QR Code Readers

Quote from the movie The Green Lantern: "The Corp is only as strong as its weakest link"

Enhancing a standard QR Code is weakening the readability. But the code itself is not the only link in the chain to keep a QR Code readable.

Using my method a code as displayed can be generated where the content of the QR Code can be made error free.

Using various readers like I-Nigma (WP7, iOS, Android), Qrafter (iOS), UpCode (WP7, Symbian) this QR Code's content is still readable.

The build in QR Code reader from the windows phone, integrated in the Bing Search App was unable to read this code.



To check if the same code containing content errors can also be read, an obvious deletion of part of the code was done.

I found it more than odd that suddenly the WP7 build in reader could actually read this code while it contained errors, while having trouble when the content was error free.

All the other readers used had no issue scanning this QR Code with error's.

When running a campaign with enhanced QR Code the readers that are used are not under your control.
Since the intention of a QR Code is to be scanned, it is just a question of how many potential clients will be unable to read a code that is enhanced with graphics and color due to the reader App that they have installed.

Stressing the readers even more a big chunk of the code was erased in the bottom right corner.

The I-Nigma and Qrafter reader had no problem correcting the missing content, the other readers mentioned could not cope with the code on my systems.

Since the amount of errors made by erasing this corner is well within the capability of the Reed Solomon correction engine, it is unfortunate that some readers refuse to decode the content.

QR Code overlay vs integration.

Quote from the movie Face-Off:: "It's like looking in a mirror, only not."

Two QR Codes to support my claim that integrating a picture in a QR code versus overlay can result in the placement of a bigger graphic.The graphic on the left is placed in a High Quality QR Code, while the picture on the right is integrated in a Medium Quality QR Code. Both codes hold the same URL as content.

For the integration a lower quality QR Code was selected to generate more room in the area that holds the padding, making room in the code to integrate the picture itself.

The overlayed image in the left picture is depleting the error correction ability of the Reed Solomon to the maximum. The integrated picture is highlighted more due to the bigger clearance between the picture and the QR Code elements. Claiming that the clearance is part of the integrated picture, in this case the picture in the right QR Code occupies a larger area compared to the one in the left QR Code.

The integration also supports automated relinking, a multitude of copies of this one code can be generated, while each individual copy made using the overlay technique has to be checked, and maybe adjusted.

QR Code Visitors

Quote from the movie Pearl Harbor: "Hey. We got a visitor." 

The main goal when using a QR Code in a marketing campaign, or just running any other advertizement campaign is to generate interest in you product, and get visitors in your store, or on your website.

In a store you will get a variation of visitors, from the just browsing to the buying type. On the internet however there is also another type of visitors.

Some of these visitors are the search engine BOT's that scan your site, but there are also various other non organic visitors on your website as  result of a campaign.
A good example of this kind of visits was mentioned in the The QR Code Gamble blog entry.

These non organic visitors could accumulate to a very high number of hits. When running a campaign and using a service that runs on a Cost Per Click (CPC) method, you could also be paying for these non organic visitors.

Custom QR Code, a ticking timebomb?

Quote from the movie Never Say Never Again: "let's hope it doesn't blow up in your face."

Sure, customized QR Codes look better, and are alleged to be scanned more often.
Just be aware that all the adaptation reduces the readability.
If not done carefully it might just blow up in your face.

When I make (your) custom QR Code, I don't only trust that the code will work. Each code will also be thoroughly tested using various and multiple tools, devices and apps.

QR Code generator...... Part three

Quote from the movie Ladder 49: "Don't you think it might fall apart?"

On the site kangaderoo.pythonanywhere.com where my relink tool is hosted, a QR Code generator tool is added.

The basic codes generated from this tool do not hold graphics, and the colors are black and white. This assures that the generated code does not fall apart.

This generator does support the variation in the shape of the code as described a few blog entries back.

The next addition to this tool will be API access, in order to generate a high number of codes.

Work in progress, more updates to follow, more tools to follow.

Merge QR Code with background images

Quote from the Movie Meet Joe Black: "Do I Blend in?"

QR Codes like this you probably have seen before.
The Background and the code is merged together as one single picture.

The locator squires are kept at a higher contrast. When a Reader can find these locator squires, it will determine the size and start position and grid of the code.

For each grid location the binary value will be determined, by checking if the location is predominantly light or dark.

Points of the background picture that hold the a opposite or undefined level compared to the QR Code's content will be pushed to hold a definite light or a definite dark level.


This pushing can accomplished by overlaying a dark or light picture on this grid position with just the right level of transparency to make sure any QR Code reader will read the right binary code for each grid position.correctly.

The Art is to find the correct mask and selecting the best code settings so that the minimum amount of grid elements would be needed to merge the picture and the code. That way most grid positions of the background would not need adjustment, and can show the actual picture.

Selecting the right QR Code

Quote from the movie Ruthless People: "Bigger is not necessarily better"

When selecting the correct size for a QR Code, its not only the physical size that needs to be selected.
With the physical size I mean the actual size in squire inch (or centimeter) room that is reserved for printing the QR Code.

QR Codes are available in various versions (grid sizes), and 4 error correction levels. You would assume that the highest error correction setting would be best choice to guarantee a working code. But is it?
There is a big chance that by selecting the highest error correction level, also a bigger version, and therefor a bigger grid size needs to be selected for the content to fit the code.
Since the total grid size will be scaled down to fit the physical dimensions as mentioned before, the resolution of the total code will degrade, thereby increasing the risk of hard to read or unreadable QR Code.

The surface where the code will be printed on will also an effect on readability. A code placed on a folder will be easier to scan than a code printed on a plastic bag.


The quality of a Custom QR Code can be degraded by three basic factors:

Error correction since part of the code is usually replaced by a graphic.

Errors introduced by placing the graphic in the code need to be corrected. The bigger the graphic the more errors are introduced, this need to be compensated with a higher error correction setting.

Resolution due to compensation for the placed graphic.

Usually the highest error correction is selected, to maximize the size of the graphic to be placed. In order no to exhaust the error correction a bigger version of the QR Code is needed.

Contrast due to the use of colors.

Black against white still gives the highest contrast.

When the content of the QR Code is an URL, using an URL shortener could be a nice help. This tool usually reduces every URL to 20 characters (or even less). Using an URL shortener can reduce a QR Code version requirement by one or more versions, resulting in a better resolution.

When a graphic is being made part of the code's content, as can be done by the service I offer, this has a positive influence on the error correction. A QR code with the highest error correction setting, but containing error due to graphic placement will be more sensitive for misreads then a QR Code with a lower error correction setting but without errors.

When placing a graphic in a QR Code, the color of the graphic will reduce the contrast, a lot of the potential errors due to this placement can be reduced by selecting a best overall fit for the graphic in relation to the elements (grid points) involved. By a slight shift of the picture and/or some retouching it can be avoided that a single grid point is 50% dark and 50% light.

QR Code Variation

Quote from the movie Animal Farm: "BUT SOME ANIMALS ARE MORE EQUAL THAN OTHERS"

Using a QR Code in a campaign that is build up with just ordinary black white squires doesn't make it stand out. To a QR Reader app this doesn't matter, it treats every input as equal.
It will try to find the three locator squires, and then read the pattern. Converts the pattern into a data-stream, checks the stream for errors and shows the result. Or reports a fail if too many errors are detected.

In order to make QR Codes more appealing, by a little bending of the rules QR Codes can generate a different appearance.
Here are some examples, that do have the bit-stream error free, the color and element shapes do not comply fully with the contrast rules. It is a fair trade off with the result however..

QR Code Enhancement

Quote from the movie A Bug's Life :"Someday I will be a beautiful butterfly"

Beauty is in the eye of the beholder. The consensus is that basic QR Codes are ugly.
Just like a caterpillar can transform into a butterfly, so QR Codes can be made beautiful, even with all QR Code features, like fast readability and error correction intact.

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QR Code Virus Threat

Quote from the movie The Lord of the Rings: The Fellowship of the Ring : "...and our people lose faith."

I have been reporting about QR Codes being a placeholder for viruses in the blog before.
Apparently there has been an occasion where a QR Code was linking to a page that incurage to install an App on your mobile. This App seemed to be the virus.

A QR Code cannot be a virus. All files on you mobile, personal computer, laptop, pad or other intelligent device can be divided in two groups:

1.) An app or programm that runs on the device, actively running tasks.
2.) Data content, or information, like a document holding text, or a photograph.

A QR Code falls in group 2! The App that reads the QR Code falls in group 1.
Just as an e-mail, or even a blog, a QR Code can hold a link to malicious content, the link itself is not a virus.

How can you protect yourself against malicious content in a QR Code?
There are various QR Reader apps available, some will directly open a browser when reading a hyperlink, other readers will show the content of the QR Code, and ask what to do with this information, asking permission before opening a link in a browser.
Using this display before act options in a QR Code reader is a simple way to protect yourself against malicious intent.

Give you users an extra motivation to belief the validity of the content of your QR Code, by branding your code with your own logo.

Shield yourself and your QR Code against malicious use, restore the faith in this beautiful tool that is the QR Code.