public void readHeader() throws IOException {
if (gotHeader) return;
if (iis == null) {
throw new IllegalStateException("Input source not set!");
}
metadata = new WBMPMetadata();
wbmpType = iis.readByte(); // TypeField
byte fixHeaderField = iis.readByte();
// check for valid wbmp image
if (fixHeaderField != 0 || !isValidWbmpType(wbmpType)) {
throw new IIOException(I18N.getString("WBMPImageReader2"));
}
metadata.wbmpType = wbmpType;
// Read image width
width = readMultiByteInteger();
metadata.width = width;
// Read image height
height = readMultiByteInteger();
metadata.height = height;
gotHeader = true;
}
private int readMultiByteInteger() throws IOException {
int value = iis.readByte();
int result = value & 0x7f;
while ((value & 0x80) == 0x80) {
result <<= 7;
value = iis.readByte();
result |= (value & 0x7f);
}
return result;
}
public BufferedImage read(int imageIndex, ImageReadParam param) throws IOException {
if (iis == null) {
throw new IllegalStateException(I18N.getString("WBMPImageReader1"));
}
checkIndex(imageIndex);
clearAbortRequest();
processImageStarted(imageIndex);
if (param == null) param = getDefaultReadParam();
// read header
readHeader();
Rectangle sourceRegion = new Rectangle(0, 0, 0, 0);
Rectangle destinationRegion = new Rectangle(0, 0, 0, 0);
computeRegions(
param, this.width, this.height, param.getDestination(), sourceRegion, destinationRegion);
int scaleX = param.getSourceXSubsampling();
int scaleY = param.getSourceYSubsampling();
int xOffset = param.getSubsamplingXOffset();
int yOffset = param.getSubsamplingYOffset();
// If the destination is provided, then use it. Otherwise, create new one
BufferedImage bi = param.getDestination();
if (bi == null)
bi =
new BufferedImage(
destinationRegion.x + destinationRegion.width,
destinationRegion.y + destinationRegion.height,
BufferedImage.TYPE_BYTE_BINARY);
boolean noTransform =
destinationRegion.equals(new Rectangle(0, 0, width, height))
&& destinationRegion.equals(new Rectangle(0, 0, bi.getWidth(), bi.getHeight()));
// Get the image data.
WritableRaster tile = bi.getWritableTile(0, 0);
// Get the SampleModel.
MultiPixelPackedSampleModel sm = (MultiPixelPackedSampleModel) bi.getSampleModel();
if (noTransform) {
if (abortRequested()) {
processReadAborted();
return bi;
}
// If noTransform is necessary, read the data.
iis.read(
((DataBufferByte) tile.getDataBuffer()).getData(), 0, height * sm.getScanlineStride());
processImageUpdate(bi, 0, 0, width, height, 1, 1, new int[] {0});
processImageProgress(100.0F);
} else {
int len = (this.width + 7) / 8;
byte[] buf = new byte[len];
byte[] data = ((DataBufferByte) tile.getDataBuffer()).getData();
int lineStride = sm.getScanlineStride();
iis.skipBytes(len * sourceRegion.y);
int skipLength = len * (scaleY - 1);
// cache the values to avoid duplicated computation
int[] srcOff = new int[destinationRegion.width];
int[] destOff = new int[destinationRegion.width];
int[] srcPos = new int[destinationRegion.width];
int[] destPos = new int[destinationRegion.width];
for (int i = destinationRegion.x, x = sourceRegion.x, j = 0;
i < destinationRegion.x + destinationRegion.width;
i++, j++, x += scaleX) {
srcPos[j] = x >> 3;
srcOff[j] = 7 - (x & 7);
destPos[j] = i >> 3;
destOff[j] = 7 - (i & 7);
}
for (int j = 0, y = sourceRegion.y, k = destinationRegion.y * lineStride;
j < destinationRegion.height;
j++, y += scaleY) {
if (abortRequested()) break;
iis.read(buf, 0, len);
for (int i = 0; i < destinationRegion.width; i++) {
// get the bit and assign to the data buffer of the raster
int v = (buf[srcPos[i]] >> srcOff[i]) & 1;
data[k + destPos[i]] |= v << destOff[i];
}
k += lineStride;
iis.skipBytes(skipLength);
processImageUpdate(bi, 0, j, destinationRegion.width, 1, 1, 1, new int[] {0});
processImageProgress(100.0F * j / destinationRegion.height);
}
}
if (abortRequested()) processReadAborted();
else processImageComplete();
return bi;
}