Placeholder-image handling

git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/trunk@613 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c

1 files changed, 299 insertions, 0 deletions

diff --git a/src/main/java/at/gv/egiz/pdfas/placeholder/SignaturePlaceholderExtractor.java b/src/main/java/at/gv/egiz/pdfas/placeholder/SignaturePlaceholderExtractor.java
new file mode 100644
index 0000000..50c3281
--- /dev/null
+++ b/src/main/java/at/gv/egiz/pdfas/placeholder/SignaturePlaceholderExtractor.java
@@ -0,0 +1,299 @@
+package at.gv.egiz.pdfas.placeholder;

+

+import java.awt.geom.AffineTransform;

+import java.awt.geom.NoninvertibleTransformException;

+import java.awt.image.BufferedImage;

+import java.io.IOException;

+import java.io.InputStream;

+import java.util.Hashtable;

+import java.util.Iterator;

+import java.util.List;

+import java.util.Map;

+import java.util.Vector;

+

+import org.apache.commons.logging.Log;

+import org.apache.commons.logging.LogFactory;

+import org.apache.pdfbox.cos.COSName;

+import org.apache.pdfbox.exceptions.WrappedIOException;

+import org.apache.pdfbox.pdmodel.PDDocument;

+import org.apache.pdfbox.pdmodel.PDPage;

+import org.apache.pdfbox.pdmodel.graphics.xobject.PDXObject;

+import org.apache.pdfbox.pdmodel.graphics.xobject.PDXObjectImage;

+import org.apache.pdfbox.util.Matrix;

+import org.apache.pdfbox.util.PDFOperator;

+import org.apache.pdfbox.util.PDFStreamEngine;

+import org.apache.pdfbox.util.ResourceLoader;

+

+import at.gv.egiz.pdfas.api.sign.SignParameters;

+import at.gv.egiz.pdfas.exceptions.ErrorCode;

+import at.gv.egiz.pdfas.exceptions.framework.PlaceholderExtractionException;

+import at.gv.egiz.pdfas.utils.PDFASUtils;

+import at.knowcenter.wag.egov.egiz.exceptions.PDFDocumentException;

+import at.knowcenter.wag.egov.egiz.pdf.TablePos;

+

+import com.google.zxing.BarcodeFormat;

+import com.google.zxing.BinaryBitmap;

+import com.google.zxing.DecodeHintType;

+import com.google.zxing.LuminanceSource;

+import com.google.zxing.MultiFormatReader;

+import com.google.zxing.NotFoundException;

+import com.google.zxing.ReaderException;

+import com.google.zxing.Result;

+import com.google.zxing.client.j2se.BufferedImageLuminanceSource;

+import com.google.zxing.common.HybridBinarizer;

+

+/**

+ * Extract all relevant information from a placeholder image.

+ * 

+ * @author exthex

+ *

+ */

+public class SignaturePlaceholderExtractor extends PDFStreamEngine {

+   /**

+    * The log.

+    */

+   private static Log log = LogFactory.getLog(SignaturePlaceholderExtractor.class);

+   

+   private List placeholders = new Vector();

+   private int currentPage = 0;

+   

+   private SignaturePlaceholderExtractor(String placeholderId, int placeholderMatchMode) throws IOException {

+      super(ResourceLoader.loadProperties("at/gv/egiz/pdfas/placeholder/pdfbox-reader.properties",

+            true));

+   }

+

+   /**

+    * Search the document for placeholder images and possibly included

+    * additional info.<br/>

+    * Searches only for the first placeholder page after page from top.

+    * 

+    * @param inputStream

+    * @return all available info from the first found placeholder.

+    * @throws PDFDocumentException if the document could not be read.

+    * @throws PlaceholderExtractionException if STRICT matching mode was requested and no suitable placeholder could be found.

+    */

+   public static SignaturePlaceholderData extract(InputStream inputStream, String placeholderId, int matchMode)

+         throws PDFDocumentException, PlaceholderExtractionException {

+      SignaturePlaceholderContext.setSignaturePlaceholderData(null);

+      PDDocument doc = null;

+      try 

+      {

+         try {

+            doc = PDDocument.load(inputStream);

+         } catch (IOException e) {

+            throw new PDFDocumentException(ErrorCode.DOCUMENT_CANNOT_BE_READ, e);

+         }

+         PDFASUtils.checkDocumentPermissions(doc);

+   

+         SignaturePlaceholderExtractor extractor;

+         try

+         {

+            extractor = new SignaturePlaceholderExtractor(placeholderId, matchMode);

+         } catch (IOException e2) {

+            throw new PDFDocumentException(ErrorCode.DOCUMENT_CANNOT_BE_READ, e2);

+         }

+         List pages = doc.getDocumentCatalog().getAllPages();

+         Iterator iter = pages.iterator();

+         int pageNr = 0;

+         while (iter.hasNext()) {

+            pageNr++;

+            PDPage page = (PDPage) iter.next();

+            try {

+               extractor.setCurrentPage(pageNr);

+               extractor.processStream( page, page.findResources(), page.getContents().getStream() );

+               SignaturePlaceholderData ret = matchPlaceholderPage(extractor.placeholders, placeholderId, matchMode);

+               if (ret != null){

+            	   SignaturePlaceholderContext.setSignaturePlaceholderData(ret);

+                  return ret;

+               }

+            } catch (IOException e1) {

+               throw new PDFDocumentException(ErrorCode.DOCUMENT_CANNOT_BE_READ, e1);

+            }

+   

+         }

+         if (extractor.placeholders.size() > 0){

+            SignaturePlaceholderData ret = matchPlaceholderDocument(extractor.placeholders, placeholderId, matchMode);

+            SignaturePlaceholderContext.setSignaturePlaceholderData(ret);

+            return ret;

+         }

+         return null;

+      }finally{

+         if (doc != null)

+            try {

+               doc.close();

+            } catch (IOException e) {

+               log.debug("Could not close document.", e);

+            }

+      }

+

+   }

+   

+   private static SignaturePlaceholderData matchPlaceholderDocument(

+         List placeholders, String placeholderId, int matchMode) throws PlaceholderExtractionException {

+      

+      if (matchMode == SignParameters.PLACEHOLDER_MATCH_MODE_STRICT)

+         throw new PlaceholderExtractionException(ErrorCode.SIGNATURE_PLACEHOLDER_EXTRACTION_FAILED, "no suitable placeholder found and STRICT matching mode requested.");

+      

+      if (placeholders.size() == 0)

+         return null;

+      

+      for (int i = 0; i < placeholders.size(); i++)

+      {

+         SignaturePlaceholderData spd = (SignaturePlaceholderData)placeholders.get(i);

+         if (spd.getId() == null)

+            return spd;

+      }

+      

+      if (matchMode == SignParameters.PLACEHOLDER_MATCH_MODE_LENIENT)

+         return (SignaturePlaceholderData)placeholders.get(0);

+

+      return null;

+   }

+

+   private static SignaturePlaceholderData matchPlaceholderPage(List placeholders,

+         String placeholderId, int matchMode) {

+      if (placeholders.size() == 0)

+         return null;

+      for (int i = 0; i < placeholders.size(); i++)

+      {

+         SignaturePlaceholderData data = (SignaturePlaceholderData)placeholders.get(i);

+         if (placeholderId != null && placeholderId.equals(data.getId()))

+            return data;

+         if (placeholderId == null && data.getId() == null)

+            return data;

+      }

+      return null;

+   }

+

+   private void setCurrentPage(int pageNr) {

+      this.currentPage = pageNr;

+   }

+

+   protected void processOperator( PDFOperator operator, List arguments ) throws IOException

+   {

+       String operation = operator.getOperation();

+       if( operation.equals( "Do" ) )

+       {

+           COSName objectName = (COSName)arguments.get( 0 );

+           Map xobjects = getResources().getXObjects();

+           PDXObject xobject = (PDXObject)xobjects.get( objectName.getName() );

+           if( xobject instanceof PDXObjectImage )

+           {

+               try

+               {

+                   PDXObjectImage image = (PDXObjectImage)xobject;

+                   SignaturePlaceholderData data = checkImage(image);

+                   if (data != null)

+                   {

+                      PDPage page = getCurrentPage();

+                      Matrix ctm = getGraphicsState().getCurrentTransformationMatrix();

+                      double rotationInRadians = (page.findRotation() * Math.PI)/180;

+   

+                      AffineTransform rotation = new AffineTransform();

+                      rotation.setToRotation( rotationInRadians );

+                      AffineTransform rotationInverse = rotation.createInverse();

+                      Matrix rotationInverseMatrix = new Matrix();

+                      rotationInverseMatrix.setFromAffineTransform( rotationInverse );

+                      Matrix rotationMatrix = new Matrix();

+                      rotationMatrix.setFromAffineTransform( rotation );

+   

+                      Matrix unrotatedCTM = ctm.multiply( rotationInverseMatrix );

+   

+                      float x = unrotatedCTM.getXPosition() - 1F;

+                      float y = unrotatedCTM.getYPosition() + unrotatedCTM.getYScale() + 1F;

+                      float w = unrotatedCTM.getXScale() + 2F;

+                      

+                      String posString = "p:" + currentPage + ";x:" + x + ";y:" + y + ";w:" + w;

+                      try

+                      {

+                         data.setTablePos(new TablePos(posString));

+                         data.setPlaceholderName(objectName.getName());

+                         placeholders.add(data);

+                      } catch (PDFDocumentException e) {

+                         throw new WrappedIOException(e);

+                      }

+                   }

+               }

+               catch( NoninvertibleTransformException e )

+               {

+                   throw new WrappedIOException( e );

+               }

+           }

+       }

+       else

+       {

+           super.processOperator( operator, arguments );

+       }

+   }

+

+   /**

+    * Checks an image if it is a placeholder for a signature.

+    * 

+    * @param image

+    * @return

+    * @throws IOException

+    */

+   private SignaturePlaceholderData checkImage(PDXObjectImage image) throws IOException {

+      BufferedImage bimg = image.getRGBImage();

+      if(bimg.getHeight() < 10 || bimg.getWidth() < 10)

+         return null;

+

+      LuminanceSource source = new BufferedImageLuminanceSource(bimg);

+      BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));

+      Result result;

+      long before = System.currentTimeMillis();

+      try {

+         Hashtable hints = new Hashtable();

+         Vector formats = new Vector();

+         formats.add(BarcodeFormat.QR_CODE);

+         hints.put(DecodeHintType.POSSIBLE_FORMATS, formats);

+         result = new MultiFormatReader().decode(bitmap, hints);

+         String text = result.getText();

+         String profile = null;

+         String type = null;

+         String sigKey = null;

+         String id = null;

+         if (text != null && text.startsWith("PDF-AS-POS")) {

+            String[] data = text.split(";");

+            if (data.length > 1) {

+               for (int i = 1; i < data.length; i++) {

+                  String kvPair = data[i];

+                  String[] kv = kvPair.split("=");

+                  if (kv.length != 2) {

+                     log.debug("invalid parameter in placeholder data: " + kvPair);

+                  } else {

+                     if (kv[0].equalsIgnoreCase(SignaturePlaceholderData.ID_KEY)) {

+                        id = kv[1];

+                     } else if (kv[0].equalsIgnoreCase(SignaturePlaceholderData.PROFILE_KEY)) {

+                        profile = kv[1];

+                     } else if (kv[0]

+                           .equalsIgnoreCase(SignaturePlaceholderData.SIG_KEY_KEY)) {

+                        sigKey = kv[1];

+                     } else if (kv[0]

+                           .equalsIgnoreCase(SignaturePlaceholderData.TYPE_KEY)) {

+                        type = kv[1];

+                     }

+                  }

+               }

+            }

+            return new SignaturePlaceholderData(profile, type, sigKey, id);

+         }

+      } catch (ReaderException re) {

+         if (log.isDebugEnabled()) {

+            log.debug("Could not decode - not a placeholder. needed: "

+                  + (System.currentTimeMillis() - before));

+         }

+         if (!(re instanceof NotFoundException)){

+            if (log.isInfoEnabled()) {

+               log.info("Failed to decode image", re);

+            }

+         }

+      } catch(ArrayIndexOutOfBoundsException e){

+         if (log.isInfoEnabled()) {

+            log.info("Failed to decode image. Probably a zxing bug", e);

+         }

+      }

+      return null;

+   }

+

+}