AutoMask_over_reflective_water.md

Auto mask over water

/!\ Works with ImageMagick 6 & 7

Apply thin mask according to surexposition

convert DJI_0514.JPG -fuzz 20% -transparent white -alpha extract -negate DJI_0514_maskn.JPG 

Densify 1/2 mask using disk shape

convert DJI_0514_maskn.JPG -morphology Dilate Disk DJI_0514_dilated_disk.JPG

Densify 2/2 using Octagon shape

convert DJI_0514_dilated_disk.JPG -morphology Dilate Octagon DJI_0514_dilated_disk_then_octagon.JPG

Reverse image to match photogrammetry mask

convert -negate DJI_0514_dilated_disk_then_octagon.JPG DJI_0514_mask.png

Automated bash script:

#!/bin/bash
for i in *.JPG;
  do
    convert $i -fuzz 20% -transparent white -alpha extract -negate ${i%.JPG}_maskn.JPG
    convert ${i%.JPG}_maskn.JPG -morphology Dilate Disk ${i%.JPG}_dilated_disk.JPG
    convert ${i%.JPG}_dilated_disk.JPG -morphology Dilate Octagon ${i%.JPG}_dilated_disk_then_octagon.JPG
    convert -negate ${i%.JPG}_dilated_disk_then_octagon.JPG ${i%.JPG}_mask.png
    rm *maskn*
    rm *dilated*
done