Knowledge Base

Problem

A user attempts to manually add a paw print that was not detected by the system using the 'Add' button in the Classify Runs view, but the box does not save or the print cannot be added.

Details

The 'Add Print' function in CatWalk XT Classify Runs is frequently misunderstood. It cannot create a print that was never detected within the system's intensity threshold range — it only allows relabeling or adjusting prints that were already detected. If a paw contact produced insufficient light reflection (below threshold), no data exists to add. Affects all CatWalk XT versions.

Solution

1. **Understand the limitation:** The 'Add Print' option in the Classify Runs interface does **not** allow you to add a paw print that was not detected during acquisition (i.e., that did not meet the Green Intensity Threshold). No amount of drawing a rectangle will save a print for data that was not captured.
2. **For prints that were detected but mislabeled or unlabeled:** Draw a rectangle over the visible print area in the print view, then select the correct label (LF, RF, LH, RH) from the label options. This will save correctly.
3. **For consistently missing prints:** The root cause is insufficient signal during acquisition. Adjust the Detection Settings (lower the Green Intensity Threshold or increase Gain) so the system captures those paw contacts in future runs. See also the article on auto-classification failures.
4. **For runs already acquired with missing prints:** Those runs may need to be repeated with corrected detection settings, or analyzed with the caveat that one paw's data is absent.