/*
* 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.sanselan.formats.gif;
import java.awt.Dimension;
import java.awt.image.BufferedImage;
import java.awt.image.DataBuffer;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.sanselan.FormatCompliance;
import org.apache.sanselan.ImageFormat;
import org.apache.sanselan.ImageInfo;
import org.apache.sanselan.ImageParser;
import org.apache.sanselan.ImageReadException;
import org.apache.sanselan.ImageWriteException;
import org.apache.sanselan.common.BinaryOutputStream;
import org.apache.sanselan.common.IImageMetadata;
import org.apache.sanselan.common.byteSources.ByteSource;
import org.apache.sanselan.common.mylzw.MyLZWCompressor;
import org.apache.sanselan.common.mylzw.MyLZWDecompressor;
import org.apache.sanselan.palette.Palette;
import org.apache.sanselan.palette.PaletteFactory;
import org.apache.sanselan.util.Debug;
import org.apache.sanselan.util.ParamMap;
public class GifImageParser extends ImageParser
{
public GifImageParser()
{
super.setByteOrder(BYTE_ORDER_LSB);
}
public String getName()
{
return "Gif-Custom";
}
public String getDefaultExtension()
{
return DEFAULT_EXTENSION;
}
private static final String DEFAULT_EXTENSION = ".gif";
private static final String ACCEPTED_EXTENSIONS[] = { DEFAULT_EXTENSION, };
protected String[] getAcceptedExtensions()
{
return ACCEPTED_EXTENSIONS;
}
protected ImageFormat[] getAcceptedTypes()
{
return new ImageFormat[] { ImageFormat.IMAGE_FORMAT_GIF, //
};
}
private static final byte GIF_HEADER_SIGNATURE[] = { 71, 73, 70 };
private GIFHeaderInfo readHeader(InputStream is,
FormatCompliance formatCompliance) throws ImageReadException,
IOException
{
byte identifier1 = readByte("identifier1", is, "Not a Valid GIF File");
byte identifier2 = readByte("identifier2", is, "Not a Valid GIF File");
byte identifier3 = readByte("identifier3", is, "Not a Valid GIF File");
byte version1 = readByte("version1", is, "Not a Valid GIF File");
byte version2 = readByte("version2", is, "Not a Valid GIF File");
byte version3 = readByte("version3", is, "Not a Valid GIF File");
if (formatCompliance != null)
{
formatCompliance.compare_bytes("Signature", GIF_HEADER_SIGNATURE,
new byte[] { identifier1, identifier2, identifier3, });
formatCompliance.compare("version", 56, version1);
formatCompliance
.compare("version", new int[] { 55, 57, }, version2);
formatCompliance.compare("version", 97, version3);
}
if (debug)
printCharQuad("identifier: ", ((identifier1 << 16)
| (identifier2 << 8) | (identifier3 << 0)));
if (debug)
printCharQuad("version: ",
((version1 << 16) | (version2 << 8) | (version3 << 0)));
int logicalScreenWidth = read2Bytes("Logical Screen Width", is,
"Not a Valid GIF File");
int logicalScreenHeight = read2Bytes("Logical Screen Height", is,
"Not a Valid GIF File");
if (formatCompliance != null)
{
formatCompliance.checkBounds("Width", 1, Integer.MAX_VALUE,
logicalScreenWidth);
formatCompliance.checkBounds("Height", 1, Integer.MAX_VALUE,
logicalScreenHeight);
}
byte packedFields = readByte("Packed Fields", is,
"Not a Valid GIF File");
byte backgroundColorIndex = readByte("Background Color Index", is,
"Not a Valid GIF File");
byte pixelAspectRatio = readByte("Pixel Aspect Ratio", is,
"Not a Valid GIF File");
if (debug)
printByteBits("PackedFields bits", packedFields);
boolean globalColorTableFlag = ((packedFields & 128) > 0);
if (debug)
System.out.println("GlobalColorTableFlag: " + globalColorTableFlag);
byte colorResolution = (byte) ((packedFields >> 4) & 7);
if (debug)
System.out.println("ColorResolution: " + colorResolution);
boolean sortFlag = ((packedFields & 8) > 0);
if (debug)
System.out.println("SortFlag: " + sortFlag);
byte sizeofGlobalColorTable = (byte) (packedFields & 7);
if (debug)
System.out.println("SizeofGlobalColorTable: "
+ sizeofGlobalColorTable);
if (formatCompliance != null)
{
if (globalColorTableFlag && backgroundColorIndex != -1)
formatCompliance.checkBounds("Background Color Index", 0,
convertColorTableSize(sizeofGlobalColorTable),
backgroundColorIndex);
}
return new GIFHeaderInfo(identifier1, identifier2, identifier3,
version1, version2, version3, logicalScreenWidth,
logicalScreenHeight, packedFields, backgroundColorIndex,
pixelAspectRatio, globalColorTableFlag, colorResolution,
sortFlag, sizeofGlobalColorTable);
}
private GraphicControlExtension readGraphicControlExtension(int code,
InputStream is) throws ImageReadException, IOException
{
readByte("block_size", is, "GIF: corrupt GraphicControlExt");
int packed = readByte("packed fields", is,
"GIF: corrupt GraphicControlExt");
int dispose = (packed & 0x1c) >> 2; // disposal method
boolean transparency = (packed & 1) != 0;
int delay = read2Bytes("delay in milliseconds", is,
"GIF: corrupt GraphicControlExt");
int transparentColorIndex = 0xff & readByte("transparent color index",
is, "GIF: corrupt GraphicControlExt");
readByte("block terminator", is, "GIF: corrupt GraphicControlExt");
return new GraphicControlExtension(code, packed, dispose, transparency,
delay, transparentColorIndex);
}
private byte[] readSubBlock(InputStream is) throws ImageReadException,
IOException
{
int block_size = 0xff & readByte("block_size", is, "GIF: corrupt block");
byte bytes[] = readByteArray("block", block_size, is,
"GIF: corrupt block");
return bytes;
}
protected GenericGIFBlock readGenericGIFBlock(InputStream is, int code)
throws ImageReadException, IOException
{
return readGenericGIFBlock(is, code, null);
}
protected GenericGIFBlock readGenericGIFBlock(InputStream is, int code,
byte first[]) throws ImageReadException, IOException
{
ArrayList subblocks = new ArrayList();
if (first != null)
subblocks.add(first);
while (true)
{
byte bytes[] = readSubBlock(is);
if (bytes.length < 1)
break;
subblocks.add(bytes);
}
return new GenericGIFBlock(code, subblocks);
}
private final static int EXTENSION_CODE = 0x21;
private final static int IMAGE_SEPARATOR = 0x2C;
private final static int GRAPHIC_CONTROL_EXTENSION = (EXTENSION_CODE << 8) | 0xf9;
private final static int COMMENT_EXTENSION = 0xfe;
private final static int PLAIN_TEXT_EXTENSION = 0x01;
private final static int XMP_EXTENSION = 0xff;
private final static int TERMINATOR_BYTE = 0x3b;
private final static int APPLICATION_EXTENSION_LABEL = 0xff;
private final static int XMP_COMPLETE_CODE = (EXTENSION_CODE << 8)
| XMP_EXTENSION;
private ArrayList readBlocks(GIFHeaderInfo ghi, InputStream is,
boolean stopBeforeImageData, FormatCompliance formatCompliance)
throws ImageReadException, IOException
{
ArrayList result = new ArrayList();
while (true)
{
int code = is.read();
switch (code)
{
case -1:
throw new ImageReadException("GIF: unexpected end of data");
case IMAGE_SEPARATOR:
ImageDescriptor id = readImageDescriptor(ghi, code, is,
stopBeforeImageData, formatCompliance);
result.add(id);
// if(stopBeforeImageData)
// return result;
break;
case EXTENSION_CODE: // extension
{
int extensionCode = is.read();
int completeCode = ((0xff & code) << 8)
| (0xff & extensionCode);
switch (extensionCode)
{
case 0xf9:
GraphicControlExtension gce = readGraphicControlExtension(
completeCode, is);
result.add(gce);
break;
case COMMENT_EXTENSION:
case PLAIN_TEXT_EXTENSION: {
GenericGIFBlock block = readGenericGIFBlock(is,
completeCode);
result.add(block);
break;
}
case APPLICATION_EXTENSION_LABEL: // 255 (hex 0xFF) Application
// Extension Label
{
byte label[] = readSubBlock(is);
if (formatCompliance != null)
formatCompliance
.addComment("Unknown Application Extension ("
+ new String(label) + ")", completeCode);
// if (label == new String("ICCRGBG1"))
{
// GIF's can have embedded ICC Profiles - who knew?
}
if ((label != null) && (label.length > 0))
{
GenericGIFBlock block = readGenericGIFBlock(is,
completeCode, label);
result.add(block);
}
break;
}
default: {
if (formatCompliance != null)
formatCompliance.addComment("Unknown block",
completeCode);
GenericGIFBlock block = readGenericGIFBlock(is,
completeCode);
result.add(block);
break;
}
}
}
break;
case TERMINATOR_BYTE:
return result;
case 0x00: // bad byte, but keep going and see what happens
break;
default:
throw new ImageReadException("GIF: unknown code: " + code);
}
}
}
private ImageDescriptor readImageDescriptor(GIFHeaderInfo ghi,
int blockCode, InputStream is, boolean stopBeforeImageData,
FormatCompliance formatCompliance) throws ImageReadException,
IOException
{
int ImageLeftPosition = read2Bytes("Image Left Position", is,
"Not a Valid GIF File");
int ImageTopPosition = read2Bytes("Image Top Position", is,
"Not a Valid GIF File");
int imageWidth = read2Bytes("Image Width", is, "Not a Valid GIF File");
int imageHeight = read2Bytes("Image Height", is, "Not a Valid GIF File");
byte PackedFields = readByte("Packed Fields", is,
"Not a Valid GIF File");
if (formatCompliance != null)
{
formatCompliance.checkBounds("Width", 1, ghi.logicalScreenWidth,
imageWidth);
formatCompliance.checkBounds("Height", 1, ghi.logicalScreenHeight,
imageHeight);
formatCompliance.checkBounds("Left Position", 0,
ghi.logicalScreenWidth - imageWidth, ImageLeftPosition);
formatCompliance.checkBounds("Top Position", 0,
ghi.logicalScreenHeight - imageHeight, ImageTopPosition);
}
if (debug)
printByteBits("PackedFields bits", PackedFields);
boolean LocalColorTableFlag = (((PackedFields >> 7) & 1) > 0);
if (debug)
System.out.println("LocalColorTableFlag: " + LocalColorTableFlag);
boolean InterlaceFlag = (((PackedFields >> 6) & 1) > 0);
if (debug)
System.out.println("Interlace Flag: " + InterlaceFlag);
boolean SortFlag = (((PackedFields >> 5) & 1) > 0);
if (debug)
System.out.println("Sort Flag: " + SortFlag);
byte SizeofLocalColorTable = (byte) (PackedFields & 7);
if (debug)
System.out.println("SizeofLocalColorTable: "
+ SizeofLocalColorTable);
byte LocalColorTable[] = null;
if (LocalColorTableFlag)
LocalColorTable = readColorTable(is, SizeofLocalColorTable,
formatCompliance);
byte imageData[] = null;
if (!stopBeforeImageData)
{
int LZWMinimumCodeSize = is.read();
GenericGIFBlock block = readGenericGIFBlock(is, -1);
byte bytes[] = block.appendSubBlocks();
InputStream bais = new ByteArrayInputStream(bytes);
int size = imageWidth * imageHeight;
MyLZWDecompressor myLzwDecompressor = new MyLZWDecompressor(
LZWMinimumCodeSize, BYTE_ORDER_LSB);
imageData = myLzwDecompressor.decompress(bais, size);
} else
{
int LZWMinimumCodeSize = is.read();
if (debug)
System.out.println("LZWMinimumCodeSize: " + LZWMinimumCodeSize);
readGenericGIFBlock(is, -1);
}
ImageDescriptor result = new ImageDescriptor(blockCode,
ImageLeftPosition, ImageTopPosition, imageWidth, imageHeight,
PackedFields, LocalColorTableFlag, InterlaceFlag, SortFlag,
SizeofLocalColorTable, LocalColorTable, imageData);
return result;
}
private int simple_pow(int base, int power)
{
int result = 1;
for (int i = 0; i < power; i++)
result *= base;
return result;
}
private int convertColorTableSize(int ct_size)
{
return 3 * simple_pow(2, ct_size + 1);
}
private byte[] readColorTable(InputStream is, int ct_size,
FormatCompliance formatCompliance) throws IOException
{
int actual_size = convertColorTableSize(ct_size);
byte bytes[] = readByteArray("block", actual_size, is,
"GIF: corrupt Color Table");
return bytes;
}
// TODO - unused
private GIFHeaderInfo readHeader(ByteSource byteSource)
throws ImageReadException, IOException
{
InputStream is = null;
try
{
is = byteSource.getInputStream();
return readHeader(is, FormatCompliance.getDefault());
} finally
{
try
{
if (is != null) {
is.close();
}
} catch (Exception e)
{
Debug.debug(e);
}
}
}
private GIFBlock findBlock(ArrayList v, int code)
{
for (int i = 0; i < v.size(); i++)
{
GIFBlock gifBlock = (GIFBlock) v.get(i);
if (gifBlock.blockCode == code)
return gifBlock;
}
return null;
}
private ImageContents readFile(ByteSource byteSource,
boolean stopBeforeImageData) throws ImageReadException, IOException
{
return readFile(byteSource, stopBeforeImageData, FormatCompliance
.getDefault());
}
private ImageContents readFile(ByteSource byteSource,
boolean stopBeforeImageData, FormatCompliance formatCompliance)
throws ImageReadException, IOException
{
InputStream is = null;
try
{
is = byteSource.getInputStream();
GIFHeaderInfo ghi = readHeader(is, formatCompliance);
byte globalColorTable[] = null;
if (ghi.globalColorTableFlag)
globalColorTable = readColorTable(is,
ghi.sizeOfGlobalColorTable, formatCompliance);
ArrayList blocks = readBlocks(ghi, is, stopBeforeImageData,
formatCompliance);
ImageContents result = new ImageContents(ghi, globalColorTable,
blocks);
return result;
} finally
{
try
{
if (is != null) {
is.close();
}
} catch (Exception e)
{
Debug.debug(e);
}
}
}
public byte[] getICCProfileBytes(ByteSource byteSource, Map params)
throws ImageReadException, IOException
{
return null;
}
public Dimension getImageSize(ByteSource byteSource, Map params)
throws ImageReadException, IOException
{
ImageContents blocks = readFile(byteSource, false);
if (blocks == null)
throw new ImageReadException("GIF: Couldn't read blocks");
GIFHeaderInfo bhi = blocks.gifHeaderInfo;
if (bhi == null)
throw new ImageReadException("GIF: Couldn't read Header");
ImageDescriptor id = (ImageDescriptor) findBlock(blocks.blocks,
IMAGE_SEPARATOR);
if (id == null)
throw new ImageReadException("GIF: Couldn't read ImageDescriptor");
// Prefer the size information in the ImageDescriptor; it is more reliable
// than the size information in the header.
return new Dimension(id.imageWidth, id.imageHeight);
}
public byte[] embedICCProfile(byte image[], byte profile[])
{
return null;
}
public boolean embedICCProfile(File src, File dst, byte profile[])
{
return false;
}
public IImageMetadata getMetadata(ByteSource byteSource, Map params)
throws ImageReadException, IOException
{
return null;
}
private ArrayList getComments(ArrayList v) throws IOException
{
ArrayList result = new ArrayList();
int code = 0x21fe;
for (int i = 0; i < v.size(); i++)
{
GIFBlock block = (GIFBlock) v.get(i);
if (block.blockCode == code)
{
byte bytes[] = ((GenericGIFBlock) block).appendSubBlocks();
result.add(new String(bytes));
}
}
return result;
}
public ImageInfo getImageInfo(ByteSource byteSource, Map params)
throws ImageReadException, IOException
{
ImageContents blocks = readFile(byteSource, false);
if (blocks == null)
throw new ImageReadException("GIF: Couldn't read blocks");
GIFHeaderInfo bhi = blocks.gifHeaderInfo;
if (bhi == null)
throw new ImageReadException("GIF: Couldn't read Header");
ImageDescriptor id = (ImageDescriptor) findBlock(blocks.blocks,
IMAGE_SEPARATOR);
if (id == null)
throw new ImageReadException("GIF: Couldn't read ImageDescriptor");
GraphicControlExtension gce = (GraphicControlExtension) findBlock(
blocks.blocks, GRAPHIC_CONTROL_EXTENSION);
// Prefer the size information in the ImageDescriptor; it is more reliable
// than the size information in the header.
int height = id.imageWidth;
int width = id.imageHeight;
ArrayList Comments;
Comments = getComments(blocks.blocks);
int BitsPerPixel = (bhi.colorResolution + 1) * 3;
ImageFormat Format = ImageFormat.IMAGE_FORMAT_GIF;
String FormatName = "GIF Graphics Interchange Format";
String MimeType = "image/gif";
// we ought to count images, but don't yet.
int NumberOfImages = -1;
boolean isProgressive = id.interlaceFlag;
int PhysicalWidthDpi = 72;
float PhysicalWidthInch = (float) ((double) width / (double) PhysicalWidthDpi);
int PhysicalHeightDpi = 72;
float PhysicalHeightInch = (float) ((double) height / (double) PhysicalHeightDpi);
String FormatDetails = "Gif " + ((char) blocks.gifHeaderInfo.version1)
+ ((char) blocks.gifHeaderInfo.version2)
+ ((char) blocks.gifHeaderInfo.version3);
boolean isTransparent = false;
if (gce != null && gce.transparency)
isTransparent = true;
boolean usesPalette = true;
int colorType = ImageInfo.COLOR_TYPE_RGB;
String compressionAlgorithm = ImageInfo.COMPRESSION_ALGORITHM_LZW;
ImageInfo result = new ImageInfo(FormatDetails, BitsPerPixel, Comments,
Format, FormatName, height, MimeType, NumberOfImages,
PhysicalHeightDpi, PhysicalHeightInch, PhysicalWidthDpi,
PhysicalWidthInch, width, isProgressive, isTransparent,
usesPalette, colorType, compressionAlgorithm);
return result;
}
public boolean dumpImageFile(PrintWriter pw, ByteSource byteSource)
throws ImageReadException, IOException
{
pw.println("gif.dumpImageFile");
{
ImageInfo imageData = getImageInfo(byteSource);
if (imageData == null)
return false;
imageData.toString(pw, "");
}
{
ImageContents blocks = readFile(byteSource, false);
if (blocks == null)
return false;
pw.println("gif.blocks: " + blocks.blocks.size());
for (int i = 0; i < blocks.blocks.size(); i++)
{
GIFBlock gifBlock = (GIFBlock) blocks.blocks.get(i);
this.debugNumber(pw, "\t" + i + " ("
+ gifBlock.getClass().getName() + ")",
gifBlock.blockCode, 4);
}
}
pw.println("");
return true;
}
private int[] getColorTable(byte bytes[]) throws ImageReadException
{
if ((bytes.length % 3) != 0)
throw new ImageReadException("Bad Color Table Length: "
+ bytes.length);
int length = bytes.length / 3;
int result[] = new int[length];
for (int i = 0; i < length; i++)
{
int red = 0xff & bytes[(i * 3) + 0];
int green = 0xff & bytes[(i * 3) + 1];
int blue = 0xff & bytes[(i * 3) + 2];
int alpha = 0xff;
int rgb = (alpha << 24) | (red << 16) | (green << 8) | (blue << 0);
result[i] = rgb;
}
return result;
}
public FormatCompliance getFormatCompliance(ByteSource byteSource)
throws ImageReadException, IOException
{
FormatCompliance result = new FormatCompliance(byteSource
.getDescription());
readFile(byteSource, false, result);
return result;
}
public BufferedImage getBufferedImage(ByteSource byteSource, Map params)
throws ImageReadException, IOException
{
ImageContents imageContents = readFile(byteSource, false);
if (imageContents == null)
throw new ImageReadException("GIF: Couldn't read blocks");
GIFHeaderInfo ghi = imageContents.gifHeaderInfo;
if (ghi == null)
throw new ImageReadException("GIF: Couldn't read Header");
ImageDescriptor id = (ImageDescriptor) findBlock(imageContents.blocks,
IMAGE_SEPARATOR);
if (id == null)
throw new ImageReadException("GIF: Couldn't read Image Descriptor");
GraphicControlExtension gce = (GraphicControlExtension) findBlock(
imageContents.blocks, GRAPHIC_CONTROL_EXTENSION);
// Prefer the size information in the ImageDescriptor; it is more reliable
// than the size information in the header.
int width = id.imageWidth;
int height = id.imageHeight;
boolean hasAlpha = false;
if (gce != null && gce.transparency)
hasAlpha = true;
BufferedImage result = getBufferedImageFactory(params)
.getColorBufferedImage(width, height, hasAlpha);
{
int colorTable[];
if (id.localColorTable != null)
colorTable = getColorTable(id.localColorTable);
else if (imageContents.globalColorTable != null)
colorTable = getColorTable(imageContents.globalColorTable);
else
throw new ImageReadException("Gif: No Color Table");
int transparentIndex = -1;
if (hasAlpha)
transparentIndex = gce.transparentColorIndex;
int counter = 0;
int rowsInPass1 = (height + 7) / 8;
int rowsInPass2 = (height + 3) / 8;
int rowsInPass3 = (height + 1) / 4;
int rowsInPass4 = (height) / 2;
DataBuffer db = result.getRaster().getDataBuffer();
for (int row = 0; row < height; row++)
{
int y;
if (id.interlaceFlag)
{
int the_row = row;
if (the_row < rowsInPass1)
y = the_row * 8;
else
{
the_row -= rowsInPass1;
if (the_row < (rowsInPass2))
y = 4 + (the_row * 8);
else
{
the_row -= rowsInPass2;
if (the_row < (rowsInPass3))
y = 2 + (the_row * 4);
else
{
the_row -= rowsInPass3;
if (the_row < (rowsInPass4))
y = 1 + (the_row * 2);
else
throw new ImageReadException(
"Gif: Strange Row");
}
}
}
} else
y = row;
for (int x = 0; x < width; x++)
{
int index = 0xff & id.imageData[counter++];
int rgb = colorTable[index];
if (transparentIndex == index)
rgb = 0x00;
db.setElem(y * width + x, rgb);
}
}
}
return result;
}
private void writeAsSubBlocks(OutputStream os, byte bytes[])
throws IOException
{
int index = 0;
while (index < bytes.length)
{
int block_size = Math.min(bytes.length - index, 255);
os.write(block_size);
os.write(bytes, index, block_size);
index += block_size;
}
os.write(0); // last block
}
private static final int LOCAL_COLOR_TABLE_FLAG_MASK = 1 << 7;
private static final int INTERLACE_FLAG_MASK = 1 << 6;
private static final int SORT_FLAG_MASK = 1 << 5;
public void writeImage(BufferedImage src, OutputStream os, Map params)
throws ImageWriteException, IOException
{
// make copy of params; we'll clear keys as we consume them.
params = new HashMap(params);
boolean verbose = ParamMap.getParamBoolean(params, PARAM_KEY_VERBOSE,
false);
// clear format key.
if (params.containsKey(PARAM_KEY_FORMAT))
params.remove(PARAM_KEY_FORMAT);
if (params.containsKey(PARAM_KEY_VERBOSE))
params.remove(PARAM_KEY_VERBOSE);
String xmpXml = null;
if (params.containsKey(PARAM_KEY_XMP_XML))
{
xmpXml = (String) params.get(PARAM_KEY_XMP_XML);
params.remove(PARAM_KEY_XMP_XML);
}
if (params.size() > 0)
{
Object firstKey = params.keySet().iterator().next();
throw new ImageWriteException("Unknown parameter: " + firstKey);
}
int width = src.getWidth();
int height = src.getHeight();
boolean hasAlpha = new PaletteFactory().hasTransparency(src);
int max_colors = hasAlpha ? 255 : 256;
Palette palette2 = new PaletteFactory().makePaletteSimple(src,
max_colors);
// int palette[] = new PaletteFactory().makePaletteSimple(src, 256);
// Map palette_map = paletteToMap(palette);
if (palette2 == null)
{
palette2 = new PaletteFactory().makePaletteQuantized(src,
max_colors);
if (verbose)
System.out.println("quantizing");
} else if (verbose)
System.out.println("exact palette");
if (palette2 == null)
throw new ImageWriteException(
"Gif: can't write images with more than 256 colors");
int palette_size = palette2.length() + (hasAlpha ? 1 : 0);
BinaryOutputStream bos = new BinaryOutputStream(os, BYTE_ORDER_LSB);
{
// write Header
os.write(0x47); // G magic numbers
os.write(0x49); // I
os.write(0x46); // F
os.write(0x38); // 8 version magic numbers
os.write(0x39); // 9
os.write(0x61); // a
// Logical Screen Descriptor.
bos.write2Bytes(width);
bos.write2Bytes(height);
int colorTableScaleLessOne = (palette_size > 128) ? 7
: (palette_size > 64) ? 6 : (palette_size > 32) ? 5
: (palette_size > 16) ? 4 : (palette_size > 8) ? 3
: (palette_size > 4) ? 2
: (palette_size > 2) ? 1 : 0;
int colorTableSizeInFormat = 1 << (colorTableScaleLessOne + 1);
int actual_size = 3 * simple_pow(2, colorTableScaleLessOne + 1);
{
byte colorResolution = (byte) colorTableScaleLessOne; // TODO:
boolean globalColorTableFlag = false;
boolean sortFlag = false;
int globalColorTableFlagMask = 1 << 7;
int sortFlagMask = 8;
int sizeOfGlobalColorTable = 0;
int packedFields = ((globalColorTableFlag ? globalColorTableFlagMask
: 0)
| (sortFlag ? sortFlagMask : 0)
| ((7 & colorResolution) << 4) | (7 & sizeOfGlobalColorTable));
bos.write(packedFields); // one byte
}
{
byte BackgroundColorIndex = 0;
bos.write(BackgroundColorIndex);
}
{
byte PixelAspectRatio = 0;
bos.write(PixelAspectRatio);
}
{ // write Global Color Table.
}
{ // ALWAYS write GraphicControlExtension
bos.write(EXTENSION_CODE);
bos.write((byte) 0xf9);
// bos.write(0xff & (kGraphicControlExtension >> 8));
// bos.write(0xff & (kGraphicControlExtension >> 0));
bos.write((byte) 4); // block size;
int packedFields = hasAlpha ? 1 : 0; // transparency flag
bos.write((byte) packedFields);
bos.write((byte) 0); // Delay Time
bos.write((byte) 0); // Delay Time
bos.write((byte) (hasAlpha ? palette2.length() : 0)); // Transparent
// Color
// Index
bos.write((byte) 0); // terminator
}
if (null != xmpXml)
{
bos.write(EXTENSION_CODE);
bos.write(APPLICATION_EXTENSION_LABEL);
bos.write(XMP_APPLICATION_ID_AND_AUTH_CODE.length); // 0x0B
bos.write(XMP_APPLICATION_ID_AND_AUTH_CODE);
byte xmpXmlBytes[] = xmpXml.getBytes("utf-8");
bos.write(xmpXmlBytes);
// write "magic trailer"
for (int magic = 0; magic <= 0xff; magic++)
bos.write(0xff - magic);
bos.write((byte) 0); // terminator
}
{ // Image Descriptor.
bos.write(IMAGE_SEPARATOR);
bos.write2Bytes(0); // Image Left Position
bos.write2Bytes(0); // Image Top Position
bos.write2Bytes(width); // Image Width
bos.write2Bytes(height); // Image Height
{
boolean LocalColorTableFlag = true;
// boolean LocalColorTableFlag = false;
boolean InterlaceFlag = false;
boolean SortFlag = false;
int SizeOfLocalColorTable = colorTableScaleLessOne;
// int SizeOfLocalColorTable = 0;
int PackedFields = ((LocalColorTableFlag ? LOCAL_COLOR_TABLE_FLAG_MASK
: 0)
| (InterlaceFlag ? INTERLACE_FLAG_MASK : 0)
| (SortFlag ? SORT_FLAG_MASK : 0) | (7 & SizeOfLocalColorTable));
bos.write(PackedFields); // one byte
}
}
{ // write Local Color Table.
for (int i = 0; i < colorTableSizeInFormat; i++)
{
if (i < palette2.length())
{
int rgb = palette2.getEntry(i);
int red = 0xff & (rgb >> 16);
int green = 0xff & (rgb >> 8);
int blue = 0xff & (rgb >> 0);
bos.write(red);
bos.write(green);
bos.write(blue);
} else
{
bos.write(0);
bos.write(0);
bos.write(0);
}
}
}
{ // get Image Data.
int image_data_total = 0;
int LZWMinimumCodeSize = colorTableScaleLessOne + 1;
// LZWMinimumCodeSize = Math.max(8, LZWMinimumCodeSize);
if (LZWMinimumCodeSize < 2)
LZWMinimumCodeSize = 2;
// TODO:
// make
// better
// choice
// here.
bos.write(LZWMinimumCodeSize);
MyLZWCompressor compressor = new MyLZWCompressor(
LZWMinimumCodeSize, BYTE_ORDER_LSB, false); // GIF
// Mode);
byte imagedata[] = new byte[width * height];
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
int argb = src.getRGB(x, y);
int rgb = 0xffffff & argb;
int index;
if (hasAlpha)
{
int alpha = 0xff & (argb >> 24);
final int alphaThreshold = 255;
if (alpha < alphaThreshold)
index = palette2.length(); // is transparent
else
index = palette2.getPaletteIndex(rgb);
} else
{
index = palette2.getPaletteIndex(rgb);
}
imagedata[y * width + x] = (byte) index;
}
}
byte compressed[] = compressor.compress(imagedata);
writeAsSubBlocks(bos, compressed);
image_data_total += compressed.length;
}
// palette2.dump();
bos.write(TERMINATOR_BYTE);
}
bos.close();
os.close();
}
private static final byte XMP_APPLICATION_ID_AND_AUTH_CODE[] = { 0x58, // X
0x4D, // M
0x50, // P
0x20, //
0x44, // D
0x61, // a
0x74, // t
0x61, // a
0x58, // X
0x4D, // M
0x50, // P
};
/**
* Extracts embedded XML metadata as XML string.
* <p>
*
* @param byteSource
* File containing image data.
* @param params
* Map of optional parameters, defined in SanselanConstants.
* @return Xmp Xml as String, if present. Otherwise, returns null.
*/
public String getXmpXml(ByteSource byteSource, Map params)
throws ImageReadException, IOException
{
InputStream is = null;
try
{
is = byteSource.getInputStream();
FormatCompliance formatCompliance = null;
GIFHeaderInfo ghi = readHeader(is, formatCompliance);
if (ghi.globalColorTableFlag)
readColorTable(is, ghi.sizeOfGlobalColorTable, formatCompliance);
ArrayList blocks = readBlocks(ghi, is, true, formatCompliance);
List result = new ArrayList();
for (int i = 0; i < blocks.size(); i++)
{
GIFBlock block = (GIFBlock) blocks.get(i);
if (block.blockCode != XMP_COMPLETE_CODE)
continue;
GenericGIFBlock genericBlock = (GenericGIFBlock) block;
byte blockBytes[] = genericBlock.appendSubBlocks(true);
if (blockBytes.length < XMP_APPLICATION_ID_AND_AUTH_CODE.length)
continue;
if (!compareByteArrays(blockBytes, 0,
XMP_APPLICATION_ID_AND_AUTH_CODE, 0,
XMP_APPLICATION_ID_AND_AUTH_CODE.length))
continue;
byte GIF_MAGIC_TRAILER[] = new byte[256];
for (int magic = 0; magic <= 0xff; magic++)
GIF_MAGIC_TRAILER[magic] = (byte) (0xff - magic);
if (blockBytes.length < XMP_APPLICATION_ID_AND_AUTH_CODE.length
+ GIF_MAGIC_TRAILER.length)
continue;
if (!compareByteArrays(blockBytes, blockBytes.length
- GIF_MAGIC_TRAILER.length, GIF_MAGIC_TRAILER, 0,
GIF_MAGIC_TRAILER.length))
throw new ImageReadException(
"XMP block in GIF missing magic trailer.");
try
{
// XMP is UTF-8 encoded xml.
String xml = new String(
blockBytes,
XMP_APPLICATION_ID_AND_AUTH_CODE.length,
blockBytes.length
- (XMP_APPLICATION_ID_AND_AUTH_CODE.length + GIF_MAGIC_TRAILER.length),
"utf-8");
result.add(xml);
} catch (UnsupportedEncodingException e)
{
throw new ImageReadException("Invalid XMP Block in GIF.");
}
}
if (result.size() < 1)
return null;
if (result.size() > 1)
throw new ImageReadException("More than one XMP Block in GIF.");
return (String) result.get(0);
} finally
{
try
{
if (is != null) {
is.close();
}
} catch (Exception e)
{
Debug.debug(e);
}
}
}
}