TransparencyFilterGrayscale.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.imaging.formats.png.transparencyfilters;
import static org.apache.commons.imaging.common.BinaryFunctions.read2Bytes;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import org.apache.commons.imaging.ImagingException;
public class TransparencyFilterGrayscale extends AbstractTransparencyFilter {
private final int transparentColor;
public TransparencyFilterGrayscale(final byte[] bytes) throws IOException {
super(bytes);
final ByteArrayInputStream is = new ByteArrayInputStream(bytes);
transparentColor = read2Bytes("transparentColor", is, "tRNS: Missing transparentColor", getByteOrder());
}
@Override
public int filter(final int rgb, final int index) throws ImagingException, IOException {
if (index != transparentColor) {
return rgb;
}
return 0x00;
}
}