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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