Image Capture Bit Depth

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Level 1

21 points

Image Capture Bit Depth

I have a Brother MFC-8640D multi-function printer/scanner connected to my Airport Extreme base station. In order to scan with it, however, I have to plug a USB cable in directly to my laptop as scanning doesn't work through the Airport. That's not my question, though. The specs on the scanner say that it can scan up to 48-bit depth. When I use Image Capture my only choices are 1-bit or 8-bit. The scanned photos don't come out like the originals. I can't figure out why. Anyone have any ideas?

MacBook White, Mac OS X (10.5.7), iPhone 3g

Posted on Jun 5, 2009 7:40 PM

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Answer 1

i.3d

Level 2

420 points

Jun 5, 2009 8:04 PM in response to mpolda

Have you tried to install the latest drivers for the device, and try Brother's software instead of Capture?

As to 48 bit colour depth, the manufacturers add all sort of bizarre numbers to their specs to try to impress potential buyers...
48 could only be 3x16 (RGB) so it'd be 16 bit per channel.
There's often a setting for "document" or "photo" scanning and the output depth will very between them.

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Answer 2

mpolda Author

Level 1

21 points

Jun 5, 2009 8:40 PM in response to i.3d

I've installed the Brother software in the past and never will again. It's very large and not easily removed. Within Image Capture there are three choices: text, b&w, or color photo. Text defaults to 1-bit whereas b&w or color photo goes to 8-bit. There are no other choices. Is this dependent on the hardware connected?

Message was edited by: mpolda

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Answer 3

i.3d

Level 2

420 points

Jun 5, 2009 8:56 PM in response to mpolda

From what you are saying all should be just fine.
Text defaults to 1 bit which is B&W - as in 100% black or 100% white.
A B&W photo is in fact a GREYSCALE image which requires 8 bits to provide you with 256 levels of grey.
Not having a Brother and not seeing what you are seeing I can only assume that Capture doesn't get enough info from the hardware to scan to full colour.
You said that images don't look right, what exactly do you mean? Do your colours photos come out with bands of colours, rather than smooth shades - let me guess - yes?
If that's the case, that means that the scanning is done to an 8 bit file with only 256 colours or greyscale.

I would first try to use the hardware buttons on the device to start scanning (maybe menu settings to tell it you want a "Colour Photo") and see what Capture does then.
Secondly install JUST the driver for the device, not all the software that comes with it.
And just as a stab in the dark, if it's connected using USB, make sure it's not connected via Airport at the same time - who knows, maybe that causes miscommunication...

Good luck and keep us posted please.

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