| java.lang.Object
 org.jivesoftware.openfire.gateway.avatars.ImageInfo
| ImageInfo | | public class ImageInfo (Code) | | 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).
Use the class like this:
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
You can also use this class as a command line program.
Call it with a number of image file names and URLs as parameters:
java ImageInfo *.jpg *.png *.gif http://somesite.tld/image.jpg
or call it without parameters and pipe data to it:
java ImageInfo < image.jpg
Known limitations:
- 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.
- 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! ;-)
Requirements:
The latest version can be found at http://schmidt.devlib.org/image-info/.
Written by Marco Schmidt.
This class is contributed to the Public Domain.
Use it at your own risk.
History:
- 2001-08-24 Initial version.
- 2001-10-13 Added support for the file formats BMP and PCX.
- 2001-10-16 Fixed bug in read(int[], int, int) that returned
- 2002-01-22 Added support for file formats Amiga IFF and Sun Raster (RAS).
- 2002-01-24 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.
- 2002-03-15 Added support to recognize number of images in file. Only works with GIF.
Use
ImageInfo.setDetermineImageNumber with
true as argument to identify animated GIFs
(
ImageInfo.getNumberOfImages() will return a value larger than 1).
- 2002-04-10 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.
- 2002-04-18 Added
ImageInfo.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:
ImageInfo.getPhysicalWidthDpi() and
ImageInfo.getPhysicalHeightDpi() .
If the physical resolution could not be retrieved, these methods return
-1.
- 2002-04-23 Added support for the new properties physical resolution and
comments for some formats. Released as 1.2.
- 2002-06-17 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.
- 2003-07-28 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.
- 2004-02-29 Added support for recognizing progressive JPEG and
interlaced PNG and GIF. A new method
ImageInfo.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.
- 2004-11-30 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.
- 2005-01-02 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 'Known
issues' section of the website.
Released as 1.6.
- 2005-07-26 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.
- 2006-02-23 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.
- 2006-11-13 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.
author:
Marco Schmidt |
| Method Summary | |
| public boolean | check()
Call this method after you have provided an input stream or file
using
ImageInfo.setInput(InputStream) or
ImageInfo.setInput(DataInput) . | | public int | getBitsPerPixel()
If
ImageInfo.check() was successful, returns the image's number of bits per pixel. | | public String | getComment(int index)
Returns the index'th comment retrieved from the file. | | public int | getFormat()
If
ImageInfo.check() was successful, returns the image format as one
of the FORMAT_xyz constants from this class. | | public String | getFormatName()
If
ImageInfo.check() was successful, returns the image format's name. | | public int | getHeight()
If
ImageInfo.check() was successful, returns one the image's vertical
resolution in pixels. | | public String | getMimeType()
If
ImageInfo.check() was successful, returns a String with the
MIME type of the format.
MIME type, e.g. | | public int | getNumberOfComments()
If
ImageInfo.check() was successful and
ImageInfo.setCollectComments(boolean) was called with
true as argument, returns the number of comments retrieved
from the input image stream / file. | | public int | getNumberOfImages()
Returns the number of images in the examined file. | | public int | getPhysicalHeightDpi()
Returns the physical height of this image in dots per inch (dpi). | | public float | getPhysicalHeightInch()
If
ImageInfo.check() was successful, returns the physical width of this image in dpi (dots per inch)
or -1 if no value could be found. | | public int | getPhysicalWidthDpi()
If
ImageInfo.check() was successful, returns the physical width of this image in dpi (dots per inch)
or -1 if no value could be found. | | public float | getPhysicalWidthInch()
Returns the physical width of an image in inches, or
-1.0f if width information is not available. | | public int | getWidth()
If
ImageInfo.check() was successful, returns one the image's horizontal
resolution in pixels. | | public boolean | isProgressive()
Returns whether the image is stored in a progressive (also called: interlaced) way. | | public static void | main(String[] args)
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. | | public void | setCollectComments(boolean newValue)
Specify whether textual comments are supposed to be extracted from input. | | public void | setDetermineImageNumber(boolean newValue)
Specify whether the number of images in a file is to be
determined - default is false. | | public void | setInput(DataInput dataInput)
Set the input stream to the argument stream (or file). | | public void | setInput(InputStream inputStream)
Set the input stream to the argument stream (or file). |
| FORMAT_BMP | | final public static int FORMAT_BMP(Code) | | Return value of
ImageInfo.getFormat() for BMP streams.
BMP only supports one image per file.
BMP does not allow for comments.
The physical resolution can be stored.
|
| FORMAT_GIF | | final public static int FORMAT_GIF(Code) | | Return value of
ImageInfo.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
ImageInfo.isProgressive() ).
|
| FORMAT_JPEG | | final public static int FORMAT_JPEG(Code) | | Return value of
ImageInfo.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
ImageInfo.isProgressive() ).
|
| FORMAT_PCX | | final public static int FORMAT_PCX(Code) | | Return value of
ImageInfo.getFormat() for PCX streams.
PCX does not allow for comments or more than one image per file.
However, the physical resolution can be stored.
|
| FORMAT_PNG | | final public static int FORMAT_PNG(Code) | | Return value of
ImageInfo.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
ImageInfo.isProgressive() ).
|
| FORMAT_RAS | | final public static int FORMAT_RAS(Code) | | Return value of
ImageInfo.getFormat() for RAS streams.
Sun Raster allows for one image per file only and is not able to
store physical resolution or comments.
|
| check | | public boolean check()(Code) | | Call this method after you have provided an input stream or file
using
ImageInfo.setInput(InputStream) or
ImageInfo.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.
if information could be retrieved from input |
| getBitsPerPixel | | public int getBitsPerPixel()(Code) | | If
ImageInfo.check() was successful, returns the image's number of bits per pixel.
Does not include transparency information like the alpha channel.
number of bits per image pixel |
| getComment | | public String getComment(int index)(Code) | | Returns the index'th comment retrieved from the file.
Parameters:
index - int index of comment to return
throws:
IllegalArgumentException - if index is smaller than 0 or larger than or equalto the number of comments retrieved
See Also: ImageInfo.getNumberOfComments referred comment from file |
| getFormat | | public int getFormat()(Code) | | If
ImageInfo.check() was successful, returns the image format as one
of the FORMAT_xyz constants from this class.
Use
ImageInfo.getFormatName() to get a textual description of the file format.
file format as a FORMAT_xyz constant |
| getHeight | | public int getHeight()(Code) | | If
ImageInfo.check() was successful, returns one the image's vertical
resolution in pixels.
image height in pixels |
| getMimeType | | public String getMimeType()(Code) | | If
ImageInfo.check() was successful, returns a String with the
MIME type of the format.
MIME type, e.g. image/jpeg |
| getNumberOfImages | | public int getNumberOfImages()(Code) | | Returns the number of images in the examined file.
Assumes that setDetermineImageNumber(true); was called before
a successful call to
ImageInfo.check() .
This value can currently be only different from 1 for GIF images.
number of images in file |
| getWidth | | public int getWidth()(Code) | | If
ImageInfo.check() was successful, returns one the image's horizontal
resolution in pixels.
image width in pixels |
| isProgressive | | public boolean isProgressive()(Code) | | Returns whether the image is stored in a progressive (also called: interlaced) way.
true for progressive/interlaced, false otherwise |
| main | | public static void main(String[] args)(Code) | | 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.
Parameters:
args - the program arguments which must be file names |
| setCollectComments | | public void setCollectComments(boolean newValue)(Code) | | Specify whether textual comments are supposed to be extracted from input.
Default is false.
If enabled, comments will be added to an internal list.
Parameters:
newValue - if true, this class will read comments
See Also: ImageInfo.getNumberOfComments
See Also: ImageInfo.getComment |
| setDetermineImageNumber | | public void setDetermineImageNumber(boolean newValue)(Code) | | Specify whether the number of images in a file is to be
determined - default is false.
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 true as argument,
the actual number of images can be queried via
ImageInfo.getNumberOfImages() after a successful call to
ImageInfo.check() .
Parameters:
newValue - will the number of images be determined?
See Also: ImageInfo.getNumberOfImages |
| setInput | | public void setInput(InputStream inputStream)(Code) | | Set the input stream to the argument stream (or file).
Parameters:
inputStream - the input stream to read from |
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