//load ImageJ
%classpath config resolver scijava.public https://maven.scijava.org/content/groups/public
%classpath add mvn net.imagej imagej 2.0.0-rc-67

//create ImageJ object
ij = new net.imagej.ImageJ()

sinusoid32 = ij.op().run("create.img", [150, 100])
formula = "63 * (Math.cos(0.3*p[0]) + Math.sin(0.3*p[1])) + 127"
ij.op().image().equation(sinusoid32, formula)

ij.notebook().display(sinusoid32)

import net.imglib2.type.numeric.real.DoubleType

percents = [0, 0.25, 0.5, 0.75, 0.999]

for(percent in percents)
    println(((percent * 100) as int) + "th quantile = " + ij.op().stats().quantile(sinusoid32, percent))