jfifmarkersegment.java

java1.6众多例子参考

                // Remove the jfif segment, which should be there.
                MarkerSegment jfif = metadata.findMarkerSegment
                    (JFIFMarkerSegment.class, true);
                if (jfif == null) {
                    throw new IllegalThumbException();
                }

                metadata.markerSequence.remove(jfif);

                /*  Use this if removing leaves a hole and causes trouble

                // Get the tree
                String format = metadata.getNativeMetadataFormatName();
                IIOMetadataNode tree = 
                (IIOMetadataNode) metadata.getAsTree(format);

                // If there is no app0jfif node, the image is bad
                NodeList jfifs = tree.getElementsByTagName("app0JFIF");
                if (jfifs.getLength() == 0) {
                throw new IllegalThumbException();
                }

                // remove the app0jfif node
                Node jfif = jfifs.item(0);
                Node parent = jfif.getParentNode();
                parent.removeChild(jfif);

                metadata.setFromTree(format, tree);
                */

                thumbWriter.write(new IIOImage(thumb, null, metadata));

                thumbWriter.dispose();
                // Now check that the size is OK
                if (baos.size() > MAZ_BUFSIZE) {
                    throw new IllegalThumbException();
                }
                data = baos.toByteArray();
            } catch (IOException e) {
                throw new IllegalThumbException();
            }
        }

        int getWidth() {
            int retval = 0;
            SOFMarkerSegment sof = 
                (SOFMarkerSegment) thumbMetadata.findMarkerSegment
                (SOFMarkerSegment.class, true);
            if (sof != null) {
                retval = sof.samplesPerLine;
            }
            return retval;
        }

        int getHeight() {
            int retval = 0;
            SOFMarkerSegment sof = 
                (SOFMarkerSegment) thumbMetadata.findMarkerSegment
                (SOFMarkerSegment.class, true);
            if (sof != null) {
                retval = sof.numLines;
            }
            return retval;
        }

        private class ThumbnailReadListener 
            implements IIOReadProgressListener {
            JPEGImageReader reader = null;
            ThumbnailReadListener (JPEGImageReader reader) {
                this.reader = reader;
            }
            public void sequenceStarted(ImageReader source, int minIndex) {}
            public void sequenceComplete(ImageReader source) {}
            public void imageStarted(ImageReader source, int imageIndex) {}
            public void imageProgress(ImageReader source, 
                                      float percentageDone) {
                reader.thumbnailProgress(percentageDone);
            }
            public void imageComplete(ImageReader source) {}
            public void thumbnailStarted(ImageReader source,
                int imageIndex, int thumbnailIndex) {}
            public void thumbnailProgress(ImageReader source, float percentageDone) {}
            public void thumbnailComplete(ImageReader source) {}
            public void readAborted(ImageReader source) {}
        }

        BufferedImage getThumbnail(ImageInputStream iis, 
                                   JPEGImageReader reader) 
            throws IOException {
            iis.mark();
            iis.seek(streamPos);
            JPEGImageReader thumbReader = new JPEGImageReader(null);
            thumbReader.setInput(iis);
            thumbReader.addIIOReadProgressListener
                (new ThumbnailReadListener(reader));
            BufferedImage ret = thumbReader.read(0, null);
            thumbReader.dispose();
            iis.reset();
            return ret;
        }

        protected Object clone() {
            JFIFThumbJPEG newGuy = (JFIFThumbJPEG) super.clone();
            if (thumbMetadata != null) {
                newGuy.thumbMetadata = (JPEGMetadata) thumbMetadata.clone();
            }
            return newGuy;
        }

        IIOMetadataNode getNativeNode() {
            IIOMetadataNode node = new IIOMetadataNode("JFIFthumbJPEG");
            if (thumbMetadata != null) {
                node.appendChild(thumbMetadata.getNativeTree()); 
            }
            return node;
        }

        int getLength() {
            if (data == null) {
                return 0;
            } else {
                return data.length;
            }
        }

        void write(ImageOutputStream ios,
                   JPEGImageWriter writer) throws IOException {
            int progInterval = data.length / 20;  // approx. every 5%
            if (progInterval == 0) {
                progInterval = 1;
            }
            for (int offset = 0; 
                 offset < data.length;) {
                int len = Math.min(progInterval, data.length-offset);
                ios.write(data, offset, len);
                offset += progInterval;
                float percentDone = ((float) offset * 100) / data.length;
                if (percentDone > 100.0F) {
                    percentDone = 100.0F;
                }
                writer.thumbnailProgress (percentDone);
            }
        }
            
        void print () {
            System.out.println("JFIF thumbnail stored as JPEG");
        }
    }

    /**
     * Write out the given profile to the stream, embedded in
     * the necessary number of APP2 segments, per the ICC spec.
     * This is the only mechanism for writing an ICC profile
     * to a stream.
     */
    static void writeICC(ICC_Profile profile, ImageOutputStream ios) 
        throws IOException {
        int LENGTH_LENGTH = 2;
        final String ID = "ICC_PROFILE";
        int ID_LENGTH = ID.length()+1; // spec says it's null-terminated
        int COUNTS_LENGTH = 2;
        int MAX_ICC_CHUNK_SIZE = 
            65535 - LENGTH_LENGTH - ID_LENGTH - COUNTS_LENGTH;

        byte [] data = profile.getData();
        int numChunks = data.length / MAX_ICC_CHUNK_SIZE;
        if ((data.length % MAX_ICC_CHUNK_SIZE) != 0) {
            numChunks++;
        }
        int chunkNum = 1;
        int offset = 0;
        for (int i = 0; i < numChunks; i++) {
            int dataLength = Math.min(data.length-offset, MAX_ICC_CHUNK_SIZE);
            int segLength = dataLength+COUNTS_LENGTH+ID_LENGTH+LENGTH_LENGTH;
            ios.write(0xff);
            ios.write(JPEG.APP2);
            MarkerSegment.write2bytes(ios, segLength);
            byte [] id = ID.getBytes("US-ASCII");
            ios.write(id);
            ios.write(0); // Null-terminate the string
            ios.write(chunkNum++);
            ios.write(numChunks);
            ios.write(data, offset, dataLength);
            offset += dataLength;
        }
    }

    /**
     * An APP2 marker segment containing an ICC profile.  In the stream
     * a profile larger than 64K is broken up into a series of chunks.
     * This inner class represents the complete profile as a single objec,
     * combining chunks as necessary.
     */
    class ICCMarkerSegment extends MarkerSegment {
        ArrayList chunks = null;
        byte [] profile = null; // The complete profile when it's fully read
                         // May remain null when writing
        private static final int ID_SIZE = 12;
        int chunksRead;
        int numChunks;
        
        ICCMarkerSegment(ICC_ColorSpace cs) {
            super(JPEG.APP2);
            chunks = null;
            chunksRead = 0;
            numChunks = 0;
            profile = cs.getProfile().getData();
        }

        ICCMarkerSegment(JPEGBuffer buffer) throws IOException {
            super(buffer);  // gets whole segment or fills the buffer
            if (debug) {
                System.out.println("Creating new ICC segment");
            }
            buffer.bufPtr += ID_SIZE; // Skip the id
            buffer.bufAvail -= ID_SIZE;
            /*
             * Reduce the stored length by the id size.  The stored 
             * length is used to store the length of the profile
             * data only.
             */
            length -= ID_SIZE;

            // get the chunk number
            int chunkNum = buffer.buf[buffer.bufPtr] & 0xff;
            // get the total number of chunks
            numChunks = buffer.buf[buffer.bufPtr+1] & 0xff;

            if (chunkNum > numChunks) {
                throw new IIOException
                    ("Image format Error; chunk num > num chunks");
            }

            // if there are no more chunks, set up the data
            if (numChunks == 1) {
                // reduce the stored length by the two chunk numbering bytes
                length -= 2;
                profile = new byte[length];
                buffer.bufPtr += 2;
                buffer.bufAvail-=2;
                buffer.readData(profile);
                inICC = false;
            } else {
                // If we store them away, include the chunk numbering bytes
                byte [] profileData = new byte[length];
                // Now reduce the stored length by the
                // two chunk numbering bytes
                length -= 2;
                buffer.readData(profileData);
                chunks = new ArrayList();
                chunks.add(profileData);
                chunksRead = 1;
                inICC = true;
            }
        }

        ICCMarkerSegment(Node node) throws IIOInvalidTreeException {
            super(JPEG.APP2);
            if (node instanceof IIOMetadataNode) {
                IIOMetadataNode ourNode = (IIOMetadataNode) node;
                ICC_Profile prof = (ICC_Profile) ourNode.getUserObject();
                if (prof != null) {  // May be null
                    profile = prof.getData();
                }
            }
        }

        protected Object clone () {
            ICCMarkerSegment newGuy = (ICCMarkerSegment) super.clone();
            if (profile != null) {
                newGuy.profile = (byte[]) profile.clone();
            }
            return newGuy;
        }

        boolean addData(JPEGBuffer buffer) throws IOException {
            if (debug) {
                System.out.println("Adding to ICC segment");
            }
            // skip the tag
            buffer.bufPtr++;
            buffer.bufAvail--;
            // Get the length, but not in length
            int dataLen = (buffer.buf[buffer.bufPtr++] & 0xff) << 8;
            dataLen |= buffer.buf[buffer.bufPtr++] & 0xff;
            buffer.bufAvail -= 2;
            // Don't include length itself
            dataLen -= 2;
            // skip the id
            buffer.bufPtr += ID_SIZE; // Skip the id
            buffer.bufAvail -= ID_SIZE;
            /*
             * Reduce the stored length by the id size.  The stored 
             * length is used to store the length of the profile
             * data only.
             */
            dataLen -= ID_SIZE;

            // get the chunk number
            int chunkNum = buffer.buf[buffer.bufPtr] & 0xff;
            if (chunkNum > numChunks) {
                throw new IIOException
                    ("Image format Error; chunk num > num chunks");
            }

            // get the number of chunks, which should match
            int newNumChunks = buffer.buf[buffer.bufPtr+1] & 0xff;
            if (numChunks != newNumChunks) {
                throw new IIOException
                    ("Image format Error; icc num chunks mismatch");
            }
            dataLen -= 2;
            if (debug) {
                System.out.println("chunkNum: " + chunkNum 
                                   + ", numChunks: " + numChunks
                                   + ", dataLen: " + dataLen);
            }
            boolean retval = false;
            byte [] profileData = new byte[dataLen];
            buffer.readData(profileData);
            chunks.add(profileData);
            length += dataLen;
            chunksRead++;
            if (chunksRead < numChunks) {
                inICC = true;
            } else {
                if (debug) {
                    System.out.println("Completing profile; total length is "
                                       + length);
                }
                // create an array for the whole thing
                profile = new byte[length];
                // copy the existing chunks, releasing them
                // Note that they may be out of order

                int index = 0;
                for (int i = 1; i <= numChunks; i++) {
                    boolean foundIt = false;
                    for (int chunk = 0; chunk < chunks.size(); chunk++) {
                        byte [] chunkData = (byte []) chunks.get(chunk);
                        if (chunkData[0] == i) { // Right one
                            System.arraycopy(chunkData, 2, 
                                             profile, index, 
                                             chunkData.length-2);
                            index += chunkData.length-2;
                            foundIt = true;
                        }
                    }
                    if (foundIt == false) {
                        throw new IIOException
                            ("Image Format Error: Missing ICC chunk num " + i);
                    }
                }

                chunks = null;
                chunksRead = 0;
                numChunks = 0;
                inICC = false;
                retval = true;
            }
            return retval;
        }

        IIOMetadataNode getNativeNode() {
            IIOMetadataNode node = new IIOMetadataNode("app2ICC");
            if (profile != null) {
                node.setUserObject(ICC_Profile.getInstance(profile));
            }
            return node;
        }

        /**
         * No-op.  Profiles are never written from metadata.
         * They are written from the ColorSpace of the image.
         */
        void write(ImageOutputStream ios) throws IOException {
            // No-op
        }

        void print () {
            printTag("ICC Profile APP2");
        }
    }
}