spandsp 3.0.0
t42.h
Go to the documentation of this file.
1/*
2 * SpanDSP - a series of DSP components for telephony
3 *
4 * t42.h - ITU T.42 JPEG for FAX image processing
5 *
6 * Written by Steve Underwood <steveu@coppice.org>
7 *
8 * Copyright (C) 2011 Steve Underwood
9 *
10 * All rights reserved.
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Lesser General Public License version 2.1,
14 * as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25
26/*! \file */
27
28#if !defined(_SPANDSP_T42_H_)
29#define _SPANDSP_T42_H_
30
31/*! \page t42_page T.42 (JPEG for FAX) image compression and decompression
32
33\section t42_page_sec_1 What does it do?
34
35\section t42_page_sec_1 How does it work?
36*/
37
38/*! State of a working instance of the T.42 encoder */
40
41/*! State of a working instance of the T.42 decoder */
43
44typedef struct lab_params_s lab_params_t;
45
46#if defined(__cplusplus)
47extern "C"
48{
49#endif
50
51/*! \brief Convert an X0, Y0, Z0 coordinate to a colour tempature */
52SPAN_DECLARE(int) xyz_to_corrected_color_temp(float *temp, float xyz[3]);
53
54/*! \brief Convert a colour temperature to an X0, Y0, Z0 coordinate */
55SPAN_DECLARE(int) colour_temp_to_xyz(float xyz[3], float temp);
56
57/*! \brief Convert a row of 8 bit pixels from Lab to sRGB
58 \param s The Lab parameters context.
59 \param lab The output pixels
60 \param srgb The input pixels
61 \param pixel The number of pixels in the row. */
62SPAN_DECLARE(void) srgb_to_lab(lab_params_t *s, uint8_t lab[], const uint8_t srgb[], int pixels);
63
64/*! \brief Convert a row of 8 bit pixels from sRGB to Lab
65 \param s The Lab parameters context.
66 \param srgb The output pixels
67 \param lab The input pixels
68 \param pixel The number of pixels in the row. */
69SPAN_DECLARE(void) lab_to_srgb(lab_params_t *s, uint8_t srgb[], const uint8_t lab[], int pixels);
70
71SPAN_DECLARE(void) set_lab_illuminant(lab_params_t *s, float new_xn, float new_yn, float new_zn);
72
73SPAN_DECLARE(void) set_lab_gamut(lab_params_t *s, int L_min, int L_max, int a_min, int a_max, int b_min, int b_max, int ab_are_signed);
74
75SPAN_DECLARE(void) set_lab_gamut2(lab_params_t *s, int L_P, int L_Q, int a_P, int a_Q, int b_P, int b_Q);
76
77SPAN_DECLARE(void) get_lab_gamut2(lab_params_t *s, int *L_P, int *L_Q, int *a_P, int *a_Q, int *b_P, int *b_Q);
78
79SPAN_DECLARE(bool) t42_analyse_header(uint32_t *width, uint32_t *length, const uint8_t data[], size_t len);
80
81SPAN_DECLARE(void) t42_encode_set_options(t42_encode_state_t *s, uint32_t l0, int quality, int options);
82
83SPAN_DECLARE(int) t42_encode_set_image_width(t42_encode_state_t *s, uint32_t image_width);
84
85SPAN_DECLARE(int) t42_encode_set_image_length(t42_encode_state_t *s, uint32_t length);
86
87SPAN_DECLARE(int) t42_encode_set_image_type(t42_encode_state_t *s, int image_type);
88
89SPAN_DECLARE(void) t42_encode_abort(t42_encode_state_t *s);
90
91SPAN_DECLARE(void) t42_encode_comment(t42_encode_state_t *s, const uint8_t comment[], size_t len);
92
93/*! \brief Check if we are at the end of the current document page.
94 \param s The T.42 context.
95 \return 0 for more data to come. SIG_STATUS_END_OF_DATA for no more data. */
97
98SPAN_DECLARE(int) t42_encode_get(t42_encode_state_t *s, uint8_t buf[], size_t max_len);
99
100SPAN_DECLARE(uint32_t) t42_encode_get_image_width(t42_encode_state_t *s);
101
102SPAN_DECLARE(uint32_t) t42_encode_get_image_length(t42_encode_state_t *s);
103
104/*! \brief Get the size of the compressed image in bits.
105 \param s The T.42 context.
106 \return The size of the image, in bits. */
108
109SPAN_DECLARE(int) t42_encode_set_row_read_handler(t42_encode_state_t *s, t4_row_read_handler_t handler, void *user_data);
110
111/*! Get the logging context associated with a T.42 encode context.
112 \brief Get the logging context associated with a T.42 encode context.
113 \param s The T.42 encode context.
114 \return A pointer to the logging context */
116
117/*! \brief Restart a T.42 encode context.
118 \param s The T.42 context.
119 \param image image_width The image width, in pixels.
120 \param image image_width The image length, in pixels.
121 \return 0 for success, otherwise -1. */
122SPAN_DECLARE(int) t42_encode_restart(t42_encode_state_t *s, uint32_t image_width, uint32_t image_length);
123
124/*! \brief Prepare to encode an image in T.42 format.
125 \param s The T.42 context.
126 \param image_width Image width, in pixels.
127 \param image_length Image length, in pixels.
128 \param handler A callback routine to handle encoded image rows.
129 \param user_data An opaque pointer passed to handler.
130 \return A pointer to the context, or NULL if there was a problem. */
132 uint32_t image_width,
133 uint32_t image_length,
134 t4_row_read_handler_t handler,
135 void *user_data);
136
137/*! \brief Release a T.42 encode context.
138 \param s The T.42 encode context.
139 \return 0 for OK, else -1. */
140SPAN_DECLARE(int) t42_encode_release(t42_encode_state_t *s);
141
142/*! \brief Free a T.42 encode context.
143 \param s The T.42 encode context.
144 \return 0 for OK, else -1. */
145SPAN_DECLARE(int) t42_encode_free(t42_encode_state_t *s);
146
147SPAN_DECLARE(void) t42_decode_rx_status(t42_decode_state_t *s, int status);
148
149/*! \brief Decode a chunk of T.42 data.
150 \param s The T.42 context.
151 \param data The data to be decoded.
152 \param len The length of the data to be decoded.
153 \return 0 for OK. */
154SPAN_DECLARE(int) t42_decode_put(t42_decode_state_t *s, const uint8_t data[], size_t len);
155
156/*! \brief Set the row handler routine.
157 \param s The T.42 context.
158 \param handler A callback routine to handle decoded image rows.
159 \param user_data An opaque pointer passed to handler.
160 \return 0 for OK. */
163 void *user_data);
164
165/*! \brief Set the comment handler routine.
166 \param s The T.42 context.
167 \param max_comment_len The maximum length of comment to be passed to the handler.
168 \param handler A callback routine to handle decoded comment.
169 \param user_data An opaque pointer passed to handler.
170 \return 0 for OK. */
172 uint32_t max_comment_len,
174 void *user_data);
175
176/*! A maliciously constructed T.42 image could consume too much memory, and constitute
177 a denial of service attack on the system. This function allows constraints to be
178 applied.
179 \brief Set constraints on the received image size.
180 \param s The T.42 context.
181 \param max_xd The maximum permitted width of the full image, in pixels
182 \param max_yd The maximum permitted height of the full image, in pixels
183 \return 0 for OK */
185 uint32_t max_xd,
186 uint32_t max_yd);
187
188/*! \brief Get the width of the image.
189 \param s The T.42 context.
190 \return The width of the image, in pixels. */
191SPAN_DECLARE(uint32_t) t42_decode_get_image_width(t42_decode_state_t *s);
192
193/*! \brief Get the length of the image.
194 \param s The T.42 context.
195 \return The length of the image, in pixels. */
196SPAN_DECLARE(uint32_t) t42_decode_get_image_length(t42_decode_state_t *s);
197
198/*! \brief Get the size of the compressed image in bits.
199 \param s The T.42 context.
200 \return The size of the image, in bits. */
202
203/*! Get the logging context associated with a T.42 decode context.
204 \brief Get the logging context associated with a T.42 decode context.
205 \param s The T.42 decode context.
206 \return A pointer to the logging context */
208
209/*! \brief Restart a T.42 decode context.
210 \param s The T.42 context. */
211SPAN_DECLARE(int) t42_decode_restart(t42_decode_state_t *s);
212
213/*! \brief Prepare to decode an image in T.42 format.
214 \param s The T.42 context.
215 \param handler A callback routine to handle decoded image rows.
216 \param user_data An opaque pointer passed to handler.
217 \return A pointer to the context, or NULL if there was a problem. */
220 void *user_data);
221
222/*! \brief Release a T.42 decode context.
223 \param s The T.42 decode context.
224 \return 0 for OK, else -1. */
225SPAN_DECLARE(int) t42_decode_release(t42_decode_state_t *s);
226
227/*! \brief Free a T.42 decode context.
228 \param s The T.42 decode context.
229 \return 0 for OK, else -1. */
230SPAN_DECLARE(int) t42_decode_free(t42_decode_state_t *s);
231
232#if defined(__cplusplus)
233}
234#endif
235
236#endif
237/*- End of file ------------------------------------------------------------*/
Definition: private/t42.h:33
Definition: private/logging.h:34
Definition: private/t42.h:99
Definition: private/t42.h:54
int t42_encode_free(t42_encode_state_t *s)
Free a T.42 encode context.
Definition: t42.c:1058
int t42_encode_get_compressed_image_size(t42_encode_state_t *s)
Get the size of the compressed image in bits.
Definition: t42.c:955
void lab_to_srgb(lab_params_t *s, uint8_t srgb[], const uint8_t lab[], int pixels)
Convert a row of 8 bit pixels from sRGB to Lab.
Definition: t42.c:534
void srgb_to_lab(lab_params_t *s, uint8_t lab[], const uint8_t srgb[], int pixels)
Convert a row of 8 bit pixels from Lab to sRGB.
Definition: t42.c:478
t42_encode_state_t * t42_encode_init(t42_encode_state_t *s, uint32_t image_width, uint32_t image_length, t4_row_read_handler_t handler, void *user_data)
Prepare to encode an image in T.42 format.
Definition: t42.c:1025
int t42_decode_release(t42_decode_state_t *s)
Release a T.42 decode context.
Definition: t42.c:1400
int t42_decode_put(t42_decode_state_t *s, const uint8_t data[], size_t len)
Decode a chunk of T.42 data.
Definition: t42.c:1265
logging_state_t * t42_encode_get_logging_state(t42_encode_state_t *s)
Get the logging context associated with a T.42 encode context.
Definition: t42.c:971
int t42_decode_set_image_size_constraints(t42_decode_state_t *s, uint32_t max_xd, uint32_t max_yd)
Set constraints on the received image size.
Definition: t42.c:1315
int t42_encode_restart(t42_encode_state_t *s, uint32_t image_width, uint32_t image_length)
Restart a T.42 encode context.
Definition: t42.c:977
int t42_decode_free(t42_decode_state_t *s)
Free a T.42 decode context.
Definition: t42.c:1427
int colour_temp_to_xyz(float xyz[3], float temp)
Convert a colour temperature to an X0, Y0, Z0 coordinate.
Definition: t42.c:303
uint32_t t42_decode_get_image_length(t42_decode_state_t *s)
Get the length of the image.
Definition: t42.c:1329
int t42_decode_set_row_write_handler(t42_decode_state_t *s, t4_row_write_handler_t handler, void *user_data)
Set the row handler routine.
Definition: t42.c:1293
int t42_decode_get_compressed_image_size(t42_decode_state_t *s)
Get the size of the compressed image in bits.
Definition: t42.c:1335
int t42_decode_restart(t42_decode_state_t *s)
Restart a T.42 decode context.
Definition: t42.c:1347
int t42_encode_image_complete(t42_encode_state_t *s)
Check if we are at the end of the current document page.
Definition: t42.c:749
int xyz_to_corrected_color_temp(float *temp, float xyz[3])
Convert an X0, Y0, Z0 coordinate to a colour tempature.
Definition: t42.c:267
uint32_t t42_decode_get_image_width(t42_decode_state_t *s)
Get the width of the image.
Definition: t42.c:1323
int t42_decode_set_comment_handler(t42_decode_state_t *s, uint32_t max_comment_len, t4_row_write_handler_t handler, void *user_data)
Set the comment handler routine.
Definition: t42.c:1303
int t42_encode_release(t42_encode_state_t *s)
Release a T.42 encode context.
Definition: t42.c:1052
t42_decode_state_t * t42_decode_init(t42_decode_state_t *s, t4_row_write_handler_t handler, void *user_data)
Prepare to decode an image in T.42 format.
Definition: t42.c:1375
logging_state_t * t42_decode_get_logging_state(t42_decode_state_t *s)
Get the logging context associated with a T.42 decode context.
Definition: t42.c:1341
int(* t4_row_write_handler_t)(void *user_data, const uint8_t buf[], size_t len)
Definition: t4_rx.h:46
int(* t4_row_read_handler_t)(void *user_data, uint8_t buf[], size_t len)
Definition: t4_tx.h:34