David Hägele hageldave

Visualization Researcher, Computer Scientist & Software Engineer

hageldave / RadonTransform.java

Last active March 22, 2019 00:39

RGB Radon Transform of Images

	package radon;

	import java.util.function.DoubleBinaryOperator;

	import hageldave.imagingkit.core.Img;
	import hageldave.imagingkit.core.io.ImageLoader;
	import hageldave.imagingkit.core.io.ImageSaver;
	import hageldave.imagingkit.core.scientific.ColorImg;
	import hageldave.imagingkit.core.util.ImageFrame;

hageldave / CriticalRegion.java

Created February 4, 2019 12:49

Semaphore with guaranteed release (even in case of exception) leveraging try with resources


	import java.util.concurrent.Semaphore;
	import java.util.concurrent.atomic.AtomicBoolean;

	/**
	* This class is a utility class for exception safe usage of a semaphore.
	* When returns {@code semaphore.acquire() } the current thread successfully entered the
	* critical region but it has to call {@code semaphore.release() } on exit to make room
	* for other threads to enter the critical region.
	* If this call is not guaranteed, thread starvation can occur (or even deadlock) since

hageldave / linalg with nn

Last active June 19, 2018 11:53

	package ezLinalg;

	import java.io.File;
	import java.io.IOException;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Scanner;
	import java.util.function.BiFunction;
	import java.util.function.BinaryOperator;
	import java.util.function.DoubleBinaryOperator;

hageldave / Radon Transform and FBP

Last active July 14, 2017 13:48

my first implementation of a radon transformation and filtered back projection

	package hageldave.imagingkit.core;

	import java.awt.BasicStroke;
	import java.awt.Color;
	import java.util.Arrays;
	import java.util.concurrent.ConcurrentHashMap;
	import java.util.concurrent.ConcurrentLinkedQueue;
	import java.util.concurrent.atomic.AtomicInteger;
	import java.util.function.Consumer;
	import java.util.function.DoubleFunction;

hageldave / Save Load raw bytes (Img)

Created April 24, 2017 21:15

loads and saves image data from and to a byte array

	private static byte[] saveImgToBytes(Img img) {
	int w = img.getWidth();
	int h = img.getHeight();
	int n = img.numValues();
	int length = n*4 + 4+4;
	byte[] b = new byte[length];
	// save width
	int i = 0;
	b[i++] = signedByteToByte(w);
	b[i++] = signedByteToByte(w>>8);

hageldave / strange directional blur

Created April 24, 2017 12:49

using the deviation from a direction vector the weight for pixels weight is determined

	import hageldave.imagingkit.core.ImageLoader;
	import hageldave.imagingkit.core.Img;
	import hageldave.imagingkit.core.util.ImageFrame;
	import hageldave.imagingkit.filter.implementations.ConvolutionFilter;

	public class testmain {
	public static void main(String[] args) throws InterruptedException {
	Img img = ImageLoader.loadImgFromURL("http://www.wellcomeimageawards.org/WI-6561.24_WIA_2017_PP_holding_screen.jpg");
	ConvolutionFilter c = new ConvolutionFilter();
	float[] kernel = new float[17*17];

hageldave / GenericNative CodeGen

Last active January 31, 2017 16:51

Code generator for generating extra methods for native types based on generic template

	package misc;

	import java.io.File;
	import java.io.FileNotFoundException;
	import java.io.PrintStream;
	import java.util.ArrayList;
	import java.util.Iterator;
	import java.util.Scanner;
	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

hageldave / Slices in Java

Last active January 21, 2017 14:42

wrapper for arrays

	package misc;

	import java.util.Arrays;
	import java.util.Iterator;
	import java.util.Spliterator;
	import java.util.function.Consumer;
	import java.util.stream.Stream;
	import java.util.stream.StreamSupport;

	public class Slice<T> implements Iterable<Slice.ArrayAccessor<T>>{

hageldave / Pixel with cached x,y (not beneficial)

Created January 18, 2017 15:49

performance test for Pixel with cached x,y values using a box blur with large neighbourhood (51x51 ~ 2600 calls to getX,getY per pixel)

	public static void main(String[] args) {
	Img img1 = new Img(4000, 4000);


	Img img2 = new Img(4000, 4000) {
	@Override
	public Pixel getPixel() {
	return new Pixol(this, 0);
	}

hageldave / converted pixel streaming

Last active December 22, 2016 23:46

convert pixel to anything else e.g float[] and stream it

	public static void main(String[] args) {

	Img img = new Img(200,200);
	img.fill(0xff000000);

	Spliterator<float[]> split = new ConvertedPixelSpliterator<>(
	img.spliterator(),
	()->{return new float[6];},
	testmain::pixel2vec,
	testmain::vec2Pixel);