/*
* This code is licensed under the Apache License, Version 2.0 (the "License");
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Source
* http://blog.jaimon.co.uk/simpleimageinfo/SimpleImageInfo.java.html
* http://jaimonmathew.wordpress.com/2011/01/29/simpleimageinfo/
* Revision history
* 0.1 - 29/Jan/2011 - Initial version created
* 0.x - 25/Oct/2011 - Refactoring and cleanups, adding length (Nuxeo)
*
* @author Jaimon Mathew <http://www.jaimon.co.uk>
* @author Florent Guillaume <http://nuxeo.com/>
*/
package org.nuxeo.ecm.core.opencmis.impl.util;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* A Java class to determine image width, height, length and MIME types for a number of image file formats without
* loading the whole image data.
*/
public class SimpleImageInfo {
protected int width;
protected int height;
protected long length;
protected String mimeType;
protected InputStream in;
public SimpleImageInfo(InputStream stream) throws IOException {
if (stream instanceof BufferedInputStream) {
in = stream;
} else {
in = new BufferedInputStream(stream);
}
processStream();
finishStream();
stream.close();
}
public int getWidth() {
return width;
}
public int getHeight() {
return height;
}
public long getLength() {
return length;
}
public String getMimeType() {
return mimeType;
}
protected void processStream() throws IOException {
int c1 = read();
int c2 = read();
int c3 = read();
mimeType = "application/octet-stream";
width = -1;
height = -1;
if (c1 == 'G' && c2 == 'I' && c3 == 'F') { // GIF
skip(3);
width = readInt(2, false);
height = readInt(2, false);
mimeType = "image/gif";
} else if (c1 == 0xFF && c2 == 0xD8) { // JPG
while (c3 == 255) {
int marker = read();
int len = readInt(2, true);
if (marker == 192 || marker == 193 || marker == 194) {
skip(1);
height = readInt(2, true);
width = readInt(2, true);
mimeType = "image/jpeg";
break;
}
skip(len - 2);
c3 = read();
}
} else if (c1 == 137 && c2 == 80 && c3 == 78) { // PNG
skip(15);
width = readInt(2, true);
skip(2);
height = readInt(2, true);
mimeType = "image/png";
} else if (c1 == 66 && c2 == 77) { // BMP
skip(15);
width = readInt(2, false);
skip(2);
height = readInt(2, false);
mimeType = "image/bmp";
} else {
int c4 = read();
if ((c1 == 'M' && c2 == 'M' && c3 == 0 && c4 == 42) || (c1 == 'I' && c2 == 'I' && c3 == 42 && c4 == 0)) { // TIFF
boolean bigEndian = c1 == 'M';
int ifd = 0;
int entries;
ifd = readInt(4, bigEndian);
skip(ifd - 8);
entries = readInt(2, bigEndian);
for (int i = 1; i <= entries; i++) {
int tag = readInt(2, bigEndian);
int fieldType = readInt(2, bigEndian);
@SuppressWarnings("unused")
long count = readInt(4, bigEndian);
int valOffset;
if ((fieldType == 3 || fieldType == 8)) {
valOffset = readInt(2, bigEndian);
skip(2);
} else {
valOffset = readInt(4, bigEndian);
}
if (tag == 256) {
width = valOffset;
} else if (tag == 257) {
height = valOffset;
}
if (width != -1 && height != -1) {
mimeType = "image/tiff";
break;
}
}
}
}
}
protected int read() throws IOException {
int c = in.read();
if (c != -1) {
length++;
}
return c;
}
protected void skip(long n) throws IOException {
long done = 0;
while (done < n) {
long num = in.skip(n - done);
if (num == 0) {
break;
}
done += num;
}
length += done;
}
protected void finishStream() throws IOException {
byte[] buf = new byte[4096];
int n;
while ((n = in.read(buf)) != -1) {
length += n;
}
}
protected int readInt(int noOfBytes, boolean bigEndian) throws IOException {
int ret = 0;
int sv = bigEndian ? (noOfBytes - 1) * 8 : 0;
int cnt = bigEndian ? -8 : 8;
for (int i = 0; i < noOfBytes; i++) {
ret |= read() << sv;
sv += cnt;
}
return ret;
}
}