/usr/include/opencv2/flann/autotuned_index.h is in libopencv-flann-dev 2.4.9.1+dfsg1-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 | /***********************************************************************
* Software License Agreement (BSD License)
*
* Copyright 2008-2009 Marius Muja (mariusm@cs.ubc.ca). All rights reserved.
* Copyright 2008-2009 David G. Lowe (lowe@cs.ubc.ca). All rights reserved.
*
* THE BSD LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*************************************************************************/
#ifndef OPENCV_FLANN_AUTOTUNED_INDEX_H_
#define OPENCV_FLANN_AUTOTUNED_INDEX_H_
#include "general.h"
#include "nn_index.h"
#include "ground_truth.h"
#include "index_testing.h"
#include "sampling.h"
#include "kdtree_index.h"
#include "kdtree_single_index.h"
#include "kmeans_index.h"
#include "composite_index.h"
#include "linear_index.h"
#include "logger.h"
namespace cvflann
{
template<typename Distance>
NNIndex<Distance>* create_index_by_type(const Matrix<typename Distance::ElementType>& dataset, const IndexParams& params, const Distance& distance);
struct AutotunedIndexParams : public IndexParams
{
AutotunedIndexParams(float target_precision = 0.8, float build_weight = 0.01, float memory_weight = 0, float sample_fraction = 0.1)
{
(*this)["algorithm"] = FLANN_INDEX_AUTOTUNED;
// precision desired (used for autotuning, -1 otherwise)
(*this)["target_precision"] = target_precision;
// build tree time weighting factor
(*this)["build_weight"] = build_weight;
// index memory weighting factor
(*this)["memory_weight"] = memory_weight;
// what fraction of the dataset to use for autotuning
(*this)["sample_fraction"] = sample_fraction;
}
};
template <typename Distance>
class AutotunedIndex : public NNIndex<Distance>
{
public:
typedef typename Distance::ElementType ElementType;
typedef typename Distance::ResultType DistanceType;
AutotunedIndex(const Matrix<ElementType>& inputData, const IndexParams& params = AutotunedIndexParams(), Distance d = Distance()) :
dataset_(inputData), distance_(d)
{
target_precision_ = get_param(params, "target_precision",0.8f);
build_weight_ = get_param(params,"build_weight", 0.01f);
memory_weight_ = get_param(params, "memory_weight", 0.0f);
sample_fraction_ = get_param(params,"sample_fraction", 0.1f);
bestIndex_ = NULL;
}
AutotunedIndex(const AutotunedIndex&);
AutotunedIndex& operator=(const AutotunedIndex&);
virtual ~AutotunedIndex()
{
if (bestIndex_ != NULL) {
delete bestIndex_;
bestIndex_ = NULL;
}
}
/**
* Method responsible with building the index.
*/
virtual void buildIndex()
{
bestParams_ = estimateBuildParams();
Logger::info("----------------------------------------------------\n");
Logger::info("Autotuned parameters:\n");
print_params(bestParams_);
Logger::info("----------------------------------------------------\n");
bestIndex_ = create_index_by_type(dataset_, bestParams_, distance_);
bestIndex_->buildIndex();
speedup_ = estimateSearchParams(bestSearchParams_);
Logger::info("----------------------------------------------------\n");
Logger::info("Search parameters:\n");
print_params(bestSearchParams_);
Logger::info("----------------------------------------------------\n");
}
/**
* Saves the index to a stream
*/
virtual void saveIndex(FILE* stream)
{
save_value(stream, (int)bestIndex_->getType());
bestIndex_->saveIndex(stream);
save_value(stream, get_param<int>(bestSearchParams_, "checks"));
}
/**
* Loads the index from a stream
*/
virtual void loadIndex(FILE* stream)
{
int index_type;
load_value(stream, index_type);
IndexParams params;
params["algorithm"] = (flann_algorithm_t)index_type;
bestIndex_ = create_index_by_type<Distance>(dataset_, params, distance_);
bestIndex_->loadIndex(stream);
int checks;
load_value(stream, checks);
bestSearchParams_["checks"] = checks;
}
/**
* Method that searches for nearest-neighbors
*/
virtual void findNeighbors(ResultSet<DistanceType>& result, const ElementType* vec, const SearchParams& searchParams)
{
int checks = get_param<int>(searchParams,"checks",FLANN_CHECKS_AUTOTUNED);
if (checks == FLANN_CHECKS_AUTOTUNED) {
bestIndex_->findNeighbors(result, vec, bestSearchParams_);
}
else {
bestIndex_->findNeighbors(result, vec, searchParams);
}
}
IndexParams getParameters() const
{
return bestIndex_->getParameters();
}
SearchParams getSearchParameters() const
{
return bestSearchParams_;
}
float getSpeedup() const
{
return speedup_;
}
/**
* Number of features in this index.
*/
virtual size_t size() const
{
return bestIndex_->size();
}
/**
* The length of each vector in this index.
*/
virtual size_t veclen() const
{
return bestIndex_->veclen();
}
/**
* The amount of memory (in bytes) this index uses.
*/
virtual int usedMemory() const
{
return bestIndex_->usedMemory();
}
/**
* Algorithm name
*/
virtual flann_algorithm_t getType() const
{
return FLANN_INDEX_AUTOTUNED;
}
private:
struct CostData
{
float searchTimeCost;
float buildTimeCost;
float memoryCost;
float totalCost;
IndexParams params;
};
void evaluate_kmeans(CostData& cost)
{
StartStopTimer t;
int checks;
const int nn = 1;
Logger::info("KMeansTree using params: max_iterations=%d, branching=%d\n",
get_param<int>(cost.params,"iterations"),
get_param<int>(cost.params,"branching"));
KMeansIndex<Distance> kmeans(sampledDataset_, cost.params, distance_);
// measure index build time
t.start();
kmeans.buildIndex();
t.stop();
float buildTime = (float)t.value;
// measure search time
float searchTime = test_index_precision(kmeans, sampledDataset_, testDataset_, gt_matches_, target_precision_, checks, distance_, nn);
float datasetMemory = float(sampledDataset_.rows * sampledDataset_.cols * sizeof(float));
cost.memoryCost = (kmeans.usedMemory() + datasetMemory) / datasetMemory;
cost.searchTimeCost = searchTime;
cost.buildTimeCost = buildTime;
Logger::info("KMeansTree buildTime=%g, searchTime=%g, build_weight=%g\n", buildTime, searchTime, build_weight_);
}
void evaluate_kdtree(CostData& cost)
{
StartStopTimer t;
int checks;
const int nn = 1;
Logger::info("KDTree using params: trees=%d\n", get_param<int>(cost.params,"trees"));
KDTreeIndex<Distance> kdtree(sampledDataset_, cost.params, distance_);
t.start();
kdtree.buildIndex();
t.stop();
float buildTime = (float)t.value;
//measure search time
float searchTime = test_index_precision(kdtree, sampledDataset_, testDataset_, gt_matches_, target_precision_, checks, distance_, nn);
float datasetMemory = float(sampledDataset_.rows * sampledDataset_.cols * sizeof(float));
cost.memoryCost = (kdtree.usedMemory() + datasetMemory) / datasetMemory;
cost.searchTimeCost = searchTime;
cost.buildTimeCost = buildTime;
Logger::info("KDTree buildTime=%g, searchTime=%g\n", buildTime, searchTime);
}
// struct KMeansSimpleDownhillFunctor {
//
// Autotune& autotuner;
// KMeansSimpleDownhillFunctor(Autotune& autotuner_) : autotuner(autotuner_) {};
//
// float operator()(int* params) {
//
// float maxFloat = numeric_limits<float>::max();
//
// if (params[0]<2) return maxFloat;
// if (params[1]<0) return maxFloat;
//
// CostData c;
// c.params["algorithm"] = KMEANS;
// c.params["centers-init"] = CENTERS_RANDOM;
// c.params["branching"] = params[0];
// c.params["max-iterations"] = params[1];
//
// autotuner.evaluate_kmeans(c);
//
// return c.timeCost;
//
// }
// };
//
// struct KDTreeSimpleDownhillFunctor {
//
// Autotune& autotuner;
// KDTreeSimpleDownhillFunctor(Autotune& autotuner_) : autotuner(autotuner_) {};
//
// float operator()(int* params) {
// float maxFloat = numeric_limits<float>::max();
//
// if (params[0]<1) return maxFloat;
//
// CostData c;
// c.params["algorithm"] = KDTREE;
// c.params["trees"] = params[0];
//
// autotuner.evaluate_kdtree(c);
//
// return c.timeCost;
//
// }
// };
void optimizeKMeans(std::vector<CostData>& costs)
{
Logger::info("KMEANS, Step 1: Exploring parameter space\n");
// explore kmeans parameters space using combinations of the parameters below
int maxIterations[] = { 1, 5, 10, 15 };
int branchingFactors[] = { 16, 32, 64, 128, 256 };
int kmeansParamSpaceSize = FLANN_ARRAY_LEN(maxIterations) * FLANN_ARRAY_LEN(branchingFactors);
costs.reserve(costs.size() + kmeansParamSpaceSize);
// evaluate kmeans for all parameter combinations
for (size_t i = 0; i < FLANN_ARRAY_LEN(maxIterations); ++i) {
for (size_t j = 0; j < FLANN_ARRAY_LEN(branchingFactors); ++j) {
CostData cost;
cost.params["algorithm"] = FLANN_INDEX_KMEANS;
cost.params["centers_init"] = FLANN_CENTERS_RANDOM;
cost.params["iterations"] = maxIterations[i];
cost.params["branching"] = branchingFactors[j];
evaluate_kmeans(cost);
costs.push_back(cost);
}
}
// Logger::info("KMEANS, Step 2: simplex-downhill optimization\n");
//
// const int n = 2;
// // choose initial simplex points as the best parameters so far
// int kmeansNMPoints[n*(n+1)];
// float kmeansVals[n+1];
// for (int i=0;i<n+1;++i) {
// kmeansNMPoints[i*n] = (int)kmeansCosts[i].params["branching"];
// kmeansNMPoints[i*n+1] = (int)kmeansCosts[i].params["max-iterations"];
// kmeansVals[i] = kmeansCosts[i].timeCost;
// }
// KMeansSimpleDownhillFunctor kmeans_cost_func(*this);
// // run optimization
// optimizeSimplexDownhill(kmeansNMPoints,n,kmeans_cost_func,kmeansVals);
// // store results
// for (int i=0;i<n+1;++i) {
// kmeansCosts[i].params["branching"] = kmeansNMPoints[i*2];
// kmeansCosts[i].params["max-iterations"] = kmeansNMPoints[i*2+1];
// kmeansCosts[i].timeCost = kmeansVals[i];
// }
}
void optimizeKDTree(std::vector<CostData>& costs)
{
Logger::info("KD-TREE, Step 1: Exploring parameter space\n");
// explore kd-tree parameters space using the parameters below
int testTrees[] = { 1, 4, 8, 16, 32 };
// evaluate kdtree for all parameter combinations
for (size_t i = 0; i < FLANN_ARRAY_LEN(testTrees); ++i) {
CostData cost;
cost.params["trees"] = testTrees[i];
evaluate_kdtree(cost);
costs.push_back(cost);
}
// Logger::info("KD-TREE, Step 2: simplex-downhill optimization\n");
//
// const int n = 1;
// // choose initial simplex points as the best parameters so far
// int kdtreeNMPoints[n*(n+1)];
// float kdtreeVals[n+1];
// for (int i=0;i<n+1;++i) {
// kdtreeNMPoints[i] = (int)kdtreeCosts[i].params["trees"];
// kdtreeVals[i] = kdtreeCosts[i].timeCost;
// }
// KDTreeSimpleDownhillFunctor kdtree_cost_func(*this);
// // run optimization
// optimizeSimplexDownhill(kdtreeNMPoints,n,kdtree_cost_func,kdtreeVals);
// // store results
// for (int i=0;i<n+1;++i) {
// kdtreeCosts[i].params["trees"] = kdtreeNMPoints[i];
// kdtreeCosts[i].timeCost = kdtreeVals[i];
// }
}
/**
* Chooses the best nearest-neighbor algorithm and estimates the optimal
* parameters to use when building the index (for a given precision).
* Returns a dictionary with the optimal parameters.
*/
IndexParams estimateBuildParams()
{
std::vector<CostData> costs;
int sampleSize = int(sample_fraction_ * dataset_.rows);
int testSampleSize = std::min(sampleSize / 10, 1000);
Logger::info("Entering autotuning, dataset size: %d, sampleSize: %d, testSampleSize: %d, target precision: %g\n", dataset_.rows, sampleSize, testSampleSize, target_precision_);
// For a very small dataset, it makes no sense to build any fancy index, just
// use linear search
if (testSampleSize < 10) {
Logger::info("Choosing linear, dataset too small\n");
return LinearIndexParams();
}
// We use a fraction of the original dataset to speedup the autotune algorithm
sampledDataset_ = random_sample(dataset_, sampleSize);
// We use a cross-validation approach, first we sample a testset from the dataset
testDataset_ = random_sample(sampledDataset_, testSampleSize, true);
// We compute the ground truth using linear search
Logger::info("Computing ground truth... \n");
gt_matches_ = Matrix<int>(new int[testDataset_.rows], testDataset_.rows, 1);
StartStopTimer t;
t.start();
compute_ground_truth<Distance>(sampledDataset_, testDataset_, gt_matches_, 0, distance_);
t.stop();
CostData linear_cost;
linear_cost.searchTimeCost = (float)t.value;
linear_cost.buildTimeCost = 0;
linear_cost.memoryCost = 0;
linear_cost.params["algorithm"] = FLANN_INDEX_LINEAR;
costs.push_back(linear_cost);
// Start parameter autotune process
Logger::info("Autotuning parameters...\n");
optimizeKMeans(costs);
optimizeKDTree(costs);
float bestTimeCost = costs[0].searchTimeCost;
for (size_t i = 0; i < costs.size(); ++i) {
float timeCost = costs[i].buildTimeCost * build_weight_ + costs[i].searchTimeCost;
if (timeCost < bestTimeCost) {
bestTimeCost = timeCost;
}
}
float bestCost = costs[0].searchTimeCost / bestTimeCost;
IndexParams bestParams = costs[0].params;
if (bestTimeCost > 0) {
for (size_t i = 0; i < costs.size(); ++i) {
float crtCost = (costs[i].buildTimeCost * build_weight_ + costs[i].searchTimeCost) / bestTimeCost +
memory_weight_ * costs[i].memoryCost;
if (crtCost < bestCost) {
bestCost = crtCost;
bestParams = costs[i].params;
}
}
}
delete[] gt_matches_.data;
delete[] testDataset_.data;
delete[] sampledDataset_.data;
return bestParams;
}
/**
* Estimates the search time parameters needed to get the desired precision.
* Precondition: the index is built
* Postcondition: the searchParams will have the optimum params set, also the speedup obtained over linear search.
*/
float estimateSearchParams(SearchParams& searchParams)
{
const int nn = 1;
const size_t SAMPLE_COUNT = 1000;
assert(bestIndex_ != NULL); // must have a valid index
float speedup = 0;
int samples = (int)std::min(dataset_.rows / 10, SAMPLE_COUNT);
if (samples > 0) {
Matrix<ElementType> testDataset = random_sample(dataset_, samples);
Logger::info("Computing ground truth\n");
// we need to compute the ground truth first
Matrix<int> gt_matches(new int[testDataset.rows], testDataset.rows, 1);
StartStopTimer t;
t.start();
compute_ground_truth<Distance>(dataset_, testDataset, gt_matches, 1, distance_);
t.stop();
float linear = (float)t.value;
int checks;
Logger::info("Estimating number of checks\n");
float searchTime;
float cb_index;
if (bestIndex_->getType() == FLANN_INDEX_KMEANS) {
Logger::info("KMeans algorithm, estimating cluster border factor\n");
KMeansIndex<Distance>* kmeans = (KMeansIndex<Distance>*)bestIndex_;
float bestSearchTime = -1;
float best_cb_index = -1;
int best_checks = -1;
for (cb_index = 0; cb_index < 1.1f; cb_index += 0.2f) {
kmeans->set_cb_index(cb_index);
searchTime = test_index_precision(*kmeans, dataset_, testDataset, gt_matches, target_precision_, checks, distance_, nn, 1);
if ((searchTime < bestSearchTime) || (bestSearchTime == -1)) {
bestSearchTime = searchTime;
best_cb_index = cb_index;
best_checks = checks;
}
}
searchTime = bestSearchTime;
cb_index = best_cb_index;
checks = best_checks;
kmeans->set_cb_index(best_cb_index);
Logger::info("Optimum cb_index: %g\n", cb_index);
bestParams_["cb_index"] = cb_index;
}
else {
searchTime = test_index_precision(*bestIndex_, dataset_, testDataset, gt_matches, target_precision_, checks, distance_, nn, 1);
}
Logger::info("Required number of checks: %d \n", checks);
searchParams["checks"] = checks;
speedup = linear / searchTime;
delete[] gt_matches.data;
delete[] testDataset.data;
}
return speedup;
}
private:
NNIndex<Distance>* bestIndex_;
IndexParams bestParams_;
SearchParams bestSearchParams_;
Matrix<ElementType> sampledDataset_;
Matrix<ElementType> testDataset_;
Matrix<int> gt_matches_;
float speedup_;
/**
* The dataset used by this index
*/
const Matrix<ElementType> dataset_;
/**
* Index parameters
*/
float target_precision_;
float build_weight_;
float memory_weight_;
float sample_fraction_;
Distance distance_;
};
}
#endif /* OPENCV_FLANN_AUTOTUNED_INDEX_H_ */
|