How much do you really know about the age-old PDF? Why does it matter?
It matters because PDFs are the go-to files for business, just as English is the language for business. The PDF, or Portable Document Format, is the standard for file transfers because of its compatibility with almost any software or device.
If you are a professional that works with PDFs on a regular basis, you should know that not all PDFs are the same. They actually fall into two main categories, and we often distinguish between searchable PDFs and raster-based PDFs.
Not knowing the difference could be annoying for yourself, your clients, and anyone you have to transfer files to.
Stick with us to find out the 5 most important things to know about searchable PDFs.
Five PDFs You Should Know
As mentioned, Adobe developed the PDF or “Portable Document Format” in 1992 to have a reliable way to present documents. These documents come in two main categories: searchable and non-searchable.
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What Is the Searchable PDF
The searchable PDF file is the “native” PDF file.
Anytime you create a PDF file in Word, InDesign, Excel, or PowerPoint, the text and images in that file are automatically selectable and searchable.
These are vector-based PDFs that actually contain real text, built through code. They can be edited with software like Adobe Acrobat.
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Why Some PDFs Are Not Searchable
When you are working in a digital space, you are working with either a vector-based file or a rasterized file.
Vector files are compiled through coded mathematical formulas that establish points on a grid. This allows them to be scaled up and down without losing any resolution.
Raster files are composed of pixels or colored blocks of size 1×1. For example, if your computer screen is 1920×1080, then it is composed of 1920 by 1080 pixels. These files cannot be scaled up and down without losing resolution.
A PDF file that is not searchable is usually a raster. This means the file no longer contains any real text and is simply an image.
To your computer, these files are no different from graphics or photos. On its own, it is unable to parse any text from them.
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Making the Non-Searchable Now Searchable
Well, how to make a pdf searchable?
To make pdf searchable, you can use OCR or Optical Character Recognition. A library like tesseract c# is one such OCR library, available for free to all developers. These libraries even contain the capability for multi-language support.
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OCR Options
There is a myriad of OCRs on the internet for everyone’s use. Some are paid, while some are free. Some are hosted on the cloud, while others are installed onto your computer.
Some can even come inbuilt into PDF software.
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How Do OCRs Work
OCRs convert the rasterized PDF into searchable text.
The way each one works is slightly different, but overall what they will do is scan the text, identify the content (whether font or language), and then use an OCR engine to convert the image to searchable text.
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Anyone who uses computers likely has worked with PDFs before. Not many people know, though, that they come in two types; hopefully, now you know what searchable PDFs are and how they may come about with OCR.
Browse our technology section for more cool tech tips!
