1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.imaging.formats.png; 18 19 /** 20 * Filter types for filter method 0. 21 * 22 * @see <a href="http://www.w3.org/TR/PNG/#9Filters">Portable Network Graphics Specification - Filtering</a> 23 */ 24 enum FilterType { 25 NONE, 26 SUB, 27 UP, 28 AVERAGE, 29 PAETH 30 }