1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
/* sane - Scanner Access Now Easy.
Copyright (C) 2019 Touboul Nathane
Copyright (C) 2019 Thierry HUCHARD <thierry@ordissimo.com>
This file is part of the SANE package.
SANE is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at your
option) any later version.
SANE is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with sane; see the file COPYING. If not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
This file implements a SANE backend for eSCL scanners. */
#define DEBUG_DECLARE_ONLY
#include "../include/sane/config.h"
#include "escl.h"
#include "../include/sane/sanei.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if(defined HAVE_LIBPNG)
#include <png.h>
#endif
#include <setjmp.h>
#if(defined HAVE_LIBPNG)
/**
* \fn SANE_Status escl_sane_decompressor(escl_sane_t *handler)
* \brief Function that aims to decompress the png image to SANE be able to read the image.
* This function is called in the "sane_read" function.
*
* \return SANE_STATUS_GOOD (if everything is OK, otherwise, SANE_STATUS_NO_MEM/SANE_STATUS_INVAL)
*/
SANE_Status
get_PNG_data(capabilities_t *scanner, int *width, int *height, int *bps)
{
unsigned int w = 0;
unsigned int h = 0;
int components = 3;
unsigned char *surface = NULL; /* Image data */
unsigned int i = 0;
png_byte magic[8];
SANE_Status status = SANE_STATUS_GOOD;
// read magic number
fread (magic, 1, sizeof (magic), scanner->tmp);
// check for valid magic number
if (!png_check_sig (magic, sizeof (magic)))
{
DBG( 1, "Escl Png : PNG error is not a valid PNG image!\n");
status = SANE_STATUS_INVAL;
goto close_file;
}
// create a png read struct
png_structp png_ptr = png_create_read_struct
(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
{
DBG( 1, "Escl Png : PNG error create a png read struct\n");
status = SANE_STATUS_INVAL;
goto close_file;
}
// create a png info struct
png_infop info_ptr = png_create_info_struct (png_ptr);
if (!info_ptr)
{
DBG( 1, "Escl Png : PNG error create a png info struct\n");
png_destroy_read_struct (&png_ptr, NULL, NULL);
status = SANE_STATUS_INVAL;
goto close_file;
}
// initialize the setjmp for returning properly after a libpng
// error occured
if (setjmp (png_jmpbuf (png_ptr)))
{
png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
if (surface)
free (surface);
DBG( 1, "Escl Png : PNG read error.\n");
status = SANE_STATUS_INVAL;
goto close_file;
}
// setup libpng for using standard C fread() function
// with our FILE pointer
png_init_io (png_ptr, scanner->tmp);
// tell libpng that we have already read the magic number
png_set_sig_bytes (png_ptr, sizeof (magic));
// read png info
png_read_info (png_ptr, info_ptr);
int bit_depth, color_type;
// get some usefull information from header
bit_depth = png_get_bit_depth (png_ptr, info_ptr);
color_type = png_get_color_type (png_ptr, info_ptr);
// convert index color images to RGB images
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb (png_ptr);
else if (color_type != PNG_COLOR_TYPE_RGB && color_type != PNG_COLOR_TYPE_RGB_ALPHA)
{
DBG(1, "PNG format not supported.\n");
status = SANE_STATUS_NO_MEM;
goto close_file;
}
if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
components = 4;
else
components = 3;
if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
png_set_tRNS_to_alpha (png_ptr);
if (bit_depth == 16)
png_set_strip_16 (png_ptr);
else if (bit_depth < 8)
png_set_packing (png_ptr);
// update info structure to apply transformations
png_read_update_info (png_ptr, info_ptr);
// retrieve updated information
png_get_IHDR (png_ptr, info_ptr,
(png_uint_32*)(&w),
(png_uint_32*)(&h),
&bit_depth, &color_type,
NULL, NULL, NULL);
*bps = components;
// we can now allocate memory for storing pixel data
surface = (unsigned char *)malloc (sizeof (unsigned char) * w
* h * components);
if (!surface) {
DBG( 1, "Escl Png : texels Memory allocation problem\n");
status = SANE_STATUS_NO_MEM;
goto close_file;
}
png_bytep *row_pointers;
// setup a pointer array. Each one points at the begening of a row.
row_pointers = (png_bytep *)malloc (sizeof (png_bytep) * h);
if (!row_pointers) {
DBG( 1, "Escl Png : row_pointers Memory allocation problem\n");
free(surface);
status = SANE_STATUS_NO_MEM;
goto close_file;
}
for (i = 0; i < h; ++i)
{
row_pointers[i] = (png_bytep)(surface +
((h - (i + 1)) * w * components));
}
// read pixel data using row pointers
png_read_image (png_ptr, row_pointers);
// If necessary, trim the image.
surface = escl_crop_surface(scanner, surface, w, h, components, width, height);
if (!surface) {
DBG( 1, "Escl Png : Surface Memory allocation problem\n");
status = SANE_STATUS_NO_MEM;
goto close_file;
}
free (row_pointers);
close_file:
if (scanner->tmp)
fclose(scanner->tmp);
scanner->tmp = NULL;
return (status);
}
#else
SANE_Status
get_PNG_data(capabilities_t __sane_unused__ *scanner,
int __sane_unused__ *width,
int __sane_unused__ *height,
int __sane_unused__ *bps)
{
return (SANE_STATUS_INVAL);
}
#endif
|
