Laboratoire RDP » Biophysics Team » FibrilTool: an ImageJ plug-in to quantify fibrillar structures

// FibrilTool by Arezki Boudaoud et al. Nature Protocols

//

// double click on the Fibril Tool to select the color channels

// select the region of interest using the polygon tool 

// then click on the image using the Tool

// the log output gives the average properties of the region

// 0) 	image title

//		cell number

// 1) 	x-coordinate of region centroid (scaled)

// 		y-coordinate of region centroid (scaled)

// 	 	area (scaled)

// 2)  nematic tensor

//		average orientation (angle in -90:90 in degrees)

// 		quality of the orientation (score between 0 and 1)

// The results are drawn on an overlay

// 3)  coordinates of polygon vertices for record

// scaling factor for drawing of segments

var norm_constant;

//threshold for flat regions

var thresh = 2;

//default for font size

var fsize = 15;

// number for cells

var num;

// default for numbering of cells

var numbering="yes";

//defaults for drawing

var fib="No";

var drw="No";

//default for width of lines

var lwidth = 2;

var pi = 3.14159265;

macro "Fibril Tool - C059L11eeL14beL41ebL178eL71e8L1a5eLa1e5" {

if ( (fib != "R") && (fib != "G") && (fib !="B") ) 

	exit("Select channel for fibrils \nPlease double-click on the tool");

if (selectionType()==-1) 

	exit("Selection required !"); 

id = getImageID(); 

title = getTitle();

getPixelSize(unit,pixelWidth,pixelHeight);

if (pixelWidth != pixelHeight) exit("Rectangular pixels!");

scale = pixelWidth;

setBatchMode(true);

//properties of selection

num++ ;

selectImage(id);

getSelectionCoordinates(vertx, verty);

c = polygonCentre(vertx,verty);

c0s = c[0]*scale ;

c1s = c[1]*scale ;

getRawStatistics(area);

areas = area*scale*scale;

pr = 2;

sortie = title+"\t"+num;

sortie = sortie+"\t"+d2s(c0s,pr)+"\t"+d2s(c1s,pr)+"\t"+d2s(areas,pr);

//extract fibril signal

selectImage(id);

run("Duplicate...", "title=Temp");

run("Crop"); 

getSelectionCoordinates(vertxloc, vertyloc);

if (fib == "R") setRGBWeights(1,0,0);

	else if (fib == "G") setRGBWeights(0,1,0); 

	else if (fib =="B") setRGBWeights(0,0,1);

	else exit("Fibril color undefined");

run("8-bit");

//compute x-gradient in "x"

selectWindow("Temp");

run("Duplicate...","title=x");

run("32-bit");

run("Translate...", "x=-0.5 y=0 interpolation=Bicubic");

run ("Duplicate...","title=x1");

run("Translate...", "x=1 y=0 interpolation=None");

imageCalculator("substract","x","x1");

selectWindow("x1");

close();

//compute y-gradient in "y"

selectWindow("Temp");

run ("Duplicate...","title=y");

run("32-bit");

run("Translate...", "x=0 y=-0.5 interpolation=Bicubic");

run ("Duplicate...","title=y1");

run("Translate...", "x=0 y=1 interpolation=None");

imageCalculator("substract","y","y1");

selectWindow("y1");

close();

//compute norm of gradient in "g"

selectWindow("x");

run("Duplicate...","title=g");

imageCalculator("multiply","g","x");

selectWindow("y");

run("Duplicate...","title=gp");

imageCalculator("multiply","gp","y");

imageCalculator("add","g","gp");

selectWindow("gp");

close();

selectWindow("g");

w = getWidth(); h = getHeight();

for (y=0; y<h; y++) {

	for (x=0; x<w; x++){

		setPixel(x, y, sqrt( getPixel(x, y)));

	}

}

//set the effect of the gradient to 1/255 when too low ; threshold = thresh

selectWindow("g");

for (y=0; y<h; y++) {

	for (x=0; x<w; x++){

		if (getPixel(x,y) < thresh) 

			setPixel(x, y, 255);

	}

}

//normalize "x" and "y" to components of normal

imageCalculator("divide","x","g");

imageCalculator("divide","y","g");

//compute nxx

selectWindow("x");

run("Duplicate...","title=nxx");

imageCalculator("multiply","nxx","x");

//compute nxy

selectWindow("x");

run("Duplicate...","title=nxy");

imageCalculator("multiply","nxy","y");

//compute nyy

selectWindow("y");

run("Duplicate...","title=nyy");

imageCalculator("multiply","nyy","y");

//closing

selectWindow("Temp");

close();

selectWindow("x");

close();

selectWindow("y");

close();

selectWindow("g");

close();

//averaging nematic tensor

selectWindow("nxx");

makeSelection("polygon",vertxloc,vertyloc);

getRawStatistics(area,xx);

close();

selectWindow("nxy");

makeSelection("polygon",vertxloc,vertyloc);

getRawStatistics(area,xy);

close();

selectWindow("nyy");

makeSelection("polygon",vertxloc,vertyloc);

getRawStatistics(area,yy);

close();

//eigenvalues and eigenvector of texture tensor

m = (xx + yy) / 2;

d = (xx - yy) / 2;

v1 = m + sqrt(xy*xy + d*d);

v2 = m - sqrt(xy*xy + d*d);

//direction

tn = - atan((v2 - xx) / xy);

//score

scoren = abs((v1-v2) / 2 / m);

//output

tsn=tn*180/pi;

// nematic tensor tensor

sortie = sortie+"\t"+d2s(tsn,pr)+"\t"+d2s(scoren,2*pr);

//polygon coordinates

np = vertx.length;

for (i=0; i<np; i++){

xp = vertx[i]; yp = verty[i];

sortie = sortie+"\t"+d2s(xp,pr)+"\t"+d2s(yp,pr);

}

//

//print output

print(sortie);

+setResult("Label", num-1, title);

setResult("x-coordinate(scaled)", num-1, d2s(c0s,pr));

setResult("y-coordinate(scaled)", num-1, d2s(c1s,pr));

setResult("Area", num-1, d2s(areas,pr));

setResult("nematic tensor average orientation", num-1, d2s(tsn,pr));

setResult("nematic tensor quality", num-1, d2s(scoren,2*pr));

setResult("polygon coordinates X", num-1, d2s(xp,pr));

setResult("polygon coordinates Y", num-1, d2s(yp,pr));

updateResults();

//

//drawing of directions and cell contour

setBatchMode(false);

selectImage(id);

run("Add Selection...", "stroke=yellow width="+lwidth);

// drawing nematic tensor

if ( drw != "No" ) {

u1 = norm_constant*sqrt(area)*cos(tn)*scoren + c[0];

v1 = - norm_constant*sqrt(area)*sin(tn)*scoren + c[1];

u2 = - norm_constant*sqrt(area)*cos(tn)*scoren + c[0];

v2 =  norm_constant*sqrt(area)*sin(tn)*scoren + c[1];

if (drw == "R") stroke = "red";

	else if (drw == "G") stroke = "green"; 

	else if (drw =="B") stroke = "blue";

	else exit("Drawing color undefined");

makeLine(u1,v1,u2,v2);

run("Add Selection...", "stroke="+stroke+" width"+lwidth);

}

//print number at center

selectImage(id);

if (numbering == "yes") { makeText(num,c[0],c[1]);

run("Add Selection...", "stroke="+stroke+" font="+fsize+" fill=none");

}

//restore original selection

makeSelection("polygon",vertx,verty);

setTool("polygon");

//end macro

}

// centroid of a polygon

function polygonCentre(x,y){

     n =x.length;

     area1 = 0;

     xc = 0; yc = 0;

     for (i=1; i<n; i++){

		  inc = x[i-1]*y[i] - x[i]*y[i-1];

         area1 += inc;

		  xc += (x[i-1]+x[i])*inc; 

		  yc += (y[i-1]+y[i])*inc;

     }

     inc = x[n-1]*y[0] - x[0]*y[n-1];

     area1 += inc;

     xc += (x[n-1]+x[0])*inc; 

     yc += (y[n-1]+y[0])*inc;    

     area1 *= 3;

     xc /= area1;

     yc /= area1;

     return newArray(xc,yc);

}

//distance between two points (x1,y1) et (x2,y2)

function distance(x1,y1,x2,y2) {

	return sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));

   }

// ImageJ runs this macro when user double-clicks on the Fibril tool icon

macro 'Fibril Tool Options' {

  Dialog.create("Fibril Tool");

  Dialog.addMessage("Choose the channel\n(Red/Green/Blue)");

  Dialog.addChoice("Channel for fibrils?\t", newArray("G", "R", "B"));

  Dialog.addChoice("Channel for drawing\t", newArray("B","No", "G", "R"));

  Dialog.addNumber("Multiply linelength by\t", 1);

  Dialog.addChoice("Nubmering ROIs?\t", newArray("yes","no"));

  Dialog.show();

  fib = Dialog.getChoice();

  drw = Dialog.getChoice();

  norm_constant = Dialog.getNumber();

  numbering = Dialog.getChoice();

  if ( drw == "No" ) waitForUser("Note that the results will not be drawn\nDouble-click on tool to set drawing on");

}