spectrs/io/
image.rs

1#[cfg(feature = "image")]
2use anyhow::Context;
3use anyhow::Result;
4use std::path::PathBuf;
5
6/// Available colormaps for spectrogram visualization
7#[derive(Debug, Clone, Copy, Default)]
8#[cfg_attr(feature = "cli", derive(clap::ValueEnum))]
9pub enum Colormap {
10    /// Perceptually uniform, great for spectrograms (matplotlib/librosa default)
11    #[default]
12    Viridis,
13    /// Perceptually uniform, good for dark backgrounds
14    Magma,
15    /// Perceptually uniform, high contrast
16    Inferno,
17    /// Perceptually uniform, bright
18    Plasma,
19    /// Grayscale
20    Gray,
21}
22
23// All colour mpas are based on https://github.com/BIDS/colormap/blob/master/colormaps.py
24const VIRIDIS_DATA: [[f32; 3]; 256] = [
25    [0.267004, 0.004874, 0.329415],
26    [0.268510, 0.009605, 0.335427],
27    [0.269944, 0.014625, 0.341379],
28    [0.271305, 0.019942, 0.347269],
29    [0.272594, 0.025563, 0.353093],
30    [0.273809, 0.031497, 0.358853],
31    [0.274952, 0.037752, 0.364543],
32    [0.276022, 0.044167, 0.370164],
33    [0.277018, 0.050344, 0.375715],
34    [0.277941, 0.056324, 0.381191],
35    [0.278791, 0.062145, 0.386592],
36    [0.279566, 0.067836, 0.391917],
37    [0.280267, 0.073417, 0.397163],
38    [0.280894, 0.078907, 0.402329],
39    [0.281446, 0.084320, 0.407414],
40    [0.281924, 0.089666, 0.412415],
41    [0.282327, 0.094955, 0.417331],
42    [0.282656, 0.100196, 0.422160],
43    [0.282910, 0.105393, 0.426902],
44    [0.283091, 0.110553, 0.431554],
45    [0.283197, 0.115680, 0.436115],
46    [0.283229, 0.120777, 0.440584],
47    [0.283187, 0.125848, 0.444960],
48    [0.283072, 0.130895, 0.449241],
49    [0.282884, 0.135920, 0.453427],
50    [0.282623, 0.140926, 0.457517],
51    [0.282290, 0.145912, 0.461510],
52    [0.281887, 0.150881, 0.465405],
53    [0.281412, 0.155834, 0.469201],
54    [0.280868, 0.160771, 0.472899],
55    [0.280255, 0.165693, 0.476498],
56    [0.279574, 0.170599, 0.479997],
57    [0.278826, 0.175490, 0.483397],
58    [0.278012, 0.180367, 0.486697],
59    [0.277134, 0.185228, 0.489898],
60    [0.276194, 0.190074, 0.493001],
61    [0.275191, 0.194905, 0.496005],
62    [0.274128, 0.199721, 0.498911],
63    [0.273006, 0.204520, 0.501721],
64    [0.271828, 0.209303, 0.504434],
65    [0.270595, 0.214069, 0.507052],
66    [0.269308, 0.218818, 0.509577],
67    [0.267968, 0.223549, 0.512008],
68    [0.266580, 0.228262, 0.514349],
69    [0.265145, 0.232956, 0.516599],
70    [0.263663, 0.237631, 0.518762],
71    [0.262138, 0.242286, 0.520837],
72    [0.260571, 0.246922, 0.522828],
73    [0.258965, 0.251537, 0.524736],
74    [0.257322, 0.256130, 0.526563],
75    [0.255645, 0.260703, 0.528312],
76    [0.253935, 0.265254, 0.529983],
77    [0.252194, 0.269783, 0.531579],
78    [0.250425, 0.274290, 0.533103],
79    [0.248629, 0.278775, 0.534556],
80    [0.246811, 0.283237, 0.535941],
81    [0.244972, 0.287675, 0.537260],
82    [0.243113, 0.292092, 0.538516],
83    [0.241237, 0.296485, 0.539709],
84    [0.239346, 0.300855, 0.540844],
85    [0.237441, 0.305202, 0.541921],
86    [0.235526, 0.309527, 0.542944],
87    [0.233603, 0.313828, 0.543914],
88    [0.231674, 0.318106, 0.544834],
89    [0.229739, 0.322361, 0.545706],
90    [0.227802, 0.326594, 0.546532],
91    [0.225863, 0.330805, 0.547314],
92    [0.223925, 0.334994, 0.548053],
93    [0.221989, 0.339161, 0.548752],
94    [0.220057, 0.343307, 0.549413],
95    [0.218130, 0.347432, 0.550038],
96    [0.216210, 0.351535, 0.550627],
97    [0.214298, 0.355619, 0.551184],
98    [0.212395, 0.359683, 0.551710],
99    [0.210503, 0.363727, 0.552206],
100    [0.208623, 0.367752, 0.552675],
101    [0.206756, 0.371758, 0.553117],
102    [0.204903, 0.375746, 0.553533],
103    [0.203063, 0.379716, 0.553925],
104    [0.201239, 0.383670, 0.554294],
105    [0.199430, 0.387607, 0.554642],
106    [0.197636, 0.391528, 0.554969],
107    [0.195860, 0.395433, 0.555276],
108    [0.194100, 0.399323, 0.555565],
109    [0.192357, 0.403199, 0.555836],
110    [0.190631, 0.407061, 0.556089],
111    [0.188923, 0.410910, 0.556326],
112    [0.187231, 0.414746, 0.556547],
113    [0.185556, 0.418570, 0.556753],
114    [0.183898, 0.422383, 0.556944],
115    [0.182256, 0.426184, 0.557120],
116    [0.180629, 0.429975, 0.557282],
117    [0.179019, 0.433756, 0.557430],
118    [0.177423, 0.437527, 0.557565],
119    [0.175841, 0.441290, 0.557685],
120    [0.174274, 0.445044, 0.557792],
121    [0.172719, 0.448791, 0.557885],
122    [0.171176, 0.452530, 0.557965],
123    [0.169646, 0.456262, 0.558030],
124    [0.168126, 0.459988, 0.558082],
125    [0.166617, 0.463708, 0.558119],
126    [0.165117, 0.467423, 0.558141],
127    [0.163625, 0.471133, 0.558148],
128    [0.162142, 0.474838, 0.558140],
129    [0.160665, 0.478540, 0.558115],
130    [0.159194, 0.482237, 0.558073],
131    [0.157729, 0.485932, 0.558013],
132    [0.156270, 0.489624, 0.557936],
133    [0.154815, 0.493313, 0.557840],
134    [0.153364, 0.497000, 0.557724],
135    [0.151918, 0.500685, 0.557587],
136    [0.150476, 0.504369, 0.557430],
137    [0.149039, 0.508051, 0.557250],
138    [0.147607, 0.511733, 0.557049],
139    [0.146180, 0.515413, 0.556823],
140    [0.144759, 0.519093, 0.556572],
141    [0.143343, 0.522773, 0.556295],
142    [0.141935, 0.526453, 0.555991],
143    [0.140536, 0.530132, 0.555659],
144    [0.139147, 0.533812, 0.555298],
145    [0.137770, 0.537492, 0.554906],
146    [0.136408, 0.541173, 0.554483],
147    [0.135066, 0.544853, 0.554029],
148    [0.133743, 0.548535, 0.553541],
149    [0.132444, 0.552216, 0.553018],
150    [0.131172, 0.555899, 0.552459],
151    [0.129933, 0.559582, 0.551864],
152    [0.128729, 0.563265, 0.551229],
153    [0.127568, 0.566949, 0.550556],
154    [0.126453, 0.570633, 0.549841],
155    [0.125394, 0.574318, 0.549086],
156    [0.124395, 0.578002, 0.548287],
157    [0.123463, 0.581687, 0.547445],
158    [0.122606, 0.585371, 0.546557],
159    [0.121831, 0.589055, 0.545623],
160    [0.121148, 0.592739, 0.544641],
161    [0.120565, 0.596422, 0.543611],
162    [0.120092, 0.600104, 0.542530],
163    [0.119738, 0.603785, 0.541400],
164    [0.119512, 0.607464, 0.540218],
165    [0.119423, 0.611141, 0.538982],
166    [0.119483, 0.614817, 0.537692],
167    [0.119699, 0.618490, 0.536347],
168    [0.120081, 0.622161, 0.534946],
169    [0.120638, 0.625828, 0.533488],
170    [0.121380, 0.629492, 0.531973],
171    [0.122312, 0.633153, 0.530398],
172    [0.123444, 0.636809, 0.528763],
173    [0.124780, 0.640461, 0.527068],
174    [0.126326, 0.644107, 0.525311],
175    [0.128087, 0.647749, 0.523491],
176    [0.130067, 0.651384, 0.521608],
177    [0.132268, 0.655014, 0.519661],
178    [0.134692, 0.658636, 0.517649],
179    [0.137339, 0.662252, 0.515571],
180    [0.140210, 0.665859, 0.513427],
181    [0.143303, 0.669459, 0.511215],
182    [0.146616, 0.673050, 0.508936],
183    [0.150148, 0.676631, 0.506589],
184    [0.153894, 0.680203, 0.504172],
185    [0.157851, 0.683765, 0.501686],
186    [0.162016, 0.687316, 0.499129],
187    [0.166383, 0.690856, 0.496502],
188    [0.170948, 0.694384, 0.493803],
189    [0.175707, 0.697900, 0.491033],
190    [0.180653, 0.701402, 0.488189],
191    [0.185783, 0.704891, 0.485273],
192    [0.191090, 0.708366, 0.482284],
193    [0.196571, 0.711827, 0.479221],
194    [0.202219, 0.715272, 0.476084],
195    [0.208030, 0.718701, 0.472873],
196    [0.214000, 0.722114, 0.469588],
197    [0.220124, 0.725509, 0.466226],
198    [0.226397, 0.728888, 0.462789],
199    [0.232815, 0.732247, 0.459277],
200    [0.239374, 0.735588, 0.455688],
201    [0.246070, 0.738910, 0.452024],
202    [0.252899, 0.742211, 0.448284],
203    [0.259857, 0.745492, 0.444467],
204    [0.266941, 0.748751, 0.440573],
205    [0.274149, 0.751988, 0.436601],
206    [0.281477, 0.755203, 0.432552],
207    [0.288921, 0.758394, 0.428426],
208    [0.296479, 0.761561, 0.424223],
209    [0.304148, 0.764704, 0.419943],
210    [0.311925, 0.767822, 0.415586],
211    [0.319809, 0.770914, 0.411152],
212    [0.327796, 0.773980, 0.406640],
213    [0.335885, 0.777018, 0.402049],
214    [0.344074, 0.780029, 0.397381],
215    [0.352360, 0.783011, 0.392636],
216    [0.360741, 0.785964, 0.387814],
217    [0.369214, 0.788888, 0.382914],
218    [0.377779, 0.791781, 0.377939],
219    [0.386433, 0.794644, 0.372886],
220    [0.395174, 0.797475, 0.367757],
221    [0.404001, 0.800275, 0.362552],
222    [0.412913, 0.803041, 0.357269],
223    [0.421908, 0.805774, 0.351910],
224    [0.430983, 0.808473, 0.346476],
225    [0.440137, 0.811138, 0.340967],
226    [0.449368, 0.813768, 0.335384],
227    [0.458674, 0.816363, 0.329727],
228    [0.468053, 0.818921, 0.323998],
229    [0.477504, 0.821444, 0.318195],
230    [0.487026, 0.823929, 0.312321],
231    [0.496615, 0.826376, 0.306377],
232    [0.506271, 0.828786, 0.300362],
233    [0.515992, 0.831158, 0.294279],
234    [0.525776, 0.833491, 0.288127],
235    [0.535621, 0.835785, 0.281908],
236    [0.545524, 0.838039, 0.275626],
237    [0.555484, 0.840254, 0.269281],
238    [0.565498, 0.842430, 0.262877],
239    [0.575563, 0.844566, 0.256415],
240    [0.585678, 0.846661, 0.249897],
241    [0.595839, 0.848717, 0.243329],
242    [0.606045, 0.850733, 0.236712],
243    [0.616293, 0.852709, 0.230052],
244    [0.626579, 0.854645, 0.223353],
245    [0.636902, 0.856542, 0.216620],
246    [0.647257, 0.858400, 0.209861],
247    [0.657642, 0.860219, 0.203082],
248    [0.668054, 0.861999, 0.196293],
249    [0.678489, 0.863742, 0.189503],
250    [0.688944, 0.865448, 0.182725],
251    [0.699415, 0.867117, 0.175971],
252    [0.709898, 0.868751, 0.169257],
253    [0.720391, 0.870350, 0.162603],
254    [0.730889, 0.871916, 0.156029],
255    [0.741388, 0.873449, 0.149561],
256    [0.751884, 0.874951, 0.143228],
257    [0.762373, 0.876424, 0.137064],
258    [0.772852, 0.877868, 0.131109],
259    [0.783315, 0.879285, 0.125405],
260    [0.793760, 0.880678, 0.120005],
261    [0.804182, 0.882046, 0.114965],
262    [0.814576, 0.883393, 0.110347],
263    [0.824940, 0.884720, 0.106217],
264    [0.835270, 0.886029, 0.102646],
265    [0.845561, 0.887322, 0.099702],
266    [0.855810, 0.888601, 0.097452],
267    [0.866013, 0.889868, 0.095953],
268    [0.876168, 0.891125, 0.095250],
269    [0.886271, 0.892374, 0.095374],
270    [0.896320, 0.893616, 0.096335],
271    [0.906311, 0.894855, 0.098125],
272    [0.916242, 0.896091, 0.100717],
273    [0.926106, 0.897330, 0.104071],
274    [0.935904, 0.898570, 0.108131],
275    [0.945636, 0.899815, 0.112838],
276    [0.955300, 0.901065, 0.118128],
277    [0.964894, 0.902323, 0.123941],
278    [0.974417, 0.903590, 0.130215],
279    [0.983868, 0.904867, 0.136897],
280    [0.993248, 0.906157, 0.143936],
281];
282
283const MAGMA_DATA: [[f32; 3]; 256] = [
284    [0.001462, 0.000466, 0.013866],
285    [0.002258, 0.001295, 0.018331],
286    [0.003279, 0.002305, 0.023708],
287    [0.004512, 0.003490, 0.029965],
288    [0.005950, 0.004843, 0.037130],
289    [0.007588, 0.006356, 0.044973],
290    [0.009426, 0.008022, 0.052844],
291    [0.011465, 0.009828, 0.060750],
292    [0.013708, 0.011771, 0.068667],
293    [0.016156, 0.013840, 0.076603],
294    [0.018815, 0.016026, 0.084584],
295    [0.021692, 0.018320, 0.092610],
296    [0.024792, 0.020715, 0.100676],
297    [0.028123, 0.023201, 0.108787],
298    [0.031696, 0.025765, 0.116965],
299    [0.035520, 0.028397, 0.125209],
300    [0.039608, 0.031090, 0.133515],
301    [0.043830, 0.033830, 0.141886],
302    [0.048062, 0.036607, 0.150327],
303    [0.052320, 0.039407, 0.158841],
304    [0.056615, 0.042160, 0.167446],
305    [0.060949, 0.044794, 0.176129],
306    [0.065330, 0.047318, 0.184892],
307    [0.069764, 0.049726, 0.193735],
308    [0.074257, 0.052017, 0.202660],
309    [0.078815, 0.054184, 0.211667],
310    [0.083446, 0.056225, 0.220755],
311    [0.088155, 0.058133, 0.229922],
312    [0.092949, 0.059904, 0.239164],
313    [0.097833, 0.061531, 0.248477],
314    [0.102815, 0.063010, 0.257854],
315    [0.107899, 0.064335, 0.267289],
316    [0.113094, 0.065492, 0.276784],
317    [0.118405, 0.066479, 0.286321],
318    [0.123833, 0.067295, 0.295879],
319    [0.129380, 0.067935, 0.305443],
320    [0.135053, 0.068391, 0.315000],
321    [0.140858, 0.068654, 0.324538],
322    [0.146785, 0.068738, 0.334011],
323    [0.152839, 0.068637, 0.343404],
324    [0.159018, 0.068354, 0.352688],
325    [0.165308, 0.067911, 0.361816],
326    [0.171713, 0.067305, 0.370771],
327    [0.178212, 0.066576, 0.379497],
328    [0.184801, 0.065732, 0.387973],
329    [0.191460, 0.064818, 0.396152],
330    [0.198177, 0.063862, 0.404009],
331    [0.204935, 0.062907, 0.411514],
332    [0.211718, 0.061992, 0.418647],
333    [0.218512, 0.061158, 0.425392],
334    [0.225302, 0.060445, 0.431742],
335    [0.232077, 0.059889, 0.437695],
336    [0.238826, 0.059517, 0.443256],
337    [0.245543, 0.059352, 0.448436],
338    [0.252220, 0.059415, 0.453248],
339    [0.258857, 0.059706, 0.457710],
340    [0.265447, 0.060237, 0.461840],
341    [0.271994, 0.060994, 0.465660],
342    [0.278493, 0.061978, 0.469190],
343    [0.284951, 0.063168, 0.472451],
344    [0.291366, 0.064553, 0.475462],
345    [0.297740, 0.066117, 0.478243],
346    [0.304081, 0.067835, 0.480812],
347    [0.310382, 0.069702, 0.483186],
348    [0.316654, 0.071690, 0.485380],
349    [0.322899, 0.073782, 0.487408],
350    [0.329114, 0.075972, 0.489287],
351    [0.335308, 0.078236, 0.491024],
352    [0.341482, 0.080564, 0.492631],
353    [0.347636, 0.082946, 0.494121],
354    [0.353773, 0.085373, 0.495501],
355    [0.359898, 0.087831, 0.496778],
356    [0.366012, 0.090314, 0.497960],
357    [0.372116, 0.092816, 0.499053],
358    [0.378211, 0.095332, 0.500067],
359    [0.384299, 0.097855, 0.501002],
360    [0.390384, 0.100379, 0.501864],
361    [0.396467, 0.102902, 0.502658],
362    [0.402548, 0.105420, 0.503386],
363    [0.408629, 0.107930, 0.504052],
364    [0.414709, 0.110431, 0.504662],
365    [0.420791, 0.112920, 0.505215],
366    [0.426877, 0.115395, 0.505714],
367    [0.432967, 0.117855, 0.506160],
368    [0.439062, 0.120298, 0.506555],
369    [0.445163, 0.122724, 0.506901],
370    [0.451271, 0.125132, 0.507198],
371    [0.457386, 0.127522, 0.507448],
372    [0.463508, 0.129893, 0.507652],
373    [0.469640, 0.132245, 0.507809],
374    [0.475780, 0.134577, 0.507921],
375    [0.481929, 0.136891, 0.507989],
376    [0.488088, 0.139186, 0.508011],
377    [0.494258, 0.141462, 0.507988],
378    [0.500438, 0.143719, 0.507920],
379    [0.506629, 0.145958, 0.507806],
380    [0.512831, 0.148179, 0.507648],
381    [0.519045, 0.150383, 0.507443],
382    [0.525270, 0.152569, 0.507192],
383    [0.531507, 0.154739, 0.506895],
384    [0.537755, 0.156894, 0.506551],
385    [0.544015, 0.159033, 0.506159],
386    [0.550287, 0.161158, 0.505719],
387    [0.556571, 0.163269, 0.505230],
388    [0.562866, 0.165368, 0.504692],
389    [0.569172, 0.167454, 0.504105],
390    [0.575490, 0.169530, 0.503466],
391    [0.581819, 0.171596, 0.502777],
392    [0.588158, 0.173652, 0.502035],
393    [0.594508, 0.175701, 0.501241],
394    [0.600868, 0.177743, 0.500394],
395    [0.607238, 0.179779, 0.499492],
396    [0.613617, 0.181811, 0.498536],
397    [0.620005, 0.183840, 0.497524],
398    [0.626401, 0.185867, 0.496456],
399    [0.632805, 0.187893, 0.495332],
400    [0.639216, 0.189921, 0.494150],
401    [0.645633, 0.191952, 0.492910],
402    [0.652056, 0.193986, 0.491611],
403    [0.658483, 0.196027, 0.490253],
404    [0.664915, 0.198075, 0.488836],
405    [0.671349, 0.200133, 0.487358],
406    [0.677786, 0.202203, 0.485819],
407    [0.684224, 0.204286, 0.484219],
408    [0.690661, 0.206384, 0.482558],
409    [0.697098, 0.208501, 0.480835],
410    [0.703532, 0.210638, 0.479049],
411    [0.709962, 0.212797, 0.477201],
412    [0.716387, 0.214982, 0.475290],
413    [0.722805, 0.217194, 0.473316],
414    [0.729216, 0.219437, 0.471279],
415    [0.735616, 0.221713, 0.469180],
416    [0.742004, 0.224025, 0.467018],
417    [0.748378, 0.226377, 0.464794],
418    [0.754737, 0.228772, 0.462509],
419    [0.761077, 0.231214, 0.460162],
420    [0.767398, 0.233705, 0.457755],
421    [0.773695, 0.236249, 0.455289],
422    [0.779968, 0.238851, 0.452765],
423    [0.786212, 0.241514, 0.450184],
424    [0.792427, 0.244242, 0.447543],
425    [0.798608, 0.247040, 0.444848],
426    [0.804752, 0.249911, 0.442102],
427    [0.810855, 0.252861, 0.439305],
428    [0.816914, 0.255895, 0.436461],
429    [0.822926, 0.259016, 0.433573],
430    [0.828886, 0.262229, 0.430644],
431    [0.834791, 0.265540, 0.427671],
432    [0.840636, 0.268953, 0.424666],
433    [0.846416, 0.272473, 0.421631],
434    [0.852126, 0.276106, 0.418573],
435    [0.857763, 0.279857, 0.415496],
436    [0.863320, 0.283729, 0.412403],
437    [0.868793, 0.287728, 0.409303],
438    [0.874176, 0.291859, 0.406205],
439    [0.879464, 0.296125, 0.403118],
440    [0.884651, 0.300530, 0.400047],
441    [0.889731, 0.305079, 0.397002],
442    [0.894700, 0.309773, 0.393995],
443    [0.899552, 0.314616, 0.391037],
444    [0.904281, 0.319610, 0.388137],
445    [0.908884, 0.324755, 0.385308],
446    [0.913354, 0.330052, 0.382563],
447    [0.917689, 0.335500, 0.379915],
448    [0.921884, 0.341098, 0.377376],
449    [0.925937, 0.346844, 0.374959],
450    [0.929845, 0.352734, 0.372677],
451    [0.933606, 0.358764, 0.370541],
452    [0.937221, 0.364929, 0.368567],
453    [0.940687, 0.371224, 0.366762],
454    [0.944006, 0.377643, 0.365136],
455    [0.947180, 0.384178, 0.363701],
456    [0.950210, 0.390820, 0.362468],
457    [0.953099, 0.397563, 0.361438],
458    [0.955849, 0.404400, 0.360619],
459    [0.958464, 0.411324, 0.360014],
460    [0.960949, 0.418323, 0.359630],
461    [0.963310, 0.425390, 0.359469],
462    [0.965549, 0.432519, 0.359529],
463    [0.967671, 0.439703, 0.359810],
464    [0.969680, 0.446936, 0.360311],
465    [0.971582, 0.454210, 0.361030],
466    [0.973381, 0.461520, 0.361965],
467    [0.975082, 0.468861, 0.363111],
468    [0.976690, 0.476226, 0.364466],
469    [0.978210, 0.483612, 0.366025],
470    [0.979645, 0.491014, 0.367783],
471    [0.981000, 0.498428, 0.369734],
472    [0.982279, 0.505851, 0.371874],
473    [0.983485, 0.513280, 0.374198],
474    [0.984622, 0.520713, 0.376698],
475    [0.985693, 0.528148, 0.379371],
476    [0.986700, 0.535582, 0.382210],
477    [0.987646, 0.543015, 0.385210],
478    [0.988533, 0.550446, 0.388365],
479    [0.989363, 0.557873, 0.391671],
480    [0.990138, 0.565296, 0.395122],
481    [0.990871, 0.572706, 0.398714],
482    [0.991558, 0.580107, 0.402441],
483    [0.992196, 0.587502, 0.406299],
484    [0.992785, 0.594891, 0.410283],
485    [0.993326, 0.602275, 0.414390],
486    [0.993834, 0.609644, 0.418613],
487    [0.994309, 0.616999, 0.422950],
488    [0.994738, 0.624350, 0.427397],
489    [0.995122, 0.631696, 0.431951],
490    [0.995480, 0.639027, 0.436607],
491    [0.995810, 0.646344, 0.441361],
492    [0.996096, 0.653659, 0.446213],
493    [0.996341, 0.660969, 0.451160],
494    [0.996580, 0.668256, 0.456192],
495    [0.996775, 0.675541, 0.461314],
496    [0.996925, 0.682828, 0.466526],
497    [0.997077, 0.690088, 0.471811],
498    [0.997186, 0.697349, 0.477182],
499    [0.997254, 0.704611, 0.482635],
500    [0.997325, 0.711848, 0.488154],
501    [0.997351, 0.719089, 0.493755],
502    [0.997351, 0.726324, 0.499428],
503    [0.997341, 0.733545, 0.505167],
504    [0.997285, 0.740772, 0.510983],
505    [0.997228, 0.747981, 0.516859],
506    [0.997138, 0.755190, 0.522806],
507    [0.997019, 0.762398, 0.528821],
508    [0.996898, 0.769591, 0.534892],
509    [0.996727, 0.776795, 0.541039],
510    [0.996571, 0.783977, 0.547233],
511    [0.996369, 0.791167, 0.553499],
512    [0.996162, 0.798348, 0.559820],
513    [0.995932, 0.805527, 0.566202],
514    [0.995680, 0.812706, 0.572645],
515    [0.995424, 0.819875, 0.579140],
516    [0.995131, 0.827052, 0.585701],
517    [0.994851, 0.834213, 0.592307],
518    [0.994524, 0.841387, 0.598983],
519    [0.994222, 0.848540, 0.605696],
520    [0.993866, 0.855711, 0.612482],
521    [0.993545, 0.862859, 0.619299],
522    [0.993170, 0.870024, 0.626189],
523    [0.992831, 0.877168, 0.633109],
524    [0.992440, 0.884330, 0.640099],
525    [0.992089, 0.891470, 0.647116],
526    [0.991688, 0.898627, 0.654202],
527    [0.991332, 0.905763, 0.661309],
528    [0.990930, 0.912915, 0.668481],
529    [0.990570, 0.920049, 0.675675],
530    [0.990175, 0.927196, 0.682926],
531    [0.989815, 0.934329, 0.690198],
532    [0.989434, 0.941470, 0.697519],
533    [0.989077, 0.948604, 0.704863],
534    [0.988717, 0.955742, 0.712242],
535    [0.988367, 0.962878, 0.719649],
536    [0.988033, 0.970012, 0.727077],
537    [0.987691, 0.977154, 0.734536],
538    [0.987387, 0.984288, 0.742002],
539    [0.987053, 0.991438, 0.749504],
540];
541
542const INFERNO_DATA: [[f32; 3]; 256] = [
543    [0.001462, 0.000466, 0.013866],
544    [0.002267, 0.001270, 0.018570],
545    [0.003299, 0.002249, 0.024239],
546    [0.004547, 0.003392, 0.030909],
547    [0.006006, 0.004692, 0.038558],
548    [0.007676, 0.006136, 0.046836],
549    [0.009561, 0.007713, 0.055143],
550    [0.011663, 0.009417, 0.063460],
551    [0.013995, 0.011225, 0.071862],
552    [0.016561, 0.013136, 0.080282],
553    [0.019373, 0.015133, 0.088767],
554    [0.022447, 0.017199, 0.097327],
555    [0.025793, 0.019331, 0.105930],
556    [0.029432, 0.021503, 0.114621],
557    [0.033385, 0.023702, 0.123397],
558    [0.037668, 0.025921, 0.132232],
559    [0.042253, 0.028139, 0.141141],
560    [0.046915, 0.030324, 0.150164],
561    [0.051644, 0.032474, 0.159254],
562    [0.056449, 0.034569, 0.168414],
563    [0.061340, 0.036590, 0.177642],
564    [0.066331, 0.038504, 0.186962],
565    [0.071429, 0.040294, 0.196354],
566    [0.076637, 0.041905, 0.205799],
567    [0.081962, 0.043328, 0.215289],
568    [0.087411, 0.044556, 0.224813],
569    [0.092990, 0.045583, 0.234358],
570    [0.098702, 0.046402, 0.243904],
571    [0.104551, 0.047008, 0.253430],
572    [0.110536, 0.047399, 0.262912],
573    [0.116656, 0.047574, 0.272321],
574    [0.122908, 0.047536, 0.281624],
575    [0.129285, 0.047293, 0.290788],
576    [0.135778, 0.046856, 0.299776],
577    [0.142378, 0.046242, 0.308553],
578    [0.149073, 0.045468, 0.317085],
579    [0.155850, 0.044559, 0.325338],
580    [0.162689, 0.043554, 0.333277],
581    [0.169575, 0.042489, 0.340874],
582    [0.176493, 0.041402, 0.348111],
583    [0.183429, 0.040329, 0.354971],
584    [0.190367, 0.039309, 0.361447],
585    [0.197297, 0.038400, 0.367535],
586    [0.204209, 0.037632, 0.373238],
587    [0.211095, 0.037030, 0.378563],
588    [0.217949, 0.036615, 0.383522],
589    [0.224763, 0.036405, 0.388129],
590    [0.231538, 0.036405, 0.392400],
591    [0.238273, 0.036621, 0.396353],
592    [0.244967, 0.037055, 0.400007],
593    [0.251620, 0.037705, 0.403378],
594    [0.258234, 0.038571, 0.406485],
595    [0.264810, 0.039647, 0.409345],
596    [0.271347, 0.040922, 0.411976],
597    [0.277850, 0.042353, 0.414392],
598    [0.284321, 0.043933, 0.416608],
599    [0.290763, 0.045644, 0.418637],
600    [0.297178, 0.047470, 0.420491],
601    [0.303568, 0.049396, 0.422182],
602    [0.309935, 0.051407, 0.423721],
603    [0.316282, 0.053490, 0.425116],
604    [0.322610, 0.055634, 0.426377],
605    [0.328921, 0.057827, 0.427511],
606    [0.335217, 0.060060, 0.428524],
607    [0.341500, 0.062325, 0.429425],
608    [0.347771, 0.064616, 0.430217],
609    [0.354032, 0.066925, 0.430906],
610    [0.360284, 0.069247, 0.431497],
611    [0.366529, 0.071579, 0.431994],
612    [0.372768, 0.073915, 0.432400],
613    [0.379001, 0.076253, 0.432719],
614    [0.385228, 0.078591, 0.432955],
615    [0.391453, 0.080927, 0.433109],
616    [0.397674, 0.083257, 0.433183],
617    [0.403894, 0.085580, 0.433179],
618    [0.410113, 0.087896, 0.433098],
619    [0.416331, 0.090203, 0.432943],
620    [0.422549, 0.092501, 0.432714],
621    [0.428768, 0.094790, 0.432412],
622    [0.434987, 0.097069, 0.432039],
623    [0.441207, 0.099338, 0.431594],
624    [0.447428, 0.101597, 0.431080],
625    [0.453651, 0.103848, 0.430498],
626    [0.459875, 0.106089, 0.429846],
627    [0.466100, 0.108322, 0.429125],
628    [0.472328, 0.110547, 0.428334],
629    [0.478558, 0.112764, 0.427475],
630    [0.484789, 0.114974, 0.426548],
631    [0.491022, 0.117179, 0.425552],
632    [0.497257, 0.119379, 0.424488],
633    [0.503493, 0.121575, 0.423356],
634    [0.509730, 0.123769, 0.422156],
635    [0.515967, 0.125960, 0.420887],
636    [0.522206, 0.128150, 0.419549],
637    [0.528444, 0.130341, 0.418142],
638    [0.534683, 0.132534, 0.416667],
639    [0.540920, 0.134729, 0.415123],
640    [0.547157, 0.136929, 0.413511],
641    [0.553392, 0.139134, 0.411829],
642    [0.559624, 0.141346, 0.410078],
643    [0.565854, 0.143567, 0.408258],
644    [0.572081, 0.145797, 0.406369],
645    [0.578304, 0.148039, 0.404411],
646    [0.584521, 0.150294, 0.402385],
647    [0.590734, 0.152563, 0.400290],
648    [0.596940, 0.154848, 0.398125],
649    [0.603139, 0.157151, 0.395891],
650    [0.609330, 0.159474, 0.393589],
651    [0.615513, 0.161817, 0.391219],
652    [0.621685, 0.164184, 0.388781],
653    [0.627847, 0.166575, 0.386276],
654    [0.633998, 0.168992, 0.383704],
655    [0.640135, 0.171438, 0.381065],
656    [0.646260, 0.173914, 0.378359],
657    [0.652369, 0.176421, 0.375586],
658    [0.658463, 0.178962, 0.372748],
659    [0.664540, 0.181539, 0.369846],
660    [0.670599, 0.184153, 0.366879],
661    [0.676638, 0.186807, 0.363849],
662    [0.682656, 0.189501, 0.360757],
663    [0.688653, 0.192239, 0.357603],
664    [0.694627, 0.195021, 0.354388],
665    [0.700576, 0.197851, 0.351113],
666    [0.706500, 0.200728, 0.347777],
667    [0.712396, 0.203656, 0.344383],
668    [0.718264, 0.206636, 0.340931],
669    [0.724103, 0.209670, 0.337424],
670    [0.729909, 0.212759, 0.333861],
671    [0.735683, 0.215906, 0.330245],
672    [0.741423, 0.219112, 0.326576],
673    [0.747127, 0.222378, 0.322856],
674    [0.752794, 0.225706, 0.319085],
675    [0.758422, 0.229097, 0.315266],
676    [0.764010, 0.232554, 0.311399],
677    [0.769556, 0.236077, 0.307485],
678    [0.775059, 0.239667, 0.303526],
679    [0.780517, 0.243327, 0.299523],
680    [0.785929, 0.247056, 0.295477],
681    [0.791293, 0.250856, 0.291390],
682    [0.796607, 0.254728, 0.287264],
683    [0.801871, 0.258674, 0.283099],
684    [0.807082, 0.262692, 0.278898],
685    [0.812239, 0.266786, 0.274661],
686    [0.817341, 0.270954, 0.270390],
687    [0.822386, 0.275197, 0.266085],
688    [0.827372, 0.279517, 0.261750],
689    [0.832299, 0.283913, 0.257383],
690    [0.837165, 0.288385, 0.252988],
691    [0.841969, 0.292933, 0.248564],
692    [0.846709, 0.297559, 0.244113],
693    [0.851384, 0.302260, 0.239636],
694    [0.855992, 0.307038, 0.235133],
695    [0.860533, 0.311892, 0.230606],
696    [0.865006, 0.316822, 0.226055],
697    [0.869409, 0.321827, 0.221482],
698    [0.873741, 0.326906, 0.216886],
699    [0.878001, 0.332060, 0.212268],
700    [0.882188, 0.337287, 0.207628],
701    [0.886302, 0.342586, 0.202968],
702    [0.890341, 0.347957, 0.198286],
703    [0.894305, 0.353399, 0.193584],
704    [0.898192, 0.358911, 0.188860],
705    [0.902003, 0.364492, 0.184116],
706    [0.905735, 0.370140, 0.179350],
707    [0.909390, 0.375856, 0.174563],
708    [0.912966, 0.381636, 0.169755],
709    [0.916462, 0.387481, 0.164924],
710    [0.919879, 0.393389, 0.160070],
711    [0.923215, 0.399359, 0.155193],
712    [0.926470, 0.405389, 0.150292],
713    [0.929644, 0.411479, 0.145367],
714    [0.932737, 0.417627, 0.140417],
715    [0.935747, 0.423831, 0.135440],
716    [0.938675, 0.430091, 0.130438],
717    [0.941521, 0.436405, 0.125409],
718    [0.944285, 0.442772, 0.120354],
719    [0.946965, 0.449191, 0.115272],
720    [0.949562, 0.455660, 0.110164],
721    [0.952075, 0.462178, 0.105031],
722    [0.954506, 0.468744, 0.099874],
723    [0.956852, 0.475356, 0.094695],
724    [0.959114, 0.482014, 0.089499],
725    [0.961293, 0.488716, 0.084289],
726    [0.963387, 0.495462, 0.079073],
727    [0.965397, 0.502249, 0.073859],
728    [0.967322, 0.509078, 0.068659],
729    [0.969163, 0.515946, 0.063488],
730    [0.970919, 0.522853, 0.058367],
731    [0.972590, 0.529798, 0.053324],
732    [0.974176, 0.536780, 0.048392],
733    [0.975677, 0.543798, 0.043618],
734    [0.977092, 0.550850, 0.039050],
735    [0.978422, 0.557937, 0.034931],
736    [0.979666, 0.565057, 0.031409],
737    [0.980824, 0.572209, 0.028508],
738    [0.981895, 0.579392, 0.026250],
739    [0.982881, 0.586606, 0.024661],
740    [0.983779, 0.593849, 0.023770],
741    [0.984591, 0.601122, 0.023606],
742    [0.985315, 0.608422, 0.024202],
743    [0.985952, 0.615750, 0.025592],
744    [0.986502, 0.623105, 0.027814],
745    [0.986964, 0.630485, 0.030908],
746    [0.987337, 0.637890, 0.034916],
747    [0.987622, 0.645320, 0.039886],
748    [0.987819, 0.652773, 0.045581],
749    [0.987926, 0.660250, 0.051750],
750    [0.987945, 0.667748, 0.058329],
751    [0.987874, 0.675267, 0.065257],
752    [0.987714, 0.682807, 0.072489],
753    [0.987464, 0.690366, 0.079990],
754    [0.987124, 0.697944, 0.087731],
755    [0.986694, 0.705540, 0.095694],
756    [0.986175, 0.713153, 0.103863],
757    [0.985566, 0.720782, 0.112229],
758    [0.984865, 0.728427, 0.120785],
759    [0.984075, 0.736087, 0.129527],
760    [0.983196, 0.743758, 0.138453],
761    [0.982228, 0.751442, 0.147565],
762    [0.981173, 0.759135, 0.156863],
763    [0.980032, 0.766837, 0.166353],
764    [0.978806, 0.774545, 0.176037],
765    [0.977497, 0.782258, 0.185923],
766    [0.976108, 0.789974, 0.196018],
767    [0.974638, 0.797692, 0.206332],
768    [0.973088, 0.805409, 0.216877],
769    [0.971468, 0.813122, 0.227658],
770    [0.969783, 0.820825, 0.238686],
771    [0.968041, 0.828515, 0.249972],
772    [0.966243, 0.836191, 0.261534],
773    [0.964394, 0.843848, 0.273391],
774    [0.962517, 0.851476, 0.285546],
775    [0.960626, 0.859069, 0.298010],
776    [0.958720, 0.866624, 0.310820],
777    [0.956834, 0.874129, 0.323974],
778    [0.954997, 0.881569, 0.337475],
779    [0.953215, 0.888942, 0.351369],
780    [0.951546, 0.896226, 0.365627],
781    [0.950018, 0.903409, 0.380271],
782    [0.948683, 0.910473, 0.395289],
783    [0.947594, 0.917399, 0.410665],
784    [0.946809, 0.924168, 0.426373],
785    [0.946392, 0.930761, 0.442367],
786    [0.946403, 0.937159, 0.458592],
787    [0.946903, 0.943348, 0.474970],
788    [0.947937, 0.949318, 0.491426],
789    [0.949545, 0.955063, 0.507860],
790    [0.951740, 0.960587, 0.524203],
791    [0.954529, 0.965896, 0.540361],
792    [0.957896, 0.971003, 0.556275],
793    [0.961812, 0.975924, 0.571925],
794    [0.966249, 0.980678, 0.587206],
795    [0.971162, 0.985282, 0.602154],
796    [0.976511, 0.989753, 0.616760],
797    [0.982257, 0.994109, 0.631017],
798    [0.988362, 0.998364, 0.644924],
799];
800
801const PLASMA_DATA: [[f32; 3]; 256] = [
802    [0.050383, 0.029803, 0.527975],
803    [0.063536, 0.028426, 0.533124],
804    [0.075353, 0.027206, 0.538007],
805    [0.086222, 0.026125, 0.542658],
806    [0.096379, 0.025165, 0.547103],
807    [0.105980, 0.024309, 0.551368],
808    [0.115124, 0.023556, 0.555468],
809    [0.123903, 0.022878, 0.559423],
810    [0.132381, 0.022258, 0.563250],
811    [0.140603, 0.021687, 0.566959],
812    [0.148607, 0.021154, 0.570562],
813    [0.156421, 0.020651, 0.574065],
814    [0.164070, 0.020171, 0.577478],
815    [0.171574, 0.019706, 0.580806],
816    [0.178950, 0.019252, 0.584054],
817    [0.186213, 0.018803, 0.587228],
818    [0.193374, 0.018354, 0.590330],
819    [0.200445, 0.017902, 0.593364],
820    [0.207435, 0.017442, 0.596333],
821    [0.214350, 0.016973, 0.599239],
822    [0.221197, 0.016497, 0.602083],
823    [0.227983, 0.016007, 0.604867],
824    [0.234715, 0.015502, 0.607592],
825    [0.241396, 0.014979, 0.610259],
826    [0.248032, 0.014439, 0.612868],
827    [0.254627, 0.013882, 0.615419],
828    [0.261183, 0.013308, 0.617911],
829    [0.267703, 0.012716, 0.620346],
830    [0.274191, 0.012109, 0.622722],
831    [0.280648, 0.011488, 0.625038],
832    [0.287076, 0.010855, 0.627295],
833    [0.293478, 0.010213, 0.629490],
834    [0.299855, 0.009561, 0.631624],
835    [0.306210, 0.008902, 0.633694],
836    [0.312543, 0.008239, 0.635700],
837    [0.318856, 0.007576, 0.637640],
838    [0.325150, 0.006915, 0.639512],
839    [0.331426, 0.006261, 0.641316],
840    [0.337683, 0.005618, 0.643049],
841    [0.343925, 0.004991, 0.644710],
842    [0.350150, 0.004382, 0.646298],
843    [0.356359, 0.003798, 0.647810],
844    [0.362553, 0.003243, 0.649245],
845    [0.368733, 0.002724, 0.650601],
846    [0.374897, 0.002245, 0.651876],
847    [0.381047, 0.001814, 0.653068],
848    [0.387183, 0.001434, 0.654177],
849    [0.393304, 0.001114, 0.655199],
850    [0.399411, 0.000859, 0.656133],
851    [0.405503, 0.000678, 0.656977],
852    [0.411580, 0.000577, 0.657730],
853    [0.417642, 0.000564, 0.658390],
854    [0.423689, 0.000646, 0.658956],
855    [0.429719, 0.000831, 0.659425],
856    [0.435734, 0.001127, 0.659797],
857    [0.441732, 0.001540, 0.660069],
858    [0.447714, 0.002080, 0.660240],
859    [0.453677, 0.002755, 0.660310],
860    [0.459623, 0.003574, 0.660277],
861    [0.465550, 0.004545, 0.660139],
862    [0.471457, 0.005678, 0.659897],
863    [0.477344, 0.006980, 0.659549],
864    [0.483210, 0.008460, 0.659095],
865    [0.489055, 0.010127, 0.658534],
866    [0.494877, 0.011990, 0.657865],
867    [0.500678, 0.014055, 0.657088],
868    [0.506454, 0.016333, 0.656202],
869    [0.512206, 0.018833, 0.655209],
870    [0.517933, 0.021563, 0.654109],
871    [0.523633, 0.024532, 0.652901],
872    [0.529306, 0.027747, 0.651586],
873    [0.534952, 0.031217, 0.650165],
874    [0.540570, 0.034950, 0.648640],
875    [0.546157, 0.038954, 0.647010],
876    [0.551715, 0.043136, 0.645277],
877    [0.557243, 0.047331, 0.643443],
878    [0.562738, 0.051545, 0.641509],
879    [0.568201, 0.055778, 0.639477],
880    [0.573632, 0.060028, 0.637349],
881    [0.579029, 0.064296, 0.635126],
882    [0.584391, 0.068579, 0.632812],
883    [0.589719, 0.072878, 0.630408],
884    [0.595011, 0.077190, 0.627917],
885    [0.600266, 0.081516, 0.625342],
886    [0.605485, 0.085854, 0.622686],
887    [0.610667, 0.090204, 0.619951],
888    [0.615812, 0.094564, 0.617140],
889    [0.620919, 0.098934, 0.614257],
890    [0.625987, 0.103312, 0.611305],
891    [0.631017, 0.107699, 0.608287],
892    [0.636008, 0.112092, 0.605205],
893    [0.640959, 0.116492, 0.602065],
894    [0.645872, 0.120898, 0.598867],
895    [0.650746, 0.125309, 0.595617],
896    [0.655580, 0.129725, 0.592317],
897    [0.660374, 0.134144, 0.588971],
898    [0.665129, 0.138566, 0.585582],
899    [0.669845, 0.142992, 0.582154],
900    [0.674522, 0.147419, 0.578688],
901    [0.679160, 0.151848, 0.575189],
902    [0.683758, 0.156278, 0.571660],
903    [0.688318, 0.160709, 0.568103],
904    [0.692840, 0.165141, 0.564522],
905    [0.697324, 0.169573, 0.560919],
906    [0.701769, 0.174005, 0.557296],
907    [0.706178, 0.178437, 0.553657],
908    [0.710549, 0.182868, 0.550004],
909    [0.714883, 0.187299, 0.546338],
910    [0.719181, 0.191729, 0.542663],
911    [0.723444, 0.196158, 0.538981],
912    [0.727670, 0.200586, 0.535293],
913    [0.731862, 0.205013, 0.531601],
914    [0.736019, 0.209439, 0.527908],
915    [0.740143, 0.213864, 0.524216],
916    [0.744232, 0.218288, 0.520524],
917    [0.748289, 0.222711, 0.516834],
918    [0.752312, 0.227133, 0.513149],
919    [0.756304, 0.231555, 0.509468],
920    [0.760264, 0.235976, 0.505794],
921    [0.764193, 0.240396, 0.502126],
922    [0.768090, 0.244817, 0.498465],
923    [0.771958, 0.249237, 0.494813],
924    [0.775796, 0.253658, 0.491171],
925    [0.779604, 0.258078, 0.487539],
926    [0.783383, 0.262500, 0.483918],
927    [0.787133, 0.266922, 0.480307],
928    [0.790855, 0.271345, 0.476706],
929    [0.794549, 0.275770, 0.473117],
930    [0.798216, 0.280197, 0.469538],
931    [0.801855, 0.284626, 0.465971],
932    [0.805467, 0.289057, 0.462415],
933    [0.809052, 0.293491, 0.458870],
934    [0.812612, 0.297928, 0.455338],
935    [0.816144, 0.302368, 0.451816],
936    [0.819651, 0.306812, 0.448306],
937    [0.823132, 0.311261, 0.444806],
938    [0.826588, 0.315714, 0.441316],
939    [0.830018, 0.320172, 0.437836],
940    [0.833422, 0.324635, 0.434366],
941    [0.836801, 0.329105, 0.430905],
942    [0.840155, 0.333580, 0.427455],
943    [0.843484, 0.338062, 0.424013],
944    [0.846788, 0.342551, 0.420579],
945    [0.850066, 0.347048, 0.417153],
946    [0.853319, 0.351553, 0.413734],
947    [0.856547, 0.356066, 0.410322],
948    [0.859750, 0.360588, 0.406917],
949    [0.862927, 0.365119, 0.403519],
950    [0.866078, 0.369660, 0.400126],
951    [0.869203, 0.374212, 0.396738],
952    [0.872303, 0.378774, 0.393355],
953    [0.875376, 0.383347, 0.389976],
954    [0.878423, 0.387932, 0.386600],
955    [0.881443, 0.392529, 0.383229],
956    [0.884436, 0.397139, 0.379860],
957    [0.887402, 0.401762, 0.376494],
958    [0.890340, 0.406398, 0.373130],
959    [0.893250, 0.411048, 0.369768],
960    [0.896131, 0.415712, 0.366407],
961    [0.898984, 0.420392, 0.363047],
962    [0.901807, 0.425087, 0.359688],
963    [0.904601, 0.429797, 0.356329],
964    [0.907365, 0.434524, 0.352970],
965    [0.910098, 0.439268, 0.349610],
966    [0.912800, 0.444029, 0.346251],
967    [0.915471, 0.448807, 0.342890],
968    [0.918109, 0.453603, 0.339529],
969    [0.920714, 0.458417, 0.336166],
970    [0.923287, 0.463251, 0.332801],
971    [0.925825, 0.468103, 0.329435],
972    [0.928329, 0.472975, 0.326067],
973    [0.930798, 0.477867, 0.322697],
974    [0.933232, 0.482780, 0.319325],
975    [0.935630, 0.487712, 0.315952],
976    [0.937990, 0.492667, 0.312575],
977    [0.940313, 0.497642, 0.309197],
978    [0.942598, 0.502639, 0.305816],
979    [0.944844, 0.507658, 0.302433],
980    [0.947051, 0.512699, 0.299049],
981    [0.949217, 0.517763, 0.295662],
982    [0.951344, 0.522850, 0.292275],
983    [0.953428, 0.527960, 0.288883],
984    [0.955470, 0.533093, 0.285490],
985    [0.957469, 0.538250, 0.282096],
986    [0.959424, 0.543431, 0.278701],
987    [0.961336, 0.548636, 0.275305],
988    [0.963203, 0.553865, 0.271909],
989    [0.965024, 0.559118, 0.268513],
990    [0.966798, 0.564396, 0.265118],
991    [0.968526, 0.569700, 0.261721],
992    [0.970205, 0.575028, 0.258325],
993    [0.971835, 0.580382, 0.254931],
994    [0.973416, 0.585761, 0.251540],
995    [0.974947, 0.591165, 0.248151],
996    [0.976428, 0.596595, 0.244767],
997    [0.977856, 0.602051, 0.241387],
998    [0.979233, 0.607532, 0.238013],
999    [0.980556, 0.613039, 0.234646],
1000    [0.981826, 0.618572, 0.231287],
1001    [0.983041, 0.624131, 0.227937],
1002    [0.984199, 0.629718, 0.224595],
1003    [0.985301, 0.635330, 0.221265],
1004    [0.986345, 0.640969, 0.217948],
1005    [0.987332, 0.646633, 0.214648],
1006    [0.988260, 0.652325, 0.211364],
1007    [0.989128, 0.658043, 0.208100],
1008    [0.989935, 0.663787, 0.204859],
1009    [0.990681, 0.669558, 0.201642],
1010    [0.991365, 0.675355, 0.198453],
1011    [0.991985, 0.681179, 0.195295],
1012    [0.992541, 0.687030, 0.192170],
1013    [0.993032, 0.692907, 0.189084],
1014    [0.993456, 0.698810, 0.186041],
1015    [0.993814, 0.704741, 0.183043],
1016    [0.994103, 0.710698, 0.180097],
1017    [0.994324, 0.716681, 0.177208],
1018    [0.994474, 0.722691, 0.174381],
1019    [0.994553, 0.728728, 0.171622],
1020    [0.994561, 0.734791, 0.168938],
1021    [0.994495, 0.740880, 0.166335],
1022    [0.994355, 0.746995, 0.163821],
1023    [0.994141, 0.753137, 0.161404],
1024    [0.993851, 0.759304, 0.159092],
1025    [0.993482, 0.765499, 0.156891],
1026    [0.993033, 0.771720, 0.154808],
1027    [0.992505, 0.777967, 0.152855],
1028    [0.991897, 0.784239, 0.151042],
1029    [0.991209, 0.790537, 0.149377],
1030    [0.990439, 0.796859, 0.147870],
1031    [0.989587, 0.803205, 0.146529],
1032    [0.988648, 0.809579, 0.145357],
1033    [0.987621, 0.815978, 0.144363],
1034    [0.986509, 0.822401, 0.143557],
1035    [0.985314, 0.828846, 0.142945],
1036    [0.984031, 0.835315, 0.142528],
1037    [0.982653, 0.841812, 0.142303],
1038    [0.981190, 0.848329, 0.142279],
1039    [0.979644, 0.854866, 0.142453],
1040    [0.977995, 0.861432, 0.142808],
1041    [0.976265, 0.868016, 0.143351],
1042    [0.974443, 0.874622, 0.144061],
1043    [0.972530, 0.881250, 0.144923],
1044    [0.970533, 0.887896, 0.145919],
1045    [0.968443, 0.894564, 0.147014],
1046    [0.966271, 0.901249, 0.148180],
1047    [0.964021, 0.907950, 0.149370],
1048    [0.961681, 0.914672, 0.150520],
1049    [0.959276, 0.921407, 0.151566],
1050    [0.956808, 0.928152, 0.152409],
1051    [0.954287, 0.934908, 0.152921],
1052    [0.951726, 0.941671, 0.152925],
1053    [0.949151, 0.948435, 0.152178],
1054    [0.946602, 0.955190, 0.150328],
1055    [0.944152, 0.961916, 0.146861],
1056    [0.941896, 0.968590, 0.140956],
1057    [0.940015, 0.975158, 0.131326],
1058];
1059
1060/// Kernel of the colormap function applicable to all color maps
1061fn apply_colormap_kernel(value: f32, colormap_data: [[f32; 3]; 256]) -> [u8; 3] {
1062    let v = value.clamp(0.0, 1.0);
1063
1064    // Map v to index (0 to 255)
1065    let idx_f = v * 255.0;
1066    let idx = idx_f.floor() as usize;
1067    let frac = idx_f - idx as f32;
1068
1069    let max_idx = colormap_data.len() - 1;
1070    let idx = idx.min(max_idx - 1); // Clamp to avoid overflow
1071
1072    // Linear interpolation between idx and idx+1
1073    let r = colormap_data[idx][0] + frac * (colormap_data[idx + 1][0] - colormap_data[idx][0]);
1074    let g = colormap_data[idx][1] + frac * (colormap_data[idx + 1][1] - colormap_data[idx][1]);
1075    let b = colormap_data[idx][2] + frac * (colormap_data[idx + 1][2] - colormap_data[idx][2]);
1076
1077    [
1078        (r * 255.0).round().clamp(0.0, 255.0) as u8,
1079        (g * 255.0).round().clamp(0.0, 255.0) as u8,
1080        (b * 255.0).round().clamp(0.0, 255.0) as u8,
1081    ]
1082}
1083
1084/// Apply a given colormap to a normalized value (0.0 to 1.0)
1085/// Returns RGB values as (r, g, b) in 0-255 range
1086fn apply_colormap(value: f32, colormap: Colormap) -> [u8; 3] {
1087    match colormap {
1088        Colormap::Viridis => apply_colormap_kernel(value, VIRIDIS_DATA),
1089        Colormap::Magma => apply_colormap_kernel(value, MAGMA_DATA),
1090        Colormap::Inferno => apply_colormap_kernel(value, INFERNO_DATA),
1091        Colormap::Plasma => apply_colormap_kernel(value, PLASMA_DATA),
1092        Colormap::Gray => {
1093            let gray = (value.clamp(0.0, 1.0) * 255.0) as u8;
1094            [gray, gray, gray]
1095        }
1096    }
1097}
1098
1099/// Save a spectrogram as an image file with colormap support
1100/// This function applies log scaling (log1p) to better visualize the spectrogram dynamics.
1101/// The image is oriented with frequency on the Y-axis (bottom to top) and time on the X-axis.
1102#[cfg(feature = "image")]
1103pub fn save_spectrogram_image(
1104    spectrogram: &[Vec<f32>],
1105    output_path: PathBuf,
1106    colormap: Colormap,
1107) -> Result<()> {
1108    use image::{ImageBuffer, Rgb};
1109
1110    let n_freq_bins = spectrogram.len();
1111    let n_frames = spectrogram[0].len();
1112
1113    // Find min and max values after log scaling for normalization
1114    let log_values: Vec<Vec<f32>> = spectrogram
1115        .iter()
1116        .map(|row| row.iter().map(|&v| (v + 1.0).ln()).collect())
1117        .collect();
1118
1119    let min_val = log_values
1120        .iter()
1121        .flatten()
1122        .copied()
1123        .fold(f32::INFINITY, f32::min);
1124    let max_val = log_values
1125        .iter()
1126        .flatten()
1127        .copied()
1128        .fold(f32::NEG_INFINITY, f32::max);
1129
1130    let range = max_val - min_val;
1131
1132    // Create image buffer (width = time, height = frequency)
1133    let mut img = ImageBuffer::new(n_frames as u32, n_freq_bins as u32);
1134
1135    // Fill the image (flip vertically so low frequencies are at bottom)
1136    for (freq_idx, row) in log_values.iter().enumerate() {
1137        for (time_idx, &value) in row.iter().enumerate() {
1138            // Normalize to 0.0-1.0
1139            let normalized = if range > 0.0 {
1140                (value - min_val) / range
1141            } else {
1142                0.5
1143            };
1144
1145            // Apply colormap
1146            let rgb = apply_colormap(normalized, colormap);
1147
1148            // Flip vertically: y = height - 1 - freq_idx
1149            let y = (n_freq_bins - 1 - freq_idx) as u32;
1150            let x = time_idx as u32;
1151
1152            img.put_pixel(x, y, Rgb(rgb));
1153        }
1154    }
1155
1156    // Ensure parent directory exists
1157    if let Some(parent) = output_path.parent() {
1158        std::fs::create_dir_all(parent)
1159            .with_context(|| format!("Failed to create directory: {}", parent.display()))?;
1160    }
1161
1162    // Save the image
1163    img.save(output_path)
1164        .with_context(|| "Failed to save image")?;
1165
1166    Ok(())
1167}
1168
1169#[cfg(not(feature = "image"))]
1170pub fn save_spectrogram_image(
1171    _spectrogram: &[Vec<f32>],
1172    _output_path: PathBuf,
1173    _colormap: Colormap,
1174) -> Result<()> {
1175    anyhow::bail!("Image feature not enabled. Compile with --features image to use this function.")
1176}
spectrs/io/image.rs

spectrs/io/
image.rs
