[Suggestion] ajouts filtres divers et variés

**pseudocode** · 24/06/2011, 14h50

Squelette pour les images en niveau de gris, en accumulant les points appartenant au squelette pour différentes valeurs de seuils.

Code java :

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package millie.plugins.free;
 
import java.awt.image.BufferedImage;
 
import millie.plugins.PluginInfo;
import millie.plugins.appimage.GenericAppImagePlugin;
import millie.plugins.parameters.CheckBoxParameter;
import millie.plugins.parameters.IntSliderParameter;
 
/**
 * @author Xavier Philippeau
 *
 */
@PluginInfo(name="Skeleton (grayscale)", category="Morphologique", description="Skeleton for grayscale image")
public class SkeletonGrayscalePlugin extends GenericAppImagePlugin {
	public SkeletonGrayscalePlugin() {
		setReinitializable(true);
		setLongProcessing(true);
		addParameter(new IntSliderParameter("step", "Gray Level step", 1, 128, 16));
		addParameter(new CheckBoxParameter("bright", "Bright background", false) );
	}
 
	@Override
	public BufferedImage filter() throws Exception {
		int step = getIntValue("step");
		boolean useBrightBackground = getBooleanValue("bright");
 
		// input image
		BufferedImage input = getInputImage();
		int W=input.getWidth(), H=input.getHeight();
		int[][] gray = new int[W][H];
 
		// convert input image to gray level array
		for(int y=0;y<H;y++) {
			for(int x=0;x<W;x++) {
				int rgb = input.getRGB(x, y);
				int r = (rgb>>16) & 0xFF, g = (rgb>>8) & 0xFF, b = (rgb) & 0xFF;
				gray[x][y] = (int)(0.5 + 0.299*r + 0.587*g + 0.114*b);
			}
		}
 
		// use negative image if required
		if (useBrightBackground) {
			for(int y=0;y<H;y++) for(int x=0;x<W;x++) gray[x][y] = 255 - gray[x][y];
		}
 
		// thinning using multiple threshold 
		int[][] result = multipleThresholdThinning(gray, W, H, step);
 
		// generate output image
		BufferedImage output = new BufferedImage(W, H, BufferedImage.TYPE_INT_RGB);
		for(int y=0;y<H;y++) {
			for(int x=0;x<W;x++) {
				output.getRaster().setSample(x, y, 0, result[x][y]);
				output.getRaster().setSample(x, y, 1, result[x][y]);
				output.getRaster().setSample(x, y, 2, result[x][y]);
			}
		}
 
		return output;
	}
 
	// ----------------------------------------------------------------------------------------------------
 
	public int[][] multipleThresholdThinning(int[][] image, int width, int height, int step) {
 
		// histogram of gray levels
		int[] grayhisto = new int[256];
		for(int y=0;y<height;y++)
			for(int x=0;x<width;x++)
				grayhisto[ image[x][y] ]++;
 
		// CDF of gray levels
		int[] graycdf = new int[256];
		graycdf[0]=0;
		for(int i=1;i<256;i++) graycdf[i]=graycdf[i-1]+grayhisto[i];
 
		// accumulator of pixels belonging to a skeleton 
		int[][] accumulator = new int[width][height];
 
		// work image
		byte[][] work = new byte[width][height];
 
		// ** multiple binary thinning for different threshold values **
 
		int plevel=0,level=0;
		int EQStep = (int)(0.5+graycdf[255]/(double)step); // step in equalized image
		while(true) {
 
			// find next threshold values
			while( (level<256) && (graycdf[level]-graycdf[plevel])<EQStep ) level++;
 
			// update accumulator
			for(int y=0;y<height;y++)
				for(int x=0;x<width;x++)
					if (work[x][y]==1) accumulator[x][y]+=(level-plevel);
 
			if (level>=256) break;
			plevel=level;
 
			System.out.println("Skeleton : binary thinning using threshold="+level);
 
			// create the thresholded image
			for(int y=0;y<height;y++)
				for(int x=0;x<width;x++)
					if (image[x][y]>=level) work[x][y]=1; else work[x][y]=0; 
 
			// perform binary thinning
			new SkeletonBinary().thinning(work, width, height);
		}
 
		/*
		for(int level=1;level<255;level++) {
 
			// if we reach a new valid level 
			if( (graycdf[level]-graycdf[plevel]) >= DELTA ) {
				plevel=level;
 
				System.out.println("Skeleton : binary thinning using threshold="+level+"  cdf="+graycdf[level]);
 
				// create the thresholded image
				for(int y=0;y<height;y++)
					for(int x=0;x<width;x++)
						if (image[x][y]>level) work[x][y]=1; else work[x][y]=0; 
 
				// perform binary thinning
				new SkeletonBinary().thinning(work, width, height);
			}
 
			// update accumulator
			for(int y=0;y<height;y++)
				for(int x=0;x<width;x++)
					if (work[x][y]==1) accumulator[x][y]++;
 
		}
		*/
 
 
		// rescale accumulator in 0...255
		int max=0;
		for(int y=0;y<height;y++) 
			for(int x=0;x<width;x++) 
				max = Math.max(max,accumulator[x][y]);
		if (max>0) {
			for(int y=0;y<height;y++) 
				for(int x=0;x<width;x++) 
					accumulator[x][y] = (int)(0.5+accumulator[x][y]*255.0/max);
		}
 
		// return the accumulator
		return accumulator;
	}
 
	// ----------------------------------------------------------------------------------------------------
 
	/** @author Xavier Philippeau (based on work of Dr. Chai Quek) */  
	class SkeletonBinary {
 
		// Smoothing pattern
		private byte[] pattern1={-1,1,0,1,0,0,0,0};
		private byte[] pattern2={0,1,0,1,-1,0,0,0};
		private byte[] pattern3={0,0,-1,1,0,1,0,0};
		private byte[] pattern4={0,0,0,1,0,1,-1,0};
		private byte[] pattern5={0,0,0,0,-1,1,0,1};
		private byte[] pattern6={-1,0,0,0,0,1,0,1};
		private byte[] pattern7={0,1,0,0,0,0,-1,1};
		private byte[] pattern8={0,1,-1,0,0,0,0,1};
 
		// Neighbourhood
		private int neighbourhood(byte[][] c,int x,int y) {
			int neighbourhood=0;
			if (c[x-1][y-1]==1) neighbourhood++;
			if (c[x-1][y  ]==1) neighbourhood++;
			if (c[x-1][y+1]==1) neighbourhood++;
			if (c[x  ][y+1]==1) neighbourhood++;
			if (c[x+1][y+1]==1) neighbourhood++;
			if (c[x+1][y  ]==1) neighbourhood++;
			if (c[x+1][y-1]==1) neighbourhood++;
			if (c[x  ][y-1]==1) neighbourhood++;
			return neighbourhood;
		}
 
		// Transitions Count
		private int transitions(byte[][] c,int x,int y) {
			int transitions=0;
			if (c[x-1][y-1]==0 && c[x-1][y  ]==1) transitions++;
			if (c[x-1][y  ]==0 && c[x-1][y+1]==1) transitions++;
			if (c[x-1][y+1]==0 && c[x  ][y+1]==1) transitions++;
			if (c[x  ][y+1]==0 && c[x+1][y+1]==1) transitions++;
			if (c[x+1][y+1]==0 && c[x+1][y  ]==1) transitions++;
			if (c[x+1][y  ]==0 && c[x+1][y-1]==1) transitions++;
			if (c[x+1][y-1]==0 && c[x  ][y-1]==1) transitions++;
			if (c[x  ][y-1]==0 && c[x-1][y-1]==1) transitions++;
			return transitions;
		}
 
		// Match a pattern
		private boolean matchPattern(byte[][] c,int x,int y,byte[] pattern) {
			if (pattern[0]!=-1 && pattern[0]!=c[x-1][y-1]) return false;
			if (pattern[1]!=-1 && pattern[1]!=c[x-1][y  ]) return false;
			if (pattern[2]!=-1 && pattern[2]!=c[x-1][y+1]) return false;
			if (pattern[3]!=-1 && pattern[3]!=c[x  ][y+1]) return false;
			if (pattern[4]!=-1 && pattern[4]!=c[x+1][y+1]) return false;
			if (pattern[5]!=-1 && pattern[5]!=c[x+1][y  ]) return false;
			if (pattern[6]!=-1 && pattern[6]!=c[x+1][y-1]) return false;
			if (pattern[7]!=-1 && pattern[7]!=c[x  ][y-1]) return false;
			return true;
		}
 
		// Match one of the 8 patterns
		private boolean matchOneOfPatterns(byte[][] c,int x,int y) {
			if (matchPattern(c,x,y,pattern1)) return true;
			if (matchPattern(c,x,y,pattern2)) return true;
			if (matchPattern(c,x,y,pattern3)) return true;
			if (matchPattern(c,x,y,pattern4)) return true;
			if (matchPattern(c,x,y,pattern5)) return true;
			if (matchPattern(c,x,y,pattern6)) return true;
			if (matchPattern(c,x,y,pattern7)) return true;
			if (matchPattern(c,x,y,pattern8)) return true;
			return false;
		}
 
		/**
                 * Skeletonize the image using succesive thinning.
                 * 
                 * @param image  the image in an array[x][y] of values "0" or "1" 
                 * @param width of the image = 1st dimension of the array
                 * @param height of the image = 2nd dimension of the array
                 */
		public void thinning(byte[][] image,int width,int height) {
 
			// 3 columns back-buffer (original values)
			byte[][] buffer = new byte[3][height];
 
			// initialize the back-buffer
			for(int y=0;y<height;y++) {
				buffer[0][y]=0;
				buffer[1][y]=image[0][y];
				buffer[2][y]=image[1][y];
			}
 
			// loop until idempotence
			while(true) {
 
				boolean changed=false;
 
				// for each columns
				for(int x=1;x<(width-1);x++) {
 
					// shift the back-buffer + set the last column
					byte[] swp0 = buffer[0]; buffer[0]=buffer[1]; buffer[1]=buffer[2]; buffer[2]=swp0;
					for(int y=0;y<height;y++) buffer[2][y]=image[x+1][y];
 
					// for each pixel
					for(int y=1;y<(height-1);y++) {
 
						// pixel value
						int v = image[x][y];
 
						// pixel not set -> next
						if (v==0) continue;
 
						// is a boundary/extremity ?
						int currentNeighbourhood = neighbourhood(buffer,1,y);
						if (currentNeighbourhood<=1) continue;
						if (currentNeighbourhood>=6) continue;
 
						// is a connection ?
						int transitionsCount = transitions(image,x,y);
						if (transitionsCount==1 && currentNeighbourhood<=3) continue;
 
						// no -> remove this pixel
						if (transitionsCount==1) {
							changed=true;
							image[x][y]=0;
							continue;
						}
 
						// can we delete this pixel ?
						boolean matchOne = matchOneOfPatterns(image,x,y);
 
						// yes -> remove this pixel
						if (matchOne) {
							changed=true;
							image[x][y]=0;
							continue;
						}
					}
				}
 
				// no change -> return result
				if (!changed) return;
			}
		}
	}
}

**pseudocode** · 24/06/2011, 14h52

Fast MeanShift (1D) en utilisant la même technique que pour le Fast Median

Code java :

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package millie.plugins.free;
 
import java.awt.image.BufferedImage;
import java.util.Arrays;
 
import millie.plugins.PluginInfo;
import millie.plugins.appimage.GenericAppImagePlugin;
import millie.plugins.parameters.CheckBoxParameter;
import millie.plugins.parameters.IntSliderParameter;
 
/**
 * Fast MeanShift (1D), using sliding histogram window
 * 
 * @author Xavier Philippeau
 * 
 */
@PluginInfo(name="FastMeanShift", category="Restauration", description="Fas tMeanShift filter (1D)")
public class FastMeanShiftPlugin extends GenericAppImagePlugin {
 
	public FastMeanShiftPlugin() {
		setLongProcessing(true);
		setReinitializable(true);
 
		addParameter(new IntSliderParameter("modeseeking_radius", "Mode seeking radius ", 1, 128, 15));
		addParameter(new IntSliderParameter("sampling_radius", "Sampling radius", 1, 128, 5));
		addParameter(new CheckBoxParameter("useYUV", "use YUV colorspace", false));	
	}
 
	@Override
	public BufferedImage filter() throws Exception {
		BufferedImage input = getInputImage();
		int sampling_radius = getParameter("sampling_radius").getIntValue();
		int modeseeking_radius = getParameter("modeseeking_radius").getIntValue();
		boolean useYUV = getParameter("useYUV").getBooleanValue();
 
		if (useYUV && input.getRaster().getNumBands()>=3) {
			BufferedImage inputcopy = new BufferedImage(input.getWidth(), input.getHeight(), BufferedImage.TYPE_INT_RGB);
			inputcopy.getGraphics().drawImage(input, 0, 0, null);
			RGB2YUV(inputcopy);
			BufferedImage output = filter(inputcopy,sampling_radius,modeseeking_radius);
			YUV2RGB(output);
			return output;
		}
 
		return filter(input,sampling_radius,modeseeking_radius);
	}
 
	// ------------------------------------------------------------
 
	private BufferedImage filter(BufferedImage input, int radius, int range) {
		int W=input.getWidth(), H=input.getHeight();
		BufferedImage output = new BufferedImage(W, H, input.getType());
 
		// histogram-left = histogram for 1st pixel at line "y"
		double[] hist_left = new double[256];
 
		// histogram updated 
		double[] hist = new double[256];
 
		// gaussian weighting function
		double[] gaussian = new double[2*range+1];
		double sigma2 = Math.pow(range/2,2); // range = 2*sigma
		for(int i=-range;i<=range;i++)
			gaussian[i+range]=Math.exp(i*i/(2*sigma2));
 
		for(int band=0;band<input.getRaster().getNumBands();band++) {
 
			// initialize histogram-left (at pixel(-1,-1))
			Arrays.fill(hist_left, 0);
			for(int dy=-radius;dy<=radius;dy++) {
				for(int dx=-radius;dx<=radius;dx++) {
					int xk = -1+dx, yk = -1+dy;
					if (xk<0) xk=-xk;
					if (xk>=W) xk=2*W-xk-1;
					if (yk<0) yk=-yk;
					if (yk>=H) yk=2*H-yk-1;
					int pk = input.getRaster().getSample(xk, yk, band);
					hist_left[pk]++;
				}
			}
 
			for(int y=0;y<H;y++) {
 
				// at each new line, slide "histogram-left" one pixel to the bottom
 
				// remove info for top horizontal-strip
				for(int dx=-radius;dx<=radius;dx++) {
					int xk = -1+dx, yk = (y-1)-radius;
					if (xk<0) xk=-xk;
					if (xk>=W) xk=2*W-xk-1;
					if (yk<0) yk=-yk;
					if (yk>=H) yk=2*H-yk-1;
					int pk = input.getRaster().getSample(xk, yk, band);
					hist_left[pk]--;
				}
 
				// add info for bottom horizontal-strip
				for(int dx=-radius;dx<=radius;dx++) {
					int xk = -1+dx, yk = y+radius;
					if (xk<0) xk=-xk;
					if (xk>=W) xk=2*W-xk-1;
					if (yk<0) yk=-yk;
					if (yk>=H) yk=2*H-yk-1;
					int pk = input.getRaster().getSample(xk, yk, band);
					hist_left[pk]++;
				}
 
				// copy histogram-left to histogram
				for(int i=0;i<256;i++) hist[i]=hist_left[i];
 
				for(int x=0;x<W;x++) {
 
					// at each new column, slide current histogram one pixel to the right
 
					// remove info for left vertical-strip
					for(int dy=-radius;dy<=radius;dy++) {
						int xk = (x-1)-radius, yk = y+dy;
						if (xk<0) xk=-xk;
						if (xk>=W) xk=2*W-xk-1;
						if (yk<0) yk=-yk;
						if (yk>=H) yk=2*H-yk-1;
						int pk = input.getRaster().getSample(xk, yk, band);
						hist[pk]--;
					}
 
					// add info for right vertical-strip  
					for(int dy=-radius;dy<=radius;dy++) {
						int xk = x+radius, yk = y+dy;
						if (xk<0) xk=-xk;
						if (xk>=W) xk=2*W-xk-1;
						if (yk<0) yk=-yk;
						if (yk>=H) yk=2*H-yk-1;
						int pk = input.getRaster().getSample(xk, yk, band);
						hist[pk]++;
					}
 
					// mode seeking
					int p = input.getRaster().getSample(x, y, band);
					for(int loop=0;loop<32;loop++) {
						int hleft  = Math.max(0,   p-range);
						int hright = Math.min(255, p+range);
						double mean=0, wsum=0;
						for(int i=hleft;i<=hright;i++) {
							double w = gaussian[i-p+range] * hist[i];
							mean+=i*w; wsum+=w; 
						}
						mean/=wsum;
						int pshift = (int)(mean+0.5);
						if (pshift==p) break;
						p=pshift;
					}
 
					// replace input pixel by mode
					output.getRaster().setSample(x, y, band, p);
				}
			}
		}
 
		return output;
	}
 
	// ------------------------------------------------------------
 
	static void RGB2YUV(BufferedImage image) {
		int W=image.getWidth(), H=image.getHeight();
		for(int y=0;y<H;y++) {
			for(int x=0;x<W;x++) {
				// get value
				int R = image.getRaster().getSample(x, y, 0);
				int G = image.getRaster().getSample(x, y, 1);
				int B = image.getRaster().getSample(x, y, 2);
 
				// convert
				double Y = 0.299*R + 0.587*G + 0.114*B;
				double U = 128 + (B-Y)*0.565;
				double V = 128 + (R-Y)*0.713;
 
				// round up
				int iY = (int)(Y+0.5);
				int iU = (int)(U+0.5);
				int iV = (int)(V+0.5);
 
				// clamp
				iY = Math.max(0, Math.min(255, iY));
				iU = Math.max(0, Math.min(255, iU));
				iV = Math.max(0, Math.min(255, iV));
 
				// replace value
				image.getRaster().setSample(x, y, 0, iY);
				image.getRaster().setSample(x, y, 1, iU);
				image.getRaster().setSample(x, y, 2, iV);
			}
		}
	}
 
	static void YUV2RGB(BufferedImage image) {
		int W=image.getWidth(), H=image.getHeight();
		for(int y=0;y<H;y++) {
			for(int x=0;x<W;x++) {
				// get value
				int Y = image.getRaster().getSample(x, y, 0);
				int U = image.getRaster().getSample(x, y, 1);
				int V = image.getRaster().getSample(x, y, 2);
 
				// convert
				double R = Y + (1.370705 * (V-128));
				double G = Y - (0.698001 * (V-128)) - (0.337633 * (U-128));
				double B = Y + (1.732446 * (U-128));
 
				// round up
				int iR = (int)(0.5+R);
				int iG = (int)(0.5+G);
				int iB = (int)(0.5+B);
 
				// clamp
				iR = Math.max(0, Math.min(255, iR));
				iG = Math.max(0, Math.min(255, iG));
				iB = Math.max(0, Math.min(255, iB));
 
				// replace value
				image.getRaster().setSample(x, y, 0, iR);
				image.getRaster().setSample(x, y, 1, iG);
				image.getRaster().setSample(x, y, 2, iB);
			}
		}
	}
 
}

**pseudocode** · 24/06/2011, 14h53

Filtrage linéaire par une dérivée de gaussienne, ordre 1 et 2.

Code java :

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package millie.plugins.free;
 
import java.awt.image.BufferedImage;
 
import millie.automation.Automatable;
import millie.plugins.PluginInfo;
import millie.plugins.appimage.GenericAppImagePlugin;
import millie.plugins.parameters.CheckBoxParameter;
import millie.plugins.parameters.ComboBoxParameter;
import millie.plugins.parameters.DoubleSliderParameter;
 
/**
 * @author Xavier Philippeau
 *
 */
@PluginInfo(name="Gaussian derivative", category="Analyse", description="Gaussian derivative filter")
public class GaussianDerivativePlugin extends GenericAppImagePlugin implements Automatable {
 
	private static String FIRSTORDER = "1st order";
	private static String SECONDORDER = "2nd order";
 
	public GaussianDerivativePlugin() {
		setPluginName("MDIF");
		setRefreshable(false);
		setLongProcessing(true);
 
		addParameter(new ComboBoxParameter("order","Derivative", new String[]{FIRSTORDER,SECONDORDER} ));
		addParameter(new DoubleSliderParameter("sigma", "sigma",   0,5,0.1,0.7));
		addParameter(new DoubleSliderParameter("logpower", "Log scale",   0,1,0.01,0.5));
		addParameter(new CheckBoxParameter("intensity", "multiply by intensity", false));
	}
 
	@Override
	public BufferedImage filter() throws Exception {
		BufferedImage input = getInputImage();
		double sigma = getDoubleValue("sigma");
		double logpower = getDoubleValue("logpower");
		boolean showintensity = getBooleanValue("intensity");
 
		int order = 0;
		if (getStringValue("order")==FIRSTORDER) order=1;
		if (getStringValue("order")==SECONDORDER) order=2;
 
		return filter(input, order, sigma, logpower, showintensity);
	}
 
	public BufferedImage filter(BufferedImage input, int order, double sigma, double logpower, boolean showintensity) throws Exception {
		int width = input.getWidth();
		int height = input.getHeight();
 
		BufferedImage output = new BufferedImage(input.getWidth(), input.getHeight(), input.getType());
 
		// luminosity input image
		int[][] in = new int[width][height];
		for (int y=0; y<height; y++) {
			for (int x=0; x<width; x++) {
				int rgb = input.getRGB(x, y);
				int r = (rgb>>16) & 0xFF, g = (rgb>>8) & 0xFF, b = (rgb) & 0xFF;
				int l = (int)(0.299*r + 0.587*g + 0.114*b);
				in[x][y] = l;
			}
		}
 
		// build kernel
		double normalizer=0;
		int radius=0;
		double[][] kernel = null;
 
		if (order==1) {
			radius = (int)(1+2*sigma);
			kernel = new double[2*radius+1][2*radius+1];
			normalizer = buildFirstOrderKernel(radius, sigma, kernel);
		}
		if (order==2) {
			radius = (int)(1+4*sigma);
			kernel = new double[2*radius+1][2*radius+1];
			normalizer = buildSecondOrderKernel(radius, sigma, kernel);
		}
 
		// logscale
		int[] logscale = new int[256];
		for(int i=0;i<256;i++) {
			logscale[i]=(int)(255*Math.pow(i/255.0,logpower));
		}
 
		// convolution
		for (int y=0; y<height; y++) {
			for (int x=0; x<width; x++) {
 
				double gx = 0, gy = 0;
				for(int dy=-radius;dy<=radius;dy++) {
					for(int dx=-radius;dx<=radius;dx++) {
						int xk = x + dx;
						int yk = y + dy;
 
						if (xk<0) xk=0;
						if (xk>=width) xk=width-1;
						if (yk<0) yk=0;
						if (yk>=height) yk=height-1;
 
						double vk = in[xk][yk];
						gx += kernel[radius-dy][radius-dx] * vk;
						gy += kernel[radius-dx][radius-dy] * vk;
					}
				}
				gx/=normalizer;
				gy/=normalizer;
 
				// norm
				double gn=Math.sqrt(gx*gx+gy*gy);
 
				// multiply by original gray value
				double v = gn;
				if (showintensity) {
					int gray = in[x][y];
					v = gn*gray/255.0;
				}
 
				if (v<0) v=0;
				if (v>255) v=255;
				int iv = logscale[(int)v];
				output.getRaster().setSample(x, y, 0, iv);
				output.getRaster().setSample(x, y, 1, iv);
				output.getRaster().setSample(x, y, 2, iv);
			}
		}
 
		return output;
	}
 
	private double buildFirstOrderKernel(int radius, double sigma, double[][] kernel) {
		double sigma2 = sigma*sigma;
		double normalizer=0;
		for(int y=-radius;y<=radius;y++) {
			for(int x=-radius;x<=radius;x++) {
				double t = (x*x+y*y)/(2*sigma2);
				double dt = -x / sigma2 ;
				double e = dt * Math.exp( -t );
				kernel[radius+x][radius+y] = e;
				normalizer+=Math.abs(e);
			}
		}
		return normalizer;
	}
 
	private double buildSecondOrderKernel(int radius, double sigma, double[][] kernel) {
		double sigma2 = sigma*sigma;
		double normalizer=0;
		for(int y=-radius;y<=radius;y++) {
			for(int x=-radius;x<=radius;x++) {
				double t = (x*x+y*y)/(2*sigma2);
				double d2t = (x*x-sigma2) / (sigma2*sigma2);
				double e = d2t * Math.exp( -t );
				kernel[radius+x][radius+y] = e;
				normalizer+=Math.abs(e);
			}
		}
		return normalizer;
	}
}

**pseudocode** · 24/06/2011, 14h54

Detection de coins par la méthode FAST

Code java :

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package millie.plugins.free;
 
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.awt.image.Raster;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
 
import millie.automation.Automatable;
import millie.plugins.PluginInfo;
import millie.plugins.appimage.GenericAppImagePlugin;
import millie.plugins.parameters.DoubleSliderParameter;
 
/**
 * @author X.Philippeau, based on work of Edward Rosten and Tom Drummond
 *
 * see "Machine learning for high-speed corner detection", for details.
 *
 */
@PluginInfo(name="FAST Corner Detector", category="Analyse", description="FAST Corner Detector")
public class FASTCornerDetectorPlugin extends GenericAppImagePlugin implements Automatable {
 
	private int[][] circle16 = {
			{ 0,-3}, {+1,-3}, {+2,-2}, {+3,-1}, {+3, 0}, {3,+1}, {+2,+2}, 
			{+1,+3}, { 0,+3}, {-1,+3}, {-2,+2},	{-3,+1}, {-3, 0}, {-3,-1},
			{-2,-2}, {-1,-3}
	};
 
	public FASTCornerDetectorPlugin() {
		setRefreshable(true);
		setCacheable(true);
		//setLongProcessing(true);
 
		addParameter(new DoubleSliderParameter("sensibility", "bright/dark sensibility", 0.0, 1.0, 0.01, 0.50));
	}
 
	@Override
	public BufferedImage filter() throws Exception {
		BufferedImage input = getInputImage();
		int width=input.getWidth(), height=input.getHeight();
 
		BufferedImage output = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
 
		BufferedImage grayscale = new BufferedImage(width, height, BufferedImage.TYPE_BYTE_GRAY);
		for (int y = 0; y < height; y++) {
			for (int x = 0; x < width; x++) {
				int rgb = input.getRGB(x, y);
				int r = (rgb>>16) & 0xFF, g = (rgb>>8) & 0xFF, b = (rgb>>0) & 0xFF;
 
				int gray = (int)(0.299*r + 0.587*g + 0.114*b);
				grayscale.getRaster().setSample(x, y, 0, gray);
 
				r*=0.8;g*=0.8;b*=0.8;
				rgb=(r<<16)|(g<<8)|(b);
				output.setRGB(x, y, rgb);
			}
		}
 
		List<int[]> corners = findCorners(grayscale, 0);
 
		Graphics2D g2d = output.createGraphics();
		g2d.setColor(Color.WHITE);
		for(int[] p : corners) g2d.drawOval(p[0]-4, p[1]-4, 2*4, 2*4);
 
		return output;
	}
 
	private List<int[]> findCorners(BufferedImage input, int band) {
		double sensibility = getDoubleValue("sensibility");
		// s=0.0 --> factor = 4
		// s=0.5 --> factor = 1
		// s=1.0 --> factor = 0
		double factor = Math.pow( 2*(1.0-sensibility) , 2);
 
		Raster raster = input.getRaster();
		int width=input.getWidth(), height=input.getHeight();
 
		double X=0,X2=0,COUNT=0;
		for (int y = 0; y < height; y++) {
			for (int x = 0; x < width; x++) {
				int i = raster.getSample(x, y, band);
				X+=i;
				X2+=i*i;
				COUNT++;
			}
		}
		double variance  = (X2/COUNT) - ((X*X)/(COUNT*COUNT));
		double stddev = Math.sqrt(variance);
		int T = (int)(stddev * factor);
 
		System.out.println("s="+sensibility+", f="+factor+" --> T="+T);
 
 
		List<int[]> corners = new LinkedList<int[]>();
 
		int R=3;
		for (int y=R; y<height-R; y++) {
			for (int x=R; x<width-R; x++) {
				int p = raster.getSample(x, y, band);
 
				// high-speed exclusion test
				int dcount=0, bcount=0;
				for (int i=0;i<16;i+=4) {
					int s = raster.getSample( x+circle16[i%16][0] , y+circle16[i%16][1] , band );
					if (s<(p-T)) dcount++;
					if (s>(p+T)) bcount++;
				}
				if (dcount<3 && bcount<3) continue;
 
				// complete scan (with overlap)
				int Vdark=0, Vbright=0;
				dcount=0; bcount=0;
				boolean isPOI = false;
				for (int i=0;i<16+12;i++) {
					int s = raster.getSample( x+circle16[i%16][0] , y+circle16[i%16][1] , band );
					if (s<(p-T)) { // dark
						if (i<16) Vdark+=(p-T)-s;
						dcount++;
						if (dcount>=12) isPOI=true;
					} else dcount=0;
					if (s>(p+T)) { // bright
						if (i<16) Vbright+=s-(p+T);
						bcount++;
						if (bcount>=12) isPOI=true;
					} else bcount=0;
				}
 
				// add POI to the list
				if (isPOI) {
					int V=Math.max(Vdark,Vbright);
					corners.add(new int[]{x,y,V});
				}
			}
		}
 
		// Non-maximal suppression
		Iterator<int[]> iter = corners.iterator();
		int dist2max = (int)Math.pow(2*R,2);
		while(iter.hasNext()) {
			int[] p = iter.next();
			for(int[] n:corners) {
				if (n==p) continue;
				int dist2 = (p[0]-n[0])*(p[0]-n[0])+(p[1]-n[1])*(p[1]-n[1]);
				if( dist2>dist2max ) continue;
				if (n[2]<p[2]) continue;
				iter.remove();
				break;
			}
		}
 
		return corners;
	}
}

**pseudocode** · 24/06/2011, 18h59

Pour ceux qui se demandent ce que ca peut donner :

**millie** · 21/09/2011, 21h05

Juste pour info, si tu vois des problèmes de performances.

J'avais mis en place il y a déjà quelques temps la classe : ImageProcessor pour travailler plus directement avec le tableau de pixel de l'image (getRGB/setRGB sur un BufferedImage pouvant être un peu long)

Exemple :

Code java :

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public class Rotation180Operator extends SimpleOperator {
 
	public void compute(BufferedImage output, BufferedImage input) {
		ImageProcessor oP = new ImageProcessor(output);
		ImageProcessor iP = new ImageProcessor(input);
		int[] pixels = iP.getPixels();
		int[] oPixels = oP.getPixels();
 
		for(int j=0; j<input.getHeight(); j++)
			for(int i=0; i<input.getWidth(); i++) {
				int pixel = pixels[i+input.getWidth()*j];
				oPixels[input.getWidth()-1-i+(input.getHeight()-1-j)*output.getWidth()] = pixel;
			}
 
		oP.commit();
 
	}
}

J'ai converti pas mal de mes opérateurs avec ça, et l'amélioration est assez flagrante

**pseudocode** · 24/09/2011, 13h45

Envoyé par millie

Juste pour info, si tu vois des problèmes de performances.

J'avais mis en place il y a déjà quelques temps la classe : ImageProcessor pour travailler plus directement avec le tableau de pixel de l'image (getRGB/setRGB sur un BufferedImage pouvant être un peu long)

J'ai converti pas mal de mes opérateurs avec ça, et l'amélioration est assez flagrante

J'ai pas trop de problème de perfs sur mon quadcore (

). C'est vrai que je pourrais utiliser ta classe (ou le DataBuffer) pour éviter les 2/3 indirections des accesseurs du Raster. Je vais voir ce que ca donne.

En fait, vu le nom de la classe (ImageProcessor), je pensais que c'était lié a l'automatisation des traitements.

[Suggestion] ajouts filtres divers et variés

Millie

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