MobileRead Forums - View Single Post - FBInk: A small tool/library to print crap on your screen!

NiLuJe · 07-19-2018, 07:58 PM

Released v1.2.0

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This one adds a major feature: displaying images! Most common formats should be handled, and you can adjust the exact positioning in all kinds of crazy ways

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As usual, for best results, properly dithered PNGs are your friend

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If you have access to ImageMagick v7, my current rescale + letterbox + grayscale + dither pass of choice looks something like this:

Code:

convert input.png -colorspace Lab -filter LanczosSharp -distort Resize 1080x1429 -colorspace sRGB -background black -gravity center -extent 1080x1429! -grayscale Rec709Luminance -colorspace sRGB -dither Riemersma -remap eink_cmap.gif -quality 75 png:out.png

1080x1429 being the effective resolution of an H2O

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With the cmap attached here.

EDIT:

An approximately 10 times faster alternative, if you *really* need on-device processing:

Code:

convert input.png -filter LanczosSharp -resize 1080x1429 -background black -gravity center -extent '1080x1429!' -colorspace Gray -dither Riemersma -remap eink_cmap.gif -quality 75 png:out.png

07-19-2018, 07:58 PM	#17
NiLuJe BLAM! Posts: 13,499 Karma: 26047188 Join Date: Jun 2010 Location: Paris, France Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E	Released v1.2.0 . This one adds a major feature: displaying images! Most common formats should be handled, and you can adjust the exact positioning in all kinds of crazy ways . As usual, for best results, properly dithered PNGs are your friend . If you have access to ImageMagick v7, my current rescale + letterbox + grayscale + dither pass of choice looks something like this: Code: convert input.png -colorspace Lab -filter LanczosSharp -distort Resize 1080x1429 -colorspace sRGB -background black -gravity center -extent 1080x1429! -grayscale Rec709Luminance -colorspace sRGB -dither Riemersma -remap eink_cmap.gif -quality 75 png:out.png 1080x1429 being the effective resolution of an H2O . With the cmap attached here. EDIT: An approximately 10 times faster alternative, if you really need on-device processing: Code: convert input.png -filter LanczosSharp -resize 1080x1429 -background black -gravity center -extent '1080x1429!' -colorspace Gray -dither Riemersma -remap eink_cmap.gif -quality 75 png:out.png Attached Thumbnails Last edited by NiLuJe; 02-12-2019 at 08:57 PM. Reason: Create true Grayscale PNGs, instead of Indexed RGB (speedier rendering in FBInk ;)).