title: extract image content in a string variable
body: <p>i would extract the text from an image in a string variable, so i use Tess4j to do this and it's work fine when i create a new project and test it: </p>
  
  <pre><code>public static void main(String[] args) throws TesseractException {  
          File image=new File("eurotext.tif");
          Tesseract instance=Tesseract.getInstance();
          String result = instance.doOCR(image);
          System.out.println(result);         
          }
  </code></pre>
  
  <p>but when i try to integrate tess4j into myproject i get exception:</p>
  
  <pre><code>java.lang.IllegalStateException: Input not set!
      at com.sun.media.imageioimpl.plugins.tiff.TIFFImageReader.getNumImages
  (TIFFImageReader.java:28)
      at net.sourceforge.vietocr.ImageIOHelper.getIIOImageList(Unknown Source)
      at net.sourceforge.tess4j.Tesseract.doOCR(Unknown Source)
      at net.sourceforge.tess4j.Tesseract.doOCR(Unknown Source)
  </code></pre>
  
  <p>is there another method to extract the text without using ocr?</p>
  
  <p>i dont know why i get this error but it  invoke TessBaseAPIGetUTF8Text  </p>
  
  <pre><code>    java.lang.Error: Invalid memory access
  at com.sun.jna.Native.invokePointer(Native Method)
  at com.sun.jna.Function.invokePointer(Function.java:470)
  at com.sun.jna.Function.invoke(Function.java:404)
  at com.sun.jna.Function.invoke(Function.java:315)
  at com.sun.jna.Library$Handler.invoke(Library.java:212)
  at sun.proxy.$Proxy7.TessBaseAPIGetUTF8Text(Unknown Source)
  at net.sourceforge.tess4j.Tesseract.getOCRText(Tesseract.java:336)
  at net.sourceforge.tess4j.Tesseract.doOCR(Tesseract.java:232)
  at net.sourceforge.tess4j.Tesseract.doOCR(Tesseract.java:173)
  at net.sourceforge.tess4j.Tesseract.doOCR(Tesseract.java:158)
  </code></pre>
  
  <p>is someone has already used tess4j with tomcat?</p>