added annotation extraction with pdfbox 0.8.0

git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/trunk@475 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c

1 files changed, 171 insertions, 0 deletions

diff --git a/src/main/java/at/knowcenter/wag/egov/egiz/pdf/ObjectExtractor.java b/src/main/java/at/knowcenter/wag/egov/egiz/pdf/ObjectExtractor.java
new file mode 100644
index 0000000..f19a2f4
--- /dev/null
+++ b/src/main/java/at/knowcenter/wag/egov/egiz/pdf/ObjectExtractor.java
@@ -0,0 +1,171 @@
+package at.knowcenter.wag.egov.egiz.pdf;

+

+import java.io.IOException;

+import java.util.ArrayList;

+import java.util.Iterator;

+import java.util.List;

+import java.util.Map;

+

+import org.apache.log4j.Logger;

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

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

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

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

+import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotation;

+

+import at.gv.egiz.pdfas.api.analyze.NonTextObjectInfo;

+import at.gv.egiz.pdfas.framework.input.PdfDataSource;

+

+/**

+ * Method for object extraction from pdf documents.

+ * This uses pdf-box 0.8.0, not 0.7.2. Packages org.apache.pdfbox instead org.pdfbox!

+ * @author dferbas

+ *

+ */

+public class ObjectExtractor {

+   private static Logger log = Logger.getLogger(ObjectExtractor.class);

+

+   /**

+    * Find annotation objects in pdf documents

+    * @param objectInfos

+    * @param pageNr

+    * @param page

+    */

+   private static void doExtractAnnotations(List objectInfos, int pageNr, PDPage page) {

+        List annotations; 

+        try {

+           annotations = page.getAnnotations();

+        } catch (IOException e) {

+           log.error("Error extracting annotations from pdf. No NonTextObjectInfo-annotations available.", e);

+           return;

+        }

+        for (Iterator it = annotations.iterator(); it.hasNext();) {

+           try {              

+              PDAnnotation anno = (PDAnnotation) it.next();

+              log.debug("found annotation: " +anno);

+              String ft = anno.getDictionary().getNameAsString("FT");              

+              if (ft != null && ft.equals("Sig")) {  // skip signature widgets

+                 log.debug("found signature widged, skip further extraction");

+                 break;

+              }             

+              NonTextObjectInfo objInfo = new NonTextObjectInfo();

+              objInfo.setName(anno.getDictionary().getString( "NM" ));

+              objInfo.setObjectType(NonTextObjectInfo.TYPE_ANNOTATION);

+

+              String subtype = anno.getDictionary().getNameAsString("Subtype");

+              String subj = anno.getDictionary().getString("Subj");

+              if (subj != null) {

+                subtype+= "/" + subj; 

+              }

+              objInfo.setSubType(subtype);

+              

+              objInfo.setPageNr(pageNr);

+              objInfo.setHeight(anno.getRectangle().getHeight());

+              objInfo.setWidth(anno.getRectangle().getWidth());

+              objectInfos.add(objInfo);              

+           } catch (Exception ex) {

+              log.info("error reading non text object info key " + ex);

+           }

+        }   

+     }

+

+   /**

+    * Find resources (images) in pdf documents

+    * @param objectInfos

+    * @param pageNr

+    * @param page

+    */

+   private static void doExtractFromResources(List objectInfos, int pageNr, PDPage page) {

+        PDResources resources = page.getResources();

+    

+        Map images;

+        try {

+           images = resources.getImages();

+        } catch (IOException e) {

+           log.error("Error extracting images from pdf. No NonTextObjectInfo-Images available.", e);

+           return;

+        }

+        if (images != null) {

+           Iterator imageIter = images.keySet().iterator();

+           while (imageIter.hasNext()) {

+              NonTextObjectInfo objInfo = new NonTextObjectInfo();

+              String key = (String) imageIter.next();

+              PDXObjectImage image = (PDXObjectImage) images.get(key);

+              System.err.println(image);

+              

+              objInfo.setHeight(image.getHeight());

+              objInfo.setWidth(image.getWidth());

+              objInfo.setName(key + image.getSuffix());

+              objInfo.setObjectType(NonTextObjectInfo.TYPE_IMAGE);

+              objInfo.setPageNr(pageNr);

+              objectInfos.add(objInfo);

+              objInfo.setSubType(image.getSuffix());

+              

+              if (log.isDebugEnabled()) {

+                 log.debug("Found non text object: " + objInfo.toString());

+              }

+           }

+        }     

+     }

+

+   /**

+      * Extract non textual data from pdf. 

+      * 

+      * @see org.pdfbox.ExtractImages

+      * 

+      * @param document

+      * @return List of {@link NonTextObjectInfo}

+      */

+     public static List extractNonTextInfo(PDDocument document) {         

+        // extraction does not work with the normalized pdf from extractTextTextual

+        log.debug("going to extract non text objects");

+        List objectInfos = new ArrayList();

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

+        Iterator iter = pages.iterator();

+        int pageNr = 0;

+        while (iter.hasNext()) {

+           pageNr++;

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

+           doExtractFromResources(objectInfos, pageNr, page);

+           doExtractAnnotations(objectInfos, pageNr, page); // does not work with pdf-box 0.7.2 -> 0.8.0 needed

+        }

+        if (log.isDebugEnabled()) {

+           log.debug("extracted non textual objects count: " + objectInfos.size());

+        }

+        log.debug("going to extract non text objects");

+        return objectInfos;

+   

+     }

+

+   /**

+      * Extract non textual data from pdf. 

+    * @param pdfDataSource 

+      * 

+      * @see org.pdfbox.ExtractImages

+      * 

+      * @return List of {@link NonTextObjectInfo}

+      */

+      public static List extractNonTextInfo(PdfDataSource pdfDataSource) {

+   

+         PDDocument doc = null;

+         try {

+            doc = PDDocument.load(pdfDataSource.createInputStream());

+            List res = extractNonTextInfo(doc);

+            doc.close();

+            return res;

+         } catch (IOException e) {

+            log.error("Error extracting images from pdf. No NonTextObjectInfo available.", e);

+            return new ArrayList();

+         } finally {

+            if (doc != null) {

+               try {

+                  doc.close();

+               } catch (IOException e) {

+                  log.error("error closing pddocument", e);

+               }            

+            }

+         }

+         

+      }

+

+}