blob: 07da949fae02d7f61de293ab8c9816372023a685 [file] [log] [blame]
DRCb4570bb2011-09-07 06:31:00 +00001/*
2 * jdcolext.c
3 *
4 * Copyright (C) 1991-1997, Thomas G. Lane.
5 * Copyright (C) 2009, 2011, D. R. Commander.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
8 *
9 * This file contains output colorspace conversion routines.
10 */
11
12
13/* This file is included by jdcolor.c */
14
15
16/*
17 * Convert some rows of samples to the output colorspace.
18 *
19 * Note that we change from noninterleaved, one-plane-per-component format
20 * to interleaved-pixel format. The output buffer is therefore three times
21 * as wide as the input buffer.
22 * A starting row offset is provided only for the input buffer. The caller
23 * can easily adjust the passed output_buf value to accommodate any row
24 * offset required on that side.
25 */
26
27INLINE
28LOCAL(void)
29ycc_rgb_convert_internal (j_decompress_ptr cinfo,
30 JSAMPIMAGE input_buf, JDIMENSION input_row,
31 JSAMPARRAY output_buf, int num_rows)
32{
33 my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
34 register int y, cb, cr;
35 register JSAMPROW outptr;
36 register JSAMPROW inptr0, inptr1, inptr2;
37 register JDIMENSION col;
38 JDIMENSION num_cols = cinfo->output_width;
39 /* copy these pointers into registers if possible */
40 register JSAMPLE * range_limit = cinfo->sample_range_limit;
41 register int * Crrtab = cconvert->Cr_r_tab;
42 register int * Cbbtab = cconvert->Cb_b_tab;
43 register INT32 * Crgtab = cconvert->Cr_g_tab;
44 register INT32 * Cbgtab = cconvert->Cb_g_tab;
45 SHIFT_TEMPS
46
47 while (--num_rows >= 0) {
48 inptr0 = input_buf[0][input_row];
49 inptr1 = input_buf[1][input_row];
50 inptr2 = input_buf[2][input_row];
51 input_row++;
52 outptr = *output_buf++;
53 for (col = 0; col < num_cols; col++) {
54 y = GETJSAMPLE(inptr0[col]);
55 cb = GETJSAMPLE(inptr1[col]);
56 cr = GETJSAMPLE(inptr2[col]);
57 /* Range-limiting is essential due to noise introduced by DCT losses. */
58 outptr[RGB_RED] = range_limit[y + Crrtab[cr]];
59 outptr[RGB_GREEN] = range_limit[y +
60 ((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
61 SCALEBITS))];
62 outptr[RGB_BLUE] = range_limit[y + Cbbtab[cb]];
DRCd89e01f2011-09-09 18:15:53 +000063 /* Set unused byte to 0xFF so it can be interpreted as an opaque */
64 /* alpha channel value */
65#ifdef RGB_ALPHA
66 outptr[RGB_ALPHA] = 0xFF;
67#endif
DRCb4570bb2011-09-07 06:31:00 +000068 outptr += RGB_PIXELSIZE;
69 }
70 }
71}
72
73
74/*
75 * Convert grayscale to RGB: just duplicate the graylevel three times.
76 * This is provided to support applications that don't want to cope
77 * with grayscale as a separate case.
78 */
79
80INLINE
81LOCAL(void)
82gray_rgb_convert_internal (j_decompress_ptr cinfo,
83 JSAMPIMAGE input_buf, JDIMENSION input_row,
84 JSAMPARRAY output_buf, int num_rows)
85{
86 register JSAMPROW inptr, outptr;
87 register JDIMENSION col;
88 JDIMENSION num_cols = cinfo->output_width;
89
90 while (--num_rows >= 0) {
91 inptr = input_buf[0][input_row++];
92 outptr = *output_buf++;
93 for (col = 0; col < num_cols; col++) {
DRCb4570bb2011-09-07 06:31:00 +000094 /* We can dispense with GETJSAMPLE() here */
95 outptr[RGB_RED] = outptr[RGB_GREEN] = outptr[RGB_BLUE] = inptr[col];
DRCd89e01f2011-09-09 18:15:53 +000096 /* Set unused byte to 0xFF so it can be interpreted as an opaque */
97 /* alpha channel value */
98#ifdef RGB_ALPHA
99 outptr[RGB_ALPHA] = 0xFF;
100#endif
DRCb4570bb2011-09-07 06:31:00 +0000101 outptr += RGB_PIXELSIZE;
102 }
103 }
104}