MobileRead Forums - View Single Post - Why does my Aura HD mess up the colours on my cover images?

NiLuJe · 11-10-2020, 09:44 AM

The Kobo fb is indeed setup in BGR order, not RGB.

Code:

red:   bitfield offset: 16, bitfield length: 8, MSB is right: no
green: bitfield offset: 8, bitfield length: 8, MSB is right: no
blue:  bitfield offset: 0, bitfield length: 8, MSB is right: no
alpha: bitfield offset: 24, bitfield length: 8, MSB is right: no

Pixel format details:
B: 0 / G: 1 / R: 2 / A: 3 (i.e., BGRA)
Should alpha be honored? Yes.

This is *mostly* harmless since the display is ultimately grayscale, but it does minimally affect the grayscaling process, as red usually isn't weighted the same as blue, no matter how you choose to grayscale.

The point is entirely moot (outside of in-book content) once you've setup Calibre to handle the grayscaling on its own for covers thumbnails

.

11-10-2020, 09:44 AM	#3
NiLuJe BLAM! Posts: 13,506 Karma: 26047202 Join Date: Jun 2010 Location: Paris, France Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E	The Kobo fb is indeed setup in BGR order, not RGB. Code: red: bitfield offset: 16, bitfield length: 8, MSB is right: no green: bitfield offset: 8, bitfield length: 8, MSB is right: no blue: bitfield offset: 0, bitfield length: 8, MSB is right: no alpha: bitfield offset: 24, bitfield length: 8, MSB is right: no Pixel format details: B: 0 / G: 1 / R: 2 / A: 3 (i.e., BGRA) Should alpha be honored? Yes. This is mostly harmless since the display is ultimately grayscale, but it does minimally affect the grayscaling process, as red usually isn't weighted the same as blue, no matter how you choose to grayscale. The point is entirely moot (outside of in-book content) once you've setup Calibre to handle the grayscaling on its own for covers thumbnails .