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.transparencyfilters; 18 19 import java.io.IOException; 20 21 import org.apache.commons.imaging.ImageReadException; 22 import org.apache.commons.imaging.common.BinaryFileParser; 23 24 public abstract class TransparencyFilter extends BinaryFileParser { 25 private final byte[] bytes; 26 27 public TransparencyFilter(final byte[] bytes) { 28 this.bytes = bytes.clone(); 29 30 } 31 32 public abstract int filter(int rgb, int index) throws ImageReadException, 33 IOException; 34 35 /** 36 * @return a byte 37 */ 38 public byte getByte(final int offset) { 39 return bytes[offset]; 40 } 41 42 /** 43 * @return the length 44 */ 45 public int getLength() { 46 return bytes.length; 47 } 48 }