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Scanning Tips
If you are just starting to use the Digit-Eyes products, click here to learn about scanning.

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 located:

  • 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 simpler.)
  • on packages that are rectangular with small sides:  on the longer of the two small sides.
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 scanner.

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.  Any tricks for scanning UPC / EAN codes?
A.  When you are starting out, you should definitely try the practice sheets. These let you become familiar with the use of the camera.

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 to reset.

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.  Any tricks for scanning Digit-Eyes codes?
A.  The codes will be captured faster if they are relatively "square" to the phone.  The camera is in the upper right back of the iPhone or iPod when you are holding the phone with the "home" button at the bottom and facing you.   Locate the code by touch and put the lens of the camera on the code with the top and right edges of the phone lined up with the top and right edges of the label.   Start the scanning operation and lift the phone away from the code.   It will make the ticking noise until it recognizes the code.  At that time it will beep and vibrate to alert you that it has found the code and is processing it.   After identifying the code, Digit-Eyes will either play the recorded content or voice the text, if the label was pre-recorded or if it includes text; otherwise, it will just invite you to record.

Some people find that aligning one of their fingers with the camera and using it "point" to the code while scanning is a helpful way to make sure the phone stays aligned, but you will probably not need to do this after you've had a little bit of practice.

Helpful hint:  if VoiceOver persists in talking to you with instructions when you want to record, you can quiet it with a two-finger double tap.

Q.  Does the orientation of the code or label matter?
A.  No.  Digit-Eyes can read any code in any direction. 

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.
  • The scan distance on the iPhone 5s and the 6 genration iPod will typically extend from 4 to 30 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 problems.

  • 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 5th 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 6 is faster than on an iPhone 5, that capture on an iPhone 5 is faster than on an iPhone 4 and that capturing on an iPhone 4 is faster than with an iPhone 3GS.  You'll also be able to capture codes from farther away with the later phones because they have better cameras. 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 Apple platforms later than the iPhone 3Gs (June, 2010).


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