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[OM] Re: E-3 BAYER PATTERN

Subject: [OM] Re: E-3 BAYER PATTERN
From: David Irisarri <div2000@xxxxxxxxxxxxxxxxx>
Date: Thu, 18 Oct 2007 06:50:48 +0200
Hi Winsor,

As you know is very difficult to achive perfect color rendition with 
imaging sensors and a truly color engine inside the camera would be very 
expensive. Despite TruePIC III processor corrects color, high-end 
profiles will work much better.
Olympus decided to use a KODAK sensor with RGRG bayer pattern because 
improves color rendition but you get lower quality in terms of 
resolution. This is why many reviewers in the past said Olympus E-1 
resolution was a little bit lower than five megapixel.

You probably have seen that many raw converters work pretty bad with ORF 
images because they are using demosaicing algorithms not optimized for 
four color RGB. A labyrinth maze pattern appears over the image and 
output quality is very low. David Coffin, has a very good utility that 
works with four color RGB images, using a demosaicing algorithm called 
Variable Number Gradients. This utility is called DCRAW.
If the camera has a RGB typical bayer patter, it can be used another 
algorithm that outputs higher quality. It is called AHD Adaptive 
Homogeneity Directed.

So...with four color rgb bayer filters a blur is requiered to avoid this 
pattern:

http://cybercom.net/~dcoffin/dcraw/ahd_maze.png 
<http://cybercom.net/%7Edcoffin/dcraw/ahd_maze.png>
http://cybercom.net/~dcoffin/dcraw/vng_grid.png 
<http://cybercom.net/%7Edcoffin/dcraw/vng_grid.png>

Sometimes DPREVIEW under camera specs, highlights if bayer pattern is 
RGB or RGBG but I haven´t found anything according to E-3.

Regards,

Dave










Winsor Crosby wrote:
> If you are talking about the new Kodak filter pattern where one of  
> the Gs is gray, I think you probably have your wish. Probably the  
> sensor is Panasonic as the past several Oly cameras have been and  
> Kodak, in their announcement, said video first anyway.  I am puzzled  
> by your statement though because I would have thought the new Kodak  
> filter would greatly improve the noise floor in physically small  
> sensors and it had nothing to do with the E-1. What problem was there  
> with the E-1 filter?
>
>
> Winsor
> Long Beach, CA
> USA
>
>
> On Oct 17, 2007, at 9:29 AM, David Irisarri wrote:
>
>   
>> I have been reading everything related to E-3 the whole day and I  
>> cannot
>> find if E-3 is using RGBG or just only RGB bayer pattern filter. If
>> TruePIC III processor is able to correct color properly coming from  
>> E-3
>> sensor, I would prefer RGB just only; otherwise we will have the same
>> problem as E-1.
>>     
>
>
>
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