Line data Source code
1 : /*
2 : * jccolext.c
3 : *
4 : * This file was part of the Independent JPEG Group's software:
5 : * Copyright (C) 1991-1996, Thomas G. Lane.
6 : * libjpeg-turbo Modifications:
7 : * Copyright (C) 2009-2012, 2015, D. R. Commander.
8 : * For conditions of distribution and use, see the accompanying README.ijg
9 : * file.
10 : *
11 : * This file contains input colorspace conversion routines.
12 : */
13 :
14 :
15 : /* This file is included by jccolor.c */
16 :
17 :
18 : /*
19 : * Convert some rows of samples to the JPEG colorspace.
20 : *
21 : * Note that we change from the application's interleaved-pixel format
22 : * to our internal noninterleaved, one-plane-per-component format.
23 : * The input buffer is therefore three times as wide as the output buffer.
24 : *
25 : * A starting row offset is provided only for the output buffer. The caller
26 : * can easily adjust the passed input_buf value to accommodate any row
27 : * offset required on that side.
28 : */
29 :
30 : INLINE
31 : LOCAL(void)
32 0 : rgb_ycc_convert_internal (j_compress_ptr cinfo,
33 : JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
34 : JDIMENSION output_row, int num_rows)
35 : {
36 0 : my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
37 : register int r, g, b;
38 0 : register JLONG * ctab = cconvert->rgb_ycc_tab;
39 : register JSAMPROW inptr;
40 : register JSAMPROW outptr0, outptr1, outptr2;
41 : register JDIMENSION col;
42 0 : JDIMENSION num_cols = cinfo->image_width;
43 :
44 0 : while (--num_rows >= 0) {
45 0 : inptr = *input_buf++;
46 0 : outptr0 = output_buf[0][output_row];
47 0 : outptr1 = output_buf[1][output_row];
48 0 : outptr2 = output_buf[2][output_row];
49 0 : output_row++;
50 0 : for (col = 0; col < num_cols; col++) {
51 0 : r = GETJSAMPLE(inptr[RGB_RED]);
52 0 : g = GETJSAMPLE(inptr[RGB_GREEN]);
53 0 : b = GETJSAMPLE(inptr[RGB_BLUE]);
54 0 : inptr += RGB_PIXELSIZE;
55 : /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
56 : * must be too; we do not need an explicit range-limiting operation.
57 : * Hence the value being shifted is never negative, and we don't
58 : * need the general RIGHT_SHIFT macro.
59 : */
60 : /* Y */
61 0 : outptr0[col] = (JSAMPLE)
62 0 : ((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
63 0 : >> SCALEBITS);
64 : /* Cb */
65 0 : outptr1[col] = (JSAMPLE)
66 0 : ((ctab[r+R_CB_OFF] + ctab[g+G_CB_OFF] + ctab[b+B_CB_OFF])
67 0 : >> SCALEBITS);
68 : /* Cr */
69 0 : outptr2[col] = (JSAMPLE)
70 0 : ((ctab[r+R_CR_OFF] + ctab[g+G_CR_OFF] + ctab[b+B_CR_OFF])
71 0 : >> SCALEBITS);
72 : }
73 : }
74 0 : }
75 :
76 :
77 : /**************** Cases other than RGB -> YCbCr **************/
78 :
79 :
80 : /*
81 : * Convert some rows of samples to the JPEG colorspace.
82 : * This version handles RGB->grayscale conversion, which is the same
83 : * as the RGB->Y portion of RGB->YCbCr.
84 : * We assume rgb_ycc_start has been called (we only use the Y tables).
85 : */
86 :
87 : INLINE
88 : LOCAL(void)
89 0 : rgb_gray_convert_internal (j_compress_ptr cinfo,
90 : JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
91 : JDIMENSION output_row, int num_rows)
92 : {
93 0 : my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
94 : register int r, g, b;
95 0 : register JLONG * ctab = cconvert->rgb_ycc_tab;
96 : register JSAMPROW inptr;
97 : register JSAMPROW outptr;
98 : register JDIMENSION col;
99 0 : JDIMENSION num_cols = cinfo->image_width;
100 :
101 0 : while (--num_rows >= 0) {
102 0 : inptr = *input_buf++;
103 0 : outptr = output_buf[0][output_row];
104 0 : output_row++;
105 0 : for (col = 0; col < num_cols; col++) {
106 0 : r = GETJSAMPLE(inptr[RGB_RED]);
107 0 : g = GETJSAMPLE(inptr[RGB_GREEN]);
108 0 : b = GETJSAMPLE(inptr[RGB_BLUE]);
109 0 : inptr += RGB_PIXELSIZE;
110 : /* Y */
111 0 : outptr[col] = (JSAMPLE)
112 0 : ((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
113 0 : >> SCALEBITS);
114 : }
115 : }
116 0 : }
117 :
118 :
119 : /*
120 : * Convert some rows of samples to the JPEG colorspace.
121 : * This version handles extended RGB->plain RGB conversion
122 : */
123 :
124 : INLINE
125 : LOCAL(void)
126 0 : rgb_rgb_convert_internal (j_compress_ptr cinfo,
127 : JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
128 : JDIMENSION output_row, int num_rows)
129 : {
130 : register JSAMPROW inptr;
131 : register JSAMPROW outptr0, outptr1, outptr2;
132 : register JDIMENSION col;
133 0 : JDIMENSION num_cols = cinfo->image_width;
134 :
135 0 : while (--num_rows >= 0) {
136 0 : inptr = *input_buf++;
137 0 : outptr0 = output_buf[0][output_row];
138 0 : outptr1 = output_buf[1][output_row];
139 0 : outptr2 = output_buf[2][output_row];
140 0 : output_row++;
141 0 : for (col = 0; col < num_cols; col++) {
142 0 : outptr0[col] = GETJSAMPLE(inptr[RGB_RED]);
143 0 : outptr1[col] = GETJSAMPLE(inptr[RGB_GREEN]);
144 0 : outptr2[col] = GETJSAMPLE(inptr[RGB_BLUE]);
145 0 : inptr += RGB_PIXELSIZE;
146 : }
147 : }
148 0 : }
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