Olympus-OM
[Top] [All Lists]

Re: [OM] nearly, or not quite

Subject: Re: [OM] nearly, or not quite
From: Dawid Loubser <dawidl@xxxxxxxxxxx>
Date: Mon, 27 Jul 2009 16:49:01 +0200
You are potentially kind-of right, your E-510 files have potentially  
more 'detail' in the form
of random noise, i.e. detail which does not represent information  
originally present in the scene.

Apart from the many other factors people have posted about already,  
such as camera settings etc,
if the E-510 has, by default, more noise and higher levels of  
sharpening, then for the same
level of JPEG compression, the E-510 file will be bigger, because the  
JPEG compression algorithm
will have much more 'random' data to deal with.

I only use the PNG format (the best lossless compression format,  
supports all colour bit depths,
and not patent-encumbered like JPEG/TIFF) to store my scanned images,  
and the problem is even more
pronounced here. A slight increase in image noise causes a massive  
increase in file size, as the
'randomness' of smooth areas of the image are much more pronounced,  
hence less compressible without
information loss.

PNG really is a wonderful format, it's unbelievable that cameras  
didn't just use it as the de-facto
lossless format. A 80MB 16bit TIFF is easily quartered in size by  
storing it as a 16-bit PNG, with
zero information loss (with some of my typical images, YMMV).

Anyway, the first parts are just wild speculation, but it correlates  
with my own experience regarding
compression and image "noise".

On 26 Jul 2009, at 4:58 AM, Brian Swale wrote:

> They should be the same size, surely?  I have the intuitive?  
> impression that
> the E-510 images have greater detail.

-- 
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz