opencv dimension_error ai_generated true

cv2.error: (-209:Sizes of input arguments do not match)

ID: opencv/size-mismatch

Also available as: JSON · Markdown
92%Fix Rate
92%Confidence
3Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
4 active — — —

Root Cause

Two Mats have different dimensions. Common with addWeighted, bitwise_and, absdiff.

generic

Workarounds

  1. 95% success Resize one image to match the other 
    img2 = cv2.resize(img2, (img1.shape[1], img1.shape[0]))  # (width, height)

    Sources: https://docs.opencv.org/4.x/

  2. 90% success Check shapes before operation 
    assert img1.shape[:2] == img2.shape[:2], f'{img1.shape} vs {img2.shape}'
  3. 82% success Use ROI to extract matching regions

Dead Ends

Common approaches that don't work:

  1. Pad smaller image with zeros 68% fail

    Zero-padding changes content and produces artifacts; resize is usually correct

  2. Crop both to minimum overlapping region without checking alignment 72% fail

    Cropping without spatial relationship gives meaningless results