Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

Small high quality PDF files

Share your software workflow. Write up your tips and tricks on how to scan, digitize, OCR, and bind ebooks.
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JThomas
Posts: 14
Joined: 31 Mar 2012, 01:00
E-book readers owned: nook
Number of books owned: 1000
Country: USA

Small high quality PDF files

Post by JThomas » 07 May 2012, 20:44

I am working on a re-print for a very old book with a lot of images.

What is the best way to get a small file size (under 400K) but still have at least 300 DPI quality images.

There has to be a balancing point between size and quality.

Anyone have any experience on this subject?

Thanks

Anonymous2
Posts: 97
Joined: 18 Oct 2011, 16:05

Re: Small high quality PDF files

Post by Anonymous2 » 07 May 2012, 22:32

Unless you lose some information, there is no way to compress an image to that size without sacrificing quality. If there was a way nobody would be using JPEG anymore.

If you use pdfbeads, add -r 200 to lower the DPI of the images. There really isn't anything else you can do aside from decreasing the number of colors or decreasing the DPI.

xorpt
Posts: 42
Joined: 24 Feb 2012, 01:37
E-book readers owned: Sony PRS-T1
Number of books owned: 2000

Re: Small high quality PDF files

Post by xorpt » 07 May 2012, 22:45

I second that...

- reduce number of colors (bitonal images will give you the lowest file size)
- use lossy compression, adapted to your image type

Depending on the support you want to read this file on, you should also consider using DJVU encoding, it gives much smaller files for the same image quality

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