2 * Small jpeg decoder library
4 * Copyright (c) 2006, Luc Saillard <luc@saillard.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
9 * - Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
12 * - Redistributions in binary form must reproduce the above copyright notice,
13 * this list of conditions and the following disclaimer in the documentation
14 * and/or other materials provided with the distribution.
16 * - Neither the name of the author nor the names of its contributors may be
17 * used to endorse or promote products derived from this software without
18 * specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
40 #include "tinyjpeg-internal.h"
48 static void YCrCB_to_Grey_1x1(struct jdec_private
*priv
)
50 const unsigned char *y
;
53 int offset_to_next_row
;
57 offset_to_next_row
= priv
->bytes_per_row
[0];
62 p
+= offset_to_next_row
;
72 static void YCrCB_to_Grey_2x1(struct jdec_private
*priv
)
74 const unsigned char *y
;
77 int offset_to_next_row
;
81 offset_to_next_row
= priv
->bytes_per_row
[0];
86 p
+= offset_to_next_row
;
99 static void YCrCB_to_Grey_1x2(struct jdec_private
*priv
)
101 const unsigned char *y
;
104 int offset_to_next_row
;
108 offset_to_next_row
= priv
->bytes_per_row
[0];
110 for (i
=0; i
<16; i
++) {
113 p
+= offset_to_next_row
;
118 * YCrCb -> Grey (2x2)
125 static void YCrCB_to_Grey_2x2(struct jdec_private
*priv
)
127 const unsigned char *y
;
130 int offset_to_next_row
;
134 offset_to_next_row
= priv
->bytes_per_row
[0];
136 for (i
=0; i
<16; i
++) {
139 p
+= offset_to_next_row
;
143 static int initialize_grey(struct jdec_private
*priv
,
144 unsigned int *bytes_per_blocklines
,
145 unsigned int *bytes_per_mcu
)
147 if (priv
->components
[0] == NULL
)
148 priv
->components
[0] = (uint8_t *)malloc(priv
->width
* priv
->height
* 3);
149 if (!priv
->bytes_per_row
[0])
150 priv
->bytes_per_row
[0] = priv
->width
* 3;
152 bytes_per_blocklines
[0] = priv
->bytes_per_row
[0];
153 bytes_per_mcu
[0] = 3*8;
155 return !priv
->components
[0];
158 static const struct tinyjpeg_colorspace format_grey
=
166 tinyjpeg_decode_mcu_1comp_table
,
170 const tinyjpeg_colorspace_t TINYJPEG_FMT_GREY
= &format_grey
;