Registration fails depending on final deformation setting

[christianrickert]

I have observed a seemingly erratic behavior when performing a registration with bUwarpJ:

Example files:

source.tif target.tif

Notice that all registrations without prior MOPS correspondence extraction fail, i.e. are significantly offset, for the given image pair. The registrations with prior MOPS fail only for final_deformation settings of Fine, Very Fine, and Super Fine. However, the registration with the Coarse setting yields a reasonable result. Please see example macro:

// Runs an image registration using bUnwarpJ with two images of the same FoV
// with different final_deformation settings.

// toggle MOPS correspondence extraction
with_MOPS = false;

// load source and target images
open("source.tif");
run("Enhance Contrast", "saturated=0.35");  // improves MOPS performance
open("target.tif");
run("Enhance Contrast", "saturated=0.35");

if ( with_MOPS ) {
    // identify registration points
    run("Extract MOPS Correspondences",
        "source_image=target.tif " +
        "target_image=source.tif " +
        "initial_gaussian_blur=1.60 " +
        "steps_per_scale_octave=3 " +
        "minimum_image_size=64 " +
        "maximum_image_size=3744 " +
        "feature_descriptor_size=16 " +
        "closest/next_closest_ratio=0.92 " +
        "maximal_alignment_error=" + 0.1 * 3744 + " " +
        "inlier_ratio=0.05 " +
        "expected_transformation=Rigid");
}

// perform registration with different final deformations
final_deformations = newArray("Coarse", "Fine", "Very Fine", "Super Fine");
for ( i = 0; i < final_deformations.length; i++ ) {
  run("bUnwarpJ", "source_image=source.tif " +
                  "target_image=target.tif " +
                  "registration=Mono " +
                  "image_subsample_factor=0 " +
                  "initial_deformation=[Very Coarse] " +
                  "final_deformation=[" + final_deformations[i] +"] " +
                  "divergence_weight=0 " +
                  "curl_weight=0 " +
                  "landmark_weight=0 " +
                  "image_weight=1 " +
                  "consistency_weight=10 " +
                  "stop_threshold=0.01");
  selectWindow("Registered Source Image");
  if ( with_MOPS ) {
    rename("MOPS + [" + final_deformations[i] + "] - Registered Source Image");
  } else {
    rename("[" + final_deformations[i] + "] - Registered Source Image");
  }
}

This observation could be related to issue #13.

Software:

• ImageJ 1.53s
• bUnwarpJ 2.6.13
• Windows 10.0.19044.1826