/*!
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* Copyright (c) 2002-2013 Pentaho Corporation.. All rights reserved.
*/
package org.pentaho.reporting.libraries.base.util;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.reporting.libraries.base.encoder.ImageEncoder;
import org.pentaho.reporting.libraries.base.encoder.UnsupportedEncoderException;
import java.awt.*;
import java.awt.image.ImageObserver;
import java.awt.image.PixelGrabber;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.CRC32;
import java.util.zip.Deflater;
import java.util.zip.DeflaterOutputStream;
/**
* PngEncoder takes a Java Image object and creates a byte string which can be saved as a PNG file. The Image is
* presumed to use the DirectColorModel. <p/> <p>Thanks to Jay Denny at KeyPoint Software http://www.keypoint.com/ who
* let me develop this code on company time.</p> <p/> <p>You may contact me with (probably very-much-needed)
* improvements, comments, and bug fixes at:</p> <p/> <p><code>david@catcode.com</code></p> <p/> <p>This library is free
* software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later
* version.</p> <p/> <p>This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
* Public License for more details.</p> <p/> <p>You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA. A copy of the GNU LGPL may be found at <code>http://www.gnu.org/copyleft/lesser
* .html</code></p>
*
* @author J. David Eisenberg
* @version 1.5, 19 Oct 2003
* <p/>
* CHANGES: -------- 19-Nov-2002 : CODING STYLE CHANGES ONLY (by David Gilbert for Object Refinery Limited);
* 19-Sep-2003 : Fix for platforms using EBCDIC (contributed by Paulo Soares); 19-Oct-2003 : Change private
* fields to protected fields so that PngEncoderB can inherit them (JDE) Fixed bug with calculation of nRows
*/
public class PngEncoder implements ImageEncoder {
/**
* A logger for debug-messages.
*/
private static final Log logger = LogFactory.getLog( PngEncoder.class );
/**
* Constant specifying that alpha channel should be encoded.
*/
public static final boolean ENCODE_ALPHA = true;
/**
* Constant specifying that alpha channel should not be encoded.
*/
public static final boolean NO_ALPHA = false;
/**
* Constants for filter (NONE).
*/
public static final int FILTER_NONE = 0;
/**
* Constants for filter (SUB).
*/
public static final int FILTER_SUB = 1;
/**
* Constants for filter (UP).
*/
public static final int FILTER_UP = 2;
/**
* Constants for filter (LAST).
*/
public static final int FILTER_LAST = 2;
/**
* IHDR tag.
*/
private static final byte[] IHDR = { 73, 72, 68, 82 };
/**
* IDAT tag.
*/
private static final byte[] IDAT = { 73, 68, 65, 84 };
/**
* IEND tag.
*/
private static final byte[] IEND = { 73, 69, 78, 68 };
/**
* PHYS tag.
*/
private static final byte[] PHYS = { (byte) 'p', (byte) 'H', (byte) 'Y', (byte) 's' };
/**
* The png bytes.
*/
private byte[] pngBytes;
/**
* The prior row.
*/
private byte[] priorRow;
/**
* The left bytes.
*/
private byte[] leftBytes;
/**
* The image.
*/
private Image image;
/**
* The width.
*/
private int width;
/**
* The height.
*/
private int height;
/**
* The byte position.
*/
private int bytePos;
/**
* The maximum position.
*/
private int maxPos;
/**
* CRC.
*/
private CRC32 crc = new CRC32();
/**
* The CRC value.
*/
private long crcValue;
/**
* A flag indicating whether the alpha channel should also be encoded.
*/
private boolean encodeAlpha;
/**
* The filter type.
*/
private int filter;
/**
* The bytes-per-pixel.
*/
private int bytesPerPixel;
/**
* The physical pixel dimension : number of pixels per inch on the X axis.
*/
private int xDpi;
/**
* The physical pixel dimension : number of pixels per inch on the Y axis.
*/
private int yDpi;
/**
* Used for conversion of DPI to Pixels per Meter.
*/
private static final float INCH_IN_METER_UNIT = 0.0254f;
/**
* The compression level (1 = best speed, 9 = best compression, 0 = no compression).
*/
private int compressionLevel;
/**
* Class constructor.
*/
public PngEncoder() {
this( null, false, PngEncoder.FILTER_NONE, 0 );
}
/**
* Class constructor specifying Image to encode, with no alpha channel encoding.
*
* @param image A Java Image object which uses the DirectColorModel
* @see java.awt.Image
*/
public PngEncoder( final Image image ) {
this( image, false, PngEncoder.FILTER_NONE, 0 );
}
/**
* Class constructor specifying Image to encode, and whether to encode alpha.
*
* @param image A Java Image object which uses the DirectColorModel
* @param encodeAlpha Encode the alpha channel? false=no; true=yes
* @see java.awt.Image
*/
public PngEncoder( final Image image, final boolean encodeAlpha ) {
this( image, encodeAlpha, PngEncoder.FILTER_NONE, 0 );
}
/**
* Class constructor specifying Image to encode, whether to encode alpha, and filter to use.
*
* @param image A Java Image object which uses the DirectColorModel
* @param encodeAlpha Encode the alpha channel? false=no; true=yes
* @param whichFilter 0=none, 1=sub, 2=up
* @see java.awt.Image
*/
public PngEncoder( final Image image, final boolean encodeAlpha, final int whichFilter ) {
this( image, encodeAlpha, whichFilter, 0 );
}
/**
* Class constructor specifying Image source to encode, whether to encode alpha, filter to use, and compression
* level.
*
* @param image A Java Image object
* @param encodeAlpha Encode the alpha channel? false=no; true=yes
* @param whichFilter 0=none, 1=sub, 2=up
* @param compLevel 0..9 (1 = best speed, 9 = best compression, 0 = no compression)
* @see java.awt.Image
*/
public PngEncoder( final Image image,
final boolean encodeAlpha,
final int whichFilter,
final int compLevel ) {
this.image = image;
this.encodeAlpha = encodeAlpha;
setFilter( whichFilter );
setCompressionLevel( compLevel );
if ( getCompressionLevel() == 0 ) {
setCompressionLevel( 5 );
}
}
/**
* Set the image to be encoded.
*
* @param image A Java Image object which uses the DirectColorModel
* @see java.awt.Image
* @see java.awt.image.DirectColorModel
*/
public void setImage( final Image image ) {
this.image = image;
this.pngBytes = null;
}
/**
* Returns the image to be encoded.
*
* @return the image to be encoded.
*/
public Image getImage() {
return image;
}
/**
* Creates an array of bytes that is the PNG equivalent of the current image, specifying whether to encode alpha or
* not.
*
* @param encodeAlpha boolean false=no alpha, true=encode alpha
* @return an array of bytes, or null if there was a problem
* @deprecated Use the other pngEncode method and select the alpha-encoding via the constructor or setter.
*/
public byte[] pngEncode( final boolean encodeAlpha ) {
setEncodeAlpha( encodeAlpha );
return pngEncode();
}
/**
* Creates an array of bytes that is the PNG equivalent of the current image, specifying whether to encode alpha or
* not.
*
* @return an array of bytes, or null if there was a problem
*/
public byte[] pngEncode() {
final byte[] pngIdBytes = { -119, 80, 78, 71, 13, 10, 26, 10 };
if ( this.image == null ) {
return null;
}
this.width = this.image.getWidth( null );
this.height = this.image.getHeight( null );
/*
* start with an array that is big enough to hold all the pixels
* (plus filter bytes), and an extra 200 bytes for header info
*/
this.pngBytes = new byte[ ( ( this.width + 1 ) * this.height * 3 ) + 200 ];
/*
* keep track of largest byte written to the array
*/
this.maxPos = 0;
this.bytePos = writeBytes( pngIdBytes, 0 );
//hdrPos = bytePos;
writeHeader();
writeResolution();
//dataPos = bytePos;
if ( writeImageData() ) {
writeEnd();
final byte[] pngBytes = resizeByteArray( this.pngBytes, this.maxPos );
this.pngBytes = null;
return pngBytes;
} else {
this.pngBytes = null;
return null;
}
}
/**
* Set the alpha encoding on or off.
*
* @param encodeAlpha false=no, true=yes
*/
public void setEncodeAlpha( final boolean encodeAlpha ) {
this.encodeAlpha = encodeAlpha;
}
/**
* Retrieve alpha encoding status.
*
* @return boolean false=no, true=yes
*/
public boolean getEncodeAlpha() {
return this.encodeAlpha;
}
/**
* Set the filter to use.
*
* @param whichFilter from constant list
*/
public void setFilter( final int whichFilter ) {
this.filter = PngEncoder.FILTER_NONE;
if ( whichFilter <= PngEncoder.FILTER_LAST ) {
this.filter = whichFilter;
}
}
/**
* Retrieve filtering scheme.
*
* @return int (see constant list)
*/
public int getFilter() {
return this.filter;
}
/**
* Set the compression level to use.
*
* @param level the compression level (1 = best speed, 9 = best compression, 0 = no compression)
*/
public void setCompressionLevel( final int level ) {
if ( level >= 0 && level <= 9 ) {
this.compressionLevel = level;
}
}
/**
* Retrieve compression level.
*
* @return int (1 = best speed, 9 = best compression, 0 = no compression)
*/
public int getCompressionLevel() {
return this.compressionLevel;
}
/**
* Increase or decrease the length of a byte array.
*
* @param array The original array.
* @param newLength The length you wish the new array to have.
* @return Array of newly desired length. If shorter than the original, the trailing elements are truncated.
*/
protected byte[] resizeByteArray( final byte[] array, final int newLength ) {
final byte[] newArray = new byte[ newLength ];
final int oldLength = array.length;
System.arraycopy( array, 0, newArray, 0, Math.min( oldLength, newLength ) );
return newArray;
}
/**
* Write an array of bytes into the pngBytes array. Note: This routine has the side effect of updating maxPos, the
* largest element written in the array. The array is resized by 1000 bytes or the length of the data to be written,
* whichever is larger.
*
* @param data The data to be written into pngBytes.
* @param offset The starting point to write to.
* @return The next place to be written to in the pngBytes array.
*/
protected int writeBytes( final byte[] data, final int offset ) {
this.maxPos = Math.max( this.maxPos, offset + data.length );
if ( data.length + offset > this.pngBytes.length ) {
this.pngBytes = resizeByteArray( this.pngBytes, this.pngBytes.length
+ Math.max( 1000, data.length ) );
}
System.arraycopy( data, 0, this.pngBytes, offset, data.length );
return offset + data.length;
}
/**
* Write an array of bytes into the pngBytes array, specifying number of bytes to write. Note: This routine has the
* side effect of updating maxPos, the largest element written in the array. The array is resized by 1000 bytes or the
* length of the data to be written, whichever is larger.
*
* @param data The data to be written into pngBytes.
* @param nBytes The number of bytes to be written.
* @param offset The starting point to write to.
* @return The next place to be written to in the pngBytes array.
*/
protected int writeBytes( final byte[] data, final int nBytes, final int offset ) {
this.maxPos = Math.max( this.maxPos, offset + nBytes );
if ( nBytes + offset > this.pngBytes.length ) {
this.pngBytes = resizeByteArray( this.pngBytes, this.pngBytes.length
+ Math.max( 1000, nBytes ) );
}
System.arraycopy( data, 0, this.pngBytes, offset, nBytes );
return offset + nBytes;
}
/**
* Write a two-byte integer into the pngBytes array at a given position.
*
* @param n The integer to be written into pngBytes.
* @param offset The starting point to write to.
* @return The next place to be written to in the pngBytes array.
*/
protected int writeInt2( final int n, final int offset ) {
final byte[] temp = { (byte) ( ( n >> 8 ) & 0xff ), (byte) ( n & 0xff ) };
return writeBytes( temp, offset );
}
/**
* Write a four-byte integer into the pngBytes array at a given position.
*
* @param n The integer to be written into pngBytes.
* @param offset The starting point to write to.
* @return The next place to be written to in the pngBytes array.
*/
protected int writeInt4( final int n, final int offset ) {
final byte[] temp = { (byte) ( ( n >> 24 ) & 0xff ),
(byte) ( ( n >> 16 ) & 0xff ),
(byte) ( ( n >> 8 ) & 0xff ),
(byte) ( n & 0xff ) };
return writeBytes( temp, offset );
}
/**
* Write a single byte into the pngBytes array at a given position.
*
* @param b The integer to be written into pngBytes.
* @param offset The starting point to write to.
* @return The next place to be written to in the pngBytes array.
*/
protected int writeByte( final int b, final int offset ) {
final byte[] temp = { (byte) b };
return writeBytes( temp, offset );
}
/**
* Write a PNG "IHDR" chunk into the pngBytes array.
*/
protected void writeHeader() {
this.bytePos = writeInt4( 13, this.bytePos );
final int startPos = bytePos;
this.bytePos = writeBytes( PngEncoder.IHDR, this.bytePos );
this.width = this.image.getWidth( null );
this.height = this.image.getHeight( null );
this.bytePos = writeInt4( this.width, this.bytePos );
this.bytePos = writeInt4( this.height, this.bytePos );
this.bytePos = writeByte( 8, this.bytePos ); // bit depth
this.bytePos = writeByte( ( this.encodeAlpha ) ? 6 : 2, this.bytePos );
// direct model
this.bytePos = writeByte( 0, this.bytePos ); // compression method
this.bytePos = writeByte( 0, this.bytePos ); // filter method
this.bytePos = writeByte( 0, this.bytePos ); // no interlace
this.crc.reset();
this.crc.update( this.pngBytes, startPos, this.bytePos - startPos );
this.crcValue = this.crc.getValue();
this.bytePos = writeInt4( (int) this.crcValue, this.bytePos );
}
/**
* Perform "sub" filtering on the given row. Uses temporary array leftBytes to store the original values of the
* previous pixels. The array is 16 bytes long, which will easily hold two-byte samples plus two-byte alpha.
*
* @param pixels The array holding the scan lines being built
* @param startPos Starting position within pixels of bytes to be filtered.
* @param width Width of a scanline in pixels.
*/
protected void filterSub( final byte[] pixels, final int startPos, final int width ) {
final int offset = this.bytesPerPixel;
final int actualStart = startPos + offset;
final int nBytes = width * this.bytesPerPixel;
int leftInsert = offset;
int leftExtract = 0;
for ( int i = actualStart; i < startPos + nBytes; i++ ) {
this.leftBytes[ leftInsert ] = pixels[ i ];
pixels[ i ] = (byte) ( ( pixels[ i ] - this.leftBytes[ leftExtract ] ) % 256 );
leftInsert = ( leftInsert + 1 ) % 0x0f;
leftExtract = ( leftExtract + 1 ) % 0x0f;
}
}
/**
* Perform "up" filtering on the given row. Side effect: refills the prior row with current row
*
* @param pixels The array holding the scan lines being built
* @param startPos Starting position within pixels of bytes to be filtered.
* @param width Width of a scanline in pixels.
*/
protected void filterUp( final byte[] pixels, final int startPos, final int width ) {
final int nBytes = width * this.bytesPerPixel;
for ( int i = 0; i < nBytes; i++ ) {
final byte currentByte = pixels[ startPos + i ];
pixels[ startPos + i ] = (byte) ( ( pixels[ startPos + i ] - this.priorRow[ i ] ) % 256 );
this.priorRow[ i ] = currentByte;
}
}
/**
* Write the image data into the pngBytes array. This will write one or more PNG "IDAT" chunks. In order to conserve
* memory, this method grabs as many rows as will fit into 32K bytes, or the whole image; whichever is less.
*
* @return true if no errors; false if error grabbing pixels
*/
protected boolean writeImageData() {
this.bytesPerPixel = ( this.encodeAlpha ) ? 4 : 3;
final Deflater scrunch = new Deflater( this.compressionLevel );
final ByteArrayOutputStream outBytes = new ByteArrayOutputStream( 1024 );
final DeflaterOutputStream compBytes = new DeflaterOutputStream( outBytes, scrunch );
try {
int startRow = 0; // starting row to process this time through
//noinspection SuspiciousNameCombination
int rowsLeft = this.height; // number of rows remaining to write
while ( rowsLeft > 0 ) {
final int nRows = Math.max( Math.min( 32767 / ( this.width * ( this.bytesPerPixel + 1 ) ), rowsLeft ), 1 );
final int[] pixels = new int[ this.width * nRows ];
final PixelGrabber pg = new PixelGrabber( this.image, 0, startRow,
this.width, nRows, pixels, 0, this.width );
try {
pg.grabPixels();
} catch ( Exception e ) {
logger.error( "interrupted waiting for pixels!", e );
return false;
}
if ( ( pg.getStatus() & ImageObserver.ABORT ) != 0 ) {
logger.error( "image fetch aborted or errored" );
return false;
}
/*
* Create a data chunk. scanLines adds "nRows" for
* the filter bytes.
*/
final byte[] scanLines = new byte[ this.width * nRows * this.bytesPerPixel + nRows ];
if ( this.filter == PngEncoder.FILTER_SUB ) {
this.leftBytes = new byte[ 16 ];
}
if ( this.filter == PngEncoder.FILTER_UP ) {
this.priorRow = new byte[ this.width * this.bytesPerPixel ];
}
int scanPos = 0;
int startPos = 1;
for ( int i = 0; i < this.width * nRows; i++ ) {
if ( i % this.width == 0 ) {
scanLines[ scanPos++ ] = (byte) this.filter;
startPos = scanPos;
}
scanLines[ scanPos++ ] = (byte) ( ( pixels[ i ] >> 16 ) & 0xff );
scanLines[ scanPos++ ] = (byte) ( ( pixels[ i ] >> 8 ) & 0xff );
scanLines[ scanPos++ ] = (byte) ( ( pixels[ i ] ) & 0xff );
if ( this.encodeAlpha ) {
scanLines[ scanPos++ ] = (byte) ( ( pixels[ i ] >> 24 )
& 0xff );
}
if ( ( i % this.width == this.width - 1 )
&& ( this.filter != PngEncoder.FILTER_NONE ) ) {
if ( this.filter == PngEncoder.FILTER_SUB ) {
filterSub( scanLines, startPos, this.width );
}
if ( this.filter == PngEncoder.FILTER_UP ) {
filterUp( scanLines, startPos, this.width );
}
}
}
/*
* Write these lines to the output area
*/
compBytes.write( scanLines, 0, scanPos );
startRow += nRows;
rowsLeft -= nRows;
}
compBytes.close();
/*
* Write the compressed bytes
*/
final byte[] compressedLines = outBytes.toByteArray();
final int nCompressed = compressedLines.length;
this.crc.reset();
this.bytePos = writeInt4( nCompressed, this.bytePos );
this.bytePos = writeBytes( PngEncoder.IDAT, this.bytePos );
this.crc.update( PngEncoder.IDAT );
this.bytePos = writeBytes( compressedLines, nCompressed,
this.bytePos );
this.crc.update( compressedLines, 0, nCompressed );
this.crcValue = this.crc.getValue();
this.bytePos = writeInt4( (int) this.crcValue, this.bytePos );
return true;
} catch ( IOException e ) {
logger.error( "Failed to write PNG Data", e );
return false;
} finally {
scrunch.finish();
scrunch.end();
}
}
/**
* Write a PNG "IEND" chunk into the pngBytes array.
*/
protected void writeEnd() {
this.bytePos = writeInt4( 0, this.bytePos );
this.bytePos = writeBytes( PngEncoder.IEND, this.bytePos );
this.crc.reset();
this.crc.update( PngEncoder.IEND );
this.crcValue = this.crc.getValue();
this.bytePos = writeInt4( (int) this.crcValue, this.bytePos );
}
/**
* Set the DPI for the X axis.
*
* @param xDpi The number of dots per inch
*/
public void setXDpi( final int xDpi ) {
this.xDpi = Math.round( xDpi / PngEncoder.INCH_IN_METER_UNIT );
}
/**
* Get the DPI for the X axis.
*
* @return The number of dots per inch
*/
public int getXDpi() {
return Math.round( xDpi * PngEncoder.INCH_IN_METER_UNIT );
}
/**
* Set the DPI for the Y axis.
*
* @param yDpi The number of dots per inch
*/
public void setYDpi( final int yDpi ) {
this.yDpi = Math.round( yDpi / PngEncoder.INCH_IN_METER_UNIT );
}
/**
* Get the DPI for the Y axis.
*
* @return The number of dots per inch
*/
public int getYDpi() {
return Math.round( yDpi * PngEncoder.INCH_IN_METER_UNIT );
}
/**
* Set the DPI resolution.
*
* @param xDpi The number of dots per inch for the X axis.
* @param yDpi The number of dots per inch for the Y axis.
*/
public void setDpi( final int xDpi, final int yDpi ) {
this.xDpi = Math.round( xDpi / PngEncoder.INCH_IN_METER_UNIT );
this.yDpi = Math.round( yDpi / PngEncoder.INCH_IN_METER_UNIT );
}
/**
* Write a PNG "pHYs" chunk into the pngBytes array.
*/
protected void writeResolution() {
if ( xDpi > 0 && yDpi > 0 ) {
bytePos = writeInt4( 9, bytePos );
final int startPos = bytePos;
bytePos = writeBytes( PngEncoder.PHYS, bytePos );
bytePos = writeInt4( xDpi, bytePos );
bytePos = writeInt4( yDpi, bytePos );
bytePos = writeByte( 1, bytePos ); // unit is the meter.
crc.reset();
crc.update( pngBytes, startPos, bytePos - startPos );
crcValue = crc.getValue();
bytePos = writeInt4( (int) crcValue, bytePos );
}
}
public void encodeImage( final Image image,
final OutputStream outputStream,
final float quality,
final boolean encodeAlpha ) throws IOException, UnsupportedEncoderException {
setCompressionLevel( Math.min( 9, Math.max( 0, (int) ( quality * 10 ) ) ) );
setImage( image );
setEncodeAlpha( encodeAlpha );
final byte[] bytes = this.pngEncode();
outputStream.write( bytes );
}
public String getMimeType() {
return "image/png";
}
}