PngChunkType chunkType = chunk.getType();
byte[] bytes = chunk.getBytes();
if (chunkType.equals(PngChunkType.IHDR)) {
PngHeader header = new PngHeader(bytes);
PngDirectory directory = metadata.getOrCreateDirectory(PngDirectory.class);
directory.setInt(PngDirectory.TAG_IMAGE_WIDTH, header.getImageWidth());
directory.setInt(PngDirectory.TAG_IMAGE_HEIGHT, header.getImageHeight());
directory.setInt(PngDirectory.TAG_BITS_PER_SAMPLE, header.getBitsPerSample());
directory.setInt(PngDirectory.TAG_COLOR_TYPE, header.getColorType().getNumericValue());
directory.setInt(PngDirectory.TAG_COMPRESSION_TYPE, header.getCompressionType());
directory.setInt(PngDirectory.TAG_FILTER_METHOD, header.getFilterMethod());
directory.setInt(PngDirectory.TAG_INTERLACE_METHOD, header.getInterlaceMethod());
} else if (chunkType.equals(PngChunkType.PLTE)) {
PngDirectory directory = metadata.getOrCreateDirectory(PngDirectory.class);
directory.setInt(PngDirectory.TAG_PALETTE_SIZE, bytes.length / 3);
} else if (chunkType.equals(PngChunkType.tRNS)) {
PngDirectory directory = metadata.getOrCreateDirectory(PngDirectory.class);
directory.setInt(PngDirectory.TAG_PALETTE_HAS_TRANSPARENCY, 1);
} else if (chunkType.equals(PngChunkType.sRGB)) {
int srgbRenderingIntent = new SequentialByteArrayReader(bytes).getInt8();
PngDirectory directory = metadata.getOrCreateDirectory(PngDirectory.class);
directory.setInt(PngDirectory.TAG_SRGB_RENDERING_INTENT, srgbRenderingIntent);
} else if (chunkType.equals(PngChunkType.cHRM)) {
PngChromaticities chromaticities = new PngChromaticities(bytes);
PngChromaticitiesDirectory directory = metadata.getOrCreateDirectory(PngChromaticitiesDirectory.class);
directory.setInt(PngChromaticitiesDirectory.TAG_WHITE_POINT_X, chromaticities.getWhitePointX());
directory.setInt(PngChromaticitiesDirectory.TAG_WHITE_POINT_X, chromaticities.getWhitePointX());
directory.setInt(PngChromaticitiesDirectory.TAG_RED_X, chromaticities.getRedX());
directory.setInt(PngChromaticitiesDirectory.TAG_RED_Y, chromaticities.getRedY());
directory.setInt(PngChromaticitiesDirectory.TAG_GREEN_X, chromaticities.getGreenX());
directory.setInt(PngChromaticitiesDirectory.TAG_GREEN_Y, chromaticities.getGreenY());
directory.setInt(PngChromaticitiesDirectory.TAG_BLUE_X, chromaticities.getBlueX());
directory.setInt(PngChromaticitiesDirectory.TAG_BLUE_Y, chromaticities.getBlueY());
} else if (chunkType.equals(PngChunkType.gAMA)) {
int gammaInt = new SequentialByteArrayReader(bytes).getInt32();
PngDirectory directory = metadata.getOrCreateDirectory(PngDirectory.class);
directory.setDouble(PngDirectory.TAG_GAMMA, gammaInt / 100000.0);
} else if (chunkType.equals(PngChunkType.iCCP)) {
SequentialReader reader = new SequentialByteArrayReader(bytes);
String profileName = reader.getNullTerminatedString(79);
PngDirectory directory = metadata.getOrCreateDirectory(PngDirectory.class);
directory.setString(PngDirectory.TAG_PROFILE_NAME, profileName);
byte compressionMethod = reader.getInt8();
if (compressionMethod == 0) {
// Only compression method allowed by the spec is zero: deflate
// This assumes 1-byte-per-char, which it is by spec.
int bytesLeft = bytes.length - profileName.length() - 2;
byte[] compressedProfile = reader.getBytes(bytesLeft);
InflaterInputStream inflateStream = new InflaterInputStream(new ByteArrayInputStream(compressedProfile));
new IccReader().extract(new RandomAccessStreamReader(inflateStream), metadata);
inflateStream.close();
}
} else if (chunkType.equals(PngChunkType.bKGD)) {
PngDirectory directory = metadata.getOrCreateDirectory(PngDirectory.class);
directory.setByteArray(PngDirectory.TAG_BACKGROUND_COLOR, bytes);
} else if (chunkType.equals(PngChunkType.tEXt)) {
SequentialReader reader = new SequentialByteArrayReader(bytes);
String keyword = reader.getNullTerminatedString(79);
int bytesLeft = bytes.length - keyword.length() - 1;
String value = reader.getNullTerminatedString(bytesLeft);
textPairs.add(new KeyValuePair(keyword, value));
} else if (chunkType.equals(PngChunkType.iTXt)) {
SequentialReader reader = new SequentialByteArrayReader(bytes);
String keyword = reader.getNullTerminatedString(79);
byte compressionFlag = reader.getInt8();
byte compressionMethod = reader.getInt8();
String languageTag = reader.getNullTerminatedString(bytes.length);
String translatedKeyword = reader.getNullTerminatedString(bytes.length);
int bytesLeft = bytes.length - keyword.length() - 1 - 1 - 1 - languageTag.length() - 1 - translatedKeyword.length() - 1;
String text = null;
if (compressionFlag == 0) {
text = reader.getNullTerminatedString(bytesLeft);
} else if (compressionFlag == 1) {
if (compressionMethod == 0) {
text = StringUtil.fromStream(new InflaterInputStream(new ByteArrayInputStream(bytes, bytes.length - bytesLeft, bytesLeft)));
} else {
metadata.getOrCreateDirectory(PngDirectory.class).addError("Invalid compression method value");
}
} else {
metadata.getOrCreateDirectory(PngDirectory.class).addError("Invalid compression flag value");
}
if (text != null) {
if (keyword.equals("XML:com.adobe.xmp")) {
// NOTE in testing images, the XMP has parsed successfully, but we are not extracting tags from it as necessary
new XmpReader().extract(text, metadata);
} else {
textPairs.add(new KeyValuePair(keyword, text));
}
}
} else if (chunkType.equals(PngChunkType.tIME)) {
SequentialByteArrayReader reader = new SequentialByteArrayReader(bytes);
int year = reader.getUInt16();
int month = reader.getUInt8() - 1;
int day = reader.getUInt8();
int hour = reader.getUInt8();
int minute = reader.getUInt8();
int second = reader.getUInt8();
Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
//noinspection MagicConstant
calendar.set(year, month, day, hour, minute, second);
PngDirectory directory = metadata.getOrCreateDirectory(PngDirectory.class);
directory.setDate(PngDirectory.TAG_LAST_MODIFICATION_TIME, calendar.getTime());
}
}
if (textPairs.size() != 0) {
PngDirectory directory = metadata.getOrCreateDirectory(PngDirectory.class);
directory.setObject(PngDirectory.TAG_TEXTUAL_DATA, textPairs);
}
return metadata;
}