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davidfor · 02-29-2016, 01:07 AM

Libron is talking about on an ereader device. Someone has made a patch for the Kobo devices to reverse the colours. So, instead of black text on a white screen, it is white text on black. But, it does this by reversing everything, so the covers and pictures in books appear as negatives. I think Libron wants an easy way to invert the images before sending them to a device so they will appear correctly on the device when using "night mode".

Libron: Assuming you are doing this for your Glo HD, a quick search found:

Code:

img {
   -webkit-filter: invert(1);
   filter: invert(1);
   }

That is supposed to be CSS3 and supported by webkit based browsers. From memory, the kepub renderer is webkit based, so it might work. You can try putting that into a "kobo_extra.css" file on the device, enabling the option to modify CSS in the driver and sending a book as a kepub (either convert to kepub or use the extended driver - either way will need extra plugins in calibre).

02-29-2016, 01:07 AM	#4
davidfor Grand Sorcerer Posts: 24,905 Karma: 47303824 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	Libron is talking about on an ereader device. Someone has made a patch for the Kobo devices to reverse the colours. So, instead of black text on a white screen, it is white text on black. But, it does this by reversing everything, so the covers and pictures in books appear as negatives. I think Libron wants an easy way to invert the images before sending them to a device so they will appear correctly on the device when using "night mode". Libron: Assuming you are doing this for your Glo HD, a quick search found: Code: img { -webkit-filter: invert(1); filter: invert(1); } That is supposed to be CSS3 and supported by webkit based browsers. From memory, the kepub renderer is webkit based, so it might work. You can try putting that into a "kobo_extra.css" file on the device, enabling the option to modify CSS in the driver and sending a book as a kepub (either convert to kepub or use the extended driver - either way will need extra plugins in calibre).