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. 2025 Sep 10;25(18):5648. doi: 10.3390/s25185648

Algorithm 1: GrassRemoval

(P)

: Grass removal from point cloud P

1:
procedure GrassRemoval(P)
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Rotate P about Z and Y axes to align vertically.
3:
if $| P_{z, m a x} - P_{z, m i n} | > 1.5$ m then
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Flag P as Potential_Grass
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$B \leftarrow {p \in P ∣ p_{y} < P_{y, m i n} + 0.6 m}$
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$P l a n e s \leftarrow \emptyset$
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while $| B | \geq 30$ do
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$(π, Inliers) \leftarrow$ RANSAC_Plane_Segment(B)
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if $| π | < 30$ then
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break
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end if
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$θ \leftarrow$ angle between normal of $π$ and Y-axis
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if $θ \leq 35^{\circ}$ then
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$P l a n e s \leftarrow P l a n e \cup {π}$
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end if
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$B \leftarrow B ∖ Inliers$
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end while
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if $P l a n e s \neq \emptyset$ then
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$π_{main} \leftarrow$ plane in $P l a n e s$ with maximum number of points
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$B \leftarrow {p \in P ∣ p_{y} < P_{y, m i n} + 0.7 m}$
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$G \leftarrow \emptyset$
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for all $p \in$ B do
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$d \leftarrow$ distance from p to $π_{main}$
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if $d \leq 0.35$ m then
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$G \leftarrow G \cup {p}$
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end if
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end for
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$P_{c l e a n} \leftarrow P ∖ G$
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return $P_{clean}$
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else
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$B \leftarrow {p \in P ∣ p_{y} < P_{y, m i n} + 0.6 m}$
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$T \leftarrow {p \in P ∣ p_{y} > P_{y, m i n} + 0.6 m}$
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$z_{min}^{T} \leftarrow min {p_{z} ∣ p \in T}$
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$G \leftarrow {p \in B ∣ p_{z} < z_{min}^{T}}$
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$P_{clean} \leftarrow P ∖ G$
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return $P_{clean}$
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end if
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else
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return P ▹ No preprocessing needed
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end if
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end procedure