Uncompress PDF files using Preview

[dcs.79c]

I have a bunch of magazine articles that I want to scan & save as PDF files. I know that I can use Preview to compress the PDF but how do I uncompress the PDF file?

I watched a YouTube video explaining how to compress a PDF file. The file had a picture. After compression the picture was fuzzy. Does Preview use a lossy compression algorithm?

There are a bunch of online PDF convertors but the though of uploading PDF files makes me very nervous.

 

[pm-r]

I know that I can use Preview to compress the PDF but how do I uncompress the PDF file?

Just open the compressed PDF file using preview as you normally do.

There are a bunch of online PDF convertors but the though of uploading PDF files makes me very nervous.

Has Apple says there may be some slight to graduation of the file depending on the compression and the original:

Compress a PDF
To save storage space, you can compress a PDF in Preview. When compressed, the PDF may be of lower quality than the original.

Open the PDF, then choose File > Export.

Click the Quartz Filter pop-up menu, then choose Reduce File Size.

Compress a PDF in Preview on Mac

In Preview on your Mac, create a compressed version of a PDF to save storage space.

support.apple.com

Depending on the source I have often found some PDF files to be already compressed pretty close to as much as they can be and there is no advantage to using any additional compression. I guess it depends on the source.

Maybe try with sone of the files you have and compare the file sizes.





- Patrick
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[Raz0rEdge]

Why are you compressing the scanned content? If you want high resolution, you need to not do that. Compression inherently optimizes for file size while sacrificing quality.

Also, you can't "uncompress" an image or PDF back to its original state. You can't get back the lost pixels.

A lot of AI tools will try to do this with images by guessing at what stuff needs to be added to make the image look right. But that might not work with text-based images.

 

[MacBiter]

If you're saving JPEGs in Preview you can choose the level of quality, but a non-lossy format like PNG should see no degradation.

 

[dcs.79c]

I have a Mac. My sister has a PC. If I use Preview to compress the file & she wants to see the file, what happens when she opens the file? Will she be able to see the file on her PC even though it was compressed on a Mac?

Does Preview use the Adobe Acrobat software or does it use an open-source PDF convertor?

So, I guess that you are saying that the Adobe convertor is a lossy compressor. I suppose that open-source PDF convertors are also lossy.

 

[ferrarr]

You can get the Adobe Acrobat Reader here,

Adobe - Download Adobe Acrobat Reader

Download free Adobe Acrobat Reader software for your Windows, Mac OS and Android devices to view, print, and comment on PDF documents.

get.adobe.com

 

[ferrarr]

See if this helps,

What Is a PDF File (and How Do I Open One)?

Stop sending people DOCX files.

www.howtogeek.com

 

[Raz0rEdge]

I have a Mac. My sister has a PC. If I use Preview to compress the file & she wants to see the file, what happens when she opens the file? Will she be able to see the file on her PC even though it was compressed on a Mac?

Does Preview use the Adobe Acrobat software or does it use an open-source PDF convertor?

So, I guess that you are saying that the Adobe convertor is a lossy compressor. I suppose that open-source PDF convertors are also lossy.

PDF is a standard owned by Adobe but the specs are shared with all OS' and many applications and can be implemented with no royalties. So that means that PDFs can be viewed on a variety of OS' without the need for any special software.

Where you need special software is to actually create PDFs. Adobe Acrobat is one such application, but there are many others as well.

A PDF that is compressed on Mac with Preview will be visible by others and will look just as good or bad as it does on your Mac.

You seem to be using many different words thinking they all mean the same, they don't. Convertors inherently convert data from one format to another. Compressors tend to reduce size by doing a variety of thing. A compressor dealing with images, and related files will reduce quality to accomplish this. Compressors like Zip accomplish the same task through entirely different means.

 

[MacBiter]

Where you need special software is to actually create PDFs. Adobe Acrobat is one such application, but there are many others as well.

Actually, there's a simple PDF creator built into Mac OS - if you print something you can elect not to use the printer but 'Save as PDF' instead.

 

[IWT]

@MacBiter:

Yes, indeed. When you come to File, hold down the Option Key which changes "Save" to "Save as"; choose that and several options are displayed including "Save as PDF".

Ian

 

[MacBiter]

@MacBiter:

Yes, indeed. When you come to File, hold down the Option Key which changes "Save" to "Save as"; choose that and several options are displayed including "Save as PDF".

Ian

I don't even use the Option key - I long ago changed the system to remove 'Duplicate' and bring back 'Save as...' on a permanent basis!.