--- /dev/null
+package org.ibex.xt;
+
+import java.awt.Image;
+import java.awt.image.BufferedImage;
+import java.awt.image.DataBuffer;
+import java.awt.image.IndexColorModel;
+import java.awt.image.ImageObserver;
+import java.awt.image.PixelGrabber;
+import java.awt.image.WritableRaster;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.zip.CRC32;
+import java.util.zip.Deflater;
+import java.util.zip.DeflaterOutputStream;
+
+/**
+ * PngEncoderB takes a Java BufferedImage object and creates a byte string which can be saved as a PNG file.
+ * The encoder will accept BufferedImages with eight-bit samples
+ * or 4-byte ARGB samples.
+ *
+ * <p>There is also code to handle 4-byte samples returned as
+ * one int per pixel, but that has not been tested.</p>
+ *
+ * <p>Thanks to Jay Denny at KeyPoint Software
+ * <code>http://www.keypoint.com/</code>
+ * who let me develop this code on company time.</p>
+ *
+ * <p>You may contact me with (probably very-much-needed) improvements,
+ * comments, and bug fixes at:</p>
+ *
+ * <p><code>david@catcode.com</code></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>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>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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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
+ *
+ * CHANGES:
+ * --------
+ * 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
+ * Added modifications for unsigned short images
+ * (contributed by Christian at xpogen.com)
+ */
+
+public class PngEncoderB extends PngEncoder
+{
+
+ /** PLTE tag. */
+ private static final byte PLTE[] = { 80, 76, 84, 69 };
+
+ protected BufferedImage image;
+ protected WritableRaster wRaster;
+ protected int tType;
+
+ /**
+ * Class constructor
+ *
+ */
+ public PngEncoderB()
+ {
+ this( null, false, FILTER_NONE, 0 );
+ }
+
+ /**
+ * Class constructor specifying BufferedImage to encode, with no alpha channel encoding.
+ *
+ * @param image A Java BufferedImage object
+ */
+ public PngEncoderB( BufferedImage image )
+ {
+ this(image, false, FILTER_NONE, 0);
+ }
+
+ /**
+ * Class constructor specifying BufferedImage to encode, and whether to encode alpha.
+ *
+ * @param image A Java BufferedImage object
+ * @param encodeAlpha Encode the alpha channel? false=no; true=yes
+ */
+ public PngEncoderB( BufferedImage image, boolean encodeAlpha )
+ {
+ this( image, encodeAlpha, FILTER_NONE, 0 );
+ }
+
+ /**
+ * Class constructor specifying BufferedImage to encode, whether to encode alpha, and filter to use.
+ *
+ * @param image A Java BufferedImage object
+ * @param encodeAlpha Encode the alpha channel? false=no; true=yes
+ * @param whichFilter 0=none, 1=sub, 2=up
+ */
+ public PngEncoderB( BufferedImage image, boolean encodeAlpha,
+ int whichFilter )
+ {
+ this( image, encodeAlpha, whichFilter, 0 );
+ }
+
+ /**
+ * Class constructor specifying BufferedImage source to encode, whether to encode alpha, filter to use, and compression level
+ *
+ * @param image A Java BufferedImage object
+ * @param encodeAlpha Encode the alpha channel? false=no; true=yes
+ * @param whichFilter 0=none, 1=sub, 2=up
+ * @param compLevel 0..9
+ */
+ public PngEncoderB( BufferedImage image, boolean encodeAlpha,
+ int whichFilter, int compLevel )
+ {
+ this.image = image;
+ this.encodeAlpha = encodeAlpha;
+ setFilter( whichFilter );
+ if (compLevel >=0 && compLevel <=9)
+ {
+ this.compressionLevel = compLevel;
+ }
+ }
+
+ /**
+ * Set the BufferedImage to be encoded
+ *
+ * @param BufferedImage A Java BufferedImage object
+ */
+ public void setImage( BufferedImage image )
+ {
+ this.image = image;
+ pngBytes = null;
+ }
+
+ /**
+ * 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
+ */
+ public byte[] pngEncode( boolean encodeAlpha )
+ {
+ byte[] pngIdBytes = { -119, 80, 78, 71, 13, 10, 26, 10 };
+ int i;
+
+ if (image == null)
+ {
+ System.err.println("pngEncode: image is null; returning null");
+ return null;
+ }
+ width = image.getWidth( null );
+ height = image.getHeight( null );
+ this.image = image;
+
+ if (!establishStorageInfo())
+ {
+ System.err.println("pngEncode: cannot establish storage info");
+ return 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
+ */
+ pngBytes = new byte[((width+1) * height * 3) + 200];
+
+ /*
+ * keep track of largest byte written to the array
+ */
+ maxPos = 0;
+
+ bytePos = writeBytes( pngIdBytes, 0 );
+ // hdrPos = bytePos;
+ writeHeader();
+// dataPos = bytePos;
+ if (writeImageData())
+ {
+ writeEnd();
+ pngBytes = resizeByteArray( pngBytes, maxPos );
+ }
+ else
+ {
+ System.err.println("pngEncode: writeImageData failed => null");
+ pngBytes = null;
+ }
+ return pngBytes;
+ }
+
+ /**
+ * Creates an array of bytes that is the PNG equivalent of the current image.
+ * Alpha encoding is determined by its setting in the constructor.
+ *
+ * @return an array of bytes, or null if there was a problem
+ */
+ public byte[] pngEncode()
+ {
+ return pngEncode( encodeAlpha );
+ }
+
+ /**
+ *
+ * Get and set variables that determine how picture is stored.
+ *
+ * Retrieves the writable raster of the buffered image,
+ * as well its transfer type.
+ *
+ * Sets number of output bytes per pixel, and, if only
+ * eight-bit bytes, turns off alpha encoding.
+ * @return true if 1-byte or 4-byte data, false otherwise
+ */
+ protected boolean establishStorageInfo()
+ {
+ int dataBytes;
+
+ wRaster = image.getRaster();
+ dataBytes = wRaster.getNumDataElements();
+ tType = wRaster.getTransferType();
+
+ if (((tType == DataBuffer.TYPE_BYTE ) && (dataBytes == 4)) ||
+ ((tType == DataBuffer.TYPE_INT ) && (dataBytes == 1)) ||
+ // on Win 2k/ME, tType == 1, dataBytes == 1
+ ((tType == DataBuffer.TYPE_USHORT) && (dataBytes == 1)) )
+ {
+ bytesPerPixel = (encodeAlpha) ? 4 : 3;
+ }
+ else if ((tType == DataBuffer.TYPE_BYTE) && (dataBytes == 1))
+ {
+ bytesPerPixel = 1;
+ encodeAlpha = false; // one-byte samples
+ }
+ else
+ {
+ System.err.println("PNG encoder cannot establish storage info:");
+ System.err.println(" TransferType == " + tType );
+ System.err.println(" NumDataElements == " + dataBytes);
+ return false;
+ }
+ return true;
+ }
+
+ /**
+ * Write a PNG "IHDR" chunk into the pngBytes array.
+ */
+ protected void writeHeader()
+ {
+ int startPos;
+
+ startPos = bytePos = writeInt4( 13, bytePos );
+ bytePos = writeBytes( IHDR, bytePos );
+ width = image.getWidth( null );
+ height = image.getHeight( null );
+ bytePos = writeInt4( width, bytePos );
+ bytePos = writeInt4( height, bytePos );
+ bytePos = writeByte( 8, bytePos ); // bit depth
+ if (bytesPerPixel != 1)
+ {
+ bytePos = writeByte( (encodeAlpha) ? 6 : 2, bytePos ); // direct model
+ }
+ else
+ {
+ bytePos = writeByte( 3, bytePos ); // indexed
+ }
+ bytePos = writeByte( 0, bytePos ); // compression method
+ bytePos = writeByte( 0, bytePos ); // filter method
+ bytePos = writeByte( 0, bytePos ); // no interlace
+ crc.reset();
+ crc.update( pngBytes, startPos, bytePos-startPos );
+ crcValue = crc.getValue();
+ bytePos = writeInt4( (int) crcValue, bytePos );
+ }
+
+ protected void writePalette( IndexColorModel icm )
+ {
+ byte[] redPal = new byte[256];
+ byte[] greenPal = new byte[256];
+ byte[] bluePal = new byte[256];
+ byte[] allPal = new byte[768];
+ int i;
+
+ icm.getReds( redPal );
+ icm.getGreens( greenPal );
+ icm.getBlues( bluePal );
+ for (i=0; i<256; i++)
+ {
+ allPal[i*3 ] = redPal[i];
+ allPal[i*3+1] = greenPal[i];
+ allPal[i*3+2] = bluePal[i];
+ }
+ bytePos = writeInt4( 768, bytePos );
+ bytePos = writeBytes( PLTE, bytePos );
+ crc.reset();
+ crc.update( PLTE );
+ bytePos = writeBytes( allPal, bytePos );
+ crc.update( allPal );
+ crcValue = crc.getValue();
+ bytePos = writeInt4( (int) crcValue, bytePos );
+ }
+
+ /**
+ * 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()
+ {
+ int rowsLeft = height; // number of rows remaining to write
+ int startRow = 0; // starting row to process this time through
+ int nRows; // how many rows to grab at a time
+
+ byte[] scanLines; // the scan lines to be compressed
+ int scanPos; // where we are in the scan lines
+ int startPos; // where this line's actual pixels start (used for filtering)
+ int readPos; // position from which source pixels are read
+
+ byte[] compressedLines; // the resultant compressed lines
+ int nCompressed; // how big is the compressed area?
+
+ byte[] pixels; // storage area for byte-sized pixels
+ int[] iPixels; // storage area for int-sized pixels
+ short[] sPixels; // for Win 2000/ME ushort pixels
+ final int type = image.getType();
+ // TYPE_INT_RGB = 1
+ // TYPE_INT_ARGB = 2
+ // TYPE_INT_ARGB_PRE = 3
+ // TYPE_INT_BGR = 4
+ // TYPE_3BYTE_BGR = 5
+ // TYPE_4BYTE_ABGR = 6
+ // TYPE_4BYTE_ABGR_PRE = 7
+ // TYPE_BYTE_GRAY = 10
+ // TYPE_BYTE_BINARY = 12
+ // TYPE_BYTE_INDEXED = 13
+ // TYPE_USHORT_GRAY = 11
+ // TYPE_USHORT_565_RGB = 8
+ // TYPE_USHORT_555_RGB = 9
+ // TYPE_CUSTOM = 0.
+
+ Deflater scrunch = new Deflater( compressionLevel );
+ ByteArrayOutputStream outBytes =
+ new ByteArrayOutputStream(1024);
+
+ DeflaterOutputStream compBytes =
+ new DeflaterOutputStream( outBytes, scrunch );
+
+ if (bytesPerPixel == 1)
+ {
+ writePalette( (IndexColorModel) image.getColorModel() );
+ }
+
+ try
+ {
+ while (rowsLeft > 0)
+ {
+ nRows = Math.min( 32767 / (width*(bytesPerPixel+1)), rowsLeft );
+ nRows = Math.max( nRows, 1 );
+
+ /*
+ * Create a data chunk. scanLines adds "nRows" for
+ * the filter bytes.
+ */
+ scanLines = new byte[width * nRows * bytesPerPixel + nRows];
+
+ if (filter == FILTER_SUB)
+ {
+ leftBytes = new byte[16];
+ }
+ if (filter == FILTER_UP)
+ {
+ priorRow = new byte[width*bytesPerPixel];
+ }
+
+ final Object data =
+ wRaster.getDataElements( 0, startRow, width, nRows, null );
+
+ pixels = null;
+ iPixels = null;
+ sPixels = null;
+ if (tType == DataBuffer.TYPE_BYTE)
+ {
+ pixels = (byte[]) data;
+ }
+ else if (tType == DataBuffer.TYPE_INT)
+ {
+ iPixels = (int[]) data;
+ }
+ else if (tType == DataBuffer.TYPE_USHORT)
+ {
+ sPixels = (short[]) data;
+ }
+
+ scanPos = 0;
+ readPos = 0;
+ startPos = 1;
+ for (int i=0; i<width*nRows; i++)
+ {
+ if (i % width == 0)
+ {
+ scanLines[scanPos++] = (byte) filter;
+ startPos = scanPos;
+ }
+
+ if (bytesPerPixel == 1) // assume TYPE_BYTE, indexed
+ {
+ scanLines[scanPos++] = pixels[readPos++];
+ }
+ else if (tType == DataBuffer.TYPE_BYTE)
+ {
+ scanLines[scanPos++] = pixels[readPos++];
+ scanLines[scanPos++] = pixels[readPos++];
+ scanLines[scanPos++] = pixels[readPos++];
+ if (encodeAlpha)
+ {
+ scanLines[scanPos++] = pixels[readPos++];
+ }
+ else
+ {
+ readPos++;
+ }
+ }
+ else if (tType == DataBuffer.TYPE_USHORT)
+ {
+ short pxl = sPixels[readPos++];
+ if (type == BufferedImage.TYPE_USHORT_565_RGB) {
+ scanLines[scanPos++] = (byte) ((pxl >> 8) & 0xf8);
+ scanLines[scanPos++] = (byte) ((pxl >> 2) & 0xfc);
+ } else { // assume USHORT_555_RGB
+ scanLines[scanPos++] = (byte) ((pxl >> 7) & 0xf8);
+ scanLines[scanPos++] = (byte) ((pxl >> 2) & 0xf8);
+ }
+ scanLines[scanPos++] = (byte) ((pxl << 3) & 0xf8);
+ }
+ else // assume tType INT and type RGB or ARGB
+ {
+ int pxl = iPixels[readPos++];
+ scanLines[scanPos++] = (byte) ((pxl >> 16) & 0xff);
+ scanLines[scanPos++] = (byte) ((pxl >> 8) & 0xff);
+ scanLines[scanPos++] = (byte) ((pxl ) & 0xff);
+ if (encodeAlpha) {
+ scanLines[scanPos++] = (byte) ((pxl >> 24) & 0xff);
+ }
+ }
+
+ if ((i % width == width-1) && (filter != FILTER_NONE))
+ {
+ if (filter == FILTER_SUB)
+ {
+ filterSub( scanLines, startPos, width );
+ }
+ if (filter == FILTER_UP)
+ {
+ filterUp( scanLines, startPos, width );
+ }
+ }
+ }
+
+ /*
+ * Write these lines to the output area
+ */
+ compBytes.write( scanLines, 0, scanPos );
+
+ startRow += nRows;
+ rowsLeft -= nRows;
+ }
+ compBytes.close();
+
+ /*
+ * Write the compressed bytes
+ */
+ compressedLines = outBytes.toByteArray();
+ nCompressed = compressedLines.length;
+
+ crc.reset();
+ bytePos = writeInt4( nCompressed, bytePos );
+ bytePos = writeBytes( IDAT, bytePos );
+ crc.update( IDAT );
+ bytePos = writeBytes( compressedLines, nCompressed, bytePos );
+ crc.update( compressedLines, 0, nCompressed );
+
+ crcValue = crc.getValue();
+ bytePos = writeInt4( (int) crcValue, bytePos );
+ scrunch.finish();
+ return true;
+ }
+ catch (IOException e)
+ {
+ System.err.println( e.toString());
+ return false;
+ }
+ }
+
+}
+
projects / org.ibex.xt.git / blobdiff