package org.rr.pm.image;
/*
* ImageInfo.java
*
* Version 1.3
*
* A Java class to determine image width, height and color depth for
* a number of image file formats.
*
* Written by Marco Schmidt <marcoschmidt@users.sourceforge.net>
*
* Contributed to the Public Domain.
*
* Last modification 2002-06-17
*/
import java.io.DataInput;
import java.io.IOException;
import java.io.InputStream;
import java.util.Vector;
import java.util.logging.Level;
import org.apache.commons.io.IOUtils;
import org.rr.commons.log.LoggerFactory;
import org.rr.commons.mufs.IResourceHandler;
/**
* 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).");
* </pre>
*
* You can also use this class as a command line program. Call it with a number of image file names as parameters:
*
* <pre>
* java ImageInfo *.jpg *.png *.gif
* </pre>
*
* or call it without parameters and pipe data to it:
*
* <pre>
* cat image.jpg | java ImageInfo
* </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="mailto:marcoschmidt@users.sourceforge.net">Marco Schmidt</a>.
* <p>
* This class is contributed to the Public Domain. Use it at your own risk.
* <p>
* Last modification 2002-06-17.
* <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>2003-09-09</strong> Added text encoding support (David Ekholm)
* </ul>
*/
public class ImageInfo {
/**
* 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.
*/
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>!
*/
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.
*/
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. <em>The specification that I have says that the values must be
* interpreted as dots per meter. However, given that I only
* encounter typical dpi values like 72 or 300, I currently
* consider those values dpi. Maybe someone can shed some light
* on this, please send me a mail in that case.</em>
*/
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 FORMAT_TIFF = 12;
public static final int FORMAT_JBIG2 = 13;
public static final int FORMAT_PDF = 14;
public static final int FORMAT_UNKNOWN = -1;
/**
* 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 int format;
private InputStream inputStream;
private IResourceHandler resourceHandler;
private boolean collectComments = true;
private Vector<String> comments;
private boolean determineNumberOfImages;
private int numberOfImages;
private int physicalHeightDpi;
private int physicalWidthDpi;
private int bitBuf;
private int bitPos;
private String encoding = "iso-8859-1";
private StringCodec codec = new StringCodec();
public ImageInfo(IResourceHandler resourceHandler) {
this.resourceHandler = resourceHandler;
this.check();
}
private void addComment(String s) {
if (comments == null) {
comments = new Vector<>();
}
comments.addElement(s);
}
/**
* Call this method after you have provided an input stream or file using {@link #setResourceHandler(InputStream)} or {@link #setResourceHandler(DataInput)}
* . If true is returned, the file format was known and you information about its 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 == 0xff && b2 == 0xd8) {
return checkJpeg();
} else if (b1 == 0x47 && b2 == 0x49) {
return checkGif();
} else if (b1 == 0x89 && b2 == 0x50) {
return checkPng();
} 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;
} finally {
IOUtils.closeQuietly(inputStream);
inputStream = null;
}
}
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 = getIntLittleEndian(a, 36);
if (x > 0) {
setPhysicalWidthDpi(x);
}
int y = getIntLittleEndian(a, 40);
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;
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) {
StringBuffer sb = new StringBuffer();
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 larger than 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 = codec.decode(chars, encoding);
comment = comment.trim();
// System.out.println(comment);
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);
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[24];
if (read(a) != 24) {
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;
}
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);
@SuppressWarnings("unused")
int minX = (int) readSBits(bitSize);
int maxX = (int) readSBits(bitSize);
@SuppressWarnings("unused")
int minY = (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 (String) 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 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) {
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;
}
private int read() throws IOException {
final InputStream in = getInputStream();
if (in != null) {
return in.read();
}
return -1;
}
private int read(byte[] a) throws IOException {
final InputStream in = getInputStream();
if (in != null) {
return in.read(a);
}
return -1;
}
private int read(byte[] a, int offset, int num) throws IOException {
final InputStream in = getInputStream();
if (in != null) {
return in.read(a, offset, num);
}
return -1;
}
private String readLine() throws IOException {
return readLine(new StringBuffer());
}
private String readLine(StringBuffer 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();
}
/**
* Read an unsigned value from the given number of bits
*/
public long readUBits(int numBits) throws IOException {
if (numBits == 0) {
return 0;
}
final InputStream in = getInputStream();
if (in == null) {
return 0;
}
int bitsLeft = numBits;
long result = 0;
if (bitPos == 0) { // no value in the buffer - read a byte
bitBuf = in.read();
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
bitBuf = in.read();
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;
}
/**
* Reset the bit buffer
*/
public void synchBits() {
bitBuf = 0;
bitPos = 0;
}
/**
* 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).
*
* @param resourceHandler
* the {@link IResourceHandler} provides the stream to read from
* @throws IOException
*/
public void setResourceHandler(IResourceHandler resourceHandler) {
this.resourceHandler = resourceHandler;
}
/**
* Gets the {@link InputStream} to be used for reading some data to identify the image.
*
* @return The desired {@link InputStream}.
*/
private InputStream getInputStream() {
if (this.inputStream == null) {
try {
inputStream = this.resourceHandler.getContentInputStream();
} catch (Exception e) {
LoggerFactory.log(Level.WARNING, this, "could not access InputStream for resource " + String.valueOf(resourceHandler), e);
}
}
return inputStream;
}
private void setPhysicalHeightDpi(int newValue) {
physicalWidthDpi = newValue;
}
private void setPhysicalWidthDpi(int newValue) {
physicalHeightDpi = newValue;
}
private void skip(int num) throws IOException {
final InputStream in = getInputStream();
if (in != null) {
in.skip(num);
}
}
public void setEncoding(String newEncoding) {
encoding = newEncoding;
}
public String getEncoding() {
return encoding;
}
}