[tabi] Re: technical info for users of the KNFB reader
- From: "Blackjack" <blackjack2@xxxxxxx>
- To: <tabi@xxxxxxxxxxxxx>
- Date: Tue, 25 Aug 2009 23:38:01 -0400
Ok, This is one reason I have not got the reader with a phone yet. I think
the technology has a way to come yet. Maybe this type of technology will get
a whole lot better in the next 10 years. That is the technology not the
company necessary. I would like to see this type of technology put on some
sort affordable digital camera. This way you could make use of the more
powerful lens they have. Just my thoughts.
Thanks,
Blackjack
blackjack2@xxxxxxx
-----Original Message-----
From: tabi-bounce@xxxxxxxxxxxxx [mailto:tabi-bounce@xxxxxxxxxxxxx] On Behalf
Of Betsy
Sent: Tuesday, August 25, 2009 5:42 PM
To: tabi@xxxxxxxxxxxxx
Subject: [tabi] Re: technical info for users of the KNFB reader
Thank you very much for this information Chip.
I reeealy want to get one of these in the next couple years. I've been
waiting and watching it evolve ever since it came out and it's only going to
get better.
Betsy
----- Original Message -----
From: Chip Orange <mailto:Corange@xxxxxxxxxxxxxxx>
To: tabi@xxxxxxxxxxxxx
Sent: Tuesday, August 25, 2009 4:25 PM
Subject: [tabi] technical info for users of the KNFB reader
>
> K-NFB Reading Technology, Inc.
>
>
>
> TECHNICAL ASSISTANCE BULLETIN
>
>
>
> Date: August 19, 2009
>
> SUBJECT: Advisory on use of polarizers
>
>
>
> Installation of polarizers over the camera lens and flash has been
a
> specified procedure of K-NFB Reading Technology since the Mobile
Reader
> products were first released in January 2008. The purpose was to
improve
> the quality of images captured by the Nokia N 82, which uses xenon
flash
> technology to illuminate target text. Polarizers minimize glare
caused by
> the flash reflecting back to the camera lens when the text is
printed on
> glossy material, or the image is captured through glass. The glare
would
> otherwise prevent accurate text recognition.
>
>
>
> Polarizers do improve image quality, as confirmed by our direct
observation
> and reports we continue to receive. But only if they are correctly
> installed and maintained in accordance with our specifications.
> Unfortunately, over time normal day-to-day use of the Mobile
Reader often
> results in polarizers being moved or dislodged, such as when the
phone is
> carried and frequently removed from a pocket, purse, or carrying
case.
> Misaligned polarizers not only fail to improve images of glossy
surfaces
> but
> also can distort all images, leading to unsatisfactory
performance.
>
>
>
> To address this, we have decided to recommend polarizers as an
optional
> rather than a required accessory. End-users may choose to have
them
> installed or not based on individual needs, requirements and
preferences.
> The information below is intended to help Mobile Reader
distributors and
> end-users decide whether to recommend polarizers or use them,
respectively.
> Additional assistance to address particular questions or concerns
is
> available from K-NFB Reading Technology's technical support
service.
>
>
>
> 1. Expected reading requirements
>
> As noted in the Mobile Reader Users Guide, polarizers are
particularly
> essential when capturing images of text printed on glossy material
or when
> a
> picture is taken through glass. An alternative to polarizers under
these
> conditions is to switch off the flash, which can be done without
> sacrificing
> image quality provided the lighting in the room or area is
moderate or
> better. Another alternative is to use a reading lamp, which can
improve
> the
> brightness of the image and still avoid glare if the light is
properly
> situated to avoid reflection from the glossy surface . So
switching the
> flash off while attending to lighting conditions is a suitable
alternative
> to polarizers, unless one needs to read glossy documents very
frequently
> and
> under varying conditions of light.
>
>
>
> 2. Installation and maintenance requirements
>
> In order for polarizers to function as intended, installation must
be
> performed in accordance with our specifications. Thereafter great
care
> must
> be taken at all times to maintain the precise positioning of each
> polarizer.
> The end user must understand this.
>
>
>
> 3. Camera considerations -
>
> Two supported phones, the Nokia N 82 and the Nokia 6220 classic,
are
> equipped with xenon flash, which produces the brightest light
possible but
> also can introduce the most glare. The Nokia N 86, first announced
as a
> supported phone in August 2009, is equipped with a camera which
has been
> optimized for low light images, including an 8 megapixel camera
and an
> advanced dual LED flash. Consequently, images of glossy content
captured
> by
> the N 86 used without polarizers tend to show less distortion even
with the
> flash turned on than comparable images taken with the xenon flash
of the N
> 82 or 6220 Classic. Images taken by the N 86 without polarizers
and the
> flash turned off usually compare favorably to images captured by
the N 82
> or
> 6220 Classic when polarizers are installed and the xenon flash is
turned
> on,
> provided there is moderate or better light. So there is less need
of
> polarizers for the N 86 than there is for the N 82 or 6220
Classic.
>
>
>
> In summary: beginning August 2009, K-NFB Reading Technology will
no longer
> specify pre-installation of polarizers as a product requirement.
Decisions
> on installation and use of polarizers as an optional accessory
should be
> made by distributors and end users based on individual needs and
> capabilities. Polarizers will remain available upon request for
all
> supported phone models.
>
> Switching the flash on and off, while attending to lighting
conditions, is
> recommended as the best all around option for end users who do not
express
> a
> significant need to read glossy documents in low or fairly low
light with
> the flash turned on. See the chart on the following page.
>
>
>
> For more information or to order polarizer sets, please contact
K-NFB
> Reading Technology by email at: support@xxxxxxxxxxxxxx or by phone
at:
> 1-877-547-1500. If ordering polarizers, please specify the
quantity and
> supported phone model. Previously published rates for multiple
polarizer
> sets shipped in quantity to distributors still apply.
>
>
>
> Explanations on the decision to use polarizers follow in both text
and
> chart
>
>
>
>
> Our recommendation as to whether polarizers should be installed
depends on
> 2
> questions:
>
>
>
> Do you frequently need to read glossy documents, and under varying
light
> conditions?
>
>
>
> Would you carefully maintain the position of the polarizers on the
camera
> lens and flash?
>
>
>
> If the answer to either of these questions is "No", our
recommendation is
> not to have the polarizers installed. Turn off the flash before
shooting
> glossy surfaces and make sure that there is at least moderate
lighting.
>
>
>
> If the answer to both of the above questions is "Yes", then your
preference
> should determine whether polarizers are installed on the Reader.
N82 and
> 6220 Classic phones have a very bright xenon flash, which can
produce a lot
> of glare in an image of a glossy document, whereas the N86 has a
dual-LED
> flash which does not create as much glare. The polarizers will
greatly
> diminish the glare which appears in an image of a glossy document,
but you
> can also turn the flash off, which will eliminate the glare and
still
> provide good reading performance if there is good ambient
lighting.
>
>
>
> If you choose to have the polarizers installed, make sure that the
> polarizers are not rubbed against surfaces or put under stress, as
this can
> cause them to move out of position. If you choose not to install
> polarizers, turn off the flash before shooting glossy surfaces and
make
> sure
> that there is good ambient lighting.
>
>
>
> Best Regards,
>
>
>
> James Gashel
>
> Vice President of Business Development
>
> K-NFB Reading Technology, Inc.
>
> Direct phone: (720) 878-4248
>
> Fax: (781) 263-9999
>
> Skype: james.gashel
>
>
>
> email: jim@xxxxxxxxxxxxxx
>
> http://www.knfbreader.com <http://www.knfbreader.com/>
>
>
>
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