diff --git a/src/ledwand_dither.rs b/src/ledwand_dither.rs
index c1caed4..9f3a634 100644
--- a/src/ledwand_dither.rs
+++ b/src/ledwand_dither.rs
@@ -1,7 +1,7 @@
 //! Based on https://github.com/WarkerAnhaltRanger/CCCB_Ledwand
 
 use image::GrayImage;
-use log::debug;
+use log::error;
 use servicepoint::{Bitmap, DisplayBitVec, PIXEL_HEIGHT};
 
 type GrayHistogram = [usize; 256];
@@ -174,7 +174,6 @@ 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(
@@ -182,7 +181,7 @@ pub(crate) fn ostromoukhov_dither(source: GrayImage, bias: u8) -> Bitmap {
                     &mut destination,
                     x,
                     width as usize,
-                    last_row,
+                    y == (height - 1) as usize,
                     1,
                     bias,
                 );
@@ -194,7 +193,7 @@ pub(crate) fn ostromoukhov_dither(source: GrayImage, bias: u8) -> Bitmap {
                     &mut destination,
                     x,
                     width as usize,
-                    last_row,
+                    y == (height - 1) as usize,
                     -1,
                     bias,
                 );
@@ -221,8 +220,7 @@ fn ostromoukhov_dither_pixel(
     let mut diffuse = |to: usize, mat: i16| {
         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
+                error!("ostromoukhov_dither_pixel - invalid index {to}");
             }
             Some(val) => {
                 let diffuse_value = *val as i16 + mat;
@@ -239,14 +237,11 @@ 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");
     }
 }