Method createMask

ij/src/main/java/ij/plugin/Selection.java:612–654

(ImagePlus imp)

	}*/
	
	void createMask(ImagePlus imp) {
		Roi roi = imp.getRoi();
		boolean useInvertingLut = Prefs.useInvertingLut;
		Prefs.useInvertingLut = false;
		boolean selectAll = roi!=null && roi.getType()==Roi.RECTANGLE && roi.getBounds().width==imp.getWidth()
			&& roi.getBounds().height==imp.getHeight() && imp.isThreshold();
		boolean overlay = imp.getOverlay()!=null && !imp.isThreshold();
		if (!overlay && (roi==null || selectAll)) {
			createMaskFromThreshold(imp);
			Prefs.useInvertingLut = useInvertingLut;
			return;
		}
		if (roi==null && imp.getOverlay()==null) {
			IJ.error("Create Mask", "Selection, overlay or threshold required");
			return;
		}
		ByteProcessor mask = imp.createRoiMask();
		if (!Prefs.blackBackground)
			mask.invertLut();
		mask.setThreshold(255, 255, ImageProcessor.NO_LUT_UPDATE);
		ImagePlus maskImp = null;
		Frame frame = WindowManager.getFrame("Mask");
		if (frame!=null && (frame instanceof ImageWindow))
			maskImp = ((ImageWindow)frame).getImagePlus();
		if (maskImp!=null && maskImp.getBitDepth()==8) {
			ImageProcessor ip = maskImp.getProcessor();
			ip.copyBits(mask, 0, 0, Blitter.OR);
			maskImp.setProcessor(ip);
		} else {
			maskImp = new ImagePlus("Mask", mask);
			maskImp.show();
		}
		Calibration cal = imp.getCalibration();
		if (cal.scaled()) {
			Calibration cal2 = maskImp.getCalibration();
			cal2.pixelWidth = cal.pixelWidth;
			cal2.pixelHeight = cal.pixelHeight;
			cal2.setUnit(cal.getUnit());
		}
		maskImp.updateAndRepaintWindow();
		Prefs.useInvertingLut = useInvertingLut;
		Recorder.recordCall("mask = imp.createRoiMask();");
	}
	
	void createMaskFromThreshold(ImagePlus imp) {
		ImageProcessor ip = imp.getProcessor();