PDFBox:将 pdf 页面转换为图像的问题 [英] PDFBox: Problem with converting pdf page into image

问题描述

我的任务非常简单:将 pdf 文件的每一页都转换为图像.我尝试使用icepdf开源版本来生成图像，但他们没有用正确的字体生成图像.所以我开始使用 PDFBox.代码如下:

My mission is pretty simple: converting every single page of a pdf file into images. I tried using icepdf open source version to generate the images but they don't generate the image with the correct font. So I start using PDFBox instead. The code is the following:

PDDocument document = PDDocument.load(new File("testing.pdf"));             
List<PDPage> pages = document.getDocumentCatalog().getAllPages();
for (int i = 0; i < pages.size(); i++) {
 PDPage singlePage = pages.get(i);
 BufferedImage buffImage = convertToImage(singlePage, 8, 12);
 ImageIO.write(buffImage, "png", new File(PdfUtil.DATA_OUTPUT_DIR+(count++)+".png"));
}

字体看起来不错，但pdf文件中的图片看起来有点模糊(见附件).我查看了源代码，但我仍然不知道如何修复它.你们知道发生了什么吗?请帮忙.谢谢！！

The font looks good, but the pictures within the pdf file look fainted out (See the attachment). I look into the source code but I still have no clue how to fix it. Do you guys have any idea what's going on? Please help. Thanks!!

推荐答案

转换 PDF 文件 04-Request-Headers.pdf 使用 pdfbox 进行图像处理.

Convert PDF file 04-Request-Headers.pdf to image using pdfbox.

下载此文件并将其粘贴到 Documents 文件夹中.

Download this file and paste it in Documents folder.

示例:

package com.pdf.pdfbox.test;

import java.awt.HeadlessException;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.List;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.util.PDFImageWriter;

public class ConvertPDFPageToImageWithoutText {
    public static void main(String[] args) {
        try {
            String oldPath = "C:/Documents/04-Request-Headers.pdf";
            File oldFile = new File(oldPath);
            if (oldFile.exists()) {
            PDDocument document = PDDocument.load(oldPath);
            @SuppressWarnings("unchecked")
            List<PDPage> list = document.getDocumentCatalog().getAllPages();

            String fileName = oldFile.getName().replace(".pdf", "");
            String imageFormat = "png";
            String password = "";
            int startPage = 1;
            int endPage = list.size();
            String outputPrefix = "C:/Documents/PDFCopy/";//converted images saved here
            File file = new File(outputPrefix);
            if (!file.exists()) {
                file.mkdirs();
            }
            int imageType = 24;
            String color = "rgb";
            int resolution;

            try {
                resolution = Toolkit.getDefaultToolkit().getScreenResolution();
            } catch (HeadlessException e) {
                resolution = 96;
            }

            if ("bilevel".equalsIgnoreCase(color)) {
                imageType = BufferedImage.TYPE_BYTE_BINARY;
            } else if ("indexed".equalsIgnoreCase(color)) {
                imageType = BufferedImage.TYPE_BYTE_INDEXED;
            } else if ("gray".equalsIgnoreCase(color)) {
                imageType = BufferedImage.TYPE_BYTE_GRAY;
            } else if ("rgb".equalsIgnoreCase(color)) {
                imageType = BufferedImage.TYPE_INT_RGB;
            } else if ("rgba".equalsIgnoreCase(color)) {
                imageType = BufferedImage.TYPE_INT_ARGB;
            } else {
                System.err.println("Error: the number of bits per pixel must be 1, 8 or 24.");
            }

            PDFImageWriter pdfImageWriter = new PDFImageWriter();
            boolean imageWriter = pdfImageWriter.writeImage(document, imageFormat, password, startPage, endPage, outputPrefix + fileName, imageType, resolution);
            if (!imageWriter) {
                throw new Exception("No writer found for format '" + imageFormat + "'");
            }
            document.close();

        } else {
            System.err.println(oldPath +" File Can't be found");
        }

    } catch (Exception e) {
        e.printStackTrace();
    }
}

}

或

尝试以下解决方案将 pdf 文件转换为图像格式.

Try the below solution for convert pdf files to image format.

如何使用 PDF Renderer 在 Java 中将 PDF 转换为具有分辨率的图像

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