
{