lensfun 0.7.0

Pure-Rust port of LensFun: camera lens correction (distortion, TCA, vignetting) without C dependencies
Documentation 
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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285

//! Port of `tests/test_modifier_regression.cpp`.
//!
//! Pins specific output pixel values within `1e-3` tolerance, against the bundled
//! XML database. These ARE the spec for the high-level `Modifier` API.
//!
//! Float tolerance: upstream uses `1e-3` for absolute coordinate / pixel match.
//! We mirror that with `approx::assert_abs_diff_eq!`.

// Expected-value literals are copied verbatim from upstream
// `test_modifier_regression.cpp` (which prints `%.8f`). The trailing digits
// past `f32` precision are preserved so a diff against upstream is trivial.
#![allow(clippy::excessive_precision)]

use std::path::{Path, PathBuf};

use approx::assert_abs_diff_eq;
use lensfun::Database;
use lensfun::modifier::Modifier;

const IMG_WIDTH: u32 = 1500;
const IMG_HEIGHT: u32 = 1000;
const TOL: f32 = 1e-3;

fn data_dir() -> PathBuf {
    Path::new(env!("CARGO_MANIFEST_DIR")).join("data/db")
}

fn load_db() -> Database {
    Database::load_dir(data_dir()).expect("bundled database loads cleanly")
}

// ---------------------- distortion ----------------------

#[test]
fn verify_dist_poly3_pentax_50_200() {
    // Port of test_modifier_regression.cpp:36 (test_verify_dist_poly3).
    let db = load_db();
    let lenses = db.find_lenses(None, "pEntax 50-200 ED");
    assert!(!lenses.is_empty(), "expected to find Pentax 50-200 ED");
    let lens = lenses[0];
    assert_eq!(lens.model, "smc Pentax-DA 50-200mm f/4-5.6 DA ED");

    let mut m = Modifier::new(lens, 80.89, 1.534, IMG_WIDTH, IMG_HEIGHT, false);
    assert!(
        m.enable_distortion_correction(lens),
        "distortion should enable"
    );

    let xs = [0.0_f32, 751.0, 810.0, 1270.0];
    let ys = [0.0_f32, 497.0, 937.0, 100.0];
    let exp_x = [-14.016061_f32, 751.0, 810.27203, 1275.1655];
    let exp_y = [-9.3409109_f32, 497.0, 938.96729, 96.035286];

    for i in 0..xs.len() {
        let mut coords = [0.0_f32; 2];
        assert!(m.apply_geometry_distortion(xs[i], ys[i], 1, 1, &mut coords));
        assert_abs_diff_eq!(coords[0], exp_x[i], epsilon = TOL);
        assert_abs_diff_eq!(coords[1], exp_y[i], epsilon = TOL);
    }
}

#[test]
fn verify_dist_poly5_canon_g12() {
    // Port of test_modifier_regression.cpp:89 (test_verify_dist_poly5).
    let db = load_db();
    let lenses = db.find_lenses(None, "Canon PowerShot G12");
    assert!(!lenses.is_empty(), "expected to find Canon PowerShot G12");
    let lens = lenses[0];
    assert_eq!(lens.model, "Canon PowerShot G12 & compatibles (Standard)");

    let mut m = Modifier::new(lens, 10.89, 4.6, IMG_WIDTH, IMG_HEIGHT, false);
    assert!(m.enable_distortion_correction(lens));

    let xs = [0.0_f32, 751.0, 810.0, 1270.0];
    let ys = [0.0_f32, 497.0, 937.0, 100.0];
    let exp_x = [28.805828_f32, 751.0, 809.50531, 1260.1396];
    let exp_y = [19.197506_f32, 497.0, 933.42279, 107.56808];

    for i in 0..xs.len() {
        let mut coords = [0.0_f32; 2];
        assert!(m.apply_geometry_distortion(xs[i], ys[i], 1, 1, &mut coords));
        assert_abs_diff_eq!(coords[0], exp_x[i], epsilon = TOL);
        assert_abs_diff_eq!(coords[1], exp_y[i], epsilon = TOL);
    }
}

#[test]
fn verify_dist_ptlens_pentax_28_80() {
    // Port of test_modifier_regression.cpp:122 (test_verify_dist_ptlens).
    let db = load_db();
    let lenses = db.find_lenses(None, "PENTAX-F 28-80mm");
    assert!(!lenses.is_empty(), "expected to find Pentax-F 28-80mm");
    let lens = lenses[0];
    assert_eq!(lens.model, "Pentax-F 28-80mm f/3.5-4.5");

    let mut m = Modifier::new(lens, 30.89, 1.534, IMG_WIDTH, IMG_HEIGHT, false);
    assert!(m.enable_distortion_correction(lens));

    let xs = [0.0_f32, 751.0, 810.0, 1270.0];
    let ys = [0.0_f32, 497.0, 937.0, 100.0];
    let exp_x = [29.019449_f32, 750.99969, 808.74231, 1255.1388];
    let exp_y = [19.339846_f32, 497.00046, 927.90521, 111.40639];

    for i in 0..xs.len() {
        let mut coords = [0.0_f32; 2];
        assert!(m.apply_geometry_distortion(xs[i], ys[i], 1, 1, &mut coords));
        assert_abs_diff_eq!(coords[0], exp_x[i], epsilon = TOL);
        assert_abs_diff_eq!(coords[1], exp_y[i], epsilon = TOL);
    }
}

// ---------------------- vignetting ----------------------

#[test]
fn verify_vignetting_pa_olympus_zuiko() {
    // Port of test_modifier_regression.cpp:153 (test_verify_vignetting_pa).
    let db = load_db();
    let lenses = db.find_lenses(None, "Olympus ED 14-42mm");
    assert!(!lenses.is_empty(), "expected to find Olympus 14-42mm");
    let lens = lenses[0];
    assert_eq!(lens.model, "Olympus Zuiko Digital ED 14-42mm f/3.5-5.6");

    let mut m = Modifier::new(lens, 17.89, 2.0, IMG_WIDTH, IMG_HEIGHT, false);
    assert!(m.enable_vignetting_correction(lens, 5.0, 1000.0));

    let xs = [0.0_f32, 751.0, 810.0, 1270.0];
    let ys = [0.0_f32, 497.0, 937.0, 100.0];
    let expected: [u16; 4] = [22406, 22406, 24156, 28803];

    // NB: upstream re-uses the same buffer across samples without resetting it
    // (see test_modifier_regression.cpp:169). Sample 1 sits at image center where
    // gain ≈ 1, so it keeps sample 0's output. Mirror that here.
    let mut buf = [16000_u16, 16000, 16000];
    for i in 0..xs.len() {
        assert!(m.apply_color_modification_u16(&mut buf, xs[i], ys[i], 1, 1, 3));
        for (ch, &v) in buf.iter().enumerate() {
            assert_eq!(
                v, expected[i],
                "vignetting ch{ch} at sample {i}: got {} expected {}",
                v, expected[i]
            );
        }
    }
}

// ---------------------- subpixel TCA ----------------------

#[test]
fn verify_subpix_linear_olympus_zuiko() {
    // Port of test_modifier_regression.cpp:208 (test_verify_subpix_linear).
    let db = load_db();
    let lenses = db.find_lenses(None, "Olympus ED 14-42mm");
    assert!(!lenses.is_empty());
    let lens = lenses[0];
    assert_eq!(lens.model, "Olympus Zuiko Digital ED 14-42mm f/3.5-5.6");

    let mut m = Modifier::new(lens, 17.89, 2.0, IMG_WIDTH, IMG_HEIGHT, false);
    assert!(m.enable_tca_correction(lens), "TCA should enable");

    let xs = [0.0_f32, 751.0, 810.0, 1270.0];
    let ys = [0.0_f32, 497.0, 937.0, 100.0];
    let expected: [[f32; 6]; 4] = [
        [
            -0.08681729,
            -0.05789410,
            0.00002450,
            -0.00001032,
            -0.02400517,
            -0.01601936,
        ],
        [
            751.00061035,
            496.99899292,
            751.00000000,
            497.00000000,
            751.00000000,
            497.00000000,
        ],
        [
            810.01995850,
            937.14440918,
            810.00000000,
            937.00000000,
            810.00042725,
            937.00305176,
        ],
        [
            1270.12915039,
            99.90086365,
            1270.00000000,
            100.00000763,
            1270.00854492,
            99.99343872,
        ],
    ];

    for i in 0..xs.len() {
        let mut coords = [0.0_f32; 6];
        assert!(m.apply_subpixel_distortion(xs[i], ys[i], 1, 1, &mut coords));
        for (j, &c) in coords.iter().enumerate() {
            assert_abs_diff_eq!(c, expected[i][j], epsilon = TOL);
        }
    }
}

#[test]
fn verify_subpix_poly3_olympus_zuiko() {
    // Port of test_modifier_regression.cpp:243 (test_verify_subpix_poly3).
    let db = load_db();
    let lenses = db.find_lenses(None, "Olympus ED 14-42mm");
    assert!(!lenses.is_empty());
    let lens = lenses[0];
    assert_eq!(lens.model, "Olympus Zuiko Digital ED 14-42mm f/3.5-5.6");

    let mut m = Modifier::new(lens, 26.89, 2.0, IMG_WIDTH, IMG_HEIGHT, false);
    assert!(m.enable_tca_correction(lens));

    let xs = [0.0_f32, 751.0, 810.0, 1270.0];
    let ys = [0.0_f32, 497.0, 937.0, 100.0];
    let expected: [[f32; 6]; 4] = [
        [
            -0.05537901,
            -0.03692452,
            0.00002450,
            -0.00001032,
            0.01445518,
            0.00962087,
        ],
        [
            751.00061035,
            496.99902344,
            751.00000000,
            497.00000000,
            750.99981689,
            497.00030518,
        ],
        [
            810.01898193,
            937.13732910,
            810.00000000,
            937.00000000,
            809.99389648,
            936.95599365,
        ],
        [
            1270.11572266,
            99.91123199,
            1270.00000000,
            100.00000763,
            1269.96374512,
            100.02780914,
        ],
    ];

    for i in 0..xs.len() {
        let mut coords = [0.0_f32; 6];
        assert!(m.apply_subpixel_distortion(xs[i], ys[i], 1, 1, &mut coords));
        for (j, &c) in coords.iter().enumerate() {
            assert_abs_diff_eq!(c, expected[i][j], epsilon = TOL);
        }
    }
}

// ---------------------- multi-pixel sanity ----------------------

#[test]
fn apply_geometry_distortion_walks_a_row() {
    // Single-row, multi-column buffer call. Compares to single-pixel calls so any
    // row-stepping bug shows up.
    let db = load_db();
    let lenses = db.find_lenses(None, "pEntax 50-200 ED");
    let lens = lenses[0];
    let mut m = Modifier::new(lens, 80.89, 1.534, IMG_WIDTH, IMG_HEIGHT, false);
    m.enable_distortion_correction(lens);

    let mut row = vec![0.0_f32; 4 * 2];
    assert!(m.apply_geometry_distortion(100.0, 200.0, 4, 1, &mut row));

    for i in 0..4 {
        let mut single = [0.0_f32; 2];
        assert!(m.apply_geometry_distortion(100.0 + i as f32, 200.0, 1, 1, &mut single));
        assert_abs_diff_eq!(row[2 * i], single[0], epsilon = TOL);
        assert_abs_diff_eq!(row[2 * i + 1], single[1], epsilon = TOL);
    }
}