private void decodeTile(int ti, int tj, int band) throws IOException {
if (DEBUG) {
System.out.println("decodeTile(" + ti + "," + tj + "," + band + ")");
}
// Compute the region covered by the strip or tile
Rectangle tileRect =
new Rectangle(
ti * tileOrStripWidth, tj * tileOrStripHeight, tileOrStripWidth, tileOrStripHeight);
// Clip against the image bounds if the image is not tiled. If it
// is tiled, the tile may legally extend beyond the image bounds.
if (!isImageTiled(currIndex)) {
tileRect = tileRect.intersection(new Rectangle(0, 0, width, height));
}
// Return if the intersection is empty.
if (tileRect.width <= 0 || tileRect.height <= 0) {
return;
}
int srcMinX = tileRect.x;
int srcMinY = tileRect.y;
int srcWidth = tileRect.width;
int srcHeight = tileRect.height;
// Determine dest region that can be derived from the
// source region
dstMinX = iceil(srcMinX - sourceXOffset, srcXSubsampling);
int dstMaxX = ifloor(srcMinX + srcWidth - 1 - sourceXOffset, srcXSubsampling);
dstMinY = iceil(srcMinY - sourceYOffset, srcYSubsampling);
int dstMaxY = ifloor(srcMinY + srcHeight - 1 - sourceYOffset, srcYSubsampling);
dstWidth = dstMaxX - dstMinX + 1;
dstHeight = dstMaxY - dstMinY + 1;
dstMinX += dstXOffset;
dstMinY += dstYOffset;
// Clip against image bounds
Rectangle dstRect =
new Rectangle(
dstMinX, dstMinY,
dstWidth, dstHeight);
dstRect = dstRect.intersection(theImage.getRaster().getBounds());
dstMinX = dstRect.x;
dstMinY = dstRect.y;
dstWidth = dstRect.width;
dstHeight = dstRect.height;
if (dstWidth <= 0 || dstHeight <= 0) {
return;
}
// Backwards map dest region to source to determine
// active source region
int activeSrcMinX = (dstMinX - dstXOffset) * srcXSubsampling + sourceXOffset;
int sxmax = (dstMinX + dstWidth - 1 - dstXOffset) * srcXSubsampling + sourceXOffset;
int activeSrcWidth = sxmax - activeSrcMinX + 1;
int activeSrcMinY = (dstMinY - dstYOffset) * srcYSubsampling + sourceYOffset;
int symax = (dstMinY + dstHeight - 1 - dstYOffset) * srcYSubsampling + sourceYOffset;
int activeSrcHeight = symax - activeSrcMinY + 1;
decompressor.setSrcMinX(srcMinX);
decompressor.setSrcMinY(srcMinY);
decompressor.setSrcWidth(srcWidth);
decompressor.setSrcHeight(srcHeight);
decompressor.setDstMinX(dstMinX);
decompressor.setDstMinY(dstMinY);
decompressor.setDstWidth(dstWidth);
decompressor.setDstHeight(dstHeight);
decompressor.setActiveSrcMinX(activeSrcMinX);
decompressor.setActiveSrcMinY(activeSrcMinY);
decompressor.setActiveSrcWidth(activeSrcWidth);
decompressor.setActiveSrcHeight(activeSrcHeight);
int tileIndex = tj * tilesAcross + ti;
if (planarConfiguration == BaselineTIFFTagSet.PLANAR_CONFIGURATION_PLANAR) {
tileIndex += band * tilesAcross * tilesDown;
}
long offset = getTileOrStripOffset(tileIndex);
long byteCount = getTileOrStripByteCount(tileIndex);
//
// Attempt to handle truncated streams, i.e., where reading the
// compressed strip or tile would result in an EOFException. The
// number of bytes to read is clamped to the number available
// from the stream starting at the indicated position in the hope
// that the decompressor will handle it.
//
long streamLength = stream.length();
if (streamLength > 0 && offset + byteCount > streamLength) {
processWarningOccurred("Attempting to process truncated stream.");
if (Math.max(byteCount = streamLength - offset, 0) == 0) {
processWarningOccurred("No bytes in strip/tile: skipping.");
return;
}
}
decompressor.setStream(stream);
decompressor.setOffset(offset);
decompressor.setByteCount((int) byteCount);
decompressor.beginDecoding();
stream.mark();
decompressor.decode();
stream.reset();
}
