diff --git a/src/hand_tracking.rs b/src/hand_tracking.rs
new file mode 100644
index 0000000..869d41a
--- /dev/null
+++ b/src/hand_tracking.rs
@@ -0,0 +1,66 @@
+use std::{
+	fs,
+	time::Instant,
+};
+
+pub fn main () {
+	let src_width = 1280usize;
+	let src_height = 720usize;
+	let src_stride = 3 * src_width;
+	
+	let path = "untracked/input.jpg";
+	let jpeg_buf = fs::read (path).unwrap ();
+	
+	let rgb = {
+		let start = Instant::now ();
+		
+		let mut decoder = zune_jpeg::JpegDecoder::new_with_options (&jpeg_buf, zune_core::options::DecoderOptions::new_fast().jpeg_set_out_colorspace(zune_core::colorspace::ColorSpace::RGB));
+		decoder.decode_headers().unwrap ();
+		
+		let info = decoder.info ().unwrap ();
+		assert_eq! (src_width, usize::try_from (info.width).unwrap ());
+		assert_eq! (src_height, usize::try_from (info.height).unwrap ());
+		
+		let mut rgb = vec! [0u8; decoder.output_buffer_size ().unwrap ()];
+		assert_eq! (rgb.len (), src_stride * src_height);
+		decoder.decode_into (&mut rgb).unwrap ();
+		
+		let stop = Instant::now ();
+		println! ("Decoded in {} ms", (stop - start).as_millis ());
+		rgb
+	};
+	
+	let dst_width = src_width / 8;
+	let dst_height = src_height / 8;
+	let dst_stride = dst_width;
+	
+	{
+		let start = Instant::now ();
+		
+		let mut buf = vec! [0u8; dst_width * dst_height];
+		
+		for y in 0..dst_height {
+			for x in 0..dst_width {
+				let dst_i = y * dst_stride + x;
+				let src_i = y * 8 * src_stride + x * 8 * 3;
+				
+				let r = rgb [src_i + 0];
+				let g = rgb [src_i + 1];
+				let b = rgb [src_i + 2];
+				
+				let x = 
+				r
+				.saturating_sub (g)
+				.saturating_add (r)
+				.saturating_sub (b);
+				
+				buf [dst_i] = x;
+			}
+		}
+		
+		let stop = Instant::now ();
+		println! ("Shrank and filtered in {} ms", (stop - start).as_millis ());
+		
+		fs::write ("untracked/skin_filter.data", &buf).unwrap ();
+	}
+}
diff --git a/src/main.rs b/src/main.rs
index 37f38a6..568a61e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -16,6 +16,7 @@ use tokio::sync::
 mod capture;
 mod controller;
 mod driver;
+mod hand_tracking;
 
 use driver::
 {
@@ -52,6 +53,7 @@ fn main() -> Result <(), Error>
             
             println! ("{} ms", (stop - start).as_millis ());
         },
+        Some ("hand-tracking") => hand_tracking::main (),
         Some ("network") => main_network (),
         Some (_) => eprintln! ("Unknown subcommand"),
     }