diff --git a/lib/av/av.cpp b/lib/av/av.cpp
index e13d72e..687ffa9 100644
--- a/lib/av/av.cpp
+++ b/lib/av/av.cpp
@@ -27,11 +27,28 @@ namespace av {
 	}
 
 
-	open_codec codec_open(AVCodecContext* ctx, AVCodec* codec, AVDictionary** options){
+	codec find_encoder(AVCodecID codec_id){
+		auto ptr = avcodec_find_encoder(codec_id);
+		if(!ptr) throw error("Could not find codec");
+		return {ptr, nullptr};
+	}
+
+	codec_context context_alloc(codec const & codec){
+		auto ptr = avcodec_alloc_context3(codec.get());
+		if(!ptr) throw av::error("Could not allocate codec context");
+		return {ptr, [](auto x){ avcodec_free_context(&x); }};
+	}
+
+	codec_context context_from_stream(format_context const & ctx, size_t i){
+		return {ctx->streams[i]->codec, nullptr};
+	}
+
+
+	open_guard codec_open(codec_context & ctx, codec const & codec, AVDictionary** options){
 		if(!ctx) throw error("Invalid codec context");
 		if(!codec) throw error("Invalid codec");
-		if(avcodec_open2(ctx, codec, options) < 0) throw error("Could not open codec");
-		return {ctx, [](auto x){ avcodec_close(x); }};
+		if(avcodec_open2(ctx.get(), codec.get(), options) < 0) throw error("Could not open codec");
+		return {ctx.get(), [](auto x){ avcodec_close(x); }};
 	}
 
 
@@ -65,7 +82,7 @@ namespace av {
 	}
 
 	frame crop(frame&& f, int left, int top, int width, int height){
-		if(left + width > f->width || top + height > f->height) throw error("Crop sizes do not match");
+		// if(left + width > f->width || top + height > f->height) throw error("Crop sizes do not match");
 
 		auto ptr = reinterpret_cast<AVPicture*>(f.get());
 		auto ret = av_picture_crop(ptr, ptr, av::get_format(f), top, left);
diff --git a/lib/av/av.hpp b/lib/av/av.hpp
index 2545c10..cbcf1c3 100644
--- a/lib/av/av.hpp
+++ b/lib/av/av.hpp
@@ -4,6 +4,7 @@
 
 extern "C" {
 #include <libavutil/pixfmt.h>
+#include <libavcodec/avcodec.h> // only needed for AVCodecID
 
 typedef struct AVDictionary AVDictionary;
 typedef struct AVFormatContext AVFormatContext;
@@ -18,22 +19,29 @@ typedef struct AVFrame AVFrame;
 
 namespace av {
 	// AVFormatContext related
-	using format_context = av::unique_ptr<AVFormatContext>;
+	using format_context = wrapper<AVFormatContext>;
 	format_context format_open_input(std::string const & filename, AVInputFormat* format, AVDictionary** options);
 	format_context format_alloc_context();
 
 	// AVCodec related
-	using open_codec = av::unique_ptr<AVCodecContext>;
-	open_codec codec_open(AVCodecContext* ctx, AVCodec* codec, AVDictionary** options);
+	using codec = wrapper<AVCodec>;
+	codec find_encoder(AVCodecID codec_id);
+
+	using codec_context = wrapper<AVCodecContext>;
+	codec_context context_alloc(codec const & codec);
+	codec_context context_from_stream(format_context const & ctx, size_t i);
+
+	using open_guard = wrapper<AVCodecContext>;
+	open_guard codec_open(codec_context & ctx, codec const & codec, AVDictionary** options);
 
 	// AVPacket related (this is somewhat strange, but matches the usecase)
 	// I need to rethink this
 	using packet_buffer = AVPacket;
-	using packet = av::unique_ptr<AVPacket>;
+	using packet = wrapper<AVPacket>;
 	packet read_frame(format_context & ctx, packet_buffer & p);
 
 	// AVFrame related
-	using frame = av::unique_ptr<AVFrame>;
+	using frame = wrapper<AVFrame>;
 	frame frame_alloc();
 	frame frame_clone(frame const & f); // creates a clone with the *same* buffer
 	AVPixelFormat get_format(frame const & f);
diff --git a/lib/av/av_base.hpp b/lib/av/av_base.hpp
index 9fe69cd..d7be969 100644
--- a/lib/av/av_base.hpp
+++ b/lib/av/av_base.hpp
@@ -13,13 +13,49 @@ namespace av {
 		using runtime_error::runtime_error;
 	};
 
-	// Type of a freeing function (for unique_ptr)
+	// Type of a freeing function (for wrapper)
 	template <typename T>
 	using deleter = void(*)(T*);
 
-	// Often used type
-	template <typename T>
-	using unique_ptr = std::unique_ptr<T, deleter<T>>;
+	// Kind of unique_ptr, but with const-semantics
+	template <typename T, typename D = deleter<T>>
+	struct wrapper {
+		wrapper(T * data_ = nullptr, D deleter_ = D())
+		: data(data_)
+		, deleter(deleter_)
+		{}
+
+		wrapper(wrapper && o)
+		: data(o.data)
+		, deleter(o.deleter)
+		{ o.release(); }
+
+		wrapper & operator=(wrapper && o) {
+			data = o.data;
+			deleter = o.deleter;
+			o.release();
+			return *this;
+		}
+
+		wrapper(wrapper const & o) = delete;
+		wrapper & operator=(wrapper const & o) = delete;
+
+		~wrapper(){ reset(); }
+
+		T *       get()       { return data; }
+		T const * get() const { return data; }
+		T &       operator*()       { return *get(); }
+		T const & operator*() const { return *get(); }
+		T *       operator->()       { return get(); }
+		T const * operator->() const { return get(); }
+
+		T * release() { auto t = data; data = nullptr; return t; }
+		void reset() { if(data && deleter) deleter(data); data = nullptr; }
+		operator bool() const { return get(); }
+	private:
+		T * data;
+		D deleter;
+	};
 
 	// Allocator
 	template <typename T>
diff --git a/lib/av/sws.cpp b/lib/av/sws.cpp
index 62e6b0b..cb87dec 100644
--- a/lib/av/sws.cpp
+++ b/lib/av/sws.cpp
@@ -20,7 +20,7 @@ namespace sws {
 		return {ptr, &sws_freeContext};
 	}
 
-	void scale(context const & c, av::frame const & src, av::frame const & dest){
+	void scale(context & c, av::frame const & src, av::frame & dest){
 		auto ret = sws_scale(c.get(), {src->data}, {src->linesize}, 0, src->height, {dest->data}, {dest->linesize});
 		if(ret < 0) throw error("boem scale");
 	}
diff --git a/lib/av/sws.hpp b/lib/av/sws.hpp
index a48bbc2..ffcfd29 100644
--- a/lib/av/sws.hpp
+++ b/lib/av/sws.hpp
@@ -11,15 +11,10 @@ typedef struct SwsContext SwsContext;
 #include <vector>
 
 namespace sws{
-	template <typename T>
-	using deleter = av::deleter<T>;
+	using namespace av;
 
-	struct error : std::runtime_error {
-		using runtime_error::runtime_error;
-	};
-
-	using context = std::unique_ptr<SwsContext, deleter<SwsContext>>;
+	using context = wrapper<SwsContext>;
 	context create_context(av::frame const & src, av::frame const & dest, int flags = 0, SwsFilter * src_filter = nullptr, SwsFilter * dest_filter = nullptr, double * params = nullptr);
 
-	void scale(context const & c, av::frame const & src, av::frame const & dest);
+	void scale(context & c, av::frame const & src, av::frame & dest);
 }
diff --git a/lib/fingerprints/math.hpp b/lib/fingerprints/math.hpp
new file mode 100644
index 0000000..99cfaaf
--- /dev/null
+++ b/lib/fingerprints/math.hpp
@@ -0,0 +1,6 @@
+#pragma once
+
+//! best function ever
+inline double square(double x){
+	return x*x;
+}
diff --git a/lib/fingerprints/rgb.cpp b/lib/fingerprints/rgb.cpp
new file mode 100644
index 0000000..15fd0e6
--- /dev/null
+++ b/lib/fingerprints/rgb.cpp
@@ -0,0 +1,58 @@
+#include "rgb.hpp"
+#include "math.hpp"
+
+#include <image_io.hpp>
+#include <av/sws.hpp>
+
+#include <algorithm>
+#include <iostream>
+
+namespace fingerprints {
+
+static raw_rgb_image downscale_step(av::frame const & frame, int factor) {
+	raw_rgb_image image(frame->width / factor, frame->height / factor);
+
+	auto context = sws::create_context(frame, image.frame);
+	sws::scale(context, frame, image.frame);
+
+	return image;
+}
+
+static raw_rgb_image downscale_to(av::frame const & frame, int w, int h){
+	// ffmpeg doesnt let us downscale all the way to 5 at once :(, so we do a loop
+	raw_rgb_image image;
+	auto* new_frame = &frame;
+	while((*new_frame)->width > 8*w && (*new_frame)->height > 8*h){
+		image = downscale_step(*new_frame, 4);
+		new_frame = &image.frame;
+	}
+	return to_raw_rgb_image(image.frame, w, h);
+}
+
+rgb rgb::pre_calculate(av::frame const & frame){
+	auto const image = downscale_to(crop_to_square(frame), 5, 5);
+
+	rgb ret;
+	ret.data.assign(image.data.size(), 0);
+
+	std::copy(image.data.begin(), image.data.end(), ret.data.begin());
+
+	return ret;
+}
+
+rgb rgb::calculate(const av::frame& frame){
+	return pre_calculate(frame);
+}
+
+double rgb::distance_to(const rgb& fingerprint) const {
+	assert(data.size() == fingerprint.data.size());
+
+	double distance = 0;
+	for(size_t i = 0; i < data.size(); ++i){
+		distance += square(data[i] - fingerprint.data[i]);
+	}
+
+	return distance;
+}
+
+} // namespace fingerprints
diff --git a/lib/fingerprints/rgb.hpp b/lib/fingerprints/rgb.hpp
new file mode 100644
index 0000000..5c06980
--- /dev/null
+++ b/lib/fingerprints/rgb.hpp
@@ -0,0 +1,30 @@
+#pragma once
+
+#include <av/av.hpp>
+#include <fingerprint_traits.hpp>
+
+#include <boost/serialization/access.hpp>
+#include <boost/serialization/vector.hpp>
+
+#include <string>
+#include <vector>
+
+
+namespace fingerprints {
+struct rgb {
+	std::vector<uint8_t> data;
+
+	static rgb pre_calculate(av::frame const & frame);
+	static rgb calculate(av::frame const & frame);
+	double distance_to(rgb const & fingerprint) const;
+
+	static std::string name(){ return "rgb-25-25-25"; }
+
+private:
+	friend class boost::serialization::access;
+	template<class Archive>
+	void serialize(Archive & ar, const unsigned int /*version*/){
+		ar & data;
+	}
+};
+} // namespace fingerprints
diff --git a/lib/fingerprints/wvlt_rgb.cpp b/lib/fingerprints/wvlt_rgb.cpp
new file mode 100644
index 0000000..059e2de
--- /dev/null
+++ b/lib/fingerprints/wvlt_rgb.cpp
@@ -0,0 +1,88 @@
+#include "wvlt_rgb.hpp"
+#include "math.hpp"
+
+#include <image_io.hpp>
+#include <utilities.hpp>
+#include <wvlt/wavelet.hpp>
+
+#include <ostream>
+#include <cmath>
+
+namespace fingerprints {
+
+static const int size = 512;
+
+wvlt_rgb::pre_fingerprint wvlt_rgb::pre_calculate(av::frame const & frame) {
+	auto const image = to_raw_rgb_image(crop_to_square(frame), size, size);
+	wvlt_rgb::pre_fingerprint ret;
+
+	// for every color
+	for(unsigned int color = 0; color < 3; ++color){
+		auto & vector = ret[color];
+		vector.assign(make_u(image.width() * image.height()), 0);
+
+		for(unsigned int n = 0; n < make_u(image.width() * image.height()); ++n){
+			vector[n] = 2.0 * image.data[3*n + color] / double(255) - 1.0;
+		}
+
+		wvlt::wavelet_2D(vector.data(), make_u(image.width()), make_u(image.height()));
+	}
+
+	return ret;
+}
+
+wvlt_rgb wvlt_rgb::calculate(av::frame const & frame){
+	auto const image = to_raw_rgb_image(crop_to_square(frame), size, size);
+	wvlt_rgb ret;
+
+	std::vector<double> vector(make_u(image.width() * image.height()), 0);
+
+	// for every color
+	for(unsigned int color = 0; color < 3; ++color){
+		auto& coefficient_array = color == 0 ? ret.reds : (color == 1 ? ret.greens : ret.blues);
+		unsigned int array_index = 0;
+
+		for(unsigned int n = 0; n < make_u(image.width() * image.height()); ++n){
+			vector[n] = 2.0 * image.data[3*n + color] / double(255) - 1.0;
+		}
+
+		wvlt::wavelet_2D(vector.data(), make_u(image.width()), make_u(image.height()));
+
+		auto copy = vector;
+		for(auto & x : copy) x = std::abs(x);
+
+		auto const n_coefficients = coefficient_array.size();
+		std::nth_element(copy.begin(), copy.begin() + n_coefficients, copy.end(), std::greater<double>());
+		auto const threshold = copy[n_coefficients-1];
+
+		for(unsigned int n = 0; n < vector.size(); ++n){
+			auto const x = vector[n];
+			if(std::abs(x) >= threshold) {
+				coefficient_array[array_index++] = std::make_pair(n, x);
+			}
+			if(array_index >= coefficient_array.size()) {
+				break;
+			}
+		}
+	}
+
+	return ret;
+}
+
+double wvlt_rgb::distance_to(pre_fingerprint const & fingerprint) const {
+	double distance = 0;
+
+	for(unsigned int color = 0; color < 3; ++color){
+		auto const & coefficients = color == 0 ? reds : (color == 1 ? greens : blues);
+
+		for(auto&& p : coefficients){
+			auto const x = p.second;
+			auto const y = fingerprint[color][p.first];
+			distance += square(x - y) - square(y);
+		}
+	}
+
+	return distance;
+}
+
+} // namespace fingerprints
diff --git a/lib/fingerprints/wvlt_rgb.hpp b/lib/fingerprints/wvlt_rgb.hpp
new file mode 100644
index 0000000..d202c28
--- /dev/null
+++ b/lib/fingerprints/wvlt_rgb.hpp
@@ -0,0 +1,50 @@
+#pragma once
+
+#include <av/av.hpp>
+#include <fingerprint_traits.hpp>
+
+#include <boost/serialization/access.hpp>
+#include <boost/serialization/array.hpp>
+#include <boost/serialization/utility.hpp>
+
+#include <array>
+#include <string>
+#include <utility>
+#include <vector>
+
+namespace boost {
+	namespace serialization {
+		template<class Archive, class T, size_t N>
+		void serialize(Archive & ar, std::array<T,N> & a, const unsigned int /*version*/) {
+			ar & make_array(a.data(), a.size());
+		}
+	} // namespace serialization
+} // namespace boost
+
+
+namespace fingerprints {
+struct wvlt_rgb {
+	// a double for (x, y) location represented in a single int
+	using coefficient = std::pair<int, double>;
+	using pre_fingerprint = std::array<std::vector<double>, 3>;
+
+	std::array<coefficient, 20> reds;
+	std::array<coefficient, 20> greens;
+	std::array<coefficient, 20> blues;
+
+	static pre_fingerprint pre_calculate(av::frame const & frame);
+	static wvlt_rgb calculate(av::frame const & frame);
+	double distance_to(pre_fingerprint const & fingerprint) const;
+
+	static std::string name(){ return "wvlt-rgb-20x20x20"; }
+
+private:
+	friend class boost::serialization::access;
+	template<class Archive>
+	void serialize(Archive & ar, const unsigned int /*version*/){
+		ar & reds;
+		ar & greens;
+		ar & blues;
+	}
+};
+} // namespace fingerprints
diff --git a/lib/image_io.cpp b/lib/image_io.cpp
index 571e639..5a78618 100644
--- a/lib/image_io.cpp
+++ b/lib/image_io.cpp
@@ -1,6 +1,8 @@
 #include "image_io.hpp"
 #include "utilities.hpp"
 
+#include <av/sws.hpp>
+
 extern "C" {
 #include <libavutil/frame.h>
 #include <libavutil/mem.h>
@@ -11,6 +13,7 @@ extern "C" {
 
 #include <algorithm>
 #include <cassert>
+#include <fstream>
 #include <iostream>
 #include <stdexcept>
 
@@ -35,35 +38,17 @@ int raw_rgb_image::height() const { return frame->height; }
 AVPixelFormat raw_rgb_image::format() const { return av::get_format(frame); }
 
 
-void save_as_ppm(raw_rgb_image const & image, std::string const & filename) {
-	// Open file
-	FILE* file = fopen(filename.c_str(), "wb");
-	if(!file) throw std::runtime_error("cannot save");
-
-	// Write header
-	fprintf(stderr, "P6\n%d %d\n255\n", image.width(), image.height());
-	fprintf(file, "P6\n%d %d\n255\n", image.width(), image.height());
-
-	// Write pixel data
-	for(int y = 0; y < image.height(); y++)
-		fwrite(image.data.data() + 3*y*image.width(), 1, make_u(3*image.width()), file);
-
-	// Close file
-	fclose(file);
-}
-
-
 av::frame open_image(std::string const & filename){
 	// Open the file
 	auto format_context = av::format_open_input(filename, nullptr, nullptr);
 
 	// Get the codec and let us own the buffers
-	auto codec_context = format_context->streams[0]->codec;
-	auto codec = avcodec_find_decoder(codec_context->codec_id);
+	auto codec_context = av::context_from_stream(format_context, 0);
+	const auto codec = avcodec_find_decoder(codec_context->codec_id);
 	codec_context->refcounted_frames = 1;
 
 	// Open the codec
-	auto opened_codec = av::codec_open(codec_context, codec, nullptr);
+	const auto opened_codec = av::codec_open(codec_context, codec, nullptr);
 
 	// Allocate frame
 	av::frame frame = av::frame_alloc();
@@ -74,7 +59,7 @@ av::frame open_image(std::string const & filename){
 	while(auto packet = av::read_frame(format_context, empty_packet)) {
 		if(packet->stream_index != 0) continue;
 
-		int ret = avcodec_decode_video2(opened_codec.get(), frame.get(), &finished, packet.get());
+		int ret = avcodec_decode_video2(codec_context.get(), frame.get(), &finished, packet.get());
 		if (ret <= 0) {
 			printf("Error [%d] while decoding frame: %s\n", ret, strerror(AVERROR(ret)));
 			throw std::runtime_error("boem packet");
@@ -86,7 +71,7 @@ av::frame open_image(std::string const & filename){
 
 	// some decoders need extra passes
 	while(!finished) {
-		avcodec_decode_video2(opened_codec.get(), frame.get(), &finished, &empty_packet);
+		avcodec_decode_video2(codec_context.get(), frame.get(), &finished, &empty_packet);
 		av_free_packet(&empty_packet);
 	}
 
@@ -115,40 +100,31 @@ av::frame crop_to_square(av::frame && frame){
 raw_rgb_image to_raw_rgb_image(av::frame const & frame, int new_width, int new_height){
 	raw_rgb_image image(new_width, new_height);
 
-	auto c = sws_getContext(frame->width, frame->height, av::get_format(frame), image.width(), image.height(), image.format(), 0, nullptr, nullptr, nullptr);
-	if(!c) throw std::runtime_error("boem sws context");
-	sws_scale (c, {frame->data}, {frame->linesize}, 0, frame->height, {image.frame->data}, {image.frame->linesize});
-	sws_freeContext(c);
+	auto context = sws::create_context(frame, image.frame);
+	sws::scale(context, frame, image.frame);
 
 	return image;
 }
 
 
 void apply_to_tiles(std::string const & filename, int h_tiles, int v_tiles, std::function<void(int, int, av::frame const &)> fun) {
-	auto org_frame = open_image(filename);
-
-	// create clone to crop
-	av::frame cropped_frame = av::frame_clone(org_frame);
+	const auto org_frame = open_image(filename);
 
 	// create raw buffer for the callback
 	// TODO: do not scale the cropped region
 	raw_rgb_image image(512, 512);
 
 	// create the tiles
-	cropped_frame->width = org_frame->width / h_tiles;
-	cropped_frame->height = org_frame->height / v_tiles;
+	const int width = org_frame->width / h_tiles;
+	const int height = org_frame->height / v_tiles;
 	for(int r = 0; r < v_tiles; ++r){
 		for(int c = 0; c < h_tiles; ++c){
-			int x_crop = c * cropped_frame->width;
-			int y_crop = r * cropped_frame->height;
-			//std::cout << "crop " << x_crop << ", " << y_crop << std::endl;
-			av_picture_crop(reinterpret_cast<AVPicture*>(cropped_frame.get()), reinterpret_cast<AVPicture*>(org_frame.get()), av::get_format(org_frame), y_crop, x_crop);
-
-			auto context = sws_getContext(cropped_frame->width, cropped_frame->height, av::get_format(org_frame), image.width(), image.height(), image.format(), 0, nullptr, nullptr, nullptr);
-			if(!context) throw std::runtime_error("boem sws context");
-			sws_scale (context, {cropped_frame->data}, {cropped_frame->linesize}, 0, cropped_frame->height, {image.frame->data}, {image.frame->linesize});
-			sws_freeContext(context);
+			const int x_crop = c * width;
+			const int y_crop = r * height;
 
+			const auto cropped_frame = av::crop(org_frame, x_crop, y_crop, width, height);
+			auto context = sws::create_context(cropped_frame, image.frame);
+			sws::scale(context, cropped_frame, image.frame);
 			fun(c, r, image.frame);
 		}
 	}
@@ -156,54 +132,41 @@ void apply_to_tiles(std::string const & filename, int h_tiles, int v_tiles, std:
 
 void save_as_jpg(av::frame const & frame, std::string const & filename){
 	const auto pix_fmt = AV_PIX_FMT_YUVJ444P;
-	const auto codec_id= AV_CODEC_ID_MJPEG;
 
-	// Convert
-	int tile_width = 800;
-	int tile_height = 600;
-
-	int h_tiles = 8;
-	int v_tiles = 6;
-
-	std::vector<uint8_t, av::allocator<uint8_t>> data(make_u(avpicture_get_size(pix_fmt, h_tiles * tile_width, v_tiles * tile_height)), 0);
+	std::vector<uint8_t, av::allocator<uint8_t>> data(make_u(avpicture_get_size(pix_fmt, frame->width,
+	frame->height)), 0);
 	av::frame converted_frame = av::frame_alloc();
-	avpicture_fill(reinterpret_cast<AVPicture*>(converted_frame.get()), data.data(), pix_fmt, h_tiles * tile_width, v_tiles * tile_height);
-	converted_frame->width = h_tiles * tile_width;
-	converted_frame->height = v_tiles * tile_height;
+	avpicture_fill(reinterpret_cast<AVPicture*>(converted_frame.get()), data.data(), pix_fmt, frame->width, frame->height);
+	converted_frame->width = frame->width;
+	converted_frame->height = frame->height;
 	converted_frame->format = pix_fmt;
 
-	auto const sws_context = sws_getContext(frame->width, frame->height, av::get_format(frame), tile_width, tile_height, av::get_format(converted_frame), 0, nullptr, nullptr, nullptr);
-	if(!sws_context) throw std::runtime_error("boem sws context");
-
-	av::frame cropped_frame = av::frame_clone(converted_frame);
-	for(int r = 0; r < v_tiles; ++r) {
-		for(int c = 0; c < h_tiles; ++c){
-			av_picture_crop(reinterpret_cast<AVPicture*>(cropped_frame.get()), reinterpret_cast<AVPicture*>(converted_frame.get()), av::get_format(converted_frame), r * tile_height, c * tile_width);
-			sws_scale (sws_context, {frame->data}, {frame->linesize}, 0, frame->height, {cropped_frame->data}, {cropped_frame->linesize});
-		}
+	{
+		auto sws_context = sws::create_context(frame, converted_frame);
+		sws::scale(sws_context, frame, converted_frame);
 	}
 
-	sws_freeContext(sws_context);
-
-	// Encode
-	auto const codec = avcodec_find_encoder(codec_id);
-	if(!codec) throw av::error("Could not find codec");
+	encode_as_jpg(converted_frame, filename);
+}
 
-	auto codec_ctx = std::unique_ptr<AVCodecContext, av::deleter<AVCodecContext>>(avcodec_alloc_context3(codec), [](auto x){ avcodec_free_context(&x); });
-	if(!codec_ctx) throw av::error("Could not allocate codec context");
+void encode_as_jpg(const av::frame& frame, const std::string& filename){
+	auto const codec_id= AV_CODEC_ID_MJPEG;
+	const auto pix_fmt = av::get_format(frame);
+	const auto codec = av::find_encoder(codec_id);
 
+	auto codec_ctx = av::context_alloc(codec);
 	codec_ctx->pix_fmt = pix_fmt;
-	codec_ctx->width = converted_frame->width;
-	codec_ctx->height = converted_frame->height;
+	codec_ctx->width = frame->width;
+	codec_ctx->height = frame->height;
 	codec_ctx->time_base = av_make_q(1, 1);
-	auto const opened_codec = av::codec_open(codec_ctx.get(), codec, nullptr);
 
-	auto const buffer_size = avpicture_get_size(pix_fmt, codec_ctx->width, codec_ctx->height);
+	const auto opened_codec = av::codec_open(codec_ctx, codec, nullptr);
+
+	const auto buffer_size = avpicture_get_size(pix_fmt, codec_ctx->width, codec_ctx->height);
 	std::vector<uint8_t> buffer(make_u(buffer_size), 0);
-	auto const output_size = avcodec_encode_video(codec_ctx.get(), buffer.data(), buffer_size, converted_frame.get());
+	const auto output_size = avcodec_encode_video(codec_ctx.get(), buffer.data(), buffer_size, frame.get());
 	assert(output_size <= buffer_size);
 
-	auto const file = fopen(filename.c_str(), "wb");
-	fwrite(buffer.data(), 1, make_u(output_size), file);
-	fclose(file);
+	std::ofstream file(filename);
+	file.write(reinterpret_cast<char*>(buffer.data()), output_size);
 }
diff --git a/lib/image_io.hpp b/lib/image_io.hpp
index e0c3b97..002d970 100644
--- a/lib/image_io.hpp
+++ b/lib/image_io.hpp
@@ -21,9 +21,6 @@ struct raw_rgb_image {
 	AVPixelFormat format() const;
 };
 
-// dumps image in ppm format
-void save_as_ppm(raw_rgb_image const & image, std::string const & filename);
-
 // opens an image in its own format
 av::frame open_image(std::string const & filename);
 
@@ -35,13 +32,11 @@ av::frame crop_to_square(av::frame && frame);
 // converts and resizes
 raw_rgb_image to_raw_rgb_image(av::frame const & frame, int new_width, int new_height);
 
-// Legacy
-inline raw_rgb_image open_as_rgb(const std::string &filename){
-	return to_raw_rgb_image(crop_to_square(open_image(filename)), 512, 512);
-}
-
 // apply function to every tile, fun :: Column, Row, Image -> Void
 void apply_to_tiles(std::string const & filename, int h_tiles, int v_tiles, std::function<void(int, int, av::frame const &)> fun);
 
 // does what you think it does
 void save_as_jpg(av::frame const & frame, std::string const & filename);
+
+// encodes an av::frame with yuv pixelformat (is used by save_as_jpg()).
+void encode_as_jpg(av::frame const & frame, std::string const & filename);
diff --git a/lib/read_database.hpp b/lib/read_database.hpp
index 03a4acd..2be3cf3 100644
--- a/lib/read_database.hpp
+++ b/lib/read_database.hpp
@@ -1,4 +1,43 @@
-#ifndef READ_DATABASE_HPP
-#define READ_DATABASE_HPP
+#pragma once
 
-#endif // READ_DATABASE_HPP
+#include <database.hpp>
+#include <utilities.hpp>
+
+#include <boost/archive/binary_iarchive.hpp>
+#include <boost/archive/binary_oarchive.hpp>
+#include <boost/filesystem.hpp>
+
+#include <iostream>
+#include <fstream>
+#include <string>
+
+template <typename T>
+auto read_database(std::string const & database_directory, bool output_files = false){
+	namespace fs = boost::filesystem;
+	namespace ar = boost::archive;
+
+	image_database<T> db;
+	auto const database_file = database_directory + "-" + db.fingerprint_name() + ".db";
+
+	if (!boost::filesystem::exists(database_file)){
+		fs::path const directory(database_directory);
+		fs::directory_iterator eod;
+		for(fs::directory_iterator it(directory); it != eod; ++it){
+			auto const path = it->path();
+			auto const ext = to_lower(path.extension().string());
+			if(ext != ".png" && ext != ".jpg" && ext != ".jpeg" && ext != ".gif") continue;
+			if(output_files) std::cout << path << std::endl;
+			db.add(path.string());
+		}
+
+		std::ofstream file(database_file);
+		ar::binary_oarchive archive(file);
+		archive << db;
+	} else {
+		std::ifstream file(database_file);
+		ar::binary_iarchive archive(file);
+		archive >> db;
+	}
+
+	return db;
+}
diff --git a/lib/utilities.hpp b/lib/utilities.hpp
index e3e8846..0f33562 100644
--- a/lib/utilities.hpp
+++ b/lib/utilities.hpp
@@ -1,20 +1,10 @@
 #pragma once
 
-#include <string>
+#include <algorithm>
+#include <cassert>
 #include <chrono>
-#include <vector>
 #include <iostream>
-#include <cassert>
-
-template <typename Int>
-bool is_pow_of_two(Int n){
-	return n && !(n & (n - 1));
-}
-
-template <typename Int>
-bool is_even(Int n){
-	return (n & 1) == 0;
-}
+#include <string>
 
 // Used to silence warnings, will assert in debug build
 inline unsigned int make_u(int x){
@@ -22,25 +12,6 @@ inline unsigned int make_u(int x){
 	return static_cast<unsigned int>(x);
 }
 
-// calculates integer 2-log such that:
-// 2^(two_log(x)) >= x > 2^(two_log(x) - 1)
-inline unsigned int two_log(unsigned int x){
-	if(x <= 1) return 0;
-	return 8*sizeof(unsigned int) - unsigned(__builtin_clz(x-1));
-}
-
-// calculates 2^x (by squaring)
-inline unsigned int pow_two(unsigned int x){
-	unsigned int base = 2;
-	unsigned int y = 1;
-	while(x){
-		if(x & 1) y *= base;
-		x >>= 1;
-		base *= base;
-	}
-	return y;
-}
-
 inline uint8_t to_uint8_t(double x){
 	if(x >= 1) return 255;
 	if(x <= 0) return 0;
@@ -70,14 +41,9 @@ inline std::string field(std::string const & str){
 	return str + ":" + std::string(add, ' ') + "\t";
 }
 
-// Prints a vector with brackets and commas
-// Does not work recursively!
-template <typename T>
-void print_vec(std::vector<T> const & v){
-	auto it = v.begin(), end = v.end();
-	std::cout << "{" << *it++;
-	while(it != end) std::cout << ", " << *it++;
-	std::cout << "}\n";
+inline std::string to_lower(std::string in){
+	std::transform(in.begin(), in.end(), in.begin(), ::tolower);
+	return in;
 }
 
 // RAII struct for timing
diff --git a/lib/wvlt/wavelet.hpp b/lib/wvlt/wavelet.hpp
new file mode 100644
index 0000000..900c981
--- /dev/null
+++ b/lib/wvlt/wavelet.hpp
@@ -0,0 +1,3 @@
+#pragma once
+
+#include "wavelet_2.hpp"
diff --git a/lib/wvlt/wavelet_2.hpp b/lib/wvlt/wavelet_2.hpp
new file mode 100644
index 0000000..11d9c66
--- /dev/null
+++ b/lib/wvlt/wavelet_2.hpp
@@ -0,0 +1,109 @@
+#pragma once
+
+#include <cassert>
+#include "wavelet_utilities.hpp"
+#include "wavelet_constants.hpp"
+
+/* Rewrite of the basic functions
+ * This will make the adaption for the parallel case easier,
+ * because we can explicitly pass the two elements which are out of range
+ * (these are normally wrap-around values)
+ *
+ * These are also faster (testcase: size = 8, stride = 1, iterations = 100000)
+ * V2	0.00377901
+ * V1	0.0345114
+ *
+ * But also less abstract (which can be both a good thing and bad thing)
+ *
+ * wavelet function does not shuffle!
+ */
+
+namespace wvlt{
+	inline namespace V2 {
+		inline double inner_product(double* x, double const* coef, unsigned int stride){
+			return x[0] * coef[0] + x[stride] * coef[1] + x[2*stride] * coef[2] + x[3*stride] * coef[3];
+		}
+
+		// will calculate part of wavelete transform (in place!)
+		// size is size of vector x (so x[size-1] is valid)
+		// does not calculate "last two" elements (it does not assume periodicity)
+		// calculates size/stride - 2 elements of the output
+		inline void wavelet_mul_base(double* x, unsigned int size, unsigned int stride){
+			assert(x && is_even(size) && is_pow_of_two(stride) && 4*stride <= size);
+
+			for(unsigned int i = 0; i < size - 2*stride; i += 2*stride){
+				double y1 = inner_product(x + i, evn_coef, stride);
+				double y2 = inner_product(x + i, odd_coef, stride);
+				x[i] = y1;
+				x[i+stride] = y2;
+			}
+		}
+
+		// x1 and x2 are next elements, or wrap around
+		// calculates size/stride elements of the output
+		inline void wavelet_mul(double* x, double x1, double x2, unsigned int size, unsigned int stride){
+			assert(x && is_even(size) && is_pow_of_two(stride) && 2*stride <= size);
+			if(4*stride <= size)
+				wavelet_mul_base(x, size, stride);
+
+			unsigned int i = size - 2*stride;
+			double y1 = x[i] * evn_coef[0] + x[i+stride] * evn_coef[1] + x1 * evn_coef[2] + x2 * evn_coef[3];
+			double y2 = x[i] * odd_coef[0] + x[i+stride] * odd_coef[1] + x1 * odd_coef[2] + x2 * odd_coef[3];
+			x[i] = y1;
+			x[i+stride] = y2;
+		}
+
+		// will overwrite x, x2 and x1 are previous elements, or wrap around
+		// size is size of vector x (so x[size-1] is valid)
+		inline void wavelet_inv(double* x, double x1, double x2, unsigned int size, unsigned int stride){
+			assert(x && is_even(size) && is_pow_of_two(stride) && 4*stride <= size);
+
+			for(unsigned int i = size - 2*stride; i >= 2*stride; i -= 2*stride){
+				double y1 = inner_product(x + i - 2*stride, evn_coef_inv, stride);
+				double y2 = inner_product(x + i - 2*stride, odd_coef_inv, stride);
+				x[i] = y1;
+				x[i+stride] = y2;
+			}
+
+			unsigned int i = 0;
+			double y1 = x2 * evn_coef_inv[0] + x1 * evn_coef_inv[1] + x[i] * evn_coef_inv[2] + x[i+stride] * evn_coef_inv[3];
+			double y2 = x2 * odd_coef_inv[0] + x1 * odd_coef_inv[1] + x[i] * odd_coef_inv[2] + x[i+stride] * odd_coef_inv[3];
+			x[i] = y1;
+			x[i+stride] = y2;
+		}
+
+		// size indicates number of elements to process (so this is different from above!)
+		inline void wavelet(double* x, unsigned int size, unsigned int stride){
+			assert(x && is_pow_of_two(size) && size >= 4);
+			auto full_size = stride*size;
+			for(unsigned int i = 1; i <= size / 4; i <<= 1){
+				auto j = stride * i;
+				wavelet_mul(x, x[0], x[j], full_size, j);
+			}
+		}
+
+		inline void wavelet_2D(double* in, unsigned int width, unsigned int height){
+			for(unsigned int y = 0; y < height; ++y)
+				wavelet(in + y*width, width, 1);
+			for(unsigned int x = 0; x < width; ++x)
+				wavelet(in + x, height, width);
+		}
+
+		// size indicates number of elements to process (so this is different from above!)
+		inline void unwavelet(double* x, unsigned int size, unsigned int stride){
+			assert(x && is_pow_of_two(size) && size >= 4);
+			auto full_size = stride*size;
+			for(unsigned int i = size / 4; i >= 1; i >>= 1){
+				auto j = stride * i;
+				wavelet_inv(x, x[full_size-j], x[full_size-2*j], full_size, j);
+			}
+		}
+
+		inline void unwavelet_2D(double* in, unsigned int width, unsigned int height){
+			for(unsigned int x = 0; x < width; ++x)
+				unwavelet(in + x, height, width);
+			for(unsigned int y = 0; y < height; ++y)
+				unwavelet(in + y*width, width, 1);
+		}
+	}
+}
diff --git a/lib/wvlt/wavelet_constants.hpp b/lib/wvlt/wavelet_constants.hpp
new file mode 100644
index 0000000..4647816
--- /dev/null
+++ b/lib/wvlt/wavelet_constants.hpp
@@ -0,0 +1,37 @@
+#pragma once
+
+#include <cmath>
+
+namespace wvlt {
+	// first row of the matrix Wn
+	static double const evn_coef[] = {
+		(1.0 + std::sqrt(3.0))/(std::sqrt(32.0)),
+		(3.0 + std::sqrt(3.0))/(std::sqrt(32.0)),
+		(3.0 - std::sqrt(3.0))/(std::sqrt(32.0)),
+		(1.0 - std::sqrt(3.0))/(std::sqrt(32.0))
+	};
+
+	// second row of the matrix Wn
+	static double const odd_coef[] = {
+		 evn_coef[3],
+		-evn_coef[2],
+		 evn_coef[1],
+		-evn_coef[0]
+	};
+
+	// first (shifted) row of the matrix Wn^-1
+	static double const evn_coef_inv[] = {
+		 evn_coef[2],
+		 evn_coef[1],
+		 evn_coef[0],
+		 evn_coef[3]
+	};
+
+	// second (shifted) row of the matrix Wn^-1
+	static double const odd_coef_inv[] = {
+		 evn_coef[3],
+		-evn_coef[0],
+		 evn_coef[1],
+		-evn_coef[2]
+	};
+}
diff --git a/lib/wvlt/wavelet_utilities.hpp b/lib/wvlt/wavelet_utilities.hpp
new file mode 100644
index 0000000..6e57edc
--- /dev/null
+++ b/lib/wvlt/wavelet_utilities.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+template <typename Int>
+bool is_pow_of_two(Int n){
+	return n && !(n & (n - 1));
+}
+
+template <typename Int>
+bool is_even(Int n){
+	return (n & 1) == 0;
+}
+
+// calculates integer 2-log such that:
+// 2^(two_log(x)) >= x > 2^(two_log(x) - 1)
+inline unsigned int two_log(unsigned int x){
+	if(x <= 1) return 0;
+	return 8*sizeof(unsigned int) - unsigned(__builtin_clz(x-1));
+}
+
diff --git a/src/compress.cpp b/src/compress.cpp
index 018b814..f73d5d2 100644
--- a/src/compress.cpp
+++ b/src/compress.cpp
@@ -5,6 +5,7 @@
  */
 
 #include <image_io.hpp>
+#include <utilities.hpp>
 #include <wvlt/wavelet.hpp>
 
 #include <boost/filesystem.hpp>
@@ -21,7 +22,7 @@ using namespace std;
 int main(){
 	av_register_all();
 
-	auto image = open_as_rgb("image.jpg");
+	auto image = to_raw_rgb_image(crop_to_square(open_image("image.jpg")), 512, 512);
 
 	std::vector<double> vector(make_u(image.width() * image.height()));
 
@@ -50,7 +51,6 @@ int main(){
 		}
 	}
 
-	// TODO: save as jpg
-	save_as_jpg(image.frame, "output.ppm");
+	save_as_jpg(image.frame, "output.jpg");
 }
 
diff --git a/src/fingerprint_test.cpp b/src/fingerprint_test.cpp
deleted file mode 100644
index d5fe8d9..0000000
--- a/src/fingerprint_test.cpp
+++ /dev/null
@@ -1,21 +0,0 @@
-#include <fingerprints.hpp>
-#include <image_io.hpp>
-
-extern "C" {
-#include <libavformat/avformat.h>
-}
-
-#include <iostream>
-
-using namespace std;
-
-int main(){
-	av_register_all();
-	auto const image = open_image("test.jpg");
-
-	auto const x = rgb_wavelet_coefficients::calculate(image);
-	auto const y = rgb_wavelet_coefficients::pre_calculate(image);
-
-	cout << x << endl;
-	cout << x.distance_to(y) << endl;
-}
diff --git a/src/main.cpp b/src/main.cpp
index 8fcedd6..9597206 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -4,6 +4,7 @@
 #include <mozaic.hpp>
 #include <read_database.hpp>
 #include <utilities.hpp>
+#include <av/av.hpp>
 #include <av/sws.hpp>
 
 #include <boost/filesystem.hpp>
@@ -12,10 +13,9 @@ extern "C" {
 #include <libavformat/avformat.h>
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
-#include <libswscale/swscale.h>
 }
 
-#include <algorithm>
+#include <fstream>
 #include <iostream>
 #include <utility>
 
@@ -24,7 +24,7 @@ static const int tile_height = 500;
 
 using namespace std;
 
-using Metric = downscale;
+using Metric = fingerprints::rgb;
 using Database = image_database<Metric>;
 
 static auto calculate_all_distances(Database const & db, string const & filename, int h_tiles, int v_tiles){
@@ -41,51 +41,37 @@ static auto calculate_all_distances(Database const & db, string const & filename
 template <typename Mozaiq>
 static void save_mozaic(Mozaiq const & mozaic, string filename){
 	auto const pix_fmt = AV_PIX_FMT_YUVJ444P;
-	auto const codec_id= AV_CODEC_ID_MJPEG;
 
 	auto const total_width = mozaic.h_tiles * tile_width;
 	auto const total_height = mozaic.v_tiles * tile_height;
 
 	// Create output frame
-	std::vector<uint8_t, av::allocator<uint8_t>> data(make_u(avpicture_get_size(pix_fmt, total_width, total_height)), 0);
-	const av::frame frame = av::frame_alloc();
-	avpicture_fill(reinterpret_cast<AVPicture*>(frame.get()), data.data(), pix_fmt, total_width, total_height);
-	frame->width = total_width;
-	frame->height = total_height;
-	frame->format = pix_fmt;
+	const auto frame_data = [=]{
+		std::vector<uint8_t, av::allocator<uint8_t>> data(make_u(avpicture_get_size(pix_fmt, total_width, total_height)), 0);
+		auto frame = av::frame_alloc();
+		avpicture_fill(reinterpret_cast<AVPicture*>(frame.get()), data.data(), pix_fmt, total_width, total_height);
+		frame->width = total_width;
+		frame->height = total_height;
+		frame->format = pix_fmt;
+		return std::make_pair(std::move(frame), std::move(data));
+	}();
+	const auto & frame = frame_data.first;
 
 	// For each tile: get the part, copy input to it
+	av::frame frame_part = av::frame_clone(frame);
+	frame_part->width = tile_width;
+	frame_part->height = tile_height;
 	for(int r = 0; r < mozaic.v_tiles; ++r) {
 		for(int c = 0; c < mozaic.h_tiles; ++c){
-			auto frame_part = av::crop(frame, c * tile_width, r * tile_height, tile_width, tile_height);
-			auto input = crop_to_square(open_image(mozaic[r][c]));
+			av_picture_crop(reinterpret_cast<AVPicture*>(frame_part.get()), reinterpret_cast<AVPicture const*>(frame.get()), av::get_format(frame), r * tile_height, c * tile_width);
+			auto const input = crop_to_square(open_image(mozaic[r][c]));
 
 			auto context = sws::create_context(input, frame_part);
 			sws::scale(context, input, frame_part);
 		}
 	}
 
-	// Encode
-	auto codec = avcodec_find_encoder(codec_id);
-	if(!codec) throw av::error("Could not find codec");
-
-	auto codec_ctx = std::unique_ptr<AVCodecContext, av::deleter<AVCodecContext>>(avcodec_alloc_context3(codec), [](auto x){ avcodec_free_context(&x); });
-	if(!codec_ctx) throw av::error("Could not allocate codec context");
-
-	codec_ctx->pix_fmt = pix_fmt;
-	codec_ctx->width = frame->width;
-	codec_ctx->height = frame->height;
-	codec_ctx->time_base = av_make_q(1, 1);
-	auto opened_codec = av::codec_open(codec_ctx.get(), codec, nullptr);
-
-	auto const buffer_size = avpicture_get_size(pix_fmt, codec_ctx->width, codec_ctx->height);
-	std::vector<uint8_t> buffer(make_u(buffer_size), 0);
-	auto const output_size = avcodec_encode_video(codec_ctx.get(), buffer.data(), buffer_size, frame.get());
-	assert(output_size <= buffer_size);
-
-	auto file = fopen(filename.c_str(), "wb");
-	fwrite(buffer.data(), 1, make_u(output_size), file);
-	fclose(file);
+	encode_as_jpg(frame, filename);
 }
 
 int main(){
@@ -93,9 +79,9 @@ int main(){
 	av_log_set_level(AV_LOG_QUIET);
 
 	// TODO: use boost::program_options
-	string const database_directory = "vakantie";
-	string const filename = "vakantie.jpg";
-	string const output = "output/vakantie.jpg";
+	string const database_directory = "basbram";
+	string const filename = "basbram.jpg";
+	string const output = "output/basbram.jpg";
 	int const h_tiles = 4*4;
 	int const v_tiles = 3*4;