org.freeeed.ocr.PDFImageExtractor.java Source code

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Here is the source code for org.freeeed.ocr.PDFImageExtractor.java

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/*
 *
 * Copyright SHMsoft, Inc. 
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
*/
package org.freeeed.ocr;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
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.freeeed.services.Project;

/**
 *
 * Class PDFImageExtractor.
 *
 * Extract images from PDF files, if any.
 *
 * @author ilazarov
 *
 */
public class PDFImageExtractor extends ImageExtractor {

    protected PDFImageExtractor(String file) {
        super(file);
    }

    @SuppressWarnings("rawtypes")
    @Override
    public List<String> extractImages() {
        File extractionDir = new File(conf.getPdfImageExtractionDir());
        extractionDir.mkdirs();

        List<String> result = new ArrayList<String>();

        PDDocument document = null;
        try {
            document = PDDocument.load(file);

            List pages = document.getDocumentCatalog().getAllPages();
            Iterator iter = pages.iterator();
            int i = 1;
            int maxNumberOfImages = Project.getCurrentProject().getOcrMaxImagesPerPDF();

            while (iter.hasNext()) {
                PDPage page = (PDPage) iter.next();
                PDResources resources = page.getResources();
                Map pageImages = resources.getImages();
                if (pageImages != null) {
                    Iterator imageIter = pageImages.keySet().iterator();
                    while (imageIter.hasNext()) {
                        if (i > maxNumberOfImages) {
                            return result;
                        }

                        String key = (String) imageIter.next();
                        PDXObjectImage image = (PDXObjectImage) pageImages.get(key);

                        String fileName = conf.getPdfImageExtractionDir() + OCRUtil.createUniqueFileName("image");
                        image.write2file(fileName);

                        result.add(fileName + "." + image.getSuffix());

                        i++;
                    }
                }
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }

        return result;
    }
}