ImageJ Automatic QRPDA Code

The following is the code used to create the macro used by ImageJ to automatically analyze pictures of test strips. (Cadle, 2010)

This code was last updated 4/5/2010.

Written by Andrew Hannum.

Code

makeRectangle('x', 'y', 'width', 'height');

run("Subtract Background...", "rolling=50 light");

run("Select First Lane");
run("Plot Lanes");

doWand('x', 'y');
run("Clear");
run("Analyze Line Graph");
Plot.getValues(x,y);

xlength=x.length;
maxy1=0;
maxx1=0;
for (i=0; i<x.length/2; i++) {
if (y[i] > maxy1) {
maxy1 = y[i];
maxx1 = x[i];
icount1=i;
}
}
maxy2=0;
maxx2=0;
for (i=x.length/2; i<x.length; i++) {
if (y[i] > maxy2) {
maxy2 = y[i];
maxx2 = x[i];
icount2=i;
}
}
close();

plotwidth=getWidth();
bandwidth=50;

x1start=maxx1-bandwidth/2;
x1end=maxx1+bandwidth/2;
x2start=maxx2-bandwidth/2;
x2end=maxx2+bandwidth/2;

y1start=y[icount1-x.length/plotwidth*50];
y1end=y[icount1+x.length/plotwidth*50];
y2start=y[icount2-x.length/plotwidth*50];
y2end=y[icount2+x.length/plotwidth*50];

drawLine(x1start-5, getHeight()-y1start-5, x1end+5, getHeight()-y1end-5);
drawLine(x2start-5, getHeight()-y2start-5, x2end+5, getHeight()-y2end-5);

doWand(maxx1, getHeight()-maxy1+5);
getStatistics(area1);
doWand(maxx2, getHeight()-maxy2+5);
getStatistics(area2);

print("Peak 1 Area:",area1," Peak 2 Area:",area2)
print("Ratio:",area2/area1);
print(error);

if(icount2+x.length/plotwidth*bandwidth > x.length) {
x2end=x2start+1;
y2end=y2start+1;
error="Error: Peak too close to edge";
}

if(icount2+x.length/plotwidth*bandwidth < x.length) {
y2end=y[icount2+x.length/plotwidth*bandwidth];
}