001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.imaging.formats.png.scanlinefilters;
018
019import java.io.IOException;
020
021import org.apache.commons.imaging.ImagingException;
022
023public class ScanlineFilterUp implements ScanlineFilter {
024
025    @Override
026    public void unfilter(final byte[] src, final byte[] dst, final byte[] up) throws ImagingException, IOException {
027        for (int i = 0; i < src.length; i++) {
028            // byte b;
029
030            if (up != null) {
031                dst[i] = (byte) ((src[i] + up[i]) % 256);
032            } else {
033                dst[i] = src[i];
034            }
035
036            // if (i<10)
037            // System.out.println("\t" + i + ": " + dst[i]);
038            // dst[i] = b;
039            // dst[i] = src[i];
040            // dst[i] = (byte) 0;
041        }
042    }
043}