/**
* Parse the IFD.
*
* @param byteOffsetIsValid If true, allow offsets on odd byte boundaries
* @param suppressErrors If true, return IFD even with errors
* @return The offset of the next IFD
*/
public long parse(boolean byteOffsetIsValid, boolean suppressErrors) throws TiffException {
try {
return parse(byteOffsetIsValid);
} catch (TiffException e) {
// If we got a TiffException and we're suppressing errors,
// cover over the exception and issue an info message;
// but we can't follow the IFD chain further.
if (suppressErrors) {
_info.setMessage(new InfoMessage(e.getMessage(), e.getOffset()));
return 0;
} else throw e;
}
}
/**
* Parse the IFD. Errors are not suppressed.
*
* @param byteOffsetIsValid If true, allow offsets on odd byte boundaries
* @return The offset of the next IFD
*/
public long parse(boolean byteOffsetIsValid) throws TiffException {
/* Start at the IFD offset, read the number of entries, then
* read the entire IFD.
*/
long offset = _offset;
_next = 0L;
byte[] buffer;
int nFields = 0;
try {
_raf.seek(offset);
nFields = ModuleBase.readUnsignedShort(_raf, _bigEndian);
offset += 2;
int len = 12 * nFields;
buffer = new byte[len];
_raf.read(buffer, 0, len);
/* Read the offset of the next IFD (or 0 if none). */
offset += len;
_next = ModuleBase.readUnsignedInt(_raf, _bigEndian);
} catch (Exception e) {
throw new TiffException("Premature EOF", offset);
}
DataInputStream ifdStream = new DataInputStream(new ByteArrayInputStream(buffer));
try {
int prevTag = 0;
for (int i = 0; i < nFields; i++) {
int tag = ModuleBase.readUnsignedShort(ifdStream, _bigEndian, null);
/* Tags must be in ascending numerical order. */
if (!debug_allowoutofsequence && tag < prevTag) {
_info.setMessage(
new ErrorMessage("Tag " + tag + " out of sequence", _offset + 2 + 12 * i));
_info.setWellFormed(false);
}
prevTag = tag;
int type = ModuleBase.readUnsignedShort(ifdStream, _bigEndian, null);
/* Skip over tags with unknown type. */
if (type < BYTE || type > IFD) {
_info.setMessage(
new ErrorMessage(
"Unknown data type", "Type = " + type + ", Tag = " + tag, _offset + 4 + 12 * i));
} else {
/* Type gives indication of the TIFF version. */
if (SBYTE <= type && type <= IFD) {
_version = 6;
}
long count = ModuleBase.readUnsignedInt(ifdStream, _bigEndian, null);
long value = ModuleBase.readUnsignedInt(ifdStream, _bigEndian, null);
if (calcValueSize(type, count) > 4) {
/* Value is the word-aligned offset of the actual
* value. */
if ((value & 1) != 0) {
if (byteOffsetIsValid) {
_info.setMessage(
new InfoMessage(
"Value offset not word-aligned: " + value, _offset + 10 + 12 * i));
} else {
throw new TiffException(
"Value offset not " + "word-aligned: " + value, _offset + 10 + 12 * i);
}
}
} else {
/* Value is the actual value; pass the offset of
* the value. */
value = _offset + 10 + 12 * i;
}
lookupTag(tag, type, count, value);
}
}
} catch (IOException e) {
throw new TiffException("Read error", _offset + 2);
}
postParseInitialization();
return _next;
}