/*
* ImageInfo.java
*
* Version 1.9
*
* A Java class to determine image width, height and color depth for
* a number of image file formats.
*
* Written by Marco Schmidt
*
* Contributed to the Public Domain.
*/
package com.revolsys.io;
import java.io.DataInput;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Vector;
import com.revolsys.util.Base64InputStream;
/**
* 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 and PSD files
* (or input streams).
* <p>
* Use the class like this:
* <pre>
* ImageInfo ii = new ImageInfo();
* ii.setInput(in); // in can be Base64InputStream 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://schmidt.devlib.org/image-info/">http://schmidt.devlib.org/image-info/</a>.
* <p>
* Written by Marco Schmidt.
* <p>
* This class is contributed to the Public Domain.
* Use it at your own risk.
* <p>
* <a name="history">History</a>:
* <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>
* <li><strong>2004-11-30</strong> Bug fix: recognizing progressive GIFs
* (interlaced in GIF terminology) did not work (thanks to Franz Jeitler for
* pointing this out). Now it should work, but only if the number of images is determined.
* This is because information on interlacing is stored in a local image header.
* In theory, different images could be stored interlaced and non-interlaced in one
* file. However, I think that's unlikely. Right now, the last image in the GIF file
* that is examined by ImageInfo is used for the "progressive" status.</li>
* <li><strong>2005-01-02</strong> Some code clean up (unused methods and variables
* commented out, missing javadoc comments, etc.). Thanks to George Sexton for a long list.
* Removed usage of Boolean.toString because
* it's a Java 1.4+ feature (thanks to Gregor Dupont).
* Changed delimiter character in compact output from semicolon to tabulator
* (for better integration with cut(1) and other Unix tools).
* Added some points to the <a href="http://schmidt.devlib.org/image-info/index.html#knownissues">'Known
* issues' section of the website</a>.
* Released as 1.6.</li>
* <li><strong>2005-07-26</strong> Removed code to identify Flash (SWF) files.
* Has repeatedly led to problems and support requests, and I don't know the
* format and don't have the time and interest to fix it myself.
* I repeatedly included fixes by others which didn't work for some people.
* I give up on SWF. Please do not contact me about it anymore.
* Set package of ImageInfo class to org.devlib.schmidt.imageinfo (a package
* was repeatedly requested by some users).
* Released as 1.7.</li>
* <li><strong>2006-02-23</strong> Removed Flash helper methods which weren't used elsewhere.
* Updated skip method which tries "read" whenever "skip(Bytes)" returns a result of 0.
* The old method didn't work with certain input stream types on truncated data streams.
* Thanks to Martin Leidig for reporting this and sending in code.
* Released as 1.8.</li>
* </li>
* <li><strong>2006-11-13</strong> Removed check that made ImageInfo report JPEG APPx
* markers smaller than 14 bytes as files in unknown format. Such JPEGs seem to be
* generated by Google's Picasa application. First reported with fix by
* Karl von Randow. Released as 1.9.</li>
* </ul>
* @author Marco Schmidt
*/
@SuppressWarnings("unchecked")
public class ImageInfo {
/**
* 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 GIF streams.
* ImageInfo can extract comments from GIFs and count the number
* of images (GIFs with more than one image are animations).
* 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 IFF streams.
*/
public static final int FORMAT_IFF = 5;
/**
* 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;
/**
* 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"
};
/** Return value of {@link #getFormat()} for PBM streams. */
public static final int FORMAT_PBM = 7;
/**
* 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 PGM streams. */
public static final int FORMAT_PGM = 8;
/**
* 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 PPM streams. */
public static final int FORMAT_PPM = 9;
/** Return value of {@link #getFormat()} for PSD streams. */
public static final int FORMAT_PSD = 10;
/*
* 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;
*/
/**
* 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;
/**
* 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"
};
/**
* Run over String list, return false iff at least one of the arguments
* equals <code>-c</code>.
* @param args string list to check
*/
private static boolean determineVerbosity(final String[] args) {
if (args != null && args.length > 0) {
for (final String arg : args) {
if ("-c".equals(arg)) {
return false;
}
}
}
return true;
}
private static boolean equals(final byte[] a1, int offs1, final byte[] a2, int offs2, int num) {
while (num-- > 0) {
if (a1[offs1++] != a2[offs2++]) {
return false;
}
}
return true;
}
private static int getIntBigEndian(final byte[] a, final int offs) {
return (a[offs] & 0xff) << 24 | (a[offs + 1] & 0xff) << 16 | (a[offs + 2] & 0xff) << 8
| a[offs + 3] & 0xff;
}
private static int getIntLittleEndian(final byte[] a, final int offs) {
return (a[offs + 3] & 0xff) << 24 | (a[offs + 2] & 0xff) << 16 | (a[offs + 1] & 0xff) << 8
| a[offs] & 0xff;
}
private static int getShortBigEndian(final byte[] a, final int offs) {
return (a[offs] & 0xff) << 8 | a[offs + 1] & 0xff;
}
private static int getShortLittleEndian(final byte[] a, final int offs) {
return a[offs] & 0xff | (a[offs + 1] & 0xff) << 8;
}
/**
* To use this class as a command line application, give it either
* some file names as parameters (information on them will be
* printed to standard output, one line per file) or call
* it with no parameters. It will then check data given to it
* via standard input.
* @param args the program arguments which must be file names
*/
public static void main(final String[] args) {
final ImageInfo imageInfo = new ImageInfo();
imageInfo.setDetermineImageNumber(true);
final boolean verbose = determineVerbosity(args);
if (args.length == 0) {
run(null, System.in, imageInfo, verbose);
} else {
int index = 0;
while (index < args.length) {
InputStream in = null;
try {
final String name = args[index++];
System.out.print(name + ";");
if (name.startsWith("http://")) {
in = new URL(name).openConnection().getInputStream();
} else {
in = new FileInputStream(name);
}
run(name, in, imageInfo, verbose);
in.close();
} catch (final IOException e) {
System.out.println(e);
try {
if (in != null) {
in.close();
}
} catch (final IOException ee) {
}
}
}
}
}
private static void print(final String sourceName, final ImageInfo ii, final boolean verbose) {
if (verbose) {
printVerbose(sourceName, ii);
} else {
printCompact(sourceName, ii);
}
}
private static void printCompact(final String sourceName, final ImageInfo imageInfo) {
final String SEP = "\t";
System.out.println(sourceName + SEP + imageInfo.getFormatName() + SEP + imageInfo.getMimeType()
+ SEP + imageInfo.getWidth() + SEP + imageInfo.getHeight() + SEP + imageInfo.getBitsPerPixel()
+ SEP + imageInfo.getNumberOfImages() + SEP + imageInfo.getPhysicalWidthDpi() + SEP
+ imageInfo.getPhysicalHeightDpi() + SEP + imageInfo.getPhysicalWidthInch() + SEP
+ imageInfo.getPhysicalHeightInch() + SEP + imageInfo.isProgressive());
}
private static void printLine(final int indentLevels, final String text, final float value,
final float minValidValue) {
if (value < minValidValue) {
return;
}
printLine(indentLevels, text, Float.toString(value));
}
private static void printLine(final int indentLevels, final String text, final int value,
final int minValidValue) {
if (value >= minValidValue) {
printLine(indentLevels, text, Integer.toString(value));
}
}
private static void printLine(int indentLevels, final String text, final String value) {
if (value == null || value.length() == 0) {
return;
}
while (indentLevels-- > 0) {
System.out.print("\t");
}
if (text != null && text.length() > 0) {
System.out.print(text);
System.out.print(" ");
}
System.out.println(value);
}
private static void printVerbose(final String sourceName, final ImageInfo ii) {
printLine(0, null, sourceName);
printLine(1, "File format: ", ii.getFormatName());
printLine(1, "MIME type: ", ii.getMimeType());
printLine(1, "Width (pixels): ", ii.getWidth(), 1);
printLine(1, "Height (pixels): ", ii.getHeight(), 1);
printLine(1, "Bits per pixel: ", ii.getBitsPerPixel(), 1);
printLine(1, "Progressive: ", ii.isProgressive() ? "yes" : "no");
printLine(1, "Number of images: ", ii.getNumberOfImages(), 1);
printLine(1, "Physical width (dpi): ", ii.getPhysicalWidthDpi(), 1);
printLine(1, "Physical height (dpi): ", ii.getPhysicalHeightDpi(), 1);
printLine(1, "Physical width (inches): ", ii.getPhysicalWidthInch(), 1.0f);
printLine(1, "Physical height (inches): ", ii.getPhysicalHeightInch(), 1.0f);
final int numComments = ii.getNumberOfComments();
printLine(1, "Number of textual comments: ", numComments, 1);
if (numComments > 0) {
for (int i = 0; i < numComments; i++) {
printLine(2, null, ii.getComment(i));
}
}
}
private static void run(final String sourceName, final InputStream in, final ImageInfo imageInfo,
final boolean verbose) {
imageInfo.setInput(in);
imageInfo.setDetermineImageNumber(true);
imageInfo.setCollectComments(verbose);
if (imageInfo.check()) {
print(sourceName, imageInfo, verbose);
}
}
private int bitsPerPixel;
private boolean collectComments = true;
private Vector comments;
private boolean determineNumberOfImages;
private DataInput din;
private int format;
private int height;
private InputStream in;
private int numberOfImages;
private int physicalHeightDpi;
private int physicalWidthDpi;
// private int colorType = COLOR_TYPE_UNKNOWN;
private boolean progressive;
private int width;
public ImageInfo() {
// TODO Auto-generated constructor stub
}
public ImageInfo(final DataInput dataInput) {
setInput(dataInput);
}
private void addComment(final String s) {
if (this.comments == null) {
this.comments = new Vector();
}
this.comments.addElement(s);
}
/**
* Call this method after you have provided an input stream or file
* using {@link #setInput(Base64InputStream)} 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() {
this.format = -1;
this.width = -1;
this.height = -1;
this.bitsPerPixel = -1;
this.numberOfImages = 1;
this.physicalHeightDpi = -1;
this.physicalWidthDpi = -1;
this.comments = null;
try {
final int b1 = read() & 0xff;
final 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 {
return false;
}
} catch (final IOException ioe) {
return false;
}
}
private boolean checkBmp() throws IOException {
final byte[] a = new byte[44];
if (read(a) != a.length) {
return false;
}
this.width = getIntLittleEndian(a, 16);
this.height = getIntLittleEndian(a, 20);
if (this.width < 1 || this.height < 1) {
return false;
}
this.bitsPerPixel = getShortLittleEndian(a, 26);
if (this.bitsPerPixel != 1 && this.bitsPerPixel != 4 && this.bitsPerPixel != 8
&& this.bitsPerPixel != 16 && this.bitsPerPixel != 24 && this.bitsPerPixel != 32) {
return false;
}
final int x = (int)(getIntLittleEndian(a, 36) * 0.0254);
if (x > 0) {
setPhysicalWidthDpi(x);
}
final int y = (int)(getIntLittleEndian(a, 40) * 0.0254);
if (y > 0) {
setPhysicalHeightDpi(y);
}
this.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
};
final 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;
}
this.format = FORMAT_GIF;
this.width = getShortLittleEndian(a, 4);
this.height = getShortLittleEndian(a, 6);
int flags = a[8] & 0xff;
this.bitsPerPixel = (flags >> 4 & 0x07) + 1;
// progressive = (flags & 0x02) != 0;
if (!this.determineNumberOfImages) {
return true;
}
// skip global color palette
if ((flags & 0x80) != 0) {
final int tableSize = (1 << (flags & 7) + 1) * 3;
skip(tableSize);
}
this.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;
this.progressive = (flags & 0x40) != 0;
/*
* int locWidth = getShortLittleEndian(a, 4); int locHeight = getShortLittleEndian(a, 6);
* System.out.println("LOCAL: " + locWidth + " x " + locHeight);
*/
final int localBitsPerPixel = (flags & 0x07) + 1;
if (localBitsPerPixel > this.bitsPerPixel) {
this.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);
this.numberOfImages++;
break;
}
case 0x21: // extension
{
final int extensionType = read();
if (this.collectComments && extensionType == 0xfe) {
final StringBuilder sb = new StringBuilder();
int n;
do {
n = read();
if (n == -1) {
return false;
}
if (n > 0) {
for (int i = 0; i < n; i++) {
final 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 {
final 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;
}
final 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;
}
final 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;
}
this.format = FORMAT_IFF;
this.width = getShortBigEndian(a, 0);
this.height = getShortBigEndian(a, 2);
this.bitsPerPixel = a[8] & 0xff;
return this.width > 0 && this.height > 0 && this.bitsPerPixel > 0 && this.bitsPerPixel < 33;
} else {
skip(size);
}
} while (true);
}
private boolean checkJpeg() throws IOException {
final byte[] data = new byte[12];
while (true) {
if (read(data, 0, 4) != 4) {
return false;
}
final 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) {
// not an APPx header as we know it, skip
skip(size - 2);
continue;
}
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)) {
// System.out.println("data 7=" + data[7]);
if (data[7] == 1) {
setPhysicalWidthDpi(getShortBigEndian(data, 8));
setPhysicalHeightDpi(getShortBigEndian(data, 10));
} else if (data[7] == 2) {
final int x = getShortBigEndian(data, 8);
final int y = getShortBigEndian(data, 10);
setPhysicalWidthDpi((int)(x * 2.54f));
setPhysicalHeightDpi((int)(y * 2.54f));
}
}
skip(size - 14);
} else if (this.collectComments && size > 2 && marker == 0xfffe) { // comment
size -= 2;
final 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;
}
this.format = FORMAT_JPEG;
this.bitsPerPixel = (data[0] & 0xff) * (data[5] & 0xff);
this.progressive = marker == 0xffc2 || marker == 0xffc6 || marker == 0xffca
|| marker == 0xffce;
this.width = getShortBigEndian(data, 3);
this.height = getShortBigEndian(data, 1);
return true;
} else {
skip(size - 2);
}
}
}
private boolean checkPcx() throws IOException {
final 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
final int x1 = getShortLittleEndian(a, 2);
final int y1 = getShortLittleEndian(a, 4);
final int x2 = getShortLittleEndian(a, 6);
final int y2 = getShortLittleEndian(a, 8);
if (x1 < 0 || x2 < x1 || y1 < 0 || y2 < y1) {
return false;
}
this.width = x2 - x1 + 1;
this.height = y2 - y1 + 1;
// color depth
final int bits = a[1];
final int planes = a[63];
if (planes == 1 && (bits == 1 || bits == 2 || bits == 4 || bits == 8)) {
// paletted
this.bitsPerPixel = bits;
} else if (planes == 3 && bits == 8) {
// RGB truecolor
this.bitsPerPixel = 24;
} else {
return false;
}
setPhysicalWidthDpi(getShortLittleEndian(a, 10));
setPhysicalHeightDpi(getShortLittleEndian(a, 10));
this.format = FORMAT_PCX;
return true;
}
private boolean checkPng() throws IOException {
final byte[] PNG_MAGIC = {
0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a
};
final byte[] a = new byte[27];
if (read(a) != 27) {
return false;
}
if (!equals(a, 0, PNG_MAGIC, 0, 6)) {
return false;
}
this.format = FORMAT_PNG;
this.width = getIntBigEndian(a, 14);
this.height = getIntBigEndian(a, 18);
this.bitsPerPixel = a[22] & 0xff;
final int colorType = a[23] & 0xff;
if (colorType == 2 || colorType == 6) {
this.bitsPerPixel *= 3;
}
this.progressive = (a[26] & 0xff) != 0;
return true;
}
private boolean checkPnm(final int id) throws IOException {
if (id < 1 || id > 6) {
return false;
}
final int[] PNM_FORMATS = {
FORMAT_PBM, FORMAT_PGM, FORMAT_PPM
};
this.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 (this.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;
}
final String widthString = s.substring(0, spaceIndex);
spaceIndex = s.lastIndexOf(' ');
if (spaceIndex == -1) {
return false;
}
final String heightString = s.substring(spaceIndex + 1);
try {
this.width = Integer.parseInt(widthString);
this.height = Integer.parseInt(heightString);
} catch (final NumberFormatException nfe) {
return false;
}
if (this.width < 1 || this.height < 1) {
return false;
}
if (this.format == FORMAT_PBM) {
this.bitsPerPixel = 1;
return true;
}
hasPixelResolution = true;
} else {
int maxSample;
try {
maxSample = Integer.parseInt(s);
} catch (final NumberFormatException nfe) {
return false;
}
if (maxSample < 0) {
return false;
}
for (int i = 0; i < 25; i++) {
if (maxSample < 1 << i + 1) {
this.bitsPerPixel = i + 1;
if (this.format == FORMAT_PPM) {
this.bitsPerPixel *= 3;
}
return true;
}
}
return false;
}
}
}
private boolean checkPsd() throws IOException {
final 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;
}
this.format = FORMAT_PSD;
this.width = getIntBigEndian(a, 16);
this.height = getIntBigEndian(a, 12);
final int channels = getShortBigEndian(a, 10);
final int depth = getShortBigEndian(a, 20);
this.bitsPerPixel = channels * depth;
return this.width > 0 && this.height > 0 && this.bitsPerPixel > 0 && this.bitsPerPixel <= 64;
}
private boolean checkRas() throws IOException {
final 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;
}
this.format = FORMAT_RAS;
this.width = getIntBigEndian(a, 2);
this.height = getIntBigEndian(a, 6);
this.bitsPerPixel = getIntBigEndian(a, 10);
return this.width > 0 && this.height > 0 && this.bitsPerPixel > 0 && this.bitsPerPixel <= 24;
}
/**
* 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 this.bitsPerPixel;
}
/**
* Returns the index'th comment retrieved from the file.
* @param index int index of comment to return
* @throws IllegalArgumentException if index is smaller than 0 or larger than or equal
* to the number of comments retrieved
* @see #getNumberOfComments
*/
public String getComment(final int index) {
if (this.comments == null || index < 0 || index >= this.comments.size()) {
throw new IllegalArgumentException("Not a valid comment index: " + index);
}
return (String)this.comments.elementAt(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 this.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 (this.format >= 0 && this.format < FORMAT_NAMES.length) {
return FORMAT_NAMES[this.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 this.height;
}
/**
* 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 (this.format >= 0 && this.format < MIME_TYPE_STRINGS.length) {
if (this.format == FORMAT_JPEG && this.progressive) {
return "image/pjpeg";
}
return MIME_TYPE_STRINGS[this.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 (this.comments == null) {
return 0;
} else {
return this.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 this.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 this.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() {
final int h = getHeight();
final 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 this.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() {
final int w = getWidth();
final int pw = getPhysicalWidthDpi();
if (w > 0 && pw > 0) {
return (float)w / (float)pw;
} else {
return -1.0f;
}
}
/**
* If {@link #check()} was successful, returns one the image's horizontal
* resolution in pixels.
* @return image width in pixels
*/
public int getWidth() {
return this.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 this.progressive;
}
private int read() throws IOException {
if (this.in != null) {
return this.in.read();
} else {
return this.din.readByte();
}
}
private int read(final byte[] a) throws IOException {
if (this.in != null) {
return this.in.read(a);
} else {
this.din.readFully(a);
return a.length;
}
}
private int read(final byte[] a, final int offset, final int num) throws IOException {
if (this.in != null) {
return this.in.read(a, offset, num);
} else {
this.din.readFully(a, offset, num);
return num;
}
}
private String readLine() throws IOException {
return readLine(new StringBuilder());
}
private String readLine(final StringBuilder sb) throws IOException {
boolean finished;
do {
final int value = read();
finished = value == -1 || value == 10;
if (!finished) {
sb.append((char)value);
}
} while (!finished);
return sb.toString();
}
/**
* 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(final boolean newValue) {
this.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(final boolean newValue) {
this.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(final DataInput dataInput) {
this.din = dataInput;
this.in = null;
}
/**
* Set the input stream to the argument stream (or file).
* @param inputStream the input stream to read from
*/
public void setInput(final InputStream inputStream) {
this.in = inputStream;
this.din = null;
}
private void setPhysicalHeightDpi(final int newValue) {
this.physicalWidthDpi = newValue;
}
private void setPhysicalWidthDpi(final int newValue) {
this.physicalHeightDpi = newValue;
}
private void skip(int num) throws IOException {
while (num > 0) {
long result;
if (this.in != null) {
result = this.in.skip(num);
} else {
result = this.din.skipBytes(num);
}
if (result > 0) {
num -= result;
} else {
if (this.in != null) {
result = this.in.read();
} else {
result = this.din.readByte();
}
if (result == -1) {
throw new IOException("Premature end of input.");
} else {
num--;
}
}
}
}
}