1 : /*
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 :
27 : INLINE
28 : LOCAL(void)
29 0 : ycc_rgb_convert_internal (j_decompress_ptr cinfo,
30 : JSAMPIMAGE input_buf, JDIMENSION input_row,
31 : JSAMPARRAY output_buf, int num_rows)
32 : {
33 0 : 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 0 : JDIMENSION num_cols = cinfo->output_width;
39 : /* copy these pointers into registers if possible */
40 0 : register JSAMPLE * range_limit = cinfo->sample_range_limit;
41 0 : register int * Crrtab = cconvert->Cr_r_tab;
42 0 : register int * Cbbtab = cconvert->Cb_b_tab;
43 0 : register INT32 * Crgtab = cconvert->Cr_g_tab;
44 0 : register INT32 * Cbgtab = cconvert->Cb_g_tab;
45 : SHIFT_TEMPS
46 :
47 0 : while (--num_rows >= 0) {
48 0 : inptr0 = input_buf[0][input_row];
49 0 : inptr1 = input_buf[1][input_row];
50 0 : inptr2 = input_buf[2][input_row];
51 0 : input_row++;
52 0 : outptr = *output_buf++;
53 0 : for (col = 0; col < num_cols; col++) {
54 0 : y = GETJSAMPLE(inptr0[col]);
55 0 : cb = GETJSAMPLE(inptr1[col]);
56 0 : cr = GETJSAMPLE(inptr2[col]);
57 : /* Range-limiting is essential due to noise introduced by DCT losses. */
58 0 : outptr[RGB_RED] = range_limit[y + Crrtab[cr]];
59 0 : outptr[RGB_GREEN] = range_limit[y +
60 0 : ((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
61 : SCALEBITS))];
62 0 : outptr[RGB_BLUE] = range_limit[y + Cbbtab[cb]];
63 : /* Set unused byte to 0xFF so it can be interpreted as an opaque */
64 : /* alpha channel value */
65 : #ifdef RGB_ALPHA
66 0 : outptr[RGB_ALPHA] = 0xFF;
67 : #endif
68 0 : outptr += RGB_PIXELSIZE;
69 : }
70 : }
71 0 : }
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 :
80 : INLINE
81 : LOCAL(void)
82 0 : gray_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 0 : JDIMENSION num_cols = cinfo->output_width;
89 :
90 0 : while (--num_rows >= 0) {
91 0 : inptr = input_buf[0][input_row++];
92 0 : outptr = *output_buf++;
93 0 : for (col = 0; col < num_cols; col++) {
94 : /* We can dispense with GETJSAMPLE() here */
95 0 : outptr[RGB_RED] = outptr[RGB_GREEN] = outptr[RGB_BLUE] = inptr[col];
96 : /* Set unused byte to 0xFF so it can be interpreted as an opaque */
97 : /* alpha channel value */
98 : #ifdef RGB_ALPHA
99 0 : outptr[RGB_ALPHA] = 0xFF;
100 : #endif
101 0 : outptr += RGB_PIXELSIZE;
102 : }
103 : }
104 0 : }
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