我正尝试使用pdfbox从pdf中提取图像。示例pdf here
但我只是在拍摄空白照片。
我正在尝试的代码： -
public static void main(String[] args) {
PDFImageExtract obj = new PDFImageExtract();
try {
obj.read_pdf();
} catch (IOException ex) {
System.out.println("" + ex);
}
}
void read_pdf() throws IOException {
PDDocument document = null;
try {
document = PDDocument.load("C:\\Users\\Pradyut\\Documents\\MCS-034.pdf");
} catch (IOException ex) {
System.out.println("" + ex);
}
List pages = document.getDocumentCatalog().getAllPages();
Iterator iter = pages.iterator();
int i =1;
String name = null;
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()) {
String key = (String) imageIter.next();
PDXObjectImage image = (PDXObjectImage) pageImages.get(key);
image.write2file("C:\\Users\\Pradyut\\Documents\\image" + i);
i ++;
}
}
}
}
由于
答案 0 :(得分：19)
以下是使用PDFBox 2.0.1的代码，它将获取PDF中所有图像的列表。这与其他代码的不同之处在于它将通过文档递归而不是尝试从顶层获取图像。
public List<RenderedImage> getImagesFromPDF(PDDocument document) throws IOException {
List<RenderedImage> images = new ArrayList<>();
for (PDPage page : document.getPages()) {
images.addAll(getImagesFromResources(page.getResources()));
}
return images;
}
private List<RenderedImage> getImagesFromResources(PDResources resources) throws IOException {
List<RenderedImage> images = new ArrayList<>();
for (COSName xObjectName : resources.getXObjectNames()) {
PDXObject xObject = resources.getXObject(xObjectName);
if (xObject instanceof PDFormXObject) {
images.addAll(getImagesFromResources(((PDFormXObject) xObject).getResources()));
} else if (xObject instanceof PDImageXObject) {
images.add(((PDImageXObject) xObject).getImage());
}
}
return images;
}
答案 1 :(得分：10)
以下GetImagesFromPDF java类获取04-Request-Headers.pdf文件中的所有图片，并将这些文件保存到目标文件夹 PDFCopy 。
import java.io.File;
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;
@SuppressWarnings({ "unchecked", "rawtypes", "deprecation" })
public class GetImagesFromPDF {
public static void main(String[] args) {
try {
String sourceDir = "C:/PDFCopy/04-Request-Headers.pdf";// Paste pdf files in PDFCopy folder to read
String destinationDir = "C:/PDFCopy/";
File oldFile = new File(sourceDir);
if (oldFile.exists()) {
PDDocument document = PDDocument.load(sourceDir);
List<PDPage> list = document.getDocumentCatalog().getAllPages();
String fileName = oldFile.getName().replace(".pdf", "_cover");
int totalImages = 1;
for (PDPage page : list) {
PDResources pdResources = page.getResources();
Map pageImages = pdResources.getImages();
if (pageImages != null) {
Iterator imageIter = pageImages.keySet().iterator();
while (imageIter.hasNext()) {
String key = (String) imageIter.next();
PDXObjectImage pdxObjectImage = (PDXObjectImage) pageImages.get(key);
pdxObjectImage.write2file(destinationDir + fileName+ "_" + totalImages);
totalImages++;
}
}
}
} else {
System.err.println("File not exists");
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
答案 2 :(得分：7)
对于PDFBox 2.0.1，由于某些API已被更改，因此必须略微修改pudaykiran的答案。
public static void testPDFBoxExtractImages() throws Exception {
PDDocument document = PDDocument.load(new File("D:/Temp/Test.pdf"));
PDPageTree list = document.getPages();
for (PDPage page : list) {
PDResources pdResources = page.getResources();
for (COSName c : pdResources.getXObjectNames()) {
PDXObject o = pdResources.getXObject(c);
if (o instanceof org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject) {
File file = new File("D:/Temp/" + System.nanoTime() + ".png");
ImageIO.write(((org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject)o).getImage(), "png", file);
}
}
}
}
答案 3 :(得分：2)
只需将.jpeg添加到路径的末尾：
image.write2file("C:\\Users\\Pradyut\\Documents\\image" + i + ".jpeg");
这适合我。
答案 4 :(得分：2)
您可以使用PDPage.convertToImage()功能将PDF页面转换为BufferedImage。接下来，您可以使用BufferedImage创建一个Image。
使用以下参考资料获取更多详细信息：
不要忘记在PDPage类中查找PDPage.convertToImage()函数。
答案 5 :(得分：1)
对于只想复制并粘贴此代码以供使用的人
import org.apache.pdfbox.contentstream.PDFStreamEngine;
import org.apache.pdfbox.contentstream.operator.Operator;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.graphics.PDXObject;
import org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject;
import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.UUID;
public class ExtractImagesUseCase extends PDFStreamEngine{
private final String filePath;
private final String outputDir;
// Constructor
public ExtractImagesUseCase(String filePath,
String outputDir){
this.filePath = filePath;
this.outputDir = outputDir;
}
// Execute
public void execute(){
try{
File file = new File(filePath);
PDDocument document = PDDocument.load(file);
for(PDPage page : document.getPages()){
processPage(page);
}
}catch(IOException e){
e.printStackTrace();
}
}
@Override
protected void processOperator(Operator operator, List<COSBase> operands) throws IOException{
String operation = operator.getName();
if("Do".equals(operation)){
COSName objectName = (COSName) operands.get(0);
PDXObject pdxObject = getResources().getXObject(objectName);
if(pdxObject instanceof PDImageXObject){
// Image
PDImageXObject image = (PDImageXObject) pdxObject;
BufferedImage bImage = image.getImage();
// File
String randomName = UUID.randomUUID().toString();
File outputFile = new File(outputDir,randomName + ".png");
// Write image to file
ImageIO.write(bImage, "PNG", outputFile);
}else if(pdxObject instanceof PDFormXObject){
PDFormXObject form = (PDFormXObject) pdxObject;
showForm(form);
}
}
else super.processOperator(operator, operands);
}
}
演示
public class ExtractImageDemo{
public static void main(String[] args){
String filePath = "C:\\Users\\John\\Downloads\\Documents\\sample-file.pdf";
String outputDir = "C:\\Users\\John\\Downloads\\Documents\\Output";
ExtractImagesUseCase useCase = new ExtractImagesUseCase(
filePath,
outputDir
);
useCase.execute();
}
}
答案 6 :(得分：0)
而不是打电话
image.write2file("C:\\Users\\Pradyut\\Documents\\image" + i);
您可以使用ImageIO.write()静态方法以您需要的任何格式写出RGB图像。我在这里使用了PNG：
File outputFile = new File( "C:\\Users\\Pradyut\\Documents\\image" + i + ".png");
ImageIO.write( image.getRGBImage(), "png", outputFile);
答案 7 :(得分：0)
这是@Matt答案的kotlin版本。
fun <R> PDResources.onImageResources(block: (RenderedImage) -> (R)): List<R> =
this.xObjectNames.flatMap {
when (val xObject = this.getXObject(it)) {
is PDFormXObject -> xObject.resources.onImageResources(block)
is PDImageXObject -> listOf(block(xObject.image))
else -> emptyList()
}
}
您可以像这样在PDPage资源上使用它：
page.resources.onImageResources { image ->
Files.createTempFile("image", "xxx").also { path->
if(!ImageIO.write(it, "xxx", file.toFile()))
IllegalStateException("Couldn't write image to file")
}
}
"xxx"是您需要的格式（例如"jpeg"）