if( fileName.endsWith("ppm") || fileName.endsWith("PPM") ) { Planar<GrayU8> color = ConvertBufferedImage.convertFromMulti(img,null,true,GrayU8.class); savePPM(color, fileName, null); } else if( fileName.endsWith("pgm") || fileName.endsWith("PGM") ) { GrayU8 gray = ConvertBufferedImage.convertFrom(img, (GrayU8) null);