ImageFileDirectory(BufferedInputStream bufferedIn, long positionAfterTIFFHeader, boolean reverse)
throws IOException {
bufferedIn.reset();
if (JPEGMarkerInputStream.skipFully(bufferedIn, positionAfterTIFFHeader)
!= positionAfterTIFFHeader) throw new IOException();
byte[] array = new byte[4];
if (JPEGMarkerInputStream.readFully(bufferedIn, array, 2, reverse) != 2)
throw new IOException("Corrupt image file directory.");
int numberOfEntries = (array[0] & 0xff) * 256 + (array[1] & 0xff);
entries = new DirectoryEntry[numberOfEntries];
for (int a = 0; a < numberOfEntries; a++) {
try {
DirectoryEntry entry = new DirectoryEntry(bufferedIn, reverse);
entries[a] = (entry);
} catch (RuntimeException e) {
System.err.println(a + " / " + numberOfEntries);
throw e;
}
}
/**
* According to the specs: what is supposed to follow is a 4-byte pointer to the next IFD.
* However I found an APP1 block that omits these 4 bytes and instead contains some
* DirectoryEntries.
*
* <p>So first I'll scan through the entries and see if any of them believe they should start
* here, and if so we just assume there is no next IFD to point to. (If anything this errs on
* the side of omitting data, instead of trying to read data where the isn't any.)
*/
long positionToExpectIFDPtr = positionAfterTIFFHeader + 2 + 12 * numberOfEntries;
boolean missingIFDPtr = false;
for (int a = 0; a < numberOfEntries && (!missingIFDPtr); a++) {
int k = entries[a].positionAfterTIFFHeader();
if (k != -1 && k == positionToExpectIFDPtr) {
missingIFDPtr = true;
}
}
if (missingIFDPtr) {
// there is no space for the IFD position to be, so assume it's zero.
nextIFDPosition = 0;
} else {
if (JPEGMarkerInputStream.readFully(bufferedIn, array, 4, reverse) != 4)
throw new IOException("Corrupt image file directory.");
nextIFDPosition =
((array[0] & 0xff) << 24)
+ ((array[1] & 0xff) << 16)
+ ((array[2] & 0xff) << 8)
+ (array[3] & 0xff);
}
}
DirectoryEntry(InputStream in, boolean reverse) throws IOException {
byte[] array = new byte[4];
if (JPEGMarkerInputStream.readFully(in, array, 2, reverse) != 2) throw new IOException();
tagNumber = (array[0] & 0xff) * 256 + (array[1] & 0xff);
if (JPEGMarkerInputStream.readFully(in, array, 2, reverse) != 2) throw new IOException();
dataFormat = (array[0] & 0xff) * 256 + (array[1] & 0xff);
if (JPEGMarkerInputStream.readFully(in, array, 4, reverse) != 4) throw new IOException();
componentCount =
((array[0] & 0xff) << 24)
+ ((array[1] & 0xff) << 16)
+ ((array[2] & 0xff) << 8)
+ ((array[3] & 0xff) << 0);
fieldValue = new byte[4];
if (JPEGMarkerInputStream.readFully(in, fieldValue, 4, reverse) != 4) throw new IOException();
}
/**
* @param in a BufferedInputStream that was last marked at the start of the TIFF header.
* @throws IOException
*/
void resolveValue(BufferedInputStream in) throws IOException {
int byteLength = getValueByteLength();
byte[] data;
if (byteLength > 4) {
// we have to read this data:
byte[] newData = new byte[byteLength];
int positionAfterTIFFHeader = readLong(fieldValue, 0);
in.reset();
if (JPEGMarkerInputStream.skipFully(in, positionAfterTIFFHeader) != positionAfterTIFFHeader)
throw new IOException();
JPEGMarkerInputStream.readFully(in, newData, byteLength, false);
data = newData;
} else {
data = fieldValue;
}
if (dataFormat == 7 || dataFormat == 0) { // UNDEFINED
value = data;
return;
} else if (dataFormat == 2) { // ASCII
StringBuffer buffer = new StringBuffer();
for (int a = 0; a < componentCount; a++) {
int i = (data[a] & 0xff);
if (i == 0) {
break;
}
char c = (char) i;
buffer.append(c);
}
value = buffer.toString();
return;
}
Object[] valueArray;
if (dataFormat == 1
|| // BYTE
dataFormat == 6
|| // SIGNED BYTE
dataFormat == 3
|| // SHORT
dataFormat == 8
|| // SIGNED SHORT
dataFormat == 4
|| // LONG
dataFormat == 9) { // SIGNED LONG
valueArray = new Integer[componentCount];
} else if (dataFormat == 5
|| // RATIONAL
dataFormat == 10) { // SIGNED RATIONAL
valueArray = new Double[componentCount];
} else {
throw new RuntimeException("unexpected data format (" + dataFormat + ")");
}
for (int a = 0; a < componentCount; a++) {
switch (dataFormat) {
case 1: // byte
valueArray[a] = new Integer(readByte(data, a * 1));
break;
case 6: // signed byte
valueArray[a] = new Integer(readSignedByte(data, a * 1));
break;
case 3: // short
valueArray[a] = new Integer(readShort(data, a * 2));
break;
case 8: // signed short
valueArray[a] = new Integer(readSignedShort(data, a * 2));
break;
case 4: // long
valueArray[a] = new Integer(readLong(data, a * 4));
break;
case 9: // signed long
valueArray[a] = new Integer(readSignedLong(data, a * 4));
break;
case 5: // rational
double numerator = readLong(data, a * 4);
double denominator = readLong(data, a * 4 + 4);
valueArray[a] = new Double(numerator / denominator);
break;
case 10: // signed rational
double numerator2 = readSignedLong(data, a * 4);
double denominator2 = readSignedLong(data, a * 4 + 4);
valueArray[a] = new Double(numerator2 / denominator2);
break;
default:
throw new RuntimeException("Unexpected condition.");
}
}
if (valueArray.length == 1) {
value = valueArray[0];
} else {
value = valueArray;
}
}