/**
* This will perform a lookup into the color lookup table.
*
* @param componentNumber The component number, probably 1,2,3,3.
* @param lookupIndex The zero-based index into the table, should not exceed the high value.
* @return The value that was from the lookup table.
* @throws IOException If there is an error looking up the color.
*/
public int lookupColor(int componentNumber, int lookupIndex) throws IOException {
COSBase lookupTable = array.getObject(3);
PDColorSpace baseColor = getBaseColorSpace();
byte[] data = getLookupData();
int numberOfComponents = baseColor.getNumberOfComponents();
return (data[componentNumber * numberOfComponents + lookupIndex] + 256) % 256;
}
/**
* This will get the color space that acts as the index for this color space.
*
* @return The base color space.
* @throws IOException If there is error creating the base color space.
*/
public PDColorSpace getBaseColorSpace() throws IOException {
PDColorSpace retval = null;
COSBase base = array.getObject(1);
if (base instanceof COSName) {
retval = PDColorSpaceFactory.createColorSpace((COSName) base);
} else {
throw new IOException("Error:unknown base colorspace");
}
return retval;
}
private byte[] getLookupData() throws IOException {
COSBase lookupTable = array.getObject(3);
byte[] data = null;
if (lookupTable instanceof COSString) {
data = ((COSString) lookupTable).getBytes();
} else if (lookupTable instanceof COSStream) {
// Data will be small so just load the whole thing into memory for
// easier processing
COSStream lookupStream = (COSStream) lookupTable;
InputStream input = lookupStream.getUnfilteredStream();
ByteArrayOutputStream output = new ByteArrayOutputStream(1024);
byte[] buffer = new byte[1024];
int amountRead;
while ((amountRead = input.read(buffer, 0, buffer.length)) != -1) {
output.write(buffer, 0, amountRead);
}
data = output.toByteArray();
} else if (lookupTable == null) {
data = new byte[0];
} else {
throw new IOException("Error: Unknown type for lookup table " + lookupTable);
}
return data;
}
/**
* Constructor.
*
* @param iccArray The ICC stream object.
*/
public PDICCBased(COSArray iccArray) {
array = iccArray;
stream = (COSStream) iccArray.getObject(1);
}
/**
* Get the highest value for the lookup.
*
* @return The hival entry.
*/
public int getHighValue() {
return ((COSNumber) array.getObject(2)).intValue();
}
