All
about PIXELS
This
article is written by Leo Bongaards ND MH
Most readers of this article would
know that the iris (and sclera) reveal most if not
all regarding the physical and mental
health of a person. Although
there are still
many different opinions and ways of
interpreting the information, all do agree that
the better the image of the eye the more accurate the interpretation will be.
New graduates looking for equipment may not have
experienced all the types of
equipment available and many have little practical
experience, with anything but
a torch and magnifying glass.
Diagnosis and teaching at the college may have
been
done from slides and
photographs.
The old pioneers of iridology used a
magnifying glass and torch as well to observe
the markings and colouring of the
iris. The later equipment consisted of an iriscope
with a lighting system, similar to the equipment that is used by optometrists.
This type of equipment is really the
best and ONLY equipment
to use to see all the
markings and colours in the iris and
sclera. The view is
multi dimensional, (the 2
eyes we are seeing through are in
different locations in our head, 2 slightly different
images are put together in our brain
to give us the ability to judge distances and see
depth).
So one can observe the depth of a radii solaris or nerve
ring, the ANW
standing on edge like a flower, psoric spots on the
surface and toxins in the fibers.
Students are best taught using this type of equipment
before moving on to single
dimension equipment like photographic
images for iris diagnosis.
To test the issue of depth check this
example:
If one had an eye injury and one eye
had a patch over it, you would still be able to
drive a car reasonably well, as the
brain remembers how far away you are from
the
car in front, but a person born with one working eye only
can not see distances and
if the brain never had the luxury of receiving stereo images
no information is
available to judge distance or see depth. Driving a car would be very
difficult.
Looking at an iris on a monitor screen
provides you with the opportunity to see every
fiber
and colour clearly but you can not see depth, it is the
experience gained by
looking at eyes in stereo that makes the correct
interpreting of the image possible.
If you wonder why we don’t have stereo monitors, no-one
has been able to design
one yet that didn’t need special
glasses and have a very limited viewing
angle.Maybe
we will, one day, have holographic images as depicted in science-fiction
movies.
Practitioners that have worked with
“slitlamp iriscopes” with a camera attached
have
had the perfect training as they can see the correlation between the
stereo and flat
image over and over again every day of
the week with every patient they see.
These practitioners are in the best
position to diagnose from photographs and (single dimension) monitors.
This brings us to digital imagery.
No one with any foresight will purchase a film operated camera any more.
Remember the bad old days if having to wait until the roll is full,
taking it to the chemist
to develop and print, only to that the irises where mixed up, or out of focus and
you try forever to find out what patient the
eyes belong to. Not to mention the difference
in colour with every
film roll. All have gone now with wonderful
DIGITAL photography…..
Camera
manufactures are falling over them selves to out-do and under price
the competition.
Digital cameras
are becoming better and cheaper by the day, just as we reached the
pinnacle
of film based
photography, the CCD was invented. This is a device that breaks up
the
image
captures into a matrix of electronic dots. Imagine many hundreds of
chess boards
put together and
miniaturized to the size of one of your finger nails. That is the
modern
capture device
called CCD (Charge Coupled Device)
Electronic dots
are stored into a memory consisting of millions of on/off switches
so no film is required.
For more
information on how a CCD works click:
http://www.oceanoptics.com/Products/howccddetectorworks.asp
The latest domestic digital cameras
may have CCDs with a number of image dots, or pixels per photographs
that can exceed 8,000,000,
as a rule the more dots, the sharper the photo so even when
enlarged, it is hard to see the dots, but if you put a magnifying
glass over the image (You can try this with your TV set or computer screen) you can
see dots, or rectangular blocks, clearly, they are in clusters off 3
to make full colour images possible. So every 3 dots, Red, Green,
Blue, form one distinctly coloured Pixel or image “dot” How many pixels do we need
for a good image? Well the more pixels the better the picture will
be. So the smaller the pixels the more may fit into a given
space.
TV Video images are produced by
following a standard, which was agreed upon in the 1940’s.
Technology has come a long way since then, however the system has not been changed
(but will be soon). Digital TV transmissions will be introduced and it has been
reported that by 2008 all the old (analog) transmissions will end in
the USA. No doubt other Countries to follow suit. A normal TV
screen can show only
153,200 pixels, if you live in the
US or 215,500 pixels for the European PAL system
that is used in Australia.
What?.......... Only 0.2 Megapixels ?
Yes ! a TV video
screen has less than ¼ MP. And your computer
screen is only a little better. The LCD screen you are looking at
now has still only capable of showing between 0.7 – 1.3 MP. To make things worse all
these numbers should be divided by 3 as each image “dot” consist of
an array of 3 sub-pixels. Below is an illustration showing pixels in
a screen.
A video monitor with 215,500 pixels can display 1024x768 (786,432
pixels),when used as computer monitor.
A pixel or picture-element, is composed of three
sub-pixels in the primary colours of red, green, and blue. At each
pixel position in an AMLCD (active matrix liquid crystal display)
flat screen monitor, three cells of liquid crystal material form the
red, green and blue sub-pixels that together allow the full range of
colours to be displayed. Individual transistors are arranged in an
array on the rear glass to control each sub-pixel. An anomaly or
break-down of any one of these individual transistors will cause a
bright or dark pixel to appear. Manufacturers have agreed that a
standard LCD screen
exhibits less then 8 non-performing or dead pixels, this would
equate to an extremely small 0.00026 percent of the total sub-pixel
failure !. Some
manufacturers now guarantee NIL dead pixels. This is remarkable
technology.
Now how do we fit some 3 – 5 Million pixels
from a camera on a 0.2
– 1 MP screen?
One would expect to have to throw
out lots of information …….
Yes that is
quite true.
I have seen images, made with
a High MP Camera that look absolutely shocking on a
screen.. Pursuing the pixel race is a
waste of time and money there is nothing to be gained by having high
megapixel images for diagnosing an iris from a screen or printing a
postcard size photograph! So
without making this article into a bookwork of technical formulas it
comes down to this:
The system is only as good as the weakest link.
Lets
look at the set - up; There is a camera, a printer and
a monitor.
The camera is rated in Mega
Pixels say from 3 to 8 MP,
(Beware of merchands
offering 12 or more MP cameras; When you read the fine print you
find that the actual CCD is only 3 MP and a system called fuzzy
logic is used to make the image appear to have a higher number of
pixels)
Domestic printers are rated
in dots per inch 300x300 – 1200x1200,
This
equates to approximately 3 MP and 8
MP for 1200-1200 on a 6x4 photo image.
Monitors are rated in lines of resolution and may have names like
VGA, XVGA,
SVGA The best 22”monitor on the
market today can only display around 1 Mp and to display this number
of pixels there needs to be, a capture card capable of capturing
this amount of pixels, the best I have seen advertised so far is
only capable of capturing 1.3 MP
divide this number by 3 to arrive at the actual number of pixels
shown. (0.4 MP) There is just NO way to increase the number of
pixels of a VIDEO monitor, or TV set, as this is bound by an
International standard.
Is there some logic in all this
?
I would say that a 2 – 4 MP
camera works well, this allows you to print 6x4 pictures of excellent
quality and even A4 prints will be good. There wouldn’t be many
iridologists at would want to print each eye on wall poster size
paper. Camera manufactures keep increasing the number of MP so a
good camera now has 7 or 8MP if one likes it or not.
Is it a fluke that EYERONEC came
up with the package they now have for sale
?
NO around 50 cameras and configurations were tested before
a decision was made to use the Canon range of Digital Cameras, with
its top quality photo
printer and a good
Video Monitor, was added for instant viewing. The result: A perfect setup for a busy
clinic.
If you have a computer and lots of
time and a patient that is not in a hurry, you can capture images,
import them into a program and view them on a computer monitor,
Although in theory the computer screen may have a slightly better
resolution than the Video Monitor, there would be , in my
view, no difference to the diagnosis at all.
The disadvantage with other cameras is
that apart from them being heavy, composing and taking the picture
is done by looking trough a tiny view finder, making focusing hard
and all use a flash.
Printed pictures will always be of
better quality than the image on a screen and pictures can
easily be stored in the patients file. If you store the images on a
computer you need lots of memory and the image needs to be
compressed (which means less pixels
!) and how will you compare them with the new
image, when the patient presents again? Write a special program for
split screen? Yes that’s possible with special software, but the
size of each eye would not be much larger
than your 6x4 photograph and certainly NOT as
sharp!.
So to
conclude:
*The
EyeRonec CANON DIGITAL
Still cameras are the
best cameras
to base an iriscope system
on because they produces instant
(live)
images on a large screen to allow precise focusing and
instant viewing.!
Taking the picture takes no more than 10 seconds per
iris providing you can SEE THE IMAGE ON A LARGE
SCREEN It totally does away with
fiddling with computers and trying to focus with a 1” mini
screen. Magnification
to well over 100x is possible, instantly. ALL other makes of
Iris cameras need focusing by looking through a tiny view
finder.
*Photographs: Top
quality prints ( 100 years CANON guarantee) take around a minute to
print; while you talk or listen to the
patient.
*No
work to be done after the
consultation, just put the patient card and the pictures in the
patient file, (which may be a large envelope).
*No
computer or software is needed so the system is much more economical and
complete.
*No
lost data when the hard disk crashes or the computer is damaged or
stolen.
*
Ease of portability due to the small size of the camera and the
printer and the super flat LCD monitor.
(Case
size 470x320x150mm Weight around
10Kg)
So all round the
EyeRonec system is the best system for YOUR
clinic.
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