private ImageProcessor findCells(ImageProcessor ip){
		ImageProcessor temp = ip.duplicate();
		temp.invert();
		ImagePlus imp = new ImagePlus("Temp", temp);
		ResultsTable blobs = new ResultsTable();
		Double min_size = 300.0;
		Double max_size = Double.POSITIVE_INFINITY;
		ParticleAnalyzer pa = new ParticleAnalyzer(ParticleAnalyzer.IN_SITU_SHOW | ParticleAnalyzer.SHOW_ROI_MASKS, 
				Measurements.AREA, blobs, min_size, max_size);
		pa.analyze(imp);
		return imp.getProcessor();
	}