mozjpeg/
qtable.rs

1#![allow(non_upper_case_globals)]
2
3use std::cmp::{max, min};
4use std::fmt;
5use std::os::raw::c_uint;
6type Coef = c_uint;
7
8pub struct QTable {
9    pub(crate) coeffs: [Coef; 64],
10}
11
12impl PartialEq for QTable {
13    fn eq(&self, other: &Self) -> bool {
14        let iter2 = other.coeffs.iter().copied();
15        self.coeffs.iter().copied().zip(iter2).all(|(s, o)| s == o)
16    }
17}
18
19impl fmt::Debug for QTable {
20    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
21        write!(fmt, "QTable{{coeffs:{:?}}}", &self.coeffs[..])
22    }
23}
24
25const low_weights : [f32; 19] = [
26    1.00, 0.85, 0.55, 0., 0., 0., 0., 0.,
27    0.85, 0.75, 0.10, 0., 0., 0., 0., 0.,
28    0.55, 0.10, 0.05,
29];
30
31impl QTable {
32    #[must_use]
33    pub fn compare(&self, other: &Self) -> (f32, f32) {
34        let mut scales = [0.; 64];
35        for (s, (&a, &b)) in scales.iter_mut().zip(self.coeffs.iter().zip(other.coeffs.iter())) {
36            *s = if b > 0 { a as f32 / b as f32 } else { 0. };
37        }
38        let avg = scales.iter().sum::<f32>() / 64.;
39        let var = scales.iter().map(|&v| (v - avg).powi(2)).sum::<f32>() / 64.;
40        (avg, var)
41    }
42
43    #[must_use]
44    pub fn scaled(&self, dc_quality: f32, ac_quality: f32) -> Self {
45        let dc_scaling = Self::quality_scaling(dc_quality);
46        let ac_scaling = Self::quality_scaling(ac_quality);
47
48        let mut out = [0; 64];
49        {
50            debug_assert_eq!(self.coeffs.len(), out.len());
51            debug_assert!(low_weights.len() < self.coeffs.len());
52
53            let (low_coefs, high_coefs) = self.coeffs.split_at(low_weights.len());
54            let (low_out, high_out) = out.split_at_mut(low_weights.len());
55
56            // TODO: that could be improved for 1x2 and 2x1 subsampling
57            for ((out, coef), w) in low_out.iter_mut().zip(low_coefs).zip(&low_weights) {
58                *out = ((*coef as f32 * (dc_scaling * w + ac_scaling * (1.-w))).round() as Coef).clamp(1, 255);
59            }
60            for (out, coef) in high_out.iter_mut().zip(high_coefs) {
61                *out = ((*coef as f32 * ac_scaling).round() as Coef).clamp(1, 255);
62            }
63        }
64        Self { coeffs: out }
65    }
66
67    #[must_use]
68    pub fn as_ptr(&self) -> *const c_uint {
69        self.coeffs.as_ptr()
70    }
71
72    // Similar to libjpeg, but result is 100x smaller
73    fn quality_scaling(quality: f32) -> f32 {
74        assert!(quality > 0. && quality <= 100.);
75
76        if quality < 50. {
77            50. / quality
78        } else {
79            (100. - quality) / 50.
80        }
81    }
82}
83
84pub static AnnexK_Luma: QTable = QTable {
85    coeffs: [
86        16, 11, 10, 16, 24, 40, 51, 61, 12, 12, 14, 19, 26, 58, 60, 55, 14, 13, 16, 24, 40, 57, 69,
87        56, 14, 17, 22, 29, 51, 87, 80, 62, 18, 22, 37, 56, 68, 109, 103, 77, 24, 35, 55, 64, 81,
88        104, 113, 92, 49, 64, 78, 87, 103, 121, 120, 101, 72, 92, 95, 98, 112, 100, 103, 99,
89    ],
90};
91
92pub static AnnexK_Chroma: QTable = QTable {
93    coeffs: [
94        17, 18, 24, 47, 99, 99, 99, 99, 18, 21, 26, 66, 99, 99, 99, 99, 24, 26, 56, 99, 99, 99, 99,
95        99, 47, 66, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
96        99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
97    ],
98};
99
100pub static Flat: QTable = QTable {
101    coeffs: [
102        16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
103        16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
104        16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
105    ],
106};
107
108pub static MSSSIM_Luma: QTable = QTable {
109    coeffs: [
110        12, 17, 20, 21, 30, 34, 56, 63, 18, 20, 20, 26, 28, 51, 61, 55, 19, 20, 21, 26, 33, 58, 69,
111        55, 26, 26, 26, 30, 46, 87, 86, 66, 31, 33, 36, 40, 46, 96, 100, 73, 40, 35, 46, 62, 81,
112        100, 111, 91, 46, 66, 76, 86, 102, 121, 120, 101, 68, 90, 90, 96, 113, 102, 105, 103,
113    ],
114};
115
116pub static MSSSIM_Chroma: QTable = QTable {
117    coeffs: [
118        8, 12, 15, 15, 86, 96, 96, 98, 13, 13, 15, 26, 90, 96, 99, 98, 12, 15, 18, 96, 99, 99, 99,
119        99, 17, 16, 90, 96, 99, 99, 99, 99, 96, 96, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
120        99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
121    ],
122};
123
124pub static NRobidoux: QTable = QTable {
125    coeffs: [
126        16, 16, 16, 18, 25, 37, 56, 85, 16, 17, 20, 27, 34, 40, 53, 75, 16, 20, 24, 31, 43, 62, 91,
127        135, 18, 27, 31, 40, 53, 74, 106, 156, 25, 34, 43, 53, 69, 94, 131, 189, 37, 40, 62, 74,
128        94, 124, 169, 238, 56, 53, 91, 106, 131, 169, 226, 311, 85, 75, 135, 156, 189, 238, 311,
129        418,
130    ],
131};
132
133pub static PSNRHVS_Luma: QTable = QTable {
134    coeffs: [
135        9, 10, 12, 14, 27, 32, 51, 62, 11, 12, 14, 19, 27, 44, 59, 73, 12, 14, 18, 25, 42, 59, 79,
136        78, 17, 18, 25, 42, 61, 92, 87, 92, 23, 28, 42, 75, 79, 112, 112, 99, 40, 42, 59, 84, 88,
137        124, 132, 111, 42, 64, 78, 95, 105, 126, 125, 99, 70, 75, 100, 102, 116, 100, 107, 98,
138    ],
139};
140pub static PSNRHVS_Chroma: QTable = QTable {
141    coeffs: [
142        9, 10, 17, 19, 62, 89, 91, 97, 12, 13, 18, 29, 84, 91, 88, 98, 14, 19, 29, 93, 95, 95, 98,
143        97, 20, 26, 84, 88, 95, 95, 98, 94, 26, 86, 91, 93, 97, 99, 98, 99, 99, 100, 98, 99, 99,
144        99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 97, 97, 99, 99, 99, 99, 97, 99,
145    ],
146};
147
148pub static KleinSilversteinCarney: QTable = QTable {
149    coeffs: [
150        /* Relevance of human vision to JPEG-DCT compression (1992) Klein, Silverstein and Carney.
151         */
152        10, 12, 14, 19, 26, 38, 57, 86, 12, 18, 21, 28, 35, 41, 54, 76, 14, 21, 25, 32, 44, 63, 92,
153        136, 19, 28, 32, 41, 54, 75, 107, 157, 26, 35, 44, 54, 70, 95, 132, 190, 38, 41, 63, 75,
154        95, 125, 170, 239, 57, 54, 92, 107, 132, 170, 227, 312, 86, 76, 136, 157, 190, 239, 312,
155        419,
156    ],
157};
158
159pub static WatsonTaylorBorthwick: QTable = QTable {
160    coeffs: [
161        /* DCTune perceptual optimization of compressed dental X-Rays (1997) Watson, Taylor, Borthwick
162         */
163        7, 8, 10, 14, 23, 44, 95, 241, 8, 8, 11, 15, 25, 47, 102, 255, 10, 11, 13, 19, 31, 58, 127,
164        255, 14, 15, 19, 27, 44, 83, 181, 255, 23, 25, 31, 44, 72, 136, 255, 255, 44, 47, 58, 83,
165        136, 255, 255, 255, 95, 102, 127, 181, 255, 255, 255, 255, 241, 255, 255, 255, 255, 255,
166        255, 255,
167    ],
168};
169
170pub static AhumadaWatsonPeterson: QTable = QTable {
171    coeffs: [
172        /* A visual detection model for DCT coefficient quantization (12/9/93) Ahumada, Watson, Peterson
173         */
174        15, 11, 11, 12, 15, 19, 25, 32, 11, 13, 10, 10, 12, 15, 19, 24, 11, 10, 14, 14, 16, 18, 22,
175        27, 12, 10, 14, 18, 21, 24, 28, 33, 15, 12, 16, 21, 26, 31, 36, 42, 19, 15, 18, 24, 31, 38,
176        45, 53, 25, 19, 22, 28, 36, 45, 55, 65, 32, 24, 27, 33, 42, 53, 65, 77,
177    ],
178};
179
180pub static PetersonAhumadaWatson: QTable = QTable {
181    coeffs: [
182        /* An improved detection model for DCT coefficient quantization (1993) Peterson, Ahumada and Watson
183         */
184        14, 10, 11, 14, 19, 25, 34, 45, 10, 11, 11, 12, 15, 20, 26, 33, 11, 11, 15, 18, 21, 25, 31,
185        38, 14, 12, 18, 24, 28, 33, 39, 47, 19, 15, 21, 28, 36, 43, 51, 59, 25, 20, 25, 33, 43, 54,
186        64, 74, 34, 26, 31, 39, 51, 64, 77, 91, 45, 33, 38, 47, 59, 74, 91, 108,
187    ],
188};
189
190pub static ALL_TABLES: [(&str, &QTable); 12] = [
191    ("Annex-K Luma", &AnnexK_Luma),
192    ("Annex-K Chroma", &AnnexK_Chroma),
193    ("Flat", &Flat),
194    ("MSSSIM Luma", &MSSSIM_Luma),
195    ("MSSSIM Chroma", &MSSSIM_Chroma),
196    ("N. Robidoux", &NRobidoux),
197    ("PSNRHVS Luma", &PSNRHVS_Luma),
198    ("PSNRHVS Chroma", &PSNRHVS_Chroma),
199    ("Klein, Silverstein, Carney", &KleinSilversteinCarney),
200    ("Watson, Taylor, Borthwick", &WatsonTaylorBorthwick),
201    ("Ahumada, Watson, Peterson", &AhumadaWatsonPeterson),
202    ("Peterson, Ahumada, Watson", &PetersonAhumadaWatson),
203];
204
205#[test]
206fn scaling() {
207    assert_eq!(QTable { coeffs: [100; 64] }, QTable { coeffs: [100; 64] });
208    assert!(QTable { coeffs: [1; 64] } != QTable { coeffs: [2; 64] });
209
210    assert_eq!(QTable{coeffs:[36; 64]}, Flat.scaled(22.,22.));
211    assert_eq!(QTable{coeffs:[8; 64]}, Flat.scaled(75.,75.));
212    assert_eq!(QTable{coeffs:[1; 64]}, Flat.scaled(100.,100.));
213    assert_eq!(QTable{coeffs:[2; 64]}, Flat.scaled(95.,95.));
214    assert_eq!(QTable{coeffs:[
215         2,  6, 15, 32, 32, 32, 32, 32,
216         6,  9, 29, 32, 32, 32, 32, 32,
217        15, 29, 30, 32, 32, 32, 32, 32,
218        32, 32, 32, 32, 32, 32, 32, 32,
219        32, 32, 32, 32, 32, 32, 32, 32,
220        32, 32, 32, 32, 32, 32, 32, 32,
221        32, 32, 32, 32, 32, 32, 32, 32,
222        32, 32, 32, 32, 32, 32, 32, 32]}, Flat.scaled(95.,25.));
223    assert_eq!(PetersonAhumadaWatson, PetersonAhumadaWatson.scaled(50.,50.));
224
225    assert_eq!(QTable { coeffs: [1; 64] }, NRobidoux.scaled(99.9, 99.9));
226    assert_eq!(QTable { coeffs: [1; 64] }, MSSSIM_Chroma.scaled(99.8, 99.8));
227}
mozjpeg/qtable.rs

mozjpeg/
qtable.rs
