Joshua Moerman
10 years ago
18 changed files with 408 additions and 301 deletions
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#define NEXP 20 |
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@ -0,0 +1,134 @@ |
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#include <includes.hpp> |
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#include <utilities.hpp> |
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#include <boost/filesystem.hpp> |
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#include <png.hpp> |
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#include "jcmp.hpp" |
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#include "wavelet.hpp" |
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using namespace wvlt::V2; |
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// Can be any functions from R+ -> R
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// as long as backward is its inverse
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static double forward(double x){ |
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//return std::log(1 + std::log(1 + x));
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return std::log(x); |
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} |
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static double backward(double x){ |
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//return std::exp(std::exp(x) - 1) - 1;
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return std::exp(x); |
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} |
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// note: we take a copy, because we will modify it in place
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static jcmp::image compress(std::vector<double> image, jcmp::uint width, double threshold, unsigned int& nzeros){ |
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jcmp::uint height = image.size() / width; |
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assert(is_pow_of_two(width)); |
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assert(is_pow_of_two(height)); |
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// wavelet transform in x-direction
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for(unsigned int i = 0; i < height; ++i){ |
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wavelet(&image[i*width], width, 1); |
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} |
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// wavelet transform in y-direction
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for(unsigned int i = 0; i < width; ++i){ |
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wavelet(&image[i], height, width); |
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} |
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double min_abs = 10000.0; |
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double max_abs = 0.0; |
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for(auto& el : image){ |
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auto absel = std::abs(el); |
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if(absel > threshold) { |
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min_abs = std::min(min_abs, absel); |
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max_abs = std::max(max_abs, absel); |
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} else { |
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el = 0; |
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} |
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} |
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jcmp::quantization q(&forward, &backward, max_abs, min_abs); |
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// save the principal coefficients
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std::vector<jcmp::coefficient> v; |
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for(unsigned int y = 0; y < height; ++y){ |
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for(unsigned int x = 0; x < width; ++x){ |
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auto&& el = image[x + width*y]; |
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if(el != 0) v.push_back({q.forwards(el), jcmp::uint(x), jcmp::uint(y)}); |
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} |
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} |
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nzeros = v.size(); |
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return jcmp::image(width, height, q.p, std::move(v)); |
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} |
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static std::vector<double> decompress(jcmp::image in){ |
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auto width = in.header.width; |
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auto height = in.header.height; |
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assert(is_pow_of_two(width)); |
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assert(is_pow_of_two(height)); |
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auto q = in.header.get_quantization(&forward, &backward); |
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std::vector<double> image(width * height, 0.0); |
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// read in coefficient on coordinates
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for(auto it = in.data.begin(); it != in.data.end(); ++it){ |
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auto&& x = *it; |
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image[x.x + width*x.y] = q.backwards(x.c); |
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} |
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in.clear(); |
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// inverse wavelet transform in y-direction
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for(unsigned int i = 0; i < width; ++i){ |
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unwavelet(&image[i], height, width); |
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} |
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// inverse wavelet transform in x-direction
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for(unsigned int i = 0; i < height; ++i){ |
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unwavelet(&image[i*width], width, 1); |
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} |
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return image; |
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} |
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int main(){ |
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namespace fs = boost::filesystem; |
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fs::path directory("images"); |
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fs::directory_iterator eod; |
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for(fs::directory_iterator it(directory); it != eod; ++it){ |
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auto && path = it->path(); |
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if(path.extension() != ".png") continue; |
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// open file
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std::string filename = path.string(); |
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std::cout << field("file") << filename << std::endl; |
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png::istream image(filename); |
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auto width = image.get_width(); |
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auto height = image.get_height(); |
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// read into vector
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std::vector<double> image_vec; |
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image_vec.reserve(width * height); |
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for(unsigned char c = 0; image >> c;) image_vec.push_back(c/255.0); |
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// compress and decompress to see how we lost information
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unsigned int nzeros = 0; |
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auto compressed_vec = decompress(compress(image_vec, width, 0.1, nzeros)); |
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// output some information
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std::cout << field("raw") << human_string(sizeof(uint8_t) * image_vec.size(), "b") << std::endl; |
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std::cout << field("compressed") << human_string(sizeof(jcmp::coefficient) * nzeros, "b") << std::endl; |
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// save to output file
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std::string cfilename = "compressed/" + path.filename().string(); |
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png::gray_ostream compressed_image(width, height, cfilename); |
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for(unsigned int i = 0; i < compressed_vec.size(); ++i) compressed_image << compressed_vec[i]; |
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} |
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} |
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@ -0,0 +1,3 @@ |
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#pragma once |
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#include "jcmp_image.hpp" |
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@ -0,0 +1,49 @@ |
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#pragma once |
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namespace jcmp { |
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// input in [0, 1], output [0, 255]
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inline uint8_t clamp_round(double x){ |
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if(x <= 0.0) return 0; |
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if(x >= 1.0) return 255; |
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return uint8_t(std::round(255.0*x)); |
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} |
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// parameters which need to be stored in the file
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// to be able to dequantize
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struct quantize_params { |
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double f_max_abs; |
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double f_min_abs; |
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}; |
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// Quantization may be non linear (given by f and f_inv)
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struct quantization { |
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std::function<double(double)> f; |
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std::function<double(double)> f_inv; |
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quantize_params p; |
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quantization() = default; |
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template <typename F> |
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quantization(F const & f_, F const & f_inv_, double max_abs, double min_abs) |
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: f(f_) |
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, f_inv(f_inv_) |
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, p{f(max_abs), f(min_abs)} |
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{} |
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uint8_t forwards(double x){ |
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double y = std::abs(x); |
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y = (f(y) - p.f_min_abs) / (p.f_max_abs - p.f_min_abs); |
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if(x < 0) y = -y; |
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return clamp_round(0.5 * (y + 1.0)); |
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} |
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double backwards(uint8_t x){ |
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double y = 2.0 * x / 255.0 - 1.0; |
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y = (p.f_max_abs - p.f_min_abs) * y; |
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if(y < 0) return -f_inv(-y + p.f_min_abs); |
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return f_inv(y + p.f_min_abs); |
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} |
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}; |
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static_assert(sizeof(quantize_params) == 16, "struct not propery packed"); |
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} |
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@ -0,0 +1,8 @@ |
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#include <includes.hpp> |
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#include <utilities.hpp> |
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#include "jcmp_quantization.hpp" |
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int main(){ |
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// no tests yet
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} |
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@ -1,102 +1,3 @@ |
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#pragma once |
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#include <includes.hpp> |
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#include "striding_iterator.hpp" |
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#include "periodic_iterator.hpp" |
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#include "wavelet_constants.hpp" |
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namespace wvlt { |
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namespace V1 { |
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// Apply the matrix Wn with the DAUB4 coefficients
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template <typename Iterator> |
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void wavelet_mul(Iterator begin, Iterator end){ |
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auto mul = end - begin; |
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std::vector<double> out(mul, 0.0); |
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for(int i = 0; i < mul; i += 2){ |
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out[i] = std::inner_product(evn_coef, evn_coef+4, periodic(begin, end) + i, 0.0); |
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out[i+1] = std::inner_product(odd_coef, odd_coef+4, periodic(begin, end) + i, 0.0); |
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} |
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for(int i = 0; i < mul; ++i){ |
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*begin++ = out[i]; |
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} |
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} |
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// Apply inverse of the matrix Wn with the DAUB4 coefficients
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template <typename Iterator> |
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void wavelet_inv(Iterator begin, Iterator end){ |
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auto mul = end - begin; |
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std::vector<double> out(mul, 0.0); |
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Iterator bc = begin; |
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for(int i = 0; i < mul; i += 2, begin += 2){ |
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Iterator b2 = begin + 1; |
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for(int j = 0; j < 4; ++j){ |
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out[(i+j) % mul] += *begin * evn_coef[j] + *b2 * odd_coef[j]; |
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} |
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} |
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for(int i = 0; i < mul; ++i){ |
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*bc++ = out[i]; |
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} |
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} |
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// Shuffle works with an extra copy, might be inefficient, but it is at least correct ;)
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// It applies the even-odd-sort matrix Sn
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template <typename Iterator> |
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void shuffle(Iterator begin, Iterator end){ |
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typedef typename std::iterator_traits<Iterator>::value_type value_type; |
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auto s = end - begin; |
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assert(s % 2 == 0); |
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std::vector<value_type> v(s); |
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std::copy(strided(begin , 2), strided(end , 2), v.begin()); |
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std::copy(strided(begin+1, 2), strided(end+1, 2), v.begin() + s/2); |
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std::copy(v.begin(), v.end(), begin); |
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} |
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template <typename Iterator> |
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void unshuffle(Iterator begin, Iterator end){ |
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typedef typename std::iterator_traits<Iterator>::value_type value_type; |
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auto s = end - begin; |
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assert(s % 2 == 0); |
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std::vector<value_type> v(s); |
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std::copy(begin, begin + s/2, strided(v.begin(), 2)); |
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std::copy(begin + s/2, end, strided(v.begin()+1, 2)); |
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std::copy(v.begin(), v.end(), begin); |
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} |
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// Combines the matrix Wn and Sn recusrively
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// Only works for inputs of size 2^m
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template <typename Iterator> |
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void wavelet(Iterator begin, Iterator end){ |
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auto s = end - begin; |
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assert(s >= 4); |
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for(int i = s; i >= 4; i >>= 1){ |
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// half interval
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end = begin + i; |
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assert(is_pow_of_two(end - begin)); |
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// multiply with Wn
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wavelet_mul(begin, end); |
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// then with Sn
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shuffle(begin, end); |
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} |
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} |
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template <typename Iterator> |
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void unwavelet(Iterator begin, Iterator end){ |
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auto s = end - begin; |
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assert(s >= 4); |
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for(int i = 4; i <= s; i <<= 1){ |
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// double interval
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end = begin + i; |
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assert(is_pow_of_two(end - begin)); |
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// unshuffle: Sn^-1
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unshuffle(begin, end); |
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// then Wn^-1
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wavelet_inv(begin, end); |
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} |
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} |
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} |
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} |
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#include "wavelet_2.hpp" |
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@ -1,107 +0,0 @@ |
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#include <includes.hpp> |
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#include <boost/filesystem.hpp> |
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#include <png.hpp> |
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#include <utilities.hpp> |
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#include "compressed_image.hpp" |
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#include "striding_iterator.hpp" |
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#include "periodic_iterator.hpp" |
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#include "wavelet.hpp" |
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using namespace wvlt::V1; |
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// note: we take a copy, because we will modify it in place
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jcmp::image compress(std::vector<double> image, int width, double threshold, int& zeros){ |
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auto height = image.size() / width; |
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assert(is_pow_of_two(width)); |
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assert(is_pow_of_two(height)); |
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// wavelet transform in x-direction
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for(int i = 0; i < height; ++i){ |
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wavelet(image.begin() + i*width, image.begin() + (i+1)*width); |
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} |
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// wavelet transform in y-direction
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for(int i = 0; i < width; ++i){ |
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wavelet(strided(image.begin() + i, width), strided(image.end() + i, width)); |
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} |
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// save the principal coefficients
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std::vector<jcmp::coefficient> v; |
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for(int y = 0; y < height; ++y){ |
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for(int x = 0; x < width; ++x){ |
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auto&& el = image[x + width*y]; |
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if(std::abs(el) > threshold) v.push_back({el, jcmp::uint(x), jcmp::uint(y)}); |
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else ++zeros; |
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} |
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} |
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return jcmp::image(width, height, std::move(v)); |
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} |
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std::vector<double> decompress(jcmp::image in){ |
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auto width = in.header.width; |
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auto height = in.header.height; |
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assert(is_pow_of_two(width)); |
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assert(is_pow_of_two(height)); |
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std::vector<double> image(width * height, 0.0); |
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// read in coefficient on coordinates
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for(auto it = in.data.begin(); it != in.data.end(); ++it){ |
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auto&& x = *it; |
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image[x.x + width*x.y] = x.c; |
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} |
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in.clear(); |
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// inverse wavelet transform in y-direction
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for(int i = 0; i < width; ++i){ |
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unwavelet(strided(image.begin() + i, width), strided(image.end() + i, width)); |
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} |
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// inverse wavelet transform in x-direction
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for(int i = 0; i < height; ++i){ |
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unwavelet(image.begin() + i*width, image.begin() + (i+1)*width); |
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} |
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return image; |
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} |
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int main(){ |
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namespace fs = boost::filesystem; |
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fs::path directory("images"); |
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fs::directory_iterator eod; |
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for(fs::directory_iterator it(directory); it != eod; ++it){ |
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auto && path = it->path(); |
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if(path.extension() != ".png") continue; |
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// open file
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std::string filename = path.string(); |
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std::cout << field("file") << filename << std::endl; |
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png::istream image(filename); |
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auto width = image.get_width(); |
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auto height = image.get_height(); |
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// read into vector
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std::vector<double> image_vec; |
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image_vec.reserve(width * height); |
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for(unsigned char c = 0; image >> c;) image_vec.push_back(c/255.0); |
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// compress and decompress to see how we lost information
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int zeros = 0; |
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auto compressed_vec = decompress(compress(image_vec, width, 0.5, zeros)); |
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// output some information
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std::cout << field("raw") << human_string(image_vec.size()) << std::endl; |
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std::cout << field("compressed") << human_string(image_vec.size() - zeros) << std::endl; |
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// save to output file
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std::string cfilename = "compressed/" + path.filename().string(); |
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png::gray_ostream compressed_image(width, height, cfilename); |
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for(int i = 0; i < compressed_vec.size(); ++i) compressed_image << compressed_vec[i]; |
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} |
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} |
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@ -0,0 +1,102 @@ |
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#pragma once |
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#include <includes.hpp> |
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#include "striding_iterator.hpp" |
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#include "periodic_iterator.hpp" |
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#include "wavelet_constants.hpp" |
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namespace wvlt { |
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namespace V1 { |
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// Apply the matrix Wn with the DAUB4 coefficients
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template <typename Iterator> |
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void wavelet_mul(Iterator begin, Iterator end){ |
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auto mul = end - begin; |
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std::vector<double> out(mul, 0.0); |
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for(int i = 0; i < mul; i += 2){ |
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out[i] = std::inner_product(evn_coef, evn_coef+4, periodic(begin, end) + i, 0.0); |
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out[i+1] = std::inner_product(odd_coef, odd_coef+4, periodic(begin, end) + i, 0.0); |
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} |
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for(int i = 0; i < mul; ++i){ |
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*begin++ = out[i]; |
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} |
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} |
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// Apply inverse of the matrix Wn with the DAUB4 coefficients
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template <typename Iterator> |
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void wavelet_inv(Iterator begin, Iterator end){ |
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auto mul = end - begin; |
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std::vector<double> out(mul, 0.0); |
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Iterator bc = begin; |
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for(int i = 0; i < mul; i += 2, begin += 2){ |
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Iterator b2 = begin + 1; |
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for(int j = 0; j < 4; ++j){ |
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out[(i+j) % mul] += *begin * evn_coef[j] + *b2 * odd_coef[j]; |
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} |
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} |
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for(int i = 0; i < mul; ++i){ |
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*bc++ = out[i]; |
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} |
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} |
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// Shuffle works with an extra copy, might be inefficient, but it is at least correct ;)
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// It applies the even-odd-sort matrix Sn
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template <typename Iterator> |
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void shuffle(Iterator begin, Iterator end){ |
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typedef typename std::iterator_traits<Iterator>::value_type value_type; |
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auto s = end - begin; |
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assert(s % 2 == 0); |
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std::vector<value_type> v(s); |
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std::copy(strided(begin , 2), strided(end , 2), v.begin()); |
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std::copy(strided(begin+1, 2), strided(end+1, 2), v.begin() + s/2); |
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std::copy(v.begin(), v.end(), begin); |
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} |
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template <typename Iterator> |
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void unshuffle(Iterator begin, Iterator end){ |
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typedef typename std::iterator_traits<Iterator>::value_type value_type; |
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auto s = end - begin; |
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assert(s % 2 == 0); |
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std::vector<value_type> v(s); |
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std::copy(begin, begin + s/2, strided(v.begin(), 2)); |
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std::copy(begin + s/2, end, strided(v.begin()+1, 2)); |
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std::copy(v.begin(), v.end(), begin); |
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} |
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// Combines the matrix Wn and Sn recusrively
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// Only works for inputs of size 2^m
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template <typename Iterator> |
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void wavelet(Iterator begin, Iterator end){ |
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auto s = end - begin; |
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assert(s >= 4); |
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for(int i = s; i >= 4; i >>= 1){ |
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// half interval
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end = begin + i; |
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assert(is_pow_of_two(end - begin)); |
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// multiply with Wn
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wavelet_mul(begin, end); |
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// then with Sn
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shuffle(begin, end); |
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} |
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} |
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template <typename Iterator> |
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void unwavelet(Iterator begin, Iterator end){ |
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auto s = end - begin; |
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assert(s >= 4); |
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for(int i = 4; i <= s; i <<= 1){ |
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// double interval
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end = begin + i; |
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assert(is_pow_of_two(end - begin)); |
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// unshuffle: Sn^-1
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unshuffle(begin, end); |
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// then Wn^-1
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wavelet_inv(begin, end); |
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} |
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} |
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} |
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} |
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