Library to pre-process scanned historical images for Structure from Motion (SfM) surface reconstruction and photogrammetric analysis.

• Download imagery from historical image archives
• Supported archives:
  • North American Glacier Photography (NAGAP)
  • USGS Earth Explorer

• Built-in application to create fiducial marker templates
• OpenCV template matching to detect fiducial marker coordinates
• Fiducial markers are detected at sub-pixel precision
• Can detect 4 midside and/or 4 corner fiducials
• Replaces poor matches with np.nan based on threshold
• Computes estimated principal point
• Quality Control
  • Outputs window image around detected fiducial marker for visual verification
  • Creates qc plots for fiducial coordinates and intersection angles before and after affine transformation

• Routines to detect proxy for midside fiducial markers, when actual fiducial markers are cropped out of image frame

• Computes affine transform between calibrated (true) fiducial marker coordinates and detected coordinates
• Affine transforms images
  • Requires minimum of 3 successfully detected fiducial markers to perform restitution
• Crops images about principal point to standard size
• Contrast Limited Adaptive Historgram Equalization (CLAHE) to improve match point detection during SfM processing

See notebooks for processing examples.

$ git clone https://github.com/friedrichknuth/hipp.git
$ cd ./hipp
$ conda env create -f environment.yml
$ conda activate hipp
$ pip install -e .

Bradski, G. (2000). "The OpenCV Library". Dr. Dobb's Journal of Software Tools.