Quote:
Originally Posted by retiredbiker
General method, if anyone wants to try. I do all this on a Linux box, but most everything or an equivalent is probably available on any platform:
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I haven't looked deeply into your post, yet, but I'm sure that I'll prove a goldmine of useful information.
Just looking at the surface of it, and that blogspot link. I'm wondering how are PDF's generated for borrowed books? They look like they're their own PDF's that just aren't listed. I tend to see similar artefacts when comparing PDF's of books that they have freely available and .jp2 source files. It's making their PDF's appalling when it comes to illustrations and photos, and a major reason why I'm making my own.
I'll post my own workflow later, if anyone is interested in it. I'm taking jp2.zip or riping .jpg's from webpage, and I'm converting them into PDF's.
I'm just wondering if it would be possible to get jp2 files using the same process? In vast majority of cases jp2's are massive overkill regarding file sizes for the quality that they offer, but they're needed simply because their PDF process obliterates quality.
Example of PDF compared to Webpage source and jp2 zip files:
Sample book:
https://archive.org/details/atlanticcrossing0000melv
PDF:
https://archive.org/download/atlanti...ng0000melv.pdf
Webpage source:
https://archive.org/details/atlantic...age/6/mode/2up
JP2 processed source:
https://archive.org/download/atlanti...00melv_jp2.zip (224mb file)
Comparisons in attachments. Artefacts should be plainly visible. I also included a spread of two pages in full resolution in zip file. ZIP is required as this site doesn't support such high resolutions. Jpeg is compressed compared to .jp2 source to keep file size down, but quality is actually comparable to other comparisons. Extra resolution isn't doing much, simply because scans aren't perfect to begin with.