réseau grid

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réseau grid#

To help re-sample images to a common format, and to correct some of the distortion in the images caused by film storage, spymicmac.matching() includes a routine to automatically find the réseau markers in the image and use their locations to resample the images using spymicmac.resample.resample_hex().

In the images below, you can see the difference between the expected location of each réseau marker and the automatically detected locations:

a KH-9 image with the Reseau field warping shown


To run the routine, use either spymicmac.matching.find_reseau_grid() or find_reseau_grid. This will produce a MeasuresIm file that will be read by spymicmac.resample.resample_hex().

Note

Before running spymicmac.resample.resample_hex(), you will also need to run spymicmac.micmac.generate_measures_files() (or generate_measures_files) in order to generate the MeasuresCamera.xml file needed, then move MeasuresCamera.xml to the Ori-InterneScan directory in the correct folder.

If you are running these steps using spymicmac.preprocessing.preprocess_kh9_mc() or preprocess_kh9_mc, these files will be automatically generated.

cross removal#

Once you have found the Reseau marks in each image half, you can “remove” the Reseau marks using either spymicmac.matching.remove_crosses() or remove_crosses.

an image showing a Reseau mark on the left, and the Reseau mark erased on the right.


After this step, you can use resample_hexagon.

Tip

Because mm3d ReSampFid calculates an affine transform based on the fiducial marker locations, it does not actually correct the image using the marker locations. For KH-9 Mapping Camera images, it’s better to use resample_hexagon.

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