packages_gee/pif at main · BzGEO/packages_gee · GitHub

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
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

//* This script implements the Pseudo-Invariant Feature matching function developed by Aaron Zuspan *//
// src: https://developers.google.com/earth-engine/tutorials/community/pseudo-invariant-feature-matching
// Last updated: 15.04.2024

// var d = require('users/servirbz/packages:pif');

////////////////////////////////////////////////////////////////////////////////////////////////////////////////

function pif(technique, to_modify, ref, roi) {

// technique options = 'SID' (Spectral Information Divergence), 'SAM' (Spectral Angle Mapper), 'SEM' (Squared Euclidean Distance)
// to_modify = image to modify; ref = reference image

function matchBand(band, technique, to_modify, ref) {

  var distance = ref.spectralDistance(to_modify, technique);

  var pif = distance.lt(distance.reduceRegion({reducer: ee.Reducer.percentile([10]), geometry: roi,
  scale: 30, bestEffort: true, maxPixels: 1e13,}).getNumber('distance'));

  var beforePif = ref.select([band]).updateMask(pif);
  var afterPif = to_modify.select([band]).updateMask(pif);
  var args = {reducer: ee.Reducer.linearFit(), geometry: roi, scale: 30, maxPixels: 1e13, bestEffort: true};
  var coeffs = ee.Image.cat([afterPif, beforePif]).reduceRegion(args);
  return to_modify.select([band]).multiply(coeffs.getNumber('scale')).add(coeffs.getNumber('offset')).toUint16().clip(roi);}

return ee.Image.cat([
  matchBand('B1', technique, to_modify, ref),
  matchBand('B2', technique, to_modify, ref),
  matchBand('B3', technique, to_modify, ref),
  matchBand('B4', technique, to_modify, ref),
  matchBand('B5', technique, to_modify, ref),
  matchBand('B7', technique, to_modify, ref)])}

///////////

exports.pif = pif;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////

function pif_ps(technique, to_modify, ref, roi) {

function matchBand(band, technique, to_modify, ref) {

  var distance = ref.spectralDistance(to_modify, technique);
  var pif = distance.lt(distance.reduceRegion({reducer: ee.Reducer.percentile([10]), geometry: roi,
  scale: 5, bestEffort: true, maxPixels: 1e13,}).getNumber('distance'));

  var beforePif = ref.select([band]).updateMask(pif);
  var afterPif = to_modify.select([band]).updateMask(pif);
  var args = {reducer: ee.Reducer.linearFit(), geometry: roi, scale: 30, maxPixels: 1e13, bestEffort: true};
  var coeffs = ee.Image.cat([afterPif, beforePif]).reduceRegion(args);
  return to_modify.select([band]).multiply(coeffs.getNumber('scale')).add(coeffs.getNumber('offset')).toUint16().clip(roi);}

return ee.Image.cat([
  matchBand('B1', technique, to_modify, ref),
  matchBand('B2', technique, to_modify, ref),
  matchBand('B3', technique, to_modify, ref),
  matchBand('B4', technique, to_modify, ref)])}

exports.pif_ps = pif_ps;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////

function pif_landsat(technique, to_modify, ref, roi) {

function matchBand(band, technique, to_modify, ref) {

  var distance = ref.spectralDistance(to_modify, technique);
  var pif = distance.lt(distance.reduceRegion({reducer: ee.Reducer.percentile([10]), geometry: roi,
  scale: 30, bestEffort: true, maxPixels: 1e13,}).getNumber('distance'));

  var beforePif = ref.select([band]).updateMask(pif);
  var afterPif = to_modify.select([band]).updateMask(pif);
  var args = {reducer: ee.Reducer.linearFit(), geometry: roi, scale: 30, maxPixels: 1e13, bestEffort: true};
  var coeffs = ee.Image.cat([afterPif, beforePif]).reduceRegion(args);
  return to_modify.select([band]).multiply(coeffs.getNumber('scale')).add(coeffs.getNumber('offset')).toUint16().clip(roi);}

return ee.Image.cat([
  matchBand('B1', technique, to_modify, ref),
  matchBand('B2', technique, to_modify, ref),
  matchBand('B3', technique, to_modify, ref),
  matchBand('B4', technique, to_modify, ref),
  matchBand('B5', technique, to_modify, ref),
  matchBand('B7', technique, to_modify, ref)])}

exports.pif_landsat = pif_landsat;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////