Image Tracking Best Practices
The following best practices will help you to implement Image Tracking effectively in your experiences.
Creating an effective target image
An effective tracking image usually incorporates three components:
| Components | Description |
|---|---|
| An Image | A regular image (.png or .jpg) which will be trained for tracking content to. |
| A Call To Action | A message or design used to tell the user how to activate AR content. |
| A Trigger | A method used to launch the AR content once scanned, such as a QR code or Deep Links. |
Users should have physical access to your image to be able to visualise tracked content.
Additionally, you should consider implementing the following features to get the most out of your target image:
A detailed design
Avoid using images that contain a large amount of blank space (such as solid color), as it isn't registered as complex graphical data.
High contrast in all parts of the image
Our scanning technology views content in grayscale. To improve tracking performance, consider viewing your image in grayscale to view the amount of contrast between different parts of an image.
Take note that in the image above, it is usually possible to see an orange tone in the water. This is not visible when the image is viewed in grayscale and therefore may be indistinguishable to the scanning technology.
Avoid the use of repetitive patterns
Repetitive patterns such as paragraphs of text or a checkerboard pattern can interfere with tracking performance.
Aspect Ratio
Keep to a width-to-height aspect ratio between 4:1 and 1:4 (0.25 or 4 if you divide your image's pixel height by width).
Make sure the image is also using a standardized resolution, for example 1024x512 px. A destandardized or odd value in either the width or the height can cause issues when training up the image.
Placed on a matte surface
Placing your image on a reflective surface can cause tracking instability.
Use the appropriate image tracking type for the surface
Placing a ‘Flat’ tracked image on a curved or conical surface can cause tracking instability. Instead, you should use the ‘Curved’ or ‘Conical’ image tracking type.
When using Curved or Conical image tracking types, make sure that your measurements are accurate to avoid possible displacement.
Guiding the user
It is important to guide the user when they are using Augmented Reality experiences, as this may be a new technology for them. The below factors will aid you to allow users to get the maximum value with their time in your experience:
Provide clear instructions
Clearly communicate to users how they can interact with the AR experience and how to position the tracked image correctly. This can be done on physical print, through on-screen instructions, tooltips, or an onboarding tutorial.
Handle when an image is not visible
Clearly convey what the user should do if the target image is no longer in view. This can be done by making tracked content screen relative, or by hiding content and asking the user to return the image in the camera view for example.
Consider the user’s environment
Different environmental factors can affect the experience. Try to control (or influence your user to control) factors such as the lighting or how far away the user is from the image itself.
For example, a well and evenly lit image is likely to be more stable when tracking than if the image was viewed in a dark room.