Log in or register to post comments

Target Scanning gets failure randomly even for 5 star image with good lighting condition.

February 13, 2019 - 6:35am #1

Vuforia SDK Version: 5.0.10 -

Description with steps to reproduce: Even though we have good light atmosphere, Image rating in 5 and wifi is connected. While doing scanning, either scan gets failure (keep on scanning, no response) or if scanned content is loading, its not loading on the top of the target (loads some where). Please advice how to achieve successful scanning followed by loading of content on the exact target. -

Development OS (Mac OS X, Windows, Linux): Mac OS -

Mobile OS and Version: iPhone 7 - 12.1.4

Mobile Device Manufacturer and Model name: Apple -

Do the Vuforia Sample Applications show the same behavior?:

Target Scanning gets failure randomly even for 5 star image with good lighting condition.

February 15, 2019 - 1:43pm #4

Hello,

rajeshins wrote:

1. Could you be more detail on the below point, also let me know what is the recommended value for the Size Value

"Check the size values you are using when uploading Targets to the Vuforia Target Manager. Note there is specific language used in the dialogue box that says Vuforia uses meters as the default unit scale. Incorrect target sizes could affect either our detection/tracking algorithm".

The size is specified in meters. This is the same scale that is used in the Unity Editor. Targets that are a different sizes, or printed in the wrong aspect ratio, may failed to be detected or perform poorly.

Please review this article: https://library.vuforia.com/articles/Solution/Optimizing-Target-Detection-and-Tracking-Stability

rajeshins wrote:

2. We are printing the target in oil printing sheets which is used for the Brochure, we felt the scanning fails frequently. What we should do to get perfect scanning and loading of content on the exact target.

Addressed in the article above.

rajeshins wrote:

3. spectral reflections - to avoid this what we should do.

Normally, we recommend against glossy prints as they can induce spectral reflections. However, for 2D image tracking, Vuforia tends to be very robust to this once detection has been established.

Thanks,

Vuforia Engine Support

Target Scanning gets failure randomly even for 5 star image with good lighting condition.

February 14, 2019 - 10:40pm #3

Hello,

Thanks for the reply, it would be great if you could answer the below queries,

1. Could you be more detail on the below point, also let me know what is the recommended value for the Size Value

"Check the size values you are using when uploading Targets to the Vuforia Target Manager. Note there is specific language used in the dialogue box that says Vuforia uses meters as the default unit scale. Incorrect target sizes could affect either our detection/tracking algorithm".

2. We are printing the target in oil printing sheets which is used for the Brochure, we felt the scanning fails frequently. What we should do to get perfect scanning and loading of content on the exact target.

3. spectral reflections - to avoid this what we should do.

Target Scanning gets failure randomly even for 5 star image with good lighting condition.

February 13, 2019 - 11:45am #2

Hello,

The star rating provides a heuristic analysis of the given target, but does not necessarily represent the actual run time detection and/or tracking performance. It is to provide some level of feedback to help guide developers to optimize their targets.

Here is some guidance on optimizing targets: https://library.vuforia.com/articles/Solution/Optimizing-Target-Detection-and-Tracking-Stability

Some additional tips:

  1. Always print the image that was uploaded to the portal to the exact same aspect ratio. Any stretching or altering of the image may cause tracking pose jitter. Some printers default to "stretch to fit", which can change the aspect ratio.
  2. Check the size values you are using when uploading Targets to the Vuforia Target Manager. Note there is specific language used in the dialogue box that says Vuforia uses meters as the default unit scale. Incorrect target sizes could affect either our detection/tracking algorithm
  3. Image Targets must be flat when in the camera's field of view
  4. Not enough lighting upon, and/or spectral reflections occluding the Image Target

Thanks,

Vuforia Engine Support

Log in or register to post comments