k2pdfopt: optimizes PDFs for viewing on e-readers - Page 145

greening · 11-11-2025, 06:46 AM

Hi! I've been able to convert a lot of scanned pdfs from unreadable to readable with the tool, for which many thanks. I have now however run into a problem: on one of my pdfs, the background is quite dark, although not dark enough to be unreadable on kobo. However, when I try to convert it, the background becomes even darker and so practically unreadable. Is there any way to fix this? None of the settings I've found googling around have really helped. Thank you!

willus · 11-13-2025, 10:12 AM

It would help the most if you could post an example page or two of the source PDF so I could try converting it myself. Or send it to me in a private message. I'd probably first try adjusting either the -cmax or the -wt command-line settings.

greening · Yesterday, 10:36 AM

Thank you for the answer! Here are two sample pages.

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11-11-2025, 06:46 AM	#2161
greening Junior Member Posts: 2 Karma: 55654 Join Date: Nov 2025 Device: kobo	Hi! I've been able to convert a lot of scanned pdfs from unreadable to readable with the tool, for which many thanks. I have now however run into a problem: on one of my pdfs, the background is quite dark, although not dark enough to be unreadable on kobo. However, when I try to convert it, the background becomes even darker and so practically unreadable. Is there any way to fix this? None of the settings I've found googling around have really helped. Thank you!

11-13-2025, 10:12 AM	#2162
willus Fuzzball, the purple cat Posts: 1,313 Karma: 11087488 Join Date: Jun 2011 Location: California Device: iPad	It would help the most if you could post an example page or two of the source PDF so I could try converting it myself. Or send it to me in a private message. I'd probably first try adjusting either the -cmax or the -wt command-line settings.