* accuracy needs slightly more computing time.
*/
public void blurGaussian(ImageProcessor ip, double sigmaX, double sigmaY, double accuracy) {
if (nPasses<=1)
nPasses = ip.getNChannels() * (sigmaX>0 && sigmaY>0 ? 2 : 1);
FloatProcessor fp = null;
for (int i=0; i<ip.getNChannels(); i++) {
fp = ip.toFloat(i, fp);
if (Thread.currentThread().isInterrupted()) return; // interruption for new parameters during preview?
blurFloat(fp, sigmaX, sigmaY, accuracy);
if (Thread.currentThread().isInterrupted()) return;