spandsp 0.0.6

image_translate.h
Go to the documentation of this file.
1/*
2 * SpanDSP - a series of DSP components for telephony
3 *
4 * image_translate.h - Image translation routines for reworking colour
5 * and gray scale images to be bi-level images of an
6 * appropriate size to be FAX compatible.
7 *
8 * Written by Steve Underwood <steveu@coppice.org>
9 *
10 * Copyright (C) 2009 Steve Underwood
11 *
12 * All rights reserved.
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Lesser General Public License version 2.1,
16 * as published by the Free Software Foundation.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU Lesser General Public License for more details.
22 *
23 * You should have received a copy of the GNU Lesser General Public
24 * License along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
27
28/*! \file */
29
30#if !defined(_SPANDSP_IMAGE_TRANSLATE_H_)
31#define _SPANDSP_IMAGE_TRANSLATE_H_
32
33/*! \page image_translate_page Image translation
34\section image_translate_page_sec_1 What does it do?
35
36\section image_translate_page_sec_2 How does it work?
37
38\section image_translate_page_sec_3 How do I use it?
39*/
40
41 typedef struct image_translate_state_s image_translate_state_t;
42
43 enum
44{
45 IMAGE_TRANSLATE_FROM_MONO = 1,
46 IMAGE_TRANSLATE_FROM_GRAY_8 = 2,
47 IMAGE_TRANSLATE_FROM_GRAY_16 = 3,
48 IMAGE_TRANSLATE_FROM_COLOUR_8 = 4,
49 IMAGE_TRANSLATE_FROM_COLOUR_16 = 5
50};
51
52#if defined(__cplusplus)
53 extern "C"
54{
55#endif
56
57/*! \brief Get the next row of a translated image.
58 \param s The image translation context.
59 \return the length of the row buffer, in bytes */
60SPAN_DECLARE(int) image_translate_row(image_translate_state_t *s, uint8_t buf[], size_t len);
61
62/*! \brief Get the width of the image being produced by an image translation context.
63 \param s The image translation context.
64 \return The width of the output image, in pixel. */
65SPAN_DECLARE(int) image_translate_get_output_width(image_translate_state_t *s);
66
67/*! \brief Get the length of the image being produced by an image translation context.
68 \param s The image translation context.
69 \return The length of the output image, in pixel. */
70SPAN_DECLARE(int) image_translate_get_output_length(image_translate_state_t *s);
71
72/*! \brief Initialise an image translation context for rescaling and squashing a gray scale
73 or colour image to a bi-level FAX type image.
74 \param s The image translation context.
75 \param input_format x
76 \param input_width The width of the source image, in pixels.
77 \param input_length The length of the source image, in pixels.
78 \param output_width The width of the output image, in pixels. The length of the output image
79 will be derived automatically from this and the source image dimension, to main the
80 geometry of the original image.
81 \param row_read_handler A callback routine used to pull rows of pixels from the source image
82 into the translation process.
83 \param row_read_user_data An opaque point passed to read_row_handler
84 \return A pointer to the context, or NULL if there was a problem. */
85SPAN_DECLARE(image_translate_state_t *) image_translate_init(image_translate_state_t *s,
86 int input_format,
87 int input_width,
88 int input_length,
89 int output_width,
90 t4_row_read_handler_t row_read_handler,
91 void *row_read_user_data);
92
93/*! \brief Release the resources associated with an image translation context.
94 \param s The image translation context.
95 \return 0 for success, otherwise -1. */
96SPAN_DECLARE(int) image_translate_release(image_translate_state_t *s);
97
98/*! \brief Free the resources associated with an image translation context.
99 \param s The image translation context.
100 \return 0 for success, otherwise -1. */
101SPAN_DECLARE(int) image_translate_free(image_translate_state_t *s);
102
103#if defined(__cplusplus)
104}
105#endif
106
107#endif
108/*- End of file ------------------------------------------------------------*/
image_translate_get_output_length
int image_translate_get_output_length(image_translate_state_t *s)
Get the length of the image being produced by an image translation context.
Definition image_translate.c:352
image_translate_row
int image_translate_row(image_translate_state_t *s, uint8_t buf[], size_t len)
Get the next row of a translated image.
Definition image_translate.c:228
image_translate_get_output_width
int image_translate_get_output_width(image_translate_state_t *s)
Get the width of the image being produced by an image translation context.
Definition image_translate.c:346
image_translate_release
int image_translate_release(image_translate_state_t *s)
Release the resources associated with an image translation context.
Definition image_translate.c:437
image_translate_init
image_translate_state_t * image_translate_init(image_translate_state_t *s, int input_format, int input_width, int input_length, int output_width, t4_row_read_handler_t row_read_handler, void *row_read_user_data)
Initialise an image translation context for rescaling and squashing a gray scale or colour image to a...
Definition image_translate.c:358
image_translate_free
int image_translate_free(image_translate_state_t *s)
Free the resources associated with an image translation context.
Definition image_translate.c:458
image_translate_state_s
Definition private/image_translate.h:32
t4_row_read_handler_t
int(* t4_row_read_handler_t)(void *user_data, uint8_t buf[], size_t len)
Definition t4_tx.h:36