org.monte.media.pgm.PGMImageReaderSpi Maven / Gradle / Ivy
/*
* @(#)PGMImageReaderSpi.java 1.0 2009-12-14
*
* Copyright (c) 2009 Werner Randelshofer, Goldau, Switzerland.
* All rights reserved.
*
* You may not use, copy or modify this file, except in compliance with the
* license agreement you entered into with Werner Randelshofer.
* For details see accompanying license terms.
*/
package org.monte.media.pgm;
import java.io.IOException;
import java.util.Locale;
import javax.imageio.ImageReader;
import javax.imageio.spi.ImageReaderSpi;
import javax.imageio.stream.ImageInputStream;
/**
* ImageIO service provider interface for images in the Netpbm grayscale image
* format (PGM).
*
* See: PGM Format Specification.
*
* @author Werner Randelshofer
* @version 1.0 2009-12-14 Created.
*/
public class PGMImageReaderSpi extends ImageReaderSpi {
public PGMImageReaderSpi() {
super("Werner Randelshofer",//vendor name
"1.0",//version
new String[]{"PGM"},//names
new String[]{"pgm"},//suffixes,
new String[]{"image/pgm"},// MIMETypes,
"org.monte.media.pgm.PGMImageReader",// readerClassName,
new Class[]{ImageInputStream.class},// inputTypes,
null,// writerSpiNames,
false,// supportsStandardStreamMetadataFormat,
null,// nativeStreamMetadataFormatName,
null,// nativeStreamMetadataFormatClassName,
null,// extraStreamMetadataFormatNames,
null,// extraStreamMetadataFormatClassNames,
false,// supportsStandardImageMetadataFormat,
null,// nativeImageMetadataFormatName,
null,// nativeImageMetadataFormatClassName,
null,// extraImageMetadataFormatNames,
null// extraImageMetadataFormatClassNames
);
}
@Override
public boolean canDecodeInput(Object source) throws IOException {
if (source instanceof ImageInputStream) {
ImageInputStream in = (ImageInputStream) source;
in.mark();
// Check if file starts with "P5"
if (in.readShort() != 0x5035) {
in.reset();
return false;
}
// Check if the next byte is a whitespace (blank, TAB, CR or LF)
int b;
if ((b = in.readUnsignedByte()) != 0x20 && b != 0x09 && b != 0x0d && b != 0x0a) {
in.reset();
return false;
}
in.reset();
return true;
}
return false;
}
@Override
public ImageReader createReaderInstance(Object extension) throws IOException {
return new PGMImageReader(this);
}
@Override
public String getDescription(Locale locale) {
return "PGM Image Reader";
}
}