The following items may be affecting detection accuracy:
Issue
Possible Solution
Lens & Perspective Distortion
Warped or tilted edges prevent exact border detection. Scan target cards using free perspective-flattening scanning apps:
Camera Angle
Sharp shooting angles cause perspective stretching. Keep your phone parallel to the target card face.
Glare & Warm Lighting
Direct glares, hard shadows, or very yellow lighting throws off detection. Use bright, uniform, indirect daylight.
Border Cutoff or Overlap
Tape, staples, or objects overlapping margins block auto-boundary scans. Keep card borders clear and fully visible.
