Coverage for python/lsst/meas/astrom/sip/genDistortedImage.py: 15%

1# 

2# LSST Data Management System 

3# Copyright 2008, 2009, 2010 LSST Corporation. 

4# 

5# This product includes software developed by the 

6# LSST Project (http://www.lsst.org/). 

7# 

8# This program is free software: you can redistribute it and/or modify 

9# it under the terms of the GNU General Public License as published by 

10# the Free Software Foundation, either version 3 of the License, or 

11# (at your option) any later version. 

12# 

13# This program is distributed in the hope that it will be useful, 

14# but WITHOUT ANY WARRANTY; without even the implied warranty of 

15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

16# GNU General Public License for more details. 

17# 

18# You should have received a copy of the LSST License Statement and 

19# the GNU General Public License along with this program. If not, 

20# see <http://www.lsstcorp.org/LegalNotices/>. 

21# 

22 

23__all__ = ["noDistort", "linearXDistort", "quadraticDistortX", 

24 "cubicDistortX", "manyTermX", "crossTerms1", 

25 "crossTerms2", "crossTerms3", "quadraticDistort", 

26 "T2DistortX", "T2DistortX"] 

27 

28 

29import math 

30 

31import lsst.afw.table as afwTable 

32 

33 

34def noDistort(src): 

35 """Do no distortion. Used for sanity checking 

36 

37 Parameters 

38 ---------- 

39 src : `lsst.afw.table.SourceRecord` 

40 Input record 

41 

42 Returns 

43 ------- 

44 out : `lsst.afw.table.SourceRecord` 

45 Copy of input record. 

46 """ 

47 

48 out = src.table.copyRecord(src) 

49 return out 

50 

51 

52def linearXDistort(src, frac=.001): 

53 """Increase the x value in a Source object by frac. E.g 

54 src.x = 1000 --> 1001 if frac=.001 

55 

56 Parameters 

57 ---------- 

58 src : `lsst.afw.table.SourceRecord` 

59 A Source object 

60 frac : `float` 

61 How much to change X by 

62 

63 Returns 

64 ------- 

65 out : `lsst.afw.table.SourceRecord` 

66 A deep copy of src, with the value of x changed 

67 """ 

68 

69 out = src.table.copyRecord(src) 

70 out.set(out.table.getCentroidSlot().getMeasKey().getX(), out.getX()*(1+frac)) 

71 return out 

72 

73 

74def quadraticDistortX(src, frac=1e-6): 

75 """Distort image by terms with power <=2 

76 i.e y, y^2, x, xy, x^2 

77 

78 Parameters 

79 ---------- 

80 src : `lsst.afw.table.SourceRecord` 

81 A Source object 

82 frac : `float` 

83 How much to change X by 

84 

85 Returns 

86 ------- 

87 out : `lsst.afw.table.SourceRecord` 

88 A deep copy of src, with the value of x changed 

89 """ 

90 

91 out = src.table.copyRecord(src) 

92 x = out.getX() 

93 y = out.getY() 

94 val = x**2 

95 

96 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x + val*frac) 

97 out.set(out.table.getCentroidSlot().getMeasKey().getY(), y) 

98 return out 

99 

100 

101def cubicDistortX(src, frac=1e-9): 

102 """Distort image by terms with power <=2 

103 i.e y, y^2, x, xy, x^2 

104 

105 Parameters 

106 ---------- 

107 src : `lsst.afw.table.SourceRecord` 

108 A Source object 

109 frac : `float` 

110 How much to change X by 

111 

112 Returns 

113 ------- 

114 out : `lsst.afw.table.SourceRecord` 

115 A deep copy of src, with the value of x changed 

116 """ 

117 

118 out = src.table.copyRecord(src) 

119 x = out.getX() 

120 y = out.getY() 

121 val = x**3 

122 

123 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x + val*frac) 

124 out.set(out.table.getCentroidSlot().getMeasKey().getY(), y) 

125 return out 

126 

127 

128def manyTermX(src, frac=1e-9): 

129 """Distort image by multiple powers of x, 'x**3 - 2*x**2 + 4*x - 9'. 

130 

131 Parameters 

132 ---------- 

133 src : `lsst.afw.table.SourceRecord` 

134 A Source object 

135 frac : `float` 

136 How much to change X by 

137 

138 Returns 

139 ------- 

140 out : `lsst.afw.table.SourceRecord` 

141 A deep copy of src, with the value of x changed 

142 """ 

143 

144 out = src.table.copyRecord(src) 

145 x = out.getX() 

146 y = out.getY() 

147 val = x**3 - 2*x**2 + 4*x - 9 

148 

149 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x + val*frac) 

150 out.set(out.table.getCentroidSlot().getMeasKey().getY(), y) 

151 return out 

152 

153 

154def linearYDistort(src, frac=.001): 

155 """Increase the y value in a Source object by frac. E.g 

156 src.x = 1000 --> 1001 if frac=.001 

157 

158 Parameters 

159 ---------- 

160 src : `lsst.afw.table.SourceRecord` 

161 A Source object 

162 frac : `float` 

163 How much to change Y by 

164 

165 Returns 

166 ------- 

167 out : `lsst.afw.table.SourceRecord` 

168 A deep copy of src, with the value of Y changed 

169 """ 

170 

171 out = src.table.copyRecord(src) 

172 out.set(out.table.getCentroidSlot().getMeasKey().getY(), out.getY()*(1+frac)) 

173 return out 

174 

175 

176def quadraticDistortY(src, frac=1e-6): 

177 """Distort image by terms with power <=2 

178 i.e y, y^2, x, xy, x^2 

179 

180 Parameters 

181 ---------- 

182 src : `lsst.afw.table.SourceRecord` 

183 A Source object 

184 frac : `float` 

185 How much to change Y by 

186 

187 Returns 

188 ------- 

189 out : `lsst.afw.table.SourceRecord` 

190 A deep copy of src, with the value of Y changed 

191 """ 

192 

193 out = src.table.copyRecord(src) 

194 x = out.getX() 

195 y = out.getY() 

196 val = y**2 

197 

198 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x) 

199 out.set(out.table.getCentroidSlot().getMeasKey().getY(), y + val*frac) 

200 return out 

201 

202 

203def cubicDistortY(src, frac=1e-9): 

204 """Distort image by terms with power <=2 

205 i.e y, y^2, x, xy, x^2 

206 

207 Parameters 

208 ---------- 

209 src : `lsst.afw.table.SourceRecord` 

210 A Source object 

211 frac : `float` 

212 How much to change Y by 

213 

214 Returns 

215 ------- 

216 out : `lsst.afw.table.SourceRecord` 

217 A deep copy of src, with the value of Y changed 

218 """ 

219 

220 out = src.table.copyRecord(src) 

221 x = out.getX() 

222 y = out.getY() 

223 val = x**3 

224 

225 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x) 

226 out.set(out.table.getCentroidSlot().getMeasKey().getY(), y + val*frac) 

227 return out 

228 

229 

230def manyTermY(src, frac=1e-9): 

231 """Distort image by multiple terms of Y, 'y**3 - 2*y**2 + 4*y - 9'. 

232 

233 Parameters 

234 ---------- 

235 src : `lsst.afw.table.SourceRecord` 

236 A Source object 

237 frac : `float` 

238 How much to change Y by 

239 

240 Returns 

241 ------- 

242 out : `lsst.afw.table.SourceRecord` 

243 A deep copy of src, with the value of Y changed 

244 """ 

245 out = src.table.copyRecord(src) 

246 x = out.getX() 

247 y = out.getY() 

248 val = y**3 - 2*y**2 + 4*y - 9 

249 

250 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x) 

251 out.set(out.table.getCentroidSlot().getMeasKey().getY(), y + val*frac) 

252 return out 

253 

254 

255def crossTerms1(src, frac=1e-11): 

256 """Distort image Y by X, leaving X unchanged, 'x**3 - 2*x**2'. 

257 

258 Parameters 

259 ---------- 

260 src : `lsst.afw.table.SourceRecord` 

261 A Source object 

262 frac : `float` 

263 How much to change Y by 

264 

265 Returns 

266 ------- 

267 out : `lsst.afw.table.SourceRecord` 

268 A deep copy of src, with the value of Y changed 

269 """ 

270 out = src.table.copyRecord(src) 

271 x = out.getX() 

272 y = out.getY() 

273 val = x**3 - 2*x**2 # + 4*x - 9 

274 

275 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x) 

276 out.set(out.table.getCentroidSlot().getMeasKey().getY(), y + val*frac) 

277 return out 

278 

279 

280def crossTerms2(src, frac=1e-11): 

281 """Distort image X by Y, leaving Y unchanged, 'y**3 - 2*y**2 + 4*y - 9'. 

282 

283 Parameters 

284 ---------- 

285 src : `lsst.afw.table.SourceRecord` 

286 A Source object 

287 frac : `float` 

288 How much to change X by 

289 

290 Returns 

291 ------- 

292 out : `lsst.afw.table.SourceRecord` 

293 A deep copy of src, with the value of X changed 

294 """ 

295 out = src.table.copyRecord(src) 

296 x = out.getX() 

297 y = out.getY() 

298 val = y**3 - 2*y**2 + 4*y - 9 

299 

300 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x + val*frac) 

301 out.set(out.table.getCentroidSlot().getMeasKey().getY(), y) 

302 return out 

303 

304 

305def crossTerms3(src, frac=1e-9): 

306 """Distort image X and Y , 'dx=x**3 - 2*x**2 + 4*x - 9', 

307 'dy=y**3 - 2*y**2 + 4*y - 9'. 

308 

309 Parameters 

310 ---------- 

311 src : `lsst.afw.table.SourceRecord` 

312 A Source object 

313 frac : `float` 

314 How much to change X and Y by 

315 

316 Returns 

317 ------- 

318 out : `lsst.afw.table.SourceRecord` 

319 A deep copy of src, with the value of X and Y changed 

320 """ 

321 out = src.table.copyRecord(src) 

322 x = out.getX() 

323 y = out.getY() 

324 valx = x**3 - 2*x**2 + 4*x - 9 

325 valy = y**3 - 2*y**2 + 4*y - 9 

326 

327 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x + valy*frac) 

328 out.set(out.table.getCentroidSlot().getMeasKey().getY(), y + valx*frac) 

329 return out 

330 

331 

332def quadraticDistort(src, frac=1e-6): 

333 """Distort image by terms with power <=2 

334 i.e y, y^2, x, xy, x^2 

335 

336 Parameters 

337 ---------- 

338 src : `lsst.afw.table.SourceRecord` 

339 A Source object 

340 frac : `float` 

341 How much to change X 

342 

343 Returns 

344 ------- 

345 out : `lsst.afw.table.SourceRecord` 

346 A deep copy of src, with the value of X 

347 """ 

348 

349 out = src.table.copyRecord(src) 

350 x = out.getX() 

351 y = out.getY() 

352 val = y + 2*y**2 

353 val += 3*x + 4*x*y 

354 val += x**2 

355 

356 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x + val*frac) 

357 out.set(out.table.getCentroidSlot().getMeasKey().getY(), y) 

358 return out 

359 

360 

361def T2DistortX(src, frac=1e-6): 

362 """Distort image by a 2nd order Cheby polynomial 

363 

364 Parameters 

365 ---------- 

366 src : `lsst.afw.table.SourceRecord` 

367 A Source object 

368 frac : `float` 

369 How much to change X 

370 

371 Returns 

372 ------- 

373 out : `lsst.afw.table.SourceRecord` 

374 A deep copy of src, with the value of X 

375 """ 

376 

377 out = src.table.copyRecord(src) 

378 x = src.getX() 

379 val = 2*(x**2) - 1 

380 out.set(out.table.getCentroidSlot().getMeasKey().getX(), x + frac*val) 

381 return out 

382 

383 

384def distortList(srcList, function): 

385 """Create a copy of srcList, and apply function to distort the 

386 values of x and y. 

387 

388 Parameters 

389 ---------- 

390 srcList : `list` of `lsst.afw.table.SourceRecord` 

391 Input list of source to distort. 

392 function : `callable` 

393 A function that does a deep copy of a single Source 

394 

395 Returns 

396 ------- 

397 out : `lsst.afw.table.SourceCatalog` 

398 Output catalog with distorted positions. 

399 """ 

400 

401 out = afwTable.SourceCatalog(srcList.table) 

402 out.reserve(len(srcList)) 

403 

404 for src in srcList: 

405 out.append(function(src)) 

406 

407 maxDiff = 0 

408 for i in range(len(srcList)): 

409 s = srcList[i] 

410 o = out[i] 

411 

412 x1, y1 = s.getX(), s.getY() 

413 x2, y2 = o.getX(), o.getY() 

414 

415 diff = math.hypot(x1-x2, y1-y2) 

416 maxDiff = max(diff, maxDiff) 

417 

418 print("Max deviation is %e pixels" % (maxDiff)) 

419 

420 return out