C++实现的图像小波变换源码

// Copyright 1996 John M. Danskin 7/30/96 // // Permission is granted to use this software for any purpose as // long as this notice stays attached to this software. // #ifndef iHistInclude #define iHistInclude #include <math.h> #define iHistDebug 0 #if iHistDebug # define iHistDBbegin(h) if (h->debug) { # define iHistDBend } #else # define iHistDBbegin(h) if (0) { # define iHistDBend } #endif // iHistogram: // provides histogram functionality needed for arithmetic coding. // Symbols are non-negative integers in the range [0,nsyms-1]. // The initial count for all symbols is 0. // // This object implements Alistair Moffat's linear time algorithm for // adaptive arithmetic coding. // // this is a function for filling in the counts in an application // specific way typedef void iHistBinFun(void *closure, int *counts); class iHistogram { protected: int totalCount; int maxCt; int nsyms; int *count; // pos to ct int *treeCount; // pos to ctLeft int *symToPos; // symbol to position int *posToSym; // position to symbol void BuildTreeCount(void); // rebuild treecount. // we do this after making some non-incrmental // change to the counts, like scaling. void ScaleCounts(void); // Divides counts by two, except that // if a count was originally non-zero, // doesn't let count drop below 1. // DOES NOT REBUILD treeCount! inline int Parent(int child) { return (child - 1) >> 1; } inline int Lchild(int parent) { return parent + parent + 1; } inline int Rchild(int parent) { return parent + parent + 2; } Real onelog2; void Reorganise(int sym); // move sym as far to left as possible int sorted(int from, int to); // predicate for an assert void swapSyms(int pos_a, int pos_b); // swap syms (no tree update) given pos-es. void pc(int from, int to); void qs(int from, int to); // pivot is count[from] void qsortSyms(void); // sorts syms, keeping symToPos & posToSym // up to date. public: int debug; iHistogram(int nsyms, int maxct); ~iHistogram(); // following two Init fcns update the count array. // rebuilding internal structures afterward. // symbol 0 goes in position 0, etc. void InitCounts(int *cnts); void InitCounts(iHistBinFun *f, void *closure); // can look at old cts // if desired. int TotalCount(); // total frequency count (scaled) int LeftCount(int sym); // count to left of symbol // freq of symbol inline int Count(int sym) { return count[symToPos[sym]];} void IncCount(int sym); // increase freq of symbol int Symbol(int val); // get symbol from value // Entropy of symbol w.r.t. histogram Real Entropy(int sym) { return -log(Count(sym)/(Real)totalCount) * onelog2; } void print(ostream &strm); // print the object void printerr(void); // print the object to stderr private: }; #endif