/** {@inheritDoc} */
@Override
public Image loadImage(final ImageInfo info, final Map hints, final ImageSessionContext session)
throws ImageException, IOException {
if (!MimeConstants.MIME_JPEG.equals(info.getMimeType())) {
throw new IllegalArgumentException(
"ImageInfo must be from a image with MIME type: " + MimeConstants.MIME_JPEG);
}
ColorSpace colorSpace = null;
boolean appeFound = false;
int sofType = 0;
ByteArrayOutputStream iccStream = null;
final Source src = session.needSource(info.getOriginalURI());
final ImageInputStream in = ImageUtil.needImageInputStream(src);
final JPEGFile jpeg = new JPEGFile(in);
in.mark();
try {
outer:
while (true) {
int reclen;
final int segID = jpeg.readMarkerSegment();
if (log.isTraceEnabled()) {
log.trace("Seg Marker: " + Integer.toHexString(segID));
}
switch (segID) {
case EOI:
log.trace("EOI found. Stopping.");
break outer;
case SOS:
log.trace("SOS found. Stopping early."); // TODO Not sure if
// this is safe
break outer;
case SOI:
case NULL:
break;
case SOF0: // baseline
case SOF1: // extended sequential DCT
case SOF2: // progressive (since PDF 1.3)
case SOFA: // progressive (since PDF 1.3)
sofType = segID;
if (log.isTraceEnabled()) {
log.trace("SOF: " + Integer.toHexString(sofType));
}
in.mark();
try {
reclen = jpeg.readSegmentLength();
in.skipBytes(1); // data precision
in.skipBytes(2); // height
in.skipBytes(2); // width
final int numComponents = in.readUnsignedByte();
if (numComponents == 1) {
colorSpace = ColorSpace.getInstance(ColorSpace.CS_GRAY);
} else if (numComponents == 3) {
colorSpace = ColorSpace.getInstance(ColorSpace.CS_LINEAR_RGB);
} else if (numComponents == 4) {
colorSpace = ColorSpaces.getDeviceCMYKColorSpace();
} else {
throw new ImageException(
"Unsupported ColorSpace for image "
+ info
+ ". The number of components supported are 1, 3 and 4.");
}
} finally {
in.reset();
}
in.skipBytes(reclen);
break;
case APP2: // ICC (see ICC1V42.pdf)
in.mark();
try {
reclen = jpeg.readSegmentLength();
// Check for ICC profile
final byte[] iccString = new byte[11];
in.readFully(iccString);
in.skipBytes(1); // string terminator (null byte)
if ("ICC_PROFILE".equals(new String(iccString, "US-ASCII"))) {
in.skipBytes(2); // chunk sequence number and total
// number of chunks
final int payloadSize = reclen - 2 - 12 - 2;
if (ignoreColorProfile(hints)) {
log.debug("Ignoring ICC profile data in JPEG");
in.skipBytes(payloadSize);
} else {
final byte[] buf = new byte[payloadSize];
in.readFully(buf);
if (iccStream == null) {
if (log.isDebugEnabled()) {
log.debug("JPEG has an ICC profile");
final DataInputStream din =
new DataInputStream(new ByteArrayInputStream(buf));
log.debug("Declared ICC profile size: " + din.readInt());
}
// ICC profiles can be split into several
// chunks
// so collect in a byte array output stream
iccStream = new ByteArrayOutputStream();
}
iccStream.write(buf);
}
}
} finally {
in.reset();
}
in.skipBytes(reclen);
break;
case APPE: // Adobe-specific (see 5116.DCT_Filter.pdf)
in.mark();
try {
reclen = jpeg.readSegmentLength();
// Check for Adobe header
final byte[] adobeHeader = new byte[5];
in.readFully(adobeHeader);
if ("Adobe".equals(new String(adobeHeader, "US-ASCII"))) {
// The reason for reading the APPE marker is that
// Adobe Photoshop
// generates CMYK JPEGs with inverted values. The
// correct thing
// to do would be to interpret the values in the
// marker, but for now
// only assume that if APPE marker is present and
// colorspace is CMYK,
// the image is inverted.
appeFound = true;
}
} finally {
in.reset();
}
in.skipBytes(reclen);
break;
default:
jpeg.skipCurrentMarkerSegment();
}
}
} finally {
in.reset();
}
final ICC_Profile iccProfile = buildICCProfile(info, colorSpace, iccStream);
if (iccProfile == null && colorSpace == null) {
throw new ImageException("ColorSpace could not be identified for JPEG image " + info);
}
boolean invertImage = false;
if (appeFound && colorSpace.getType() == ColorSpace.TYPE_CMYK) {
if (log.isDebugEnabled()) {
log.debug(
"JPEG has an Adobe APPE marker. Note: CMYK Image will be inverted. ("
+ info.getOriginalURI()
+ ")");
}
invertImage = true;
}
final ImageRawJPEG rawImage =
new ImageRawJPEG(
info, ImageUtil.needInputStream(src), sofType, colorSpace, iccProfile, invertImage);
return rawImage;
}