|If you are just starting to use the Digit-Eyes products,
to learn about scanning.
Q. Where will I find the Digit-Eyes codes?
A. The Digit-Eyes codes are printed on address
labels before being stuck on the item that they label.
The labels can be quickly and easily found by touch; since you
are the person who sticks them on the item, you can put them
anyplace that seems convenient.
Q. Where will I find UPC codes?
A. UPC codes are typically located where humans will not
find them. They are oblong, typically at least one
half inch /1 cm in height and at least three times as
long as they are tall. You will find the bar codes are often
They will almost always be within 4 inches of the bottom of the
object because that is typically the maximum scan height of a supermarket
- on boxes: away from the side that is opened.
- on cans with wrapped labels: adjacent to the seam
where the labels are joined
- on jars with a single label: as far away from the center
portion of the label as possible.
- on jars with two labels: on the back label
(typically the front label will be larger and may be more
elaborate in shape; back labels are typically smaller and
- on packages that are rectangular with small sides:
on the longer of the two small sides.
Q. What about soda cans and things that don't
have obvious labels?
A. It can be difficult to locate codes on items that are
round and that have continuous wrap labels or where the bar
code is part of the printing, as on a soda can. In this
case, it is typically necessary to scan the entire label
surface. We've found it convenient to do this by bracing the
bottom of the phone on a table and putting the can in front of
it. When the phone is scanning, it makes ticking noises. Each
time that there is a tick, turn the can 1/4 turn in front of
the camera. We have found that it rarely takes all four turns
to get a scan.
Q. What is the easiest way to scan?
A. When you are starting out, you should definitely try
sheets. These let you become familiar with the use of the
After getting comfortable with the practice exercises, try
a real item and start with a box. Initially, you will probably
find that it is usually easier to hold the phone steady and
turn the item slowly in front of it. One of our
customers reports that he got great results by using a holder
from his wife's plate collection, putting the phone in it and
turning the item in front of it. After you have more a
feel for the process, you'll probably want to transition to
holding the phone in your hand, but a hands-free approach can
be very useful when putting the groceries away!
Helpful Hint: If you are having
problems with the object, we recommend rotating it 90
degrees; the bar codes can be scanned from any angle and
rotating the object will cause the autofocus on the camera
Q. Does the orientation of the code or label
A. No. Digit-Eyes can read any code in any
Q. How far away should the camera be from the
item being scanned?
A. The answer to this question depends on which kind of equipment you have:
iPhone 3GS, iPhone 4/4S or iPad. All these devices work fine,
but we've found that the cameras behave very differently.
Generally for UPC codes and the standard Digit-Eyes tags,
- the 3GS
works well about the distance of your hand (4 - 6 inches / 10
- 15 cm.) away. A quick way to gauge this is by putting
the edge of one hand on the object you are scanning and
putting your thumb in the air. Touch your thumb
with your camera hand and you'll be about 6 inches / 12 cm
from the object. If you are using some of the very
large (4 - 8 inch / 10 - 20 cm) labels, you will need to scan
from a distance of about 36 inches / 1 meter.
- If you have the
iPhone 4, you'll find that you can scan at distances that
range between 4 and 12 inches / 10 / 30 cm.
- If you have
the iPad or iPhone 4S, both of which have very good camera, the distances
will range from between 4 and 20 inches / 10 / 50 cm.
- The scan distance
on the iPhone 5 and the 4th genration iPod will typically extend from 4 to 24 inches.
Q. How much light is needed to scan?
A. The cameras on the the iPhones and iPad will read bar codes in
the same type of light that sighted people use for
reading. If you have an iPhone 4 or or later model, Digit-Eyes will simply use
the flash if it finds that there is not enough light to scan. The iPhone 3gs and iPad
do not have a flash, so in this case, Digit-Eyes will warn you if
there is not enough light for it to be able to get a good
scan. As a general rule, cameras work better when there
is more light.
Q. Is reflection or shadow a problem?
A. Not generally. Bar codes are recognized
by the difference between light and dark, which is perceptible
to the camera in most cases. However, if you are
in a very extreme light environment, there are a couple of
possible issues. Please note that these are not common
- In extremely bright light and with very smooth surfaces,
the contrast may be such that the camera "sees"
a white reflection instead of the label.
- Likewise if you are in a very bright area and casting a
shadow on the label, it is possible that the
"light" portion of the label in shadow does not
appear very different to the camera from the dark portion
that is not in shadow.
If you are in doubt or having a lot of trouble, just turn
around; this will generally change the lighting environment
enough that the problem will be solved.
Q. Are there any tricks for getting the
autofocus to work?
A. We have found that the camera works best when you are
holding fairly still or when you are slowly moving the camera
away from the object (or the object away from the camera).
Q. This seems a little complicated. Does
it get easier?
A. Yes. Like any tool, there is a learning
curve. You will initially find using the text and voice
labels easier because it is simple to locate them by
touch. After you have used the Digit-Eyes for a day or
two, you'll find that it has become a habit and you won't
think about it any more.
Helpful Hint: If you are putting groceries away and want to make
the UPC codes easier to find later, put a piece of scotch tape over it. Digit-Eyes
will easly read through the tape later and it is easy to find by touch.
Q. Does it matter if the code is flat?
A. Not a lot, but if the camera can't manage to capture
an image of the whole label, Digit-Eyes won't be able to
resolve it. We'd suggest starting by flattening a couple
of wrappers and scanning them. Then move on to objects with
less regular surfaces.
Q. Curved surfaces seem harder to scan
A. You are correct; they are. This is because
there is some optical distortion because of the depth of the
curve. If you are having problems, try rotating either
the object or the phone (slowly) 90 degrees.
Q. Is the camera on the iPhone 4/4S and the iPad different from
that on the 3GS? How about the iPhone 5 and the 4th generation iPod? If so, how does this affect scanning?
A. Yes, the cameras are quite different. The camera on
the 3GS is a 3-megapixel camera with autofocus but no flash.
The camera on the 4 is a 5-megapixel camera that has flash
built in and has considerably quicker autofocus logic. The iPhone 5 has an 8-megapixel camera that
works better than the earlier cameras in low light situations. The
practical result is that you'll find that capturing the bar
code using an iPhone 5 is faster than on an iPhone 4 and that capturing on an iPhone 4 is faster than with an iPhone 3GS, and
you'll be able to capture codes from farther away. Please
note, however, that Digit-Eyes was completely developed and
tested using the 3GS. As a result, the Digit-Eyes app works
excellently on all three platforms.
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