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[OM] Re: E-3 BAYER PATTERN

Subject: [OM] Re: E-3 BAYER PATTERN
From: Winsor Crosby <wincros@xxxxxxxxxxx>
Date: Thu, 18 Oct 2007 09:57:51 -0700
Besides the announced Kodak array with some pixels not color  
filtered, the only alternative color filter patterns for sensors I  
have heard about are the CMY arrays used previously on Coolpix  
cameras and the Sony RGB-E filter which added a turquoise element to  
RGB. It is the only 4 color array ever used as far as I know.

RGB and RGBG are commonly used interchangeably to describe the Bayer  
array. The second G is just to point out that there are two green  
sites for each red or blue site in the standard Bayer array. So I  
don't know what you mean by a 4 color Bayer array, nor could I find  
anything about it using google. Maybe you know of a place that  
explains it?



Winsor
Long Beach, California, USA




On / October 17, 2007 CE, at 9:50 PM, David Irisarri wrote:

> 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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