diff --git a/src/ledwand_dither.rs b/src/ledwand_dither.rs
index 95ffe02..c1caed4 100644
--- a/src/ledwand_dither.rs
+++ b/src/ledwand_dither.rs
@@ -1,6 +1,7 @@
 //! Based on https://github.com/WarkerAnhaltRanger/CCCB_Ledwand
 
 use image::GrayImage;
+use log::debug;
 use servicepoint::{Bitmap, DisplayBitVec, PIXEL_HEIGHT};
 
 type GrayHistogram = [usize; 256];
@@ -173,6 +174,7 @@ pub(crate) fn ostromoukhov_dither(source: GrayImage, bias: u8) -> Bitmap {
 
     for y in 0..height as usize {
         let start = y * width as usize;
+        let last_row = y == (height - 1) as usize;
         if y % 2 == 0 {
             for x in start..start + width as usize {
                 ostromoukhov_dither_pixel(
@@ -180,7 +182,7 @@ pub(crate) fn ostromoukhov_dither(source: GrayImage, bias: u8) -> Bitmap {
                     &mut destination,
                     x,
                     width as usize,
-                    y == (height - 1) as usize,
+                    last_row,
                     1,
                     bias,
                 );
@@ -192,7 +194,7 @@ pub(crate) fn ostromoukhov_dither(source: GrayImage, bias: u8) -> Bitmap {
                     &mut destination,
                     x,
                     width as usize,
-                    y == (height - 1) as usize,
+                    last_row,
                     -1,
                     bias,
                 );
@@ -217,8 +219,16 @@ fn ostromoukhov_dither_pixel(
     destination.set(position, destination_value);
 
     let mut diffuse = |to: usize, mat: i16| {
-        let diffuse_value = source[to] as i16 + mat;
-        source[to] = diffuse_value.clamp(u8::MIN.into(), u8::MAX.into()) as u8;
+        match source.get(to) {
+            None => {
+                // last row has a out of bounds error on the last pixel
+                // TODO fix the iter bounds instead of ignoring here
+            }
+            Some(val) => {
+                let diffuse_value = *val as i16 + mat;
+                source[to] = diffuse_value.clamp(u8::MIN.into(), u8::MAX.into()) as u8;
+            }
+        };
     };
 
     let lookup = if destination_value {
@@ -229,11 +239,14 @@ fn ostromoukhov_dither_pixel(
     diffuse((position as isize + direction) as usize, lookup[0]);
 
     if !last_row {
+        debug!("begin");
         diffuse(
             ((position + width) as isize - direction) as usize,
             lookup[1],
         );
+        debug!("mit");
         diffuse(((position + width) as isize) as usize, lookup[2]);
+        debug!("end");
     }
 }
 
diff --git a/src/main.rs b/src/main.rs
index a485526..cdae13c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -7,7 +7,7 @@ use crate::{
 };
 use clap::Parser;
 use log::debug;
-use servicepoint::{Brightness, HardResetCommand, UdpSocketExt};
+use servicepoint::{Brightness, HardResetCommand};
 
 mod brightness;
 mod cli;