We Keep Coding

Do any Java OCR tools convert images of text into editable text files?

I'm working on a project that entails photographing text (from any hard copy of text) and converting that text into a text file. Then I'd like to use that text file to do some different things, such as provide hyperlinks to news articles or allow the user to edit the document.
The tool I've tried so far is Java OCR from sourceforge.net, which works fine on the images provided in the package. But when I photograph my own text, it doesnt work at all. Is there some training process I should be implementing? If so, does anybody know how to implement it? Any help will go a long way. Thank you!

I have a java application where I ended up deciding to use Tesseract OCR, and just call out to it using Runtime.exec(). Perhaps not quite the answer you need, but just in case you'd not considered it.
Edit + code added in response to comment reply
On a Windows installation I think I was able to use an installer, or unzip a ready made binary.
On a Linux server, I needed to compile Tesseract myself, but it's not too hard if you're used to that kind of thing (gcc); the only gotcha is that there's a dependency on Leptonica which also needs to be compiled.
// Tesseract can only handle .tif format, so we have to convert it
ImageIO.write( ImageIO.read( new java.io.File(file.getPath())), "tif", tmpFile[0]);
String[] tesseractCmd = new String[]{"tesseract", tmpFile[0].getAbsolutePath(), StringUtils.removeEnd(tmpFile[1].getAbsolutePath(), ".txt")};
final Process process = Runtime.getRuntime().exec(tesseractCmd);
try {
int exitValue = process.waitFor();
if(exitValue == 0) {
final String extractedText = SearchableTextExtractionUtils.extractPlainText(new FileReader(tmpFile[1]));
return extractedText;
}
throw new SearchableTextExtractionException(exitValue, Arrays.toString(tesseractCmd));
} catch (InterruptedException e) {
throw new SearchableTextExtractionException(e);
} finally {
process.destroy();
}

missing javax.swing

I'm trying to use the pdf library from jpedal, using the code snippet found here: http://www.jpedal.org/simple_image_example.php
/**instance of PdfDecoder to convert PDF into image*/
PdfDecoder decode_pdf = new PdfDecoder(true);
/**set mappings for non-embedded fonts to use*/
FontMappings.setFontReplacements();
/**open the PDF file - can also be a URL or a byte array*/
try {
decode_pdf.openPdfFile("C:/myPDF.pdf"); //file
//decode_pdf.openPdfFile("C:/myPDF.pdf", "password"); //encrypted file
//decode_pdf.openPdfArray(bytes); //bytes is byte[] array with PDF
//decode_pdf.openPdfFileFromURL("http://www.mysite.com/myPDF.pdf",false);
/**get page 1 as an image*/
//page range if you want to extract all pages with a loop
//int start = 1, end = decode_pdf.getPageCount();
BufferedImage img=decode_pdf.getPageAsImage(1);
/**close the pdf file*/
decode_pdf.closePdfFile();
} catch (PdfException e) {
e.printStackTrace();
}
But on this line:
decode_pdf.openPdfFile("C:/myPDF.pdf"); //file
Eclipse trows an error:
The type javax.swing.JPanel cannot be resolved. It is indirectly
referenced from required .class files
It seems as if I'm missing javax.swing.*
Intellisence does give me other javax.* options but not the swing class.
I already searched google for this but I had no luck finding a solution.
Any ideas?

Can't get any clearer than this:
http://www.jpedal.org/PDFblog/2011/09/java-is-not-android/
Appears that the library I wanted to use was not compatible with android at all.
Also not the last sentence:
that makes converting a Java PDF viewer to Android a major task.
Thanks for crushing that last bit of hope for me jpedal...

I doubt path is not resolved, Try this
decode_pdf.openPdfFile("C:\\myPDF.pdf");

How do we convert WMF/EMF (MS metafiles) into standard images like JPG or PNG using any Java API?

I have been stuck in converting WMF/EMF images into standard image format such as JPG or PNG using Java.
What are the best options available?

The Batik library is a toolkit to handle SVG in Java. There are converters included like WMFTranscoder to convert from WMF to SVG and JPEGTranscoder and PNGTranscoder to convert SVG to JPEG/PNG. See Transcoder API Docs for more details.
Another alternative is ImageMagick. It's not Java but has Java bindings: im4java and JMagick.

wmf is a vector file format. For best results, convert them to .svg or .pdf format.
I did it in two stages
1) wmf2fig --auto XXXX.wmf
2) fig2pdf --nogv XXXX.fig
I created a python script for bulk conversion
import subprocess as sbp
a = sbp.Popen("ls *.wmf",shell=True, stderr=sbp.PIPE, stdout=sbp.PIPE)
filelist = a.communicate()[0].splitlines()
for ele in filelist:
cmdarg = 'wmf2fig --auto '+ ele.rsplit('.',1)[0]+'.wmf'
a = sbp.Popen(cmdarg, shell=True, stderr=sbp.PIPE, stdout=sbp.PIPE)
out = a.communicate()
for ele in filelist:
cmdarg = 'fig2pdf --nogv '+ ele.rsplit('.',1)[0]+'.fig'
a = sbp.Popen(cmdarg, shell=True, stderr=sbp.PIPE, stdout=sbp.PIPE)
out = a.communicate()
cmdarg = 'rm *.fig'
a = sbp.Popen(cmdarg, shell=True, stderr=sbp.PIPE, stdout=sbp.PIPE)
out = a.communicate()

If you are deploying your application in a Windows environment, then SWT can handle the conversion for you.
Image image = new Image(Display.getCurrent(), "test.wmf");
ImageLoader loader = new ImageLoader();
loader.data = new ImageData[] { image.getImageData() };
try(FileOutputStream stream = new FileOutputStream("test.png"))
{
loader.save(stream, SWT.IMAGE_PNG);
}
image.dispose();
The purpose of SWT is to provide a Java wrapper around native functionality, and in this case it is calling the windows GDI directly to get it to render the WMF.

I've created some wrappers around the Batik package (as mentioned by vanje's answer) some time ago, that provides ImageIO support for SVG and WMF/EMF.
With these plugins you should be able to write:
ImageIO.write(ImageIO.read(wmfFile), pngFile, "png");
Source code on GitHub.
While the ImageIO plugins are convenient, im4java and JMagick might still have better format support.

Here is one way.
Get (or make) a Java component that can render the files in question.
Create a BufferedImage the same size as the component needs to display the image.
Get the Graphics object from the BufferedImage.
Call renderComponent.paintComponent(Graphics)
Save the image using one of the ImageIO.write() variants.
See my answer to Swing: Obtain Image of JFrame for steps 2-5. Step 1. is something I'd ask Google about.

Display Image from Server in Java

I am new in Java programming. My query is that I am having an image which is present on a server and I want to display that image inside the JFrame. I tried using the Image class but that seems to be not working.
Please Note: I don't want to use applets for this, so is there some other method by which this can be done?
Thanks & Regards,

Assuming that it's a public accessible webserver, you can use URL#openStream() to get an InputStream out of an URL.
InputStream input = new URL("http://example.com/image.png").openStream();
Then you can just create the BufferedImage with help of ImageIO#read() the usual way.
BufferedImage image = ImageIO.read(input);
// ...

Is there a 100% Java alternative to ImageIO for reading JPEG files?

We are using Java2D to resize photos uploaded to our website, but we run into an issue (a seemingly old one, cf.: http://forums.sun.com/thread.jspa?threadID=5425569) - a few particular JPEGs raise a CMMException when we try to ImageIO.read() an InputStream containing their binary data:
java.awt.color.CMMException: Invalid image format
at sun.awt.color.CMM.checkStatus(CMM.java:131)
at sun.awt.color.ICC_Transform.<init>(ICC_Transform.java:89)
at java.awt.image.ColorConvertOp.filter(ColorConvertOp.java:516)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.acceptPixels(JPEGImageReader.java:1114)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.readImage(Native Method)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.readInternal(JPEGImageReader.java:1082)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.read(JPEGImageReader.java:897)
at javax.imageio.ImageIO.read(ImageIO.java:1422)
at javax.imageio.ImageIO.read(ImageIO.java:1326)
...
(snipped the remainder of the stack trace, which is our ImageIO.read() call, servlet code and such)
We narrowed it down to photos taken on specific cameras, and I selected a photo that triggers this error: http://img214.imageshack.us/img214/5121/estacaosp.jpg.
We noticed that this only happens with Sun's JVM (on Linux and Mac, just tested it on 1.6.0_20) - a test machine with OpenJDK reads the same photos without a hitch, possibly due to a different implementation of the JPEG reader.
Unfortunately, we are unable to switch JVMs in production, nor to use native-dependent solutions such as ImageMagick ( http://www.imagemagick.org/ ).
Considering that, my question is: Does a replacement for ImageIOs JPEG reader which can handle photos such as the linked one exist? If not, is there another 100% pure Java photo resizing solution which we can use?
Thank you!

One possibly useful library for you could be the Java Advanced Imaging Library (JAI)
Using this library can be quite a bit more complicated than using ImageIO but in a quick test I just ran, it did open and display the problem image file you linked.
public static void main(String[] args) {
RenderedImage image = JAI.create("fileload", "estacaosp.jpg");
float scale=(float) 0.5;
ParameterBlock pb = new ParameterBlock();
pb.addSource(image);
pb.add(scale);
pb.add(scale);
pb.add(1.0F);
pb.add(1.0F);
pb.add(new InterpolationNearest() );// ;InterpolationBilinear());
image = JAI.create("scale", pb);
// Create an instance of DisplayJAI.
DisplayJAI srcdj = new DisplayJAI(image);
JScrollPane srcScrollPaneImage = new JScrollPane(srcdj);
// Use a label to display the image
JFrame frame = new JFrame();
frame.getContentPane().add(srcScrollPaneImage, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
}
After running this code the image seems to load fine. It is then resized by 50% using the ParamaterBlock
And finally if you wish to save the file you can just call :
String filename2 = new String ("tofile.jpg");
String format = new String ("JPEG");
RenderedOp op = JAI.create ("filestore", image, filename2, format);
I hope this helps you out. Best of luck.

Old post, but for future reference:
Inspired by this question and links found here, I've written a JPEGImageReader plugin for ImageIO that supports JPEG images with these kind of "bad" ICC color profiles (the "issue" is the rendering intent in the ICC profile is incompatible with Java's ColorConvertOp). It's plain Java and does not require JAI.
The source code and linked binary builds are freely available from the TwelveMonkeys project on GitHub.

I faced the same issue. I was reluctant to use JAI as it is outdated but it looks like it's the shortest solution.
This code converts an InputStream to a BufferedImage, using sun's ImageIO (fast) or in the few cases where this problem occur, using JAI:
public static BufferedImage read(InputStream is) throws IOException {
try {
// We try it with ImageIO
return ImageIO.read(ImageIO.createImageInputStream(is));
} catch (CMMException ex) {
// If we failed...
// We reset the inputStream (start from the beginning)
is.reset();
// And use JAI
return JAI.create("stream", SeekableStream.wrapInputStream(is, true)).getAsBufferedImage();
}
}