diff --git a/src/lib.rs b/src/lib.rs
index 979abad..fdd39d5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -39,10 +39,8 @@ pub fn add_tiles(game_data: String, image: String, prefix: String) -> String {
     let height = image.height();
     assert_eq!(width  % 8, 0);
     assert_eq!(height % 8, 0);
-    let columns = (width  as f64 / 8 as f64).floor() as u32;
-    let rows    = (height as f64 / 8 as f64).floor() as u32;
-
-    // todo iterate over 8x8 tiles in image
+    let columns = (width  as f64 / 8.).floor() as u32;
+    let rows    = (height as f64 / 8.).floor() as u32;
 
     let mut tile_index = 1;
 
@@ -53,7 +51,7 @@ pub fn add_tiles(game_data: String, image: String, prefix: String) -> String {
             for y in (row * SD)..((row + 1) * SD) {
                 for x in (column * SD)..((column + 1) * SD) {
                     let pixel = image.get_pixel(x, y).to_rgb();
-                    let total: u32 = (pixel[0] as u32 + pixel[1] as u32 + pixel[2] as u32) as u32;
+                    let total = pixel[0] as u32 + pixel[1] as u32 + pixel[2] as u32;
                     // is each channel brighter than 128/255 on average?
                     pixels.push(if total >= 384 {1} else {0});
                 }