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
|
/*
* jccolext.c
*
* This file was part of the Independent JPEG Group's software:
* Copyright (C) 1991-1996, Thomas G. Lane.
* libjpeg-turbo Modifications:
* Copyright (C) 2009-2012, 2015, D. R. Commander.
* For conditions of distribution and use, see the accompanying README.ijg
* file.
*
* This file contains input colorspace conversion routines.
*/
/* This file is included by jccolor.c */
/*
* Convert some rows of samples to the JPEG colorspace.
*
* Note that we change from the application's interleaved-pixel format
* to our internal noninterleaved, one-plane-per-component format.
* The input buffer is therefore three times as wide as the output buffer.
*
* A starting row offset is provided only for the output buffer. The caller
* can easily adjust the passed input_buf value to accommodate any row
* offset required on that side.
*/
INLINE
LOCAL(void)
rgb_ycc_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPIMAGE output_buf, JDIMENSION output_row,
int num_rows)
{
my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
register int r, g, b;
register JLONG *ctab = cconvert->rgb_ycc_tab;
register JSAMPROW inptr;
register JSAMPROW outptr0, outptr1, outptr2;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->image_width;
while (--num_rows >= 0) {
inptr = *input_buf++;
outptr0 = output_buf[0][output_row];
outptr1 = output_buf[1][output_row];
outptr2 = output_buf[2][output_row];
output_row++;
for (col = 0; col < num_cols; col++) {
r = inptr[RGB_RED];
g = inptr[RGB_GREEN];
b = inptr[RGB_BLUE];
inptr += RGB_PIXELSIZE;
/* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
* must be too; we do not need an explicit range-limiting operation.
* Hence the value being shifted is never negative, and we don't
* need the general RIGHT_SHIFT macro.
*/
/* Y */
outptr0[col] = (JSAMPLE)((ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] +
ctab[b + B_Y_OFF]) >> SCALEBITS);
/* Cb */
outptr1[col] = (JSAMPLE)((ctab[r + R_CB_OFF] + ctab[g + G_CB_OFF] +
ctab[b + B_CB_OFF]) >> SCALEBITS);
/* Cr */
outptr2[col] = (JSAMPLE)((ctab[r + R_CR_OFF] + ctab[g + G_CR_OFF] +
ctab[b + B_CR_OFF]) >> SCALEBITS);
}
}
}
/**************** Cases other than RGB -> YCbCr **************/
/*
* Convert some rows of samples to the JPEG colorspace.
* This version handles RGB->grayscale conversion, which is the same
* as the RGB->Y portion of RGB->YCbCr.
* We assume rgb_ycc_start has been called (we only use the Y tables).
*/
INLINE
LOCAL(void)
rgb_gray_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPIMAGE output_buf, JDIMENSION output_row,
int num_rows)
{
my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
register int r, g, b;
register JLONG *ctab = cconvert->rgb_ycc_tab;
register JSAMPROW inptr;
register JSAMPROW outptr;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->image_width;
while (--num_rows >= 0) {
inptr = *input_buf++;
outptr = output_buf[0][output_row];
output_row++;
for (col = 0; col < num_cols; col++) {
r = inptr[RGB_RED];
g = inptr[RGB_GREEN];
b = inptr[RGB_BLUE];
inptr += RGB_PIXELSIZE;
/* Y */
outptr[col] = (JSAMPLE)((ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] +
ctab[b + B_Y_OFF]) >> SCALEBITS);
}
}
}
/*
* Convert some rows of samples to the JPEG colorspace.
* This version handles extended RGB->plain RGB conversion
*/
INLINE
LOCAL(void)
rgb_rgb_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPIMAGE output_buf, JDIMENSION output_row,
int num_rows)
{
register JSAMPROW inptr;
register JSAMPROW outptr0, outptr1, outptr2;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->image_width;
while (--num_rows >= 0) {
inptr = *input_buf++;
outptr0 = output_buf[0][output_row];
outptr1 = output_buf[1][output_row];
outptr2 = output_buf[2][output_row];
output_row++;
for (col = 0; col < num_cols; col++) {
outptr0[col] = inptr[RGB_RED];
outptr1[col] = inptr[RGB_GREEN];
outptr2[col] = inptr[RGB_BLUE];
inptr += RGB_PIXELSIZE;
}
}
}
|
