Final steps in Stereo Stereoscopic reconstruction for good result?

I feel like I’m so close to nailing the whole process having gone through every step individually and tested many permutations.

However I have 2 remaining issues to resolve and wonder if anyone has experience fine tuning the output with this process to get a quality elevation map. First is how to clear up the noise within the output raster, and the other is related to preventing the steep drop off at the shoreline - see all the steps listed and example of the issue on screen caps at the bottom:

Extract ROI:
Left Image:

otbcli_ExtractROI \
-in D:/stereo/16JUN18143623-P1BS-057461431010_01_P001.TIF \
-out D:/14_10_19/stereo_test_2_small_L.tif uint16
-startx -5.16675
-starty 57.90735
-sizex 8192
-sizey 8192

Having extracted Left I then used the ‘fit’ feature of ExtractROI process to get the Right image:

otbcli_ExtractROI \
-in D:/stereo/16JUN18143537-P1BS-057461431010_01_P001.TIF
-out D:/14_10_19/stereo_test_1_small_R.tif float
-mode fit
-mode.fit.im D:/14_10_19/stereo_test_2_small_L.tif
-ram 128

Stereo Rectification Grid Generator:

otbcli_StereoRectificationGridGenerator
-io.inleft D:/14_10_19/stereo_test_2_small_L.tif
-io.inright D:/14_10_19/stereo_test_1_small_R.tif
-epi.elevation.dem D:/dem/opentopo
-io.outleft D:/14_10_19/31_grid_stereo_test_2_small_L.tif
-io.outright D:/14_10_19/31_grid_stereo_test_1_small_R.tif

Grid Based Image Resampling:

Left Image:

otbcli_GridBasedImageResampling
-io.in D:/14_10_19/stereo_test_2_small_L.tif
-io.out D:/14_10_19/31_epi_stereo_test_2_small_L.tif
-grid.in D:/14_10_19/31_grid_stereo_test_2_small_L.tif
-out.sizex 10220
-out.sizey 10220

Right Image:

otbcli_GridBasedImageResampling -io.in D:/14_10_19/stereo_test_1_small_R2.tif -io.out D:/14_10_19/31_epi_stereo_test_1_small_R.tif
-grid.in D:/14_10_19/31_grid_stereo_test_1_small_R.tif
-out.sizex 10220
-out.sizey 10220

Block matching:

otbcli_BlockMatching
-io.inleft D:/14_10_19/31_epi_stereo_test_2_small_L.tif
-io.inright D:/14_10_19/31_epi_stereo_test_1_small_R.tif
-io.out D:/14_10_19/31_disparity_map_3_1.tif
-bm.minhd -279
-bm.maxhd -75
-bm.minvd -1
-bm.maxvd 1
-mask.nodata 0
-mask.variancet 50
-io.outmetric 1
-bm.metric ncc
-bm.medianfilter.radius 10
-bm.medianfilter.incoherence 2.0

Disparity Map To Elevation Map:

otbcli_DisparityMapToElevationMap
-io.in D:/14_10_19/31_disparity_map_3_1.tif
-io.left D:/14_10_19/stereo_test_2_small_L.tif
-io.right D:/14_10_19/stereo_test_1_small_R.tif
-io.lgrid D:/14_10_19/31_grid_stereo_test_2_small_L.tif
-io.rgrid D:/14_10_19/31_grid_stereo_test_1_small_R.tif
-io.out D:/14_10_19/31_disparity_map_to_elevation_3_1.tif
-hmin 0
-hmax 286
-step 2
-elev.dem D:/dem/opentopo

The median filter seems to clear most of the noise, but I’m left with these patches, they seem to be linked to large flat area’s with little variation in shadows, some at the highest position on the terrain some at the lowest:

And this clearly shows the noise but also the shoreline drop off:

I haven’t tried referencing a geoid file at the Stereo Rectification Grid Generator step yet, but I gave it DEM folder option so thought that was enough to clarify sea height?

I think I have resolved 1 of my issues - ‘steep drop off at shoreline’

Seems that adding a geoid file into the Stereo Rectification Grid Generator step did indeed get rid of the big drop to sea level.

Previous attempt without the geoid file referenced had sea at 0mtr, but caused steep drop off on shoreline:

Latest attempt referencing geoid file, has sea at 55mtr but smooth transition from shore to sea:

Shoreline looks fine, however I still can’t figure out how to resolve the noise spikes from output?

I’m not sure why sea has to be at 55mtr for this to work as expected?