如果您有扫描的PDF 文件(PDF file)，则无法突出显示PDF、搜索文本、修改、复制PDF内容等。要解决此问题，您需要将扫描的 PDF(scanned PDF)转换为可搜索的 PDF(searchable PDF)。这篇文章将帮助您通过一些免费选项来做到这一点。这篇文章中介绍的选项通过尽可能保留PDF布局来提供良好的结果。(PDF)
将(Convert)扫描的PDF转换为可搜索的 PDF(Searchable PDF)
我们介绍了 2 种免费服务和 2 种免费软件，以使PDF可搜索。无论PDF内容是在表格中还是在某个框中，所有PDF内容都从扫描的页面中获取，并生成一个新的可搜索PDF。获得输出后，您可以在 Microsoft Word或其他PDF 编辑器软件中编辑 PDF 、搜索文本、突出显示 PDF(highlight PDF)，以及做任何您想做的事情。
请注意，对于大型PDF文件，转换扫描的(PDF)PDF文件的过程会较慢，因为这些PDF(PDFs)中存在的字数和页数较多。让我们先从服务开始。
1] PDF2Go
此 PDF2Go 服务可让您将多个扫描的 PDF 文件(convert multiple scanned PDF files)一起转换。它会自动检测输入文件的源语言以开始转换。它有两个免费计划(two free plans)——未注册和注册。在第一个计划中，无需注册即可使用该服务，最多可上传50 MB PDF 。此外，可以一次转换3 个 PDF 文件。(3 PDF files)在第二个计划中，您可以创建一个免费帐户，然后它可以让您上传最大100 MB大小的PDF 。最多可以添加 5 个 PDF(Maximum 5 PDFs)以使其可搜索。使用适合您的计划。
此链接(This link)将打开其制作PDF可搜索页面。使用Google Drive(Google Drive)、在线 PDF(online PDF)、Dropbox和桌面(desktop)这四个选项中的任何一个上传 PDF(Upload PDF)。添加 PDF(Add PDF)，它将检测PDF语言。您还可以使用下拉菜单设置PDF语言。(PDF)使用START按钮开始转换。等到(Wait)该过程完成，然后下载可搜索的PDF。
2]免费在线PDF
Free PDF Online有多种工具可用于转换、查看和编辑PDF文件。在这些工具中，您可以使用其OCR PDF 工具(OCR PDF tool)将扫描的PDF转换为可搜索的PDF文档。它没有提到上传PDF的大小限制，但是您可以在一天内(PDFs in a day)转换 20 个(convert 20)扫描的 PDF ，这已经足够了。一个扫描的PDF可以一次转换。
您可以单击此处(click here)打开其扫描的PDF转换器页面。打开页面后，从桌面添加PDF ，并设置(PDF)PDF语言。最后，按开始(Start)按钮开始扫描的PDF转换过程。转换完成后，将输出的可搜索PDF下载到 PC。
提示(TIP)：您可以使用免费的 Acrobat Online 工具转换、压缩、签署 PDF 文档。
3] PDF24创作者
PDF24 Creator软件是一个PDF套件，带来了PDF阅读器、压缩器、创建器、截屏(screen capture)、识别文本等工具。您需要使用其识别文本功能来转换扫描的PDF文件。此功能可让您批量转换扫描的 PDF 文件(batch convert scanned PDF files)，使其成为更好的选择。对于每个输入的PDF文件，它还显示为使PDF可搜索而提取的字数和页数。
要将扫描的PDF文件转换为可搜索的PDF文件，请使用添加文件(Add files)按钮。之后，您可以设置输入语言和输出PDF质量（低、高、最佳、传真质量等）。您还可以使用一些其他选项。它允许您为输出PDF(PDFs)、跳过页面和已包含可搜索文本的PDF(PDFs)的名称添加后缀，提供输出文件夹位置等。设置选项，然后开始工作。它会一一转换PDF(PDFs)并将可搜索的PDF文件保存在输出目录中。
您可以使用此链接(this link)获取此软件。
4] ByteScout PDF 多功能工具
ByteScout PDF Multitool也是一个PDF套件，可免费用于非商业目的(free for non-commercial purposes)。它具有将PDF转换为多页 TIFF 、从(multipage TIFF)PDF中提取文本为TXT、XLSX、CSV 、从(CSV)PDF中删除文本和图像、将图像添加到PDF、拆分和合并PDF等功能。您需要使用其使 PDF 文档可搜索(Make PDF document searchable)的功能来转换扫描的 PDF。
此功能附带的一个独特选项是您可以定义页面范围(page range)以转换扫描的 PDF(convert scanned PDF)。因此，如果您想转换 100 个扫描页面中的 1-10 个，则只需设置页面范围，它将仅转换这些页面并将其余扫描页面保留在输出PDF中。
在其界面的左侧，使用Open Document选项添加PDF。之后，单击左侧边栏中可见的“使PDF文档可搜索”选项。(PDF)将打开一个设置框。在那里，您可以设置PDF语言、处理当前页面、所有页面或特定页面范围等选项，检测输入文件中的旋转页面，自动歪斜扫描图像(automatically deskew scanned images)以进行输出等。设置选项后，按处理文档(Process Document)按钮。转换扫描的PDF后，您可以将可搜索的PDF保存在任何文件夹中。
在此处(here)下载此软件。
这就是您可以使用这些服务和软件将扫描的PDF转换为可搜索的PDF的方式。(PDF)希望(Hope)这些选项对您有用。
How to Convert Scanned PDF to Searchable PDF?
If you have a scanned PDF file, you cannot highlight PDF, search text, modify, copy PDF content, etc. To solve this problem, you need to convert scanned PDF to searchable PDF. This post will help you on how to do that with some free options. The options covered in this post give good results by retaining PDF layout as much as possible.
Convert Scanned PDF to Searchable PDF
We have covered 2 free services and 2 free software to make PDF searchable. Whether the PDF content is available in a table or some box, all the PDF content is fetched from the scanned pages and a new searchable PDF is generated. When you get the output, you can edit PDF in Microsoft Word or other PDF editor software, search text, highlight PDF, and do anything you want.
Do note that the process to convert scanned PDF files will be slower for large PDF files because of the number of words and pages present in those PDFs. Let’s start with the services first.
1] PDF2Go
This PDF2Go service lets you convert multiple scanned PDF files together. It automatically detects the source language of input files to begin the conversion. It has two free plans– unregistered and registered. In the first plan, the service can be used without sign up and up to 50 MB PDF can be uploaded. Also, 3 PDF files can be converted in one go. In the second plan, you can create a free account, and then it will let you upload a PDF up to 100 MB size. Maximum 5 PDFs can be added to make them searchable. Use the plan that suits you.
This link will open its make PDF searchable page. Upload PDF using any of the four options- Google Drive, online PDF, Dropbox, and desktop. Add PDF and it will detect PDF language. You can also set PDF language using the drop-down menu. Use the START button to begin the conversion. Wait till the process is finished and then download searchable PDF.
2] Free PDF Online
Free PDF Online has multiple tools for converting, viewing, and editing a PDF file. Among those tools, you can use its OCR PDF tool to convert a scanned PDF to searchable PDF document. It doesn’t mention size limit to upload PDF, but you can convert 20 scanned PDFs in a day, which is good enough. One scanned PDF can be converted in a single time.
You can click here to open its scanned PDF converter page. Once the page is opened, add PDF from desktop, and set the PDF language. Finally, press the Start button to begin the scanned PDF conversion process. When the conversion is completed, download the output searchable PDF to PC.
TIP: You can convert, compress, sign PDF documents using free Acrobat Online tools.
3] PDF24 Creator
PDF24 Creator software is a PDF suite that brings PDF reader, compressor, creator, screen capture, recognize text, and other tools. You need to use its recognize text feature for converting scanned PDF files. This feature lets you batch convert scanned PDF files which makes it a better option. For each input PDF file, it also shows the number of words and pages fetched to make PDF searchable.
To convert scanned PDF files to searchable PDF files, use Add files button. After that, you can set input language and output PDF quality (low, high, best, fax quality, etc.). There are also some additional options that you can use. It lets you add a suffix to the name of output PDFs, skip pages, and PDFs that already include searchable text, provide output folder location, etc. Set the options and then begin the job. One by one, it will convert PDFs and save searchable PDF files in the output directory.
You can get this software using this link.
4] ByteScout PDF Multitool
ByteScout PDF Multitool is also a PDF suite and available to use free for non-commercial purposes. It comes with features like convert PDF to multipage TIFF, extract text from PDF as TXT, XLSX, CSV, remove text and images from PDF, add images to PDF, split and merge PDF, and more. You need to use its Make PDF document searchable feature to convert scanned PDF.
One unique option that comes with this feature is you can define page range to convert scanned PDF. Thus, if you want to convert 1-10 scanned pages out of 100, then simply set the page range, and it will convert only those pages and keep the rest of pages scanned in the output PDF.
On the left-hand side of its interface, use the Open Document option to add PDF. After that, click on the ‘Make PDF document searchable’ option visible on the left sidebar. A settings box will open. There you can set options like PDF language, process current page, all pages, or a specific page range, detect rotated pages in the input file, automatically deskew scanned images for output, etc. When the options are set, press Process Document button. When scanned PDF is converted, you can save the searchable PDF in any folder.
Download this software here.
That’s how you can convert a scanned PDF to searchable PDF using these services and software. Hope these options will work for you.
