libdtw - Dynamic time warping library

General information

This library contains DTW related code.
Two files: dtw_parm.h/cpp <-depend on-- dtw_util.h/cpp.
Support multi-threading for batch processing (multiple queries searching for multiple documents):
- Create N threads.
- Dispatcher holds all (query, doc) pairs.
- Each thread requests a (query, doc) pair in a while loop.

dtw_parm.h/cpp

class DtwParm Contains parameters to run DTW.

functions (partial)

DtwParm::LoadParm is overloaded with three prototype.
- All three types can be used in frame-based DTW.
- The 2nd type has additional basic segment infomation (but not supersegment informations)
- Only 3rd type can be used in segment-based DTW. See section 3.3

namespace DtwUtil {
  class DtwParm {
    public:
      enum ParmType {FRAME = 0, SEGMENT = 1, SUPERSEG = 2};
      DtwParm();

      /* Load data */
      void LoadParm(const string feat_fname); // 1st type: Load feature only
      void LoadParm(const string feat_fname,  // 2nd type: Load feature and segment
                    const double bseg_ratio,
                    const string tree_fname = "");
      void LoadParm(const string feat_fname,  // 3rd type: Load feature,segment,supersegment
                    const double bseg_ratio,
                    const double superseg_ratio,
                    const unsigned width,
                    const unsigned gran,
                    const string tree_fname = "");

      void DumpData() const;
  };
} /* namespace DtwUtil */

dtw_util.h/cpp

Functions

InitDtw(): setup input/output for DTW run
DTW(): perform DTW on a query-document pair
See test/example2.cpp for examples.

Batch: multithreading

Assuming you have a query, and you want to search for hypothesized regions in all documents. The DTWs performed on different (query, document) pairs are disjoint. Therefore we divide them into smaller tasks, namely a (query, document) pairs. All threads can perform DTW on each task simultaneously.

DtwManager

namespace DtwUtil {
  class DtwManager : public ThreadRunner {
    public:
      DtwManager();
      void Install(DtwBatchParamSet* paramset, DtwRunner* runner) {
      virtual void* Run() {
        while (paramset_->InstallDtwRunner(runner_)) runner_->DTW();
        return NULL;
      }
    private:
      DtwBatchParamSet* paramset_; // Make sure all DtwMangers share the same DtwBatchParamSet.
      DtwRunner* runner_; // Make sure all DtwManagers have *distinct* DtwRunners, otherwise it will fail.
  };
} /* namespace DtwUtil */

stegben/libdtw