GCC Code Coverage Report

Directory: ./
File: libfprint/fpi-image.c
Date: 2025-12-06 02:24:24
Exec Total Coverage
Lines: 35 35 100.0%
Functions: 3 3 100.0%
Branches: 6 6 100.0%
Line Branch Exec Source
1 /*
2 * FPrint Image - Private APIs
3 * Copyright (C) 2007 Daniel Drake <dsd@gentoo.org>
4 * Copyright (C) 2019 Benjamin Berg <bberg@redhat.com>
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #define FP_COMPONENT "image"
22
23 #include "fpi-image.h"
24 #include "fpi-log.h"
25
26 #include <nbis.h>
27 #include <config.h>
28
29 #ifdef HAVE_PIXMAN
30 #include <pixman.h>
31 #endif
32
33 /**
34 * SECTION: fpi-image
35 * @title: Internal FpImage
36 * @short_description: Internal image handling routines
37 *
38 * Internal image handling routines. See #FpImage for public routines.
39 */
40
41 /**
42 * fpi_std_sq_dev:
43 * @buf: buffer (usually bitmap, one byte per pixel)
44 * @size: size of @buffer
45 *
46 * Calculates the squared standard deviation of the individual
47 * pixels in the buffer, as per the following formula:
48 * |[<!-- -->
49 * mean = sum (buf[0..size]) / size
50 * sq_dev = sum ((buf[0.size] - mean) ^ 2)
51 * ]|
52 * This function is usually used to determine whether image
53 * is empty.
54 *
55 * Returns: the squared standard deviation for @buffer
56 */
57 gint
58 2093 fpi_std_sq_dev (const guint8 *buf,
59 gint size)
60 {
61 2093 guint64 res = 0, mean = 0;
62 2093 gint i;
63
64
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65 743552 mean += buf[i];
66
67 2093 mean /= size;
68
69
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70 {
71 743552 int dev = (int) buf[i] - mean;
72 743552 res += dev * dev;
73 }
74
75 2093 return res / size;
76 }
77
78 /**
79 * fpi_mean_sq_diff_norm:
80 * @buf1: buffer (usually bitmap, one byte per pixel)
81 * @buf2: buffer (usually bitmap, one byte per pixel)
82 * @size: buffer size of smallest buffer
83 *
84 * This function calculates the normalized mean square difference of
85 * two buffers, usually two lines, as per the following formula:
86 * |[<!-- -->
87 * sq_diff = sum ((buf1[0..size] - buf2[0..size]) ^ 2) / size
88 * ]|
89 *
90 * This functions is usually used to get numerical difference
91 * between two images.
92 *
93 * Returns: the normalized mean squared difference between @buf1 and @buf2
94 */
95 gint
96 2058 fpi_mean_sq_diff_norm (const guint8 *buf1,
97 const guint8 *buf2,
98 gint size)
99 {
100 2058 int res = 0, i;
101
102
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103 {
104 329280 int dev = (int) buf1[i] - (int) buf2[i];
105 329280 res += dev * dev;
106 }
107
108 2058 return res / size;
109 }
110
111 FpImage *
112 3 fpi_image_resize (FpImage *orig_img,
113 guint w_factor,
114 guint h_factor)
115 {
116 #ifdef HAVE_PIXMAN
117 3 int new_width = orig_img->width * w_factor;
118 3 int new_height = orig_img->height * h_factor;
119 3 pixman_image_t *orig, *resized;
120 3 pixman_transform_t transform;
121 3 FpImage *newimg;
122
123 3 orig = pixman_image_create_bits (PIXMAN_a8, orig_img->width, orig_img->height, (uint32_t *) orig_img->data, orig_img->width);
124 3 resized = pixman_image_create_bits (PIXMAN_a8, new_width, new_height, NULL, new_width);
125
126 3 pixman_transform_init_identity (&transform);
127 3 pixman_transform_scale (NULL, &transform, pixman_int_to_fixed (w_factor), pixman_int_to_fixed (h_factor));
128 3 pixman_image_set_transform (orig, &transform);
129 3 pixman_image_set_filter (orig, PIXMAN_FILTER_BILINEAR, NULL, 0);
130 3 pixman_image_composite32 (PIXMAN_OP_SRC,
131 orig, /* src */
132 NULL, /* mask */
133 resized, /* dst */
134 0, 0, /* src x y */
135 0, 0, /* mask x y */
136 0, 0, /* dst x y */
137 new_width, new_height /* width height */
138 );
139
140 3 newimg = fp_image_new (new_width, new_height);
141 3 newimg->flags = orig_img->flags;
142
143 3 memcpy (newimg->data, pixman_image_get_data (resized), new_width * new_height);
144
145 3 pixman_image_unref (orig);
146 3 pixman_image_unref (resized);
147
148 3 return newimg;
149 #else
150 fp_err ("Libfprint compiled without pixman support, impossible to resize");
151
152 return g_object_ref (orig_img);
153 #endif
154 }
155