chromasync-extract 0.6.0

Wallpaper seed color extraction for Chromasync
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

use std::path::PathBuf;

use chromasync_extract::{extract_seed_candidates, extract_seed_candidates_from_bytes};

#[test]
fn extracts_dominant_seed_candidates_from_wallpaper_fixture() {
    let result = extract_seed_candidates(&fixture("wallpaper-blocks.png"))
        .expect("wallpaper extraction should succeed");

    assert_eq!(result.original_width, 6);
    assert_eq!(result.original_height, 4);
    assert_eq!(result.processed_width, 6);
    assert_eq!(result.processed_height, 4);
    assert_eq!(result.seeds.len(), 3);
    assert_eq!(result.seeds[0].hex, "#d1495b");
    assert_eq!(result.seeds[1].hex, "#2b9eb3");
    assert_eq!(result.seeds[2].hex, "#4361ee");
    assert_eq!(
        result.seeds[0].source_region.as_deref(),
        Some("center-left")
    );
    assert_eq!(result.seeds[1].source_region.as_deref(), Some("center"));
    assert_eq!(
        result.seeds[2].source_region.as_deref(),
        Some("center-right")
    );
    assert_close(result.seeds[0].dominance, 0.5);
    assert_close(result.seeds[1].dominance, 8.0 / 24.0);
    assert_close(result.seeds[2].dominance, 4.0 / 24.0);
}

#[test]
fn encoded_image_bytes_match_path_extraction() {
    let path = fixture("wallpaper-blocks.png");
    let bytes = std::fs::read(&path).expect("fixture should be readable");

    let from_path = extract_seed_candidates(&path).expect("path extraction should succeed");
    let from_bytes =
        extract_seed_candidates_from_bytes(&bytes).expect("byte extraction should succeed");

    assert_eq!(from_bytes, from_path);
}

#[test]
fn invalid_encoded_image_bytes_return_a_decode_error() {
    let error = extract_seed_candidates_from_bytes(b"not an image")
        .expect_err("invalid image bytes should fail");

    assert!(
        error
            .to_string()
            .starts_with("failed to decode image bytes:")
    );
}

#[test]
fn low_color_images_return_a_single_seed() {
    let result = extract_seed_candidates(&fixture("wallpaper-monochrome.png"))
        .expect("monochrome extraction should succeed");

    assert_eq!(result.seeds.len(), 1);
    assert_eq!(result.seeds[0].hex, "#204060");
    assert_eq!(result.seeds[0].source_region.as_deref(), Some("center"));
    assert_close(result.seeds[0].dominance, 1.0);
}

#[test]
fn noisy_images_extract_individual_seeds_above_threshold() {
    let result = extract_seed_candidates(&fixture("wallpaper-noisy.png"))
        .expect("noisy extraction should succeed");

    assert_eq!(result.seeds.len(), 3);
    assert!(result.seeds[0].dominance > 0.0);
    assert!(result.seeds[0].source_region.is_some());
}

fn fixture(name: &str) -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .join("tests/fixtures")
        .join(name)
}

fn assert_close(actual: f32, expected: f32) {
    let delta = (actual - expected).abs();
    assert!(
        delta < 0.001,
        "expected {actual} to be within 0.001 of {expected}"
    );
}