Different QR code file formats for different purposes
A QR code is a 2D barcode consisting of squares arranged in a specific order to depict digital infomation. In order to represent these squares, they need to be drawn on a canvas and stored for later display.
QR Code file types
The way QR codes can be saved fall into two bsic catagories:
Bitmap (small dots)
Bitmap QR Codes
Bitmaps are images made of dots called pixels. The amount of pixels (per inch) or DPI (dots per inch) determines the resolution. The resolution determines the size and the clarity of the image when viewed on a screen or printed on paper. The higher the resolution (DPI) the better it will be suited for printing and also the bigger the file becomes.
An example: A compter screen also uses pixels to display or show images. The resolution of a computer screen is typically 72 DPI = 72 pixels per inch. Commercial printing euipment has resolutions from 300 to 2400 DPI in order to produce sharp quality images on printed matter. This indicates that printed matter requires nearly 5 times the pixels to represent it than on a computer screen.
These QR codes are made from a predetermined amount of dots that are generally good for computer screen display (72 - 96 DPI) but may not be suitable for printed matter printed at the same size (300 - 2400 DPI).
Other Bitmap Information
Not all bitmap file formats support everything that may be required at any one time for your QR code presentation. Colour range may be important (display and print), transparency and opacity or transfer speed via public networks. The table below shows the difference between the most common bitmap file formats used to create QR codes.
||Tagged Image File
||Image pixel data preserved 100%, easy to exchange between different systems and applications. Large file size.
||Graphics Interface Format
||Only supports 256 colours from a palette, meaning limited colour variation. Small file size. supports transparency and animation.
||Joint Photographics Expert Group
||Can store 16000000 colour variations. Lossy data compression. Ideal for displaying photographic material on the web.
||Mainly for Windows platforms, can store various colour depth types. Uses lossy data compression.
||Portable Network Graphics
||Preserves all colour information as well as alpha channel information (opacity and transparency) Relative large file size. Ideal for web dispaly and printing.
The table above is not complete (omits proprietary and rayt racing formats), however what to look for when chosing what sort of bitmap QR code will suit your need best. Here are some points to consider:
- Is colour fidelity important (corporate business colours) - Although QR codes should be black and white!
- Transparency and opacity needs (use the same image on varying backgrounds where the QR code looks like it is part of the complete image)
- Is file size, transfer speed and compatibility with applications important (support for all browsers and fast Internet transfer)
Once you have decided which factors are best suited for the presentation and transfer of the QR codes it is time to look at the medium it will be used on. We know bitmap QR codes are best suited for 'radiant presentation' like on TV, video and computer screens (PNG and TIFF at the correct resolution being the exceptions as they are have worthy print potential at the expense of large file size).
In my humble opinion.., if file size in not crutial, PNG QR Codes are winners as it is suitable for display and print media, supports alpha channels (transparency and opcity) and has the additional benifit of a choice between interlaced and non-interlaced for the best quality display results on Television, video as well as any computer and smart-phone screen formats.
Vector QR Codes
It's a fancy name for QR codes drawn using lines to make boxes (or containers) and then filling these boxes with a colour. The magic here is the fact that they are drawn using lines and the fact that you can make a line as short or as long as you like is the secret to it's success in the printing industry, although WEB 2.0 has some very smart formats as well for use with all media visualization options.
QR codes created using vector tecnology can be (proportionately) resized to any size, yes ANY SIZE, without loosing any quality = perfect presentation. This statement applies for all printed collateral, but not for all radiant display media.
The most common file format for printing is PostScript or EPS (Encapsulated PostScript). PostScript is a page description language that can draw just about anything, from fonts to graphics and bitmaps on a page. An EPS is a piece of a Postscript page without a page, meaning it can be 'pasted' and resized into another page at any location.
Other types of scalable vector graphics
||A graphical page description language used to describe and draw objects on a page.
||Portable Document Format
||An open document exchange format able to accuratly store and present bitmaps, vector graphics across multiple platforms.
||Scalable Vector Graphics
||XML-based system for describing two dimentional graphics which supports animation. Not popular for printing due to no native support for CMYK.
||Windows Meta File
||Popular graphics format for users of MS Office, supports bitmaps and vector grpahics. Generally used in office documents.
||Extensible Application Markup Language
||Microsft XML language to initiate structured objects and values. Is extensively used in the .NET framework. More directed towards presentational graphics than printed matter.
Which type of QR code file format to choose?
The most important factor that needs to be considered is where and how the QR code is going to be used. If it is only for display on a normal computer screen then PNG and JPG are probably the best choices. However if it is to be used for (professional) printing purposes then EPS or PDF are probably the best choice with the option to use high-resoltion PNG as well.
If video and television are important PNG with interlacing, opacity and transparency is the winner.
Not sure which QR code file format is best for you, then please contact us as we can advise you on what will work best for you based on your requirements for your QR code(s). QR4 does with QR codes what others only talk about.