private static double decodeWord(byte[] plane, int index, int pixelType, boolean little) {
final double value;
switch (pixelType) {
case FormatTools.UINT8:
value = plane[index] & 0xff;
break;
case FormatTools.INT8:
value = plane[index];
break;
case FormatTools.UINT16:
value = DataTools.bytesToShort(plane, 2 * index, 2, little) & 0xffff;
break;
case FormatTools.INT16:
value = DataTools.bytesToShort(plane, 2 * index, 2, little);
break;
case FormatTools.UINT32:
value = DataTools.bytesToInt(plane, 4 * index, 4, little) & 0xffffffffL;
break;
case FormatTools.INT32:
value = DataTools.bytesToInt(plane, 4 * index, 4, little);
break;
case FormatTools.FLOAT:
value = DataTools.bytesToFloat(plane, 4 * index, 4, little);
break;
case FormatTools.DOUBLE:
value = DataTools.bytesToDouble(plane, 8 * index, 8, little);
break;
default:
value = Double.NaN;
}
return value;
}
private void writePixels(String chunk, byte[] stream, int x, int y, int width, int height)
throws FormatException, IOException {
MetadataRetrieve r = getMetadataRetrieve();
int sizeC = getSamplesPerPixel();
String type = r.getPixelsType(series).toString();
int pixelType = FormatTools.pixelTypeFromString(type);
boolean signed = FormatTools.isSigned(pixelType);
if (!isFullPlane(x, y, width, height)) {
throw new FormatException("APNGWriter does not support writing tiles.");
}
ByteArrayOutputStream s = new ByteArrayOutputStream();
s.write(chunk.getBytes());
if (chunk.equals("fdAT")) {
s.write(DataTools.intToBytes(nextSequenceNumber++, false));
}
DeflaterOutputStream deflater = new DeflaterOutputStream(s);
int planeSize = stream.length / sizeC;
int rowLen = stream.length / height;
int bytesPerPixel = stream.length / (width * height * sizeC);
byte[] rowBuf = new byte[rowLen];
for (int i = 0; i < height; i++) {
deflater.write(0);
if (interleaved) {
if (littleEndian) {
for (int col = 0; col < width * sizeC; col++) {
int offset = (i * sizeC * width + col) * bytesPerPixel;
int pixel = DataTools.bytesToInt(stream, offset, bytesPerPixel, littleEndian);
DataTools.unpackBytes(pixel, rowBuf, col * bytesPerPixel, bytesPerPixel, false);
}
} else System.arraycopy(stream, i * rowLen, rowBuf, 0, rowLen);
} else {
int max = (int) Math.pow(2, bytesPerPixel * 8 - 1);
for (int col = 0; col < width; col++) {
for (int c = 0; c < sizeC; c++) {
int offset = c * planeSize + (i * width + col) * bytesPerPixel;
int pixel = DataTools.bytesToInt(stream, offset, bytesPerPixel, littleEndian);
if (signed) {
if (pixel < max) pixel += max;
else pixel -= max;
}
int output = (col * sizeC + c) * bytesPerPixel;
DataTools.unpackBytes(pixel, rowBuf, output, bytesPerPixel, false);
}
}
}
deflater.write(rowBuf);
}
deflater.finish();
byte[] b = s.toByteArray();
// write chunk length
out.writeInt(b.length - 4);
out.write(b);
// write checksum
out.writeInt(crc(b));
}