Mega Code Archive
Image format info
<![CDATA[
/*
#IFNDEF ALT_LICENSE
ThinWire(R) RIA Ajax Framework
Copyright (C) 2003-2007 Custom Credit Systems
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free
Software Foundation; either version 2.1 of the License, or (at your option) any
later version.
This library is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this library; if not, write to the Free Software Foundation, Inc., 59
Temple Place, Suite 330, Boston, MA 02111-1307 USA
Users who would rather have a commercial license, warranty or support should
contact the following company who invented, built and supports the technology:
Custom Credit Systems, Richardson, TX 75081, USA.
email: info@thinwire.com ph: +1 (888) 644-6405
http://www.thinwire.com
#ENDIF
[ v1.2_RC2 ]
*/
import java.io.DataInput;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
/**
* @author Joshua J. Gertzen
*/
public class ImageInfo {
public enum Format {GIF,JPEG,PNG}
private String stringValue;
private String name;
private Format format;
private int width;
private int height;
public ImageInfo(String name) {
setName(name);
}
public int getWidth() {
return width;
}
public int getHeight() {
return height;
}
public Format getFormat() {
return format;
}
public String getName() {
return name;
}
private void setName(String name) {
try {
InputStream is = new FileInputStream(name);
if (is != null) {
this.name = name;
ImageParser ii = new ImageParser();
ii.setInput(is);
if (!ii.check())
throw new UnsupportedOperationException("Unknown image file format for file.");
switch (ii.getFormat()) {
case ImageParser.FORMAT_GIF:
this.format = Format.GIF;
break;
case ImageParser.FORMAT_JPEG:
this.format = Format.JPEG;
break;
case ImageParser.FORMAT_PNG:
this.format = Format.PNG;
break;
default:
throw new UnsupportedOperationException("Unsupported image file format '" + ii.getFormatName() + "'.");
}
this.width = ii.getWidth();
this.height = ii.getHeight();
} else {
this.width = -1;
this.height = -1;
this.format = null;
this.name = "";
}
} catch (Exception e) {
if (!(e instanceof RuntimeException)) e = new RuntimeException(e);
throw (RuntimeException)e;
}
}
public boolean equals(Object o) {
return o instanceof ImageInfo && toString().equals(o.toString());
}
public int hashCode() {
return toString().hashCode();
}
public String toString() {
if (stringValue == null) stringValue = "ImageInfo{name:" + name + ",format:" + format + ",width:" + width + ",height:" + height + "}";
return stringValue;
}
}
/* XXX Note: This class is a public domain class that is used by
* ImageInfo (above) to determine the width and height of an image.
* It is made package-private because it is not intended to be used
* directly.
*/
/*
* ImageInfo.java
*
* Version 1.5
*
* A Java class to determine image width, height and color depth for
* a number of image file formats.
*
* Written by Marco Schmidt
* <http://www.geocities.com/marcoschmidt.geo/contact.html>.
*
* Contributed to the Public Domain.
*
* Last modification 2004-02-29
*/
/**
* Get file format, image resolution, number of bits per pixel and optionally
* number of images, comments and physical resolution from
* JPEG, GIF, BMP, PCX, PNG, IFF, RAS, PBM, PGM, PPM, PSD and SWF files
* (or input streams).
* <p>
* Use the class like this:
* <pre>
* ImageInfo ii = new ImageInfo();
* ii.setInput(in); // in can be InputStream or RandomAccessFile
* ii.setDetermineImageNumber(true); // default is false
* ii.setCollectComments(true); // default is false
* if (!ii.check()) {
* System.err.println("Not a supported image file format.");
* return;
* }
* System.out.println(ii.getFormatName() + ", " + ii.getMimeType() +
* ", " + ii.getWidth() + " x " + ii.getHeight() + " pixels, " +
* ii.getBitsPerPixel() + " bits per pixel, " + ii.getNumberOfImages() +
* " image(s), " + ii.getNumberOfComments() + " comment(s).");
* // there are other properties, check out the API documentation
* </pre>
* You can also use this class as a command line program.
* Call it with a number of image file names and URLs as parameters:
* <pre>
* java ImageInfo *.jpg *.png *.gif http://somesite.tld/image.jpg
* </pre>
* or call it without parameters and pipe data to it:
* <pre>
* java ImageInfo < image.jpg
* </pre>
* <p>
* Known limitations:
* <ul>
* <li>When the determination of the number of images is turned off, GIF bits
* per pixel are only read from the global header.
* For some GIFs, local palettes change this to a typically larger
* value. To be certain to get the correct color depth, call
* setDetermineImageNumber(true) before calling check().
* The complete scan over the GIF file will take additional time.</li>
* <li>Transparency information is not included in the bits per pixel count.
* Actually, it was my decision not to include those bits, so it's a feature! ;-)</li>
* </ul>
* <p>
* Requirements:
* <ul>
* <li>Java 1.1 or higher</li>
* </ul>
* <p>
* The latest version can be found at <a href="http://www.geocities.com/marcoschmidt.geo/image-info.html">http://www.geocities.com/marcoschmidt.geo/image-info.html</a>.
* <p>
* Written by <a href="http://www.geocities.com/marcoschmidt.geo/contact.html">Marco Schmidt</a>.
* <p>
* This class is contributed to the Public Domain.
* Use it at your own risk.
* <p>
* Last modification 2004-02-29.
* <p>
* History:
* <ul>
* <li><strong>2001-08-24</strong> Initial version.</li>
* <li><strong>2001-10-13</strong> Added support for the file formats BMP and PCX.</li>
* <li><strong>2001-10-16</strong> Fixed bug in read(int[], int, int) that returned
* <li><strong>2002-01-22</strong> Added support for file formats Amiga IFF and Sun Raster (RAS).</li>
* <li><strong>2002-01-24</strong> Added support for file formats Portable Bitmap / Graymap / Pixmap (PBM, PGM, PPM) and Adobe Photoshop (PSD).
* Added new method getMimeType() to return the MIME type associated with a particular file format.</li>
* <li><strong>2002-03-15</strong> Added support to recognize number of images in file. Only works with GIF.
* Use {@link #setDetermineImageNumber} with <code>true</code> as argument to identify animated GIFs
* ({@link #getNumberOfImages()} will return a value larger than <code>1</code>).</li>
* <li><strong>2002-04-10</strong> Fixed a bug in the feature 'determine number of images in animated GIF' introduced with version 1.1.
* Thanks to Marcelo P. Lima for sending in the bug report.
* Released as 1.1.1.</li>
* <li><strong>2002-04-18</strong> Added {@link #setCollectComments(boolean)}.
* That new method lets the user specify whether textual comments are to be
* stored in an internal list when encountered in an input image file / stream.
* Added two methods to return the physical width and height of the image in dpi:
* {@link #getPhysicalWidthDpi()} and {@link #getPhysicalHeightDpi()}.
* If the physical resolution could not be retrieved, these methods return <code>-1</code>.
* </li>
* <li><strong>2002-04-23</strong> Added support for the new properties physical resolution and
* comments for some formats. Released as 1.2.</li>
* <li><strong>2002-06-17</strong> Added support for SWF, sent in by Michael Aird.
* Changed checkJpeg() so that other APP markers than APP0 will not lead to a failure anymore.
* Released as 1.3.</li>
* <li><strong>2003-07-28</strong> Bug fix - skip method now takes return values into consideration.
* Less bytes than necessary may have been skipped, leading to flaws in the retrieved information in some cases.
* Thanks to Bernard Bernstein for pointing that out.
* Released as 1.4.</li>
* <li><strong>2004-02-29</strong> Added support for recognizing progressive JPEG and
* interlaced PNG and GIF. A new method {@link #isProgressive()} returns whether ImageInfo
* has found that the storage type is progressive (or interlaced).
* Thanks to Joe Germuska for suggesting the feature.
* Bug fix: BMP physical resolution is now correctly determined.
* Released as 1.5.</li>
* </ul>
*/
final class ImageParser {
/**
* Return value of {@link #getFormat()} for JPEG streams.
* ImageInfo can extract physical resolution and comments
* from JPEGs (only from APP0 headers).
* Only one image can be stored in a file.
* It is determined whether the JPEG stream is progressive
* (see {@link #isProgressive()}).
*/
public static final int FORMAT_JPEG = 0;
/**
* Return value of {@link #getFormat()} for GIF streams.
* ImageInfo can extract comments from GIFs and count the number
* of images (GIFs with more than one image are animations).
* If you know of a place where GIFs store the physical resolution
* of an image, please
* <a href="http://www.geocities.com/marcoschmidt.geo/contact.html">send me a mail</a>!
* It is determined whether the GIF stream is interlaced (see {@link #isProgressive()}).
*/
public static final int FORMAT_GIF = 1;
/**
* Return value of {@link #getFormat()} for PNG streams.
* PNG only supports one image per file.
* Both physical resolution and comments can be stored with PNG,
* but ImageInfo is currently not able to extract those.
* It is determined whether the PNG stream is interlaced (see {@link #isProgressive()}).
*/
public static final int FORMAT_PNG = 2;
/**
* Return value of {@link #getFormat()} for BMP streams.
* BMP only supports one image per file.
* BMP does not allow for comments.
* The physical resolution can be stored.
*/
public static final int FORMAT_BMP = 3;
/**
* Return value of {@link #getFormat()} for PCX streams.
* PCX does not allow for comments or more than one image per file.
* However, the physical resolution can be stored.
*/
public static final int FORMAT_PCX = 4;
/**
* Return value of {@link #getFormat()} for IFF streams.
*/
public static final int FORMAT_IFF = 5;
/**
* Return value of {@link #getFormat()} for RAS streams.
* Sun Raster allows for one image per file only and is not able to
* store physical resolution or comments.
*/
public static final int FORMAT_RAS = 6;
/** Return value of {@link #getFormat()} for PBM streams. */
public static final int FORMAT_PBM = 7;
/** Return value of {@link #getFormat()} for PGM streams. */
public static final int FORMAT_PGM = 8;
/** Return value of {@link #getFormat()} for PPM streams. */
public static final int FORMAT_PPM = 9;
/** Return value of {@link #getFormat()} for PSD streams. */
public static final int FORMAT_PSD = 10;
/** Return value of {@link #getFormat()} for SWF (Shockwave) streams. */
public static final int FORMAT_SWF = 11;
public static final int COLOR_TYPE_UNKNOWN = -1;
public static final int COLOR_TYPE_TRUECOLOR_RGB = 0;
public static final int COLOR_TYPE_PALETTED = 1;
public static final int COLOR_TYPE_GRAYSCALE= 2;
public static final int COLOR_TYPE_BLACK_AND_WHITE = 3;
/**
* The names of all supported file formats.
* The FORMAT_xyz int constants can be used as index values for
* this array.
*/
private static final String[] FORMAT_NAMES =
{"JPEG", "GIF", "PNG", "BMP", "PCX",
"IFF", "RAS", "PBM", "PGM", "PPM",
"PSD", "SWF"};
/**
* The names of the MIME types for all supported file formats.
* The FORMAT_xyz int constants can be used as index values for
* this array.
*/
private static final String[] MIME_TYPE_STRINGS =
{"image/jpeg", "image/gif", "image/png", "image/bmp", "image/pcx",
"image/iff", "image/ras", "image/x-portable-bitmap", "image/x-portable-graymap", "image/x-portable-pixmap",
"image/psd", "application/x-shockwave-flash"};
private int width;
private int height;
private int bitsPerPixel;
private boolean progressive;
private int format;
private InputStream in;
private DataInput din;
private boolean collectComments = true;
private List<String> comments;
private boolean determineNumberOfImages;
private int numberOfImages;
private int physicalHeightDpi;
private int physicalWidthDpi;
private int bitBuf;
private int bitPos;
private void addComment(String s) {
if (comments == null) {
comments = new ArrayList<String>();
}
comments.add(s);
}
/**
* Call this method after you have provided an input stream or file
* using {@link #setInput(InputStream)} or {@link #setInput(DataInput)}.
* If true is returned, the file format was known and information
* on the file's content can be retrieved using the various getXyz methods.
* @return if information could be retrieved from input
*/
public boolean check() {
format = -1;
width = -1;
height = -1;
bitsPerPixel = -1;
numberOfImages = 1;
physicalHeightDpi = -1;
physicalWidthDpi = -1;
comments = null;
try {
int b1 = read() & 0xff;
int b2 = read() & 0xff;
if (b1 == 0x47 && b2 == 0x49) {
return checkGif();
}
else
if (b1 == 0x89 && b2 == 0x50) {
return checkPng();
}
else
if (b1 == 0xff && b2 == 0xd8) {
return checkJpeg();
}
else
if (b1 == 0x42 && b2 == 0x4d) {
return checkBmp();
}
else
if (b1 == 0x0a && b2 < 0x06) {
return checkPcx();
}
else
if (b1 == 0x46 && b2 == 0x4f) {
return checkIff();
}
else
if (b1 == 0x59 && b2 == 0xa6) {
return checkRas();
}
else
if (b1 == 0x50 && b2 >= 0x31 && b2 <= 0x36) {
return checkPnm(b2 - '0');
}
else
if (b1 == 0x38 && b2 == 0x42) {
return checkPsd();
}
else
if (b1 == 0x46 && b2 == 0x57) {
return checkSwf();
}
else {
return false;
}
} catch (IOException ioe) {
return false;
}
}
private boolean checkBmp() throws IOException {
byte[] a = new byte[44];
if (read(a) != a.length) {
return false;
}
width = getIntLittleEndian(a, 16);
height = getIntLittleEndian(a, 20);
if (width < 1 || height < 1) {
return false;
}
bitsPerPixel = getShortLittleEndian(a, 26);
if (bitsPerPixel != 1 && bitsPerPixel != 4 &&
bitsPerPixel != 8 && bitsPerPixel != 16 &&
bitsPerPixel != 24 && bitsPerPixel != 32) {
return false;
}
int x = (int)(getIntLittleEndian(a, 36) * 0.0254);
if (x > 0) {
setPhysicalWidthDpi(x);
}
int y = (int)(getIntLittleEndian(a, 40) * 0.0254);
if (y > 0) {
setPhysicalHeightDpi(y);
}
format = FORMAT_BMP;
return true;
}
private boolean checkGif() throws IOException {
final byte[] GIF_MAGIC_87A = {0x46, 0x38, 0x37, 0x61};
final byte[] GIF_MAGIC_89A = {0x46, 0x38, 0x39, 0x61};
byte[] a = new byte[11]; // 4 from the GIF signature + 7 from the global header
if (read(a) != 11) {
return false;
}
if ((!equals(a, 0, GIF_MAGIC_89A, 0, 4)) &&
(!equals(a, 0, GIF_MAGIC_87A, 0, 4))) {
return false;
}
format = FORMAT_GIF;
width = getShortLittleEndian(a, 4);
height = getShortLittleEndian(a, 6);
int flags = a[8] & 0xff;
bitsPerPixel = ((flags >> 4) & 0x07) + 1;
progressive = (flags & 0x02) != 0;
if (!determineNumberOfImages) {
return true;
}
// skip global color palette
if ((flags & 0x80) != 0) {
int tableSize = (1 << ((flags & 7) + 1)) * 3;
skip(tableSize);
}
numberOfImages = 0;
int blockType;
do
{
blockType = read();
switch(blockType)
{
case(0x2c): // image separator
{
if (read(a, 0, 9) != 9) {
return false;
}
flags = a[8] & 0xff;
int localBitsPerPixel = (flags & 0x07) + 1;
if (localBitsPerPixel > bitsPerPixel) {
bitsPerPixel = localBitsPerPixel;
}
if ((flags & 0x80) != 0) {
skip((1 << localBitsPerPixel) * 3);
}
skip(1); // initial code length
int n;
do
{
n = read();
if (n > 0) {
skip(n);
}
else
if (n == -1) {
return false;
}
}
while (n > 0);
numberOfImages++;
break;
}
case(0x21): // extension
{
int extensionType = read();
if (collectComments && extensionType == 0xfe) {
StringBuilder sb = new StringBuilder();
int n;
do
{
n = read();
if (n == -1) {
return false;
}
if (n > 0) {
for (int i = 0; i < n; i++) {
int ch = read();
if (ch == -1) {
return false;
}
sb.append((char)ch);
}
}
}
while (n > 0);
} else {
int n;
do
{
n = read();
if (n > 0) {
skip(n);
}
else
if (n == -1) {
return false;
}
}
while (n > 0);
}
break;
}
case(0x3b): // end of file
{
break;
}
default:
{
return false;
}
}
}
while (blockType != 0x3b);
return true;
}
private boolean checkIff() throws IOException {
byte[] a = new byte[10];
// read remaining 2 bytes of file id, 4 bytes file size
// and 4 bytes IFF subformat
if (read(a, 0, 10) != 10) {
return false;
}
final byte[] IFF_RM = {0x52, 0x4d};
if (!equals(a, 0, IFF_RM, 0, 2)) {
return false;
}
int type = getIntBigEndian(a, 6);
if (type != 0x494c424d && // type must be ILBM...
type != 0x50424d20) { // ...or PBM
return false;
}
// loop chunks to find BMHD chunk
do {
if (read(a, 0, 8) != 8) {
return false;
}
int chunkId = getIntBigEndian(a, 0);
int size = getIntBigEndian(a, 4);
if ((size & 1) == 1) {
size++;
}
if (chunkId == 0x424d4844) { // BMHD chunk
if (read(a, 0, 9) != 9) {
return false;
}
format = FORMAT_IFF;
width = getShortBigEndian(a, 0);
height = getShortBigEndian(a, 2);
bitsPerPixel = a[8] & 0xff;
return (width > 0 && height > 0 && bitsPerPixel > 0 && bitsPerPixel < 33);
} else {
skip(size);
}
} while (true);
}
private boolean checkJpeg() throws IOException {
byte[] data = new byte[12];
while (true) {
if (read(data, 0, 4) != 4) {
return false;
}
int marker = getShortBigEndian(data, 0);
int size = getShortBigEndian(data, 2);
if ((marker & 0xff00) != 0xff00) {
return false; // not a valid marker
}
if (marker == 0xffe0) { // APPx
if (size < 14) {
return false; // APPx header must be >= 14 bytes
}
if (read(data, 0, 12) != 12) {
return false;
}
final byte[] APP0_ID = {0x4a, 0x46, 0x49, 0x46, 0x00};
if (equals(APP0_ID, 0, data, 0, 5)) {
if (data[7] == 1) {
setPhysicalWidthDpi(getShortBigEndian(data, 8));
setPhysicalHeightDpi(getShortBigEndian(data, 10));
}
else
if (data[7] == 2) {
int x = getShortBigEndian(data, 8);
int y = getShortBigEndian(data, 10);
setPhysicalWidthDpi((int)(x * 2.54f));
setPhysicalHeightDpi((int)(y * 2.54f));
}
}
skip(size - 14);
}
else
if (collectComments && size > 2 && marker == 0xfffe) { // comment
size -= 2;
byte[] chars = new byte[size];
if (read(chars, 0, size) != size) {
return false;
}
String comment = new String(chars, "iso-8859-1");
comment = comment.trim();
addComment(comment);
}
else
if (marker >= 0xffc0 && marker <= 0xffcf && marker != 0xffc4 && marker != 0xffc8) {
if (read(data, 0, 6) != 6) {
return false;
}
format = FORMAT_JPEG;
bitsPerPixel = (data[0] & 0xff) * (data[5] & 0xff);
progressive = marker == 0xffc2 || marker == 0xffc6 ||
marker == 0xffca || marker == 0xffce;
width = getShortBigEndian(data, 3);
height = getShortBigEndian(data, 1);
return true;
} else {
skip(size - 2);
}
}
}
private boolean checkPcx() throws IOException {
byte[] a = new byte[64];
if (read(a) != a.length) {
return false;
}
if (a[0] != 1) { // encoding, 1=RLE is only valid value
return false;
}
// width / height
int x1 = getShortLittleEndian(a, 2);
int y1 = getShortLittleEndian(a, 4);
int x2 = getShortLittleEndian(a, 6);
int y2 = getShortLittleEndian(a, 8);
if (x1 < 0 || x2 < x1 || y1 < 0 || y2 < y1) {
return false;
}
width = x2 - x1 + 1;
height = y2 - y1 + 1;
// color depth
int bits = a[1];
int planes = a[63];
if (planes == 1 &&
(bits == 1 || bits == 2 || bits == 4 || bits == 8)) {
// paletted
bitsPerPixel = bits;
} else
if (planes == 3 && bits == 8) {
// RGB truecolor
bitsPerPixel = 24;
} else {
return false;
}
setPhysicalWidthDpi(getShortLittleEndian(a, 10));
setPhysicalHeightDpi(getShortLittleEndian(a, 10));
format = FORMAT_PCX;
return true;
}
private boolean checkPng() throws IOException {
final byte[] PNG_MAGIC = {0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a};
byte[] a = new byte[27];
if (read(a) != 27) {
return false;
}
if (!equals(a, 0, PNG_MAGIC, 0, 6)) {
return false;
}
format = FORMAT_PNG;
width = getIntBigEndian(a, 14);
height = getIntBigEndian(a, 18);
bitsPerPixel = a[22] & 0xff;
int colorType = a[23] & 0xff;
if (colorType == 2 || colorType == 6) {
bitsPerPixel *= 3;
}
progressive = (a[26] & 0xff) != 0;
return true;
}
private boolean checkPnm(int id) throws IOException {
if (id < 1 || id > 6) {
return false;
}
final int[] PNM_FORMATS = {FORMAT_PBM, FORMAT_PGM, FORMAT_PPM};
format = PNM_FORMATS[(id - 1) % 3];
boolean hasPixelResolution = false;
String s;
while (true)
{
s = readLine();
if (s != null) {
s = s.trim();
}
if (s == null || s.length() < 1) {
continue;
}
if (s.charAt(0) == '#') { // comment
if (collectComments && s.length() > 1) {
addComment(s.substring(1));
}
continue;
}
if (!hasPixelResolution) { // split "343 966" into width=343, height=966
int spaceIndex = s.indexOf(' ');
if (spaceIndex == -1) {
return false;
}
String widthString = s.substring(0, spaceIndex);
spaceIndex = s.lastIndexOf(' ');
if (spaceIndex == -1) {
return false;
}
String heightString = s.substring(spaceIndex + 1);
try {
width = Integer.parseInt(widthString);
height = Integer.parseInt(heightString);
} catch (NumberFormatException nfe) {
return false;
}
if (width < 1 || height < 1) {
return false;
}
if (format == FORMAT_PBM) {
bitsPerPixel = 1;
return true;
}
hasPixelResolution = true;
}
else
{
int maxSample;
try {
maxSample = Integer.parseInt(s);
} catch (NumberFormatException nfe) {
return false;
}
if (maxSample < 0) {
return false;
}
for (int i = 0; i < 25; i++) {
if (maxSample < (1 << (i + 1))) {
bitsPerPixel = i + 1;
if (format == FORMAT_PPM) {
bitsPerPixel *= 3;
}
return true;
}
}
return false;
}
}
}
private boolean checkPsd() throws IOException {
byte[] a = new byte[24];
if (read(a) != a.length) {
return false;
}
final byte[] PSD_MAGIC = {0x50, 0x53};
if (!equals(a, 0, PSD_MAGIC, 0, 2)) {
return false;
}
format = FORMAT_PSD;
width = getIntBigEndian(a, 16);
height = getIntBigEndian(a, 12);
int channels = getShortBigEndian(a, 10);
int depth = getShortBigEndian(a, 20);
bitsPerPixel = channels * depth;
return (width > 0 && height > 0 && bitsPerPixel > 0 && bitsPerPixel <= 64);
}
private boolean checkRas() throws IOException {
byte[] a = new byte[14];
if (read(a) != a.length) {
return false;
}
final byte[] RAS_MAGIC = {0x6a, (byte)0x95};
if (!equals(a, 0, RAS_MAGIC, 0, 2)) {
return false;
}
format = FORMAT_RAS;
width = getIntBigEndian(a, 2);
height = getIntBigEndian(a, 6);
bitsPerPixel = getIntBigEndian(a, 10);
return (width > 0 && height > 0 && bitsPerPixel > 0 && bitsPerPixel <= 24);
}
// Written by Michael Aird.
private boolean checkSwf() throws IOException {
//get rid of the last byte of the signature, the byte of the version and 4 bytes of the size
byte[] a = new byte[6];
if (read(a) != a.length) {
return false;
}
format = FORMAT_SWF;
int bitSize = (int)readUBits( 5 );
int maxX = (int)readSBits( bitSize );
int maxY = (int)readSBits( bitSize );
width = maxX/20; //cause we're in twips
height = maxY/20; //cause we're in twips
setPhysicalWidthDpi(72);
setPhysicalHeightDpi(72);
return (width > 0 && height > 0);
}
private boolean equals(byte[] a1, int offs1, byte[] a2, int offs2, int num) {
while (num-- > 0) {
if (a1[offs1++] != a2[offs2++]) {
return false;
}
}
return true;
}
/**
* If {@link #check()} was successful, returns the image's number of bits per pixel.
* Does not include transparency information like the alpha channel.
* @return number of bits per image pixel
*/
public int getBitsPerPixel() {
return bitsPerPixel;
}
/**
* Returns the index'th comment retrieved from the image.
* @throws IllegalArgumentException if index is smaller than 0 or larger than or equal
* to the number of comments retrieved
* @see #getNumberOfComments
*/
public String getComment(int index) {
if (comments == null || index < 0 || index >= comments.size()) {
throw new IllegalArgumentException("Not a valid comment index: " + index);
}
return comments.get(index);
}
/**
* If {@link #check()} was successful, returns the image format as one
* of the FORMAT_xyz constants from this class.
* Use {@link #getFormatName()} to get a textual description of the file format.
* @return file format as a FORMAT_xyz constant
*/
public int getFormat() {
return format;
}
/**
* If {@link #check()} was successful, returns the image format's name.
* Use {@link #getFormat()} to get a unique number.
* @return file format name
*/
public String getFormatName() {
if (format >= 0 && format < FORMAT_NAMES.length) {
return FORMAT_NAMES[format];
} else {
return "?";
}
}
/**
* If {@link #check()} was successful, returns one the image's vertical
* resolution in pixels.
* @return image height in pixels
*/
public int getHeight() {
return height;
}
private int getIntBigEndian(byte[] a, int offs) {
return
(a[offs] & 0xff) << 24 |
(a[offs + 1] & 0xff) << 16 |
(a[offs + 2] & 0xff) << 8 |
a[offs + 3] & 0xff;
}
private int getIntLittleEndian(byte[] a, int offs) {
return
(a[offs + 3] & 0xff) << 24 |
(a[offs + 2] & 0xff) << 16 |
(a[offs + 1] & 0xff) << 8 |
a[offs] & 0xff;
}
/**
* If {@link #check()} was successful, returns a String with the
* MIME type of the format.
* @return MIME type, e.g. <code>image/jpeg</code>
*/
public String getMimeType() {
if (format >= 0 && format < MIME_TYPE_STRINGS.length) {
if (format == FORMAT_JPEG && progressive)
{
return "image/pjpeg";
}
return MIME_TYPE_STRINGS[format];
} else {
return null;
}
}
/**
* If {@link #check()} was successful and {@link #setCollectComments(boolean)} was called with
* <code>true</code> as argument, returns the number of comments retrieved
* from the input image stream / file.
* Any number >= 0 and smaller than this number of comments is then a
* valid argument for the {@link #getComment(int)} method.
* @return number of comments retrieved from input image
*/
public int getNumberOfComments()
{
if (comments == null) {
return 0;
} else {
return comments.size();
}
}
/**
* Returns the number of images in the examined file.
* Assumes that <code>setDetermineImageNumber(true);</code> was called before
* a successful call to {@link #check()}.
* This value can currently be only different from <code>1</code> for GIF images.
* @return number of images in file
*/
public int getNumberOfImages()
{
return numberOfImages;
}
/**
* Returns the physical height of this image in dots per inch (dpi).
* Assumes that {@link #check()} was successful.
* Returns <code>-1</code> on failure.
* @return physical height (in dpi)
* @see #getPhysicalWidthDpi()
* @see #getPhysicalHeightInch()
*/
public int getPhysicalHeightDpi() {
return physicalHeightDpi;
}
/**
* If {@link #check()} was successful, returns the physical width of this image in dpi (dots per inch)
* or -1 if no value could be found.
* @return physical height (in dpi)
* @see #getPhysicalHeightDpi()
* @see #getPhysicalWidthDpi()
* @see #getPhysicalWidthInch()
*/
public float getPhysicalHeightInch() {
int h = getHeight();
int ph = getPhysicalHeightDpi();
if (h > 0 && ph > 0) {
return ((float)h) / ((float)ph);
} else {
return -1.0f;
}
}
/**
* If {@link #check()} was successful, returns the physical width of this image in dpi (dots per inch)
* or -1 if no value could be found.
* @return physical width (in dpi)
* @see #getPhysicalHeightDpi()
* @see #getPhysicalWidthInch()
* @see #getPhysicalHeightInch()
*/
public int getPhysicalWidthDpi() {
return physicalWidthDpi;
}
/**
* Returns the physical width of an image in inches, or
* <code>-1.0f</code> if width information is not available.
* Assumes that {@link #check} has been called successfully.
* @return physical width in inches or <code>-1.0f</code> on failure
* @see #getPhysicalWidthDpi
* @see #getPhysicalHeightInch
*/
public float getPhysicalWidthInch() {
int w = getWidth();
int pw = getPhysicalWidthDpi();
if (w > 0 && pw > 0) {
return ((float)w) / ((float)pw);
} else {
return -1.0f;
}
}
private int getShortBigEndian(byte[] a, int offs) {
return
(a[offs] & 0xff) << 8 |
(a[offs + 1] & 0xff);
}
private int getShortLittleEndian(byte[] a, int offs) {
return (a[offs] & 0xff) | (a[offs + 1] & 0xff) << 8;
}
/**
* If {@link #check()} was successful, returns one the image's horizontal
* resolution in pixels.
* @return image width in pixels
*/
public int getWidth() {
return width;
}
/**
* Returns whether the image is stored in a progressive (also called: interlaced) way.
* @return true for progressive/interlaced, false otherwise
*/
public boolean isProgressive()
{
return progressive;
}
private int read() throws IOException {
if (in != null) {
return in.read();
} else {
return din.readByte();
}
}
private int read(byte[] a) throws IOException {
if (in != null) {
return in.read(a);
} else {
din.readFully(a);
return a.length;
}
}
private int read(byte[] a, int offset, int num) throws IOException {
if (in != null) {
return in.read(a, offset, num);
} else {
din.readFully(a, offset, num);
return num;
}
}
private String readLine() throws IOException {
return readLine(new StringBuilder());
}
private String readLine(StringBuilder sb) throws IOException {
boolean finished;
do {
int value = read();
finished = (value == -1 || value == 10);
if (!finished) {
sb.append((char)value);
}
} while (!finished);
return sb.toString();
}
private long readUBits( int numBits ) throws IOException
{
if (numBits == 0) {
return 0;
}
int bitsLeft = numBits;
long result = 0;
if (bitPos == 0) { //no value in the buffer - read a byte
if (in != null) {
bitBuf = in.read();
} else {
bitBuf = din.readByte();
}
bitPos = 8;
}
while( true )
{
int shift = bitsLeft - bitPos;
if( shift > 0 )
{
// Consume the entire buffer
result |= bitBuf << shift;
bitsLeft -= bitPos;
// Get the next byte from the input stream
if (in != null) {
bitBuf = in.read();
} else {
bitBuf = din.readByte();
}
bitPos = 8;
}
else
{
// Consume a portion of the buffer
result |= bitBuf >> -shift;
bitPos -= bitsLeft;
bitBuf &= 0xff >> (8 - bitPos); // mask off the consumed bits
return result;
}
}
}
/**
* Read a signed value from the given number of bits
*/
private int readSBits( int numBits ) throws IOException
{
// Get the number as an unsigned value.
long uBits = readUBits( numBits );
// Is the number negative?
if( ( uBits & (1L << (numBits - 1))) != 0 )
{
// Yes. Extend the sign.
uBits |= -1L << numBits;
}
return (int)uBits;
}
/**
* Specify whether textual comments are supposed to be extracted from input.
* Default is <code>false</code>.
* If enabled, comments will be added to an internal list.
* @param newValue if <code>true</code>, this class will read comments
* @see #getNumberOfComments
* @see #getComment
*/
public void setCollectComments(boolean newValue)
{
collectComments = newValue;
}
/**
* Specify whether the number of images in a file is to be
* determined - default is <code>false</code>.
* This is a special option because some file formats require running over
* the entire file to find out the number of images, a rather time-consuming
* task.
* Not all file formats support more than one image.
* If this method is called with <code>true</code> as argument,
* the actual number of images can be queried via
* {@link #getNumberOfImages()} after a successful call to
* {@link #check()}.
* @param newValue will the number of images be determined?
* @see #getNumberOfImages
*/
public void setDetermineImageNumber(boolean newValue)
{
determineNumberOfImages = newValue;
}
/**
* Set the input stream to the argument stream (or file).
* Note that {@link java.io.RandomAccessFile} implements
* {@link java.io.DataInput}.
* @param dataInput the input stream to read from
*/
public void setInput(DataInput dataInput) {
din = dataInput;
in = null;
}
/**
* Set the input stream to the argument stream (or file).
* @param inputStream the input stream to read from
*/
public void setInput(InputStream inputStream) {
in = inputStream;
din = null;
}
private void setPhysicalHeightDpi(int newValue) {
physicalWidthDpi = newValue;
}
private void setPhysicalWidthDpi(int newValue) {
physicalHeightDpi = newValue;
}
private void skip(int num) throws IOException {
while (num > 0) {
long result;
if (in != null) {
result = in.skip(num);
} else {
result = din.skipBytes(num);
}
if (result > 0) {
num -= result;
}
}
}
}
]]>