diff --git a/Cargo.lock b/Cargo.lock
index 88537b3..de2bba7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -211,7 +211,7 @@ dependencies = [
  "bitflags 2.9.1",
  "cexpr",
  "clang-sys",
- "itertools 0.12.1",
+ "itertools 0.13.0",
  "log",
  "prettyplease",
  "proc-macro2",
@@ -504,6 +504,7 @@ dependencies = [
  "error-stack",
  "fast_image_resize",
  "image",
+ "itertools 0.14.0",
  "linfa",
  "mnn",
  "mnn-bridge",
@@ -512,6 +513,7 @@ dependencies = [
  "ndarray 0.16.1",
  "ndarray-image",
  "ndarray-resize",
+ "ordered-float",
  "rusqlite",
  "tap",
  "thiserror 2.0.12",
@@ -1487,6 +1489,15 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b4ce411919553d3f9fa53a0880544cda985a112117a0444d5ff1e870a893d6ea"
 
+[[package]]
+name = "ordered-float"
+version = "5.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2c1f9f56e534ac6a9b8a4600bdf0f530fb393b5f393e7b4d03489c3cf0c3f01"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "overload"
 version = "0.1.1"
diff --git a/Cargo.toml b/Cargo.toml
index eb6a62e..ea89789 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -51,6 +51,8 @@ mnn-bridge = { workspace = true }
 mnn-sync = { workspace = true }
 bounding-box = { version = "0.1.0", path = "bounding-box" }
 color = "0.3.1"
+itertools = "0.14.0"
+ordered-float = "5.0.0"
 
 [profile.release]
 debug = true
diff --git a/bounding-box/src/draw.rs b/bounding-box/src/draw.rs
index 6d8e044..1f97b2a 100644
--- a/bounding-box/src/draw.rs
+++ b/bounding-box/src/draw.rs
@@ -57,12 +57,17 @@ impl Drawable<Array3<u8>> for Aabb2<usize> {
         lines.into_iter().for_each(|line| {
             canvas
                 .roi_mut(line)
-                .expect("Failed to get Roi")
-                .lanes_mut(ndarray::Axis(2))
-                .into_iter()
-                .for_each(|mut pixel| {
-                    pixel.assign(&color);
-                });
+                .map(|mut line| {
+                    line.lanes_mut(ndarray::Axis(2))
+                        .into_iter()
+                        .for_each(|mut pixel| {
+                            pixel.assign(&color);
+                        })
+                })
+                .inspect_err(|e| {
+                    dbg!(e);
+                })
+                .ok();
         });
     }
 }
diff --git a/src/facedet/retinaface.rs b/src/facedet/retinaface.rs
index d0afe5d..6f36d24 100644
--- a/src/facedet/retinaface.rs
+++ b/src/facedet/retinaface.rs
@@ -1,5 +1,5 @@
 use crate::errors::*;
-use bounding_box::Aabb2;
+use bounding_box::{Aabb2, nms::nms};
 use error_stack::ResultExt;
 use mnn_bridge::ndarray::*;
 use nalgebra::{Point2, Vector2};
@@ -56,6 +56,7 @@ pub struct FaceDetection {
     handle: mnn_sync::SessionHandle,
 }
 
+#[derive(Debug, Clone, PartialEq)]
 pub struct FaceDetectionModelOutput {
     pub bbox: ndarray::Array3<f32>,
     pub confidence: ndarray::Array3<f32>,
@@ -63,6 +64,7 @@ pub struct FaceDetectionModelOutput {
 }
 
 /// Represents the 5 facial landmarks detected by RetinaFace
+#[derive(Debug, Copy, Clone, PartialEq)]
 pub struct FaceLandmarks {
     pub left_eye: Point2<f32>,
     pub right_eye: Point2<f32>,
@@ -70,14 +72,23 @@ pub struct FaceLandmarks {
     pub left_mouth: Point2<f32>,
     pub right_mouth: Point2<f32>,
 }
+
+#[derive(Debug, Clone, PartialEq)]
 pub struct FaceDetectionProcessedOutput {
     pub bbox: Vec<Aabb2<f32>>,
     pub confidence: Vec<f32>,
     pub landmarks: Vec<FaceLandmarks>,
 }
 
+#[derive(Debug, Clone, PartialEq)]
+pub struct FaceDetectionOutput {
+    pub bbox: Vec<Aabb2<usize>>,
+    pub confidence: Vec<f32>,
+    pub landmark: Vec<FaceLandmarks>,
+}
+
 impl FaceDetectionModelOutput {
-    pub fn postprocess(self, config: FaceDetectionConfig) -> Result<FaceDetectionProcessedOutput> {
+    pub fn postprocess(self, config: &FaceDetectionConfig) -> Result<FaceDetectionProcessedOutput> {
         let mut anchors = Vec::new();
         for (k, &step) in config.steps.iter().enumerate() {
             let feature_size = 640 / step;
@@ -204,7 +215,48 @@ impl FaceDetection {
         Ok(FaceDetection { handle })
     }
 
-    pub fn detect_faces(&self, image: ndarray::Array3<u8>) -> Result<FaceDetectionModelOutput> {
+    pub fn detect_faces(
+        &self,
+        image: ndarray::Array3<u8>,
+        config: FaceDetectionConfig,
+    ) -> Result<FaceDetectionOutput> {
+        let (height, width, channels) = image.dim();
+        let output = self
+            .run_models(image)
+            .change_context(Error)
+            .attach_printable("Failed to detect faces")?;
+        // denormalize the bounding boxes
+        let factor = Vector2::new(width as f32, height as f32);
+        let mut processed = output
+            .postprocess(&config)
+            .attach_printable("Failed to postprocess")?;
+
+        use itertools::Itertools;
+        let (boxes, scores, landmarks): (Vec<_>, Vec<_>, Vec<_>) = processed
+            .bbox
+            .iter()
+            .cloned()
+            .zip(processed.confidence.iter().cloned())
+            .zip(processed.landmarks.iter().cloned())
+            .sorted_by_key(|((_, score), _)| ordered_float::OrderedFloat(*score))
+            .map(|((b, s), l)| (b, s, l))
+            .multiunzip();
+
+        let boxes = nms(&boxes, &scores, config.threshold, config.nms_threshold);
+
+        let bboxes = boxes
+            .into_iter()
+            .flat_map(|x| x.denormalize(factor).try_cast::<usize>())
+            .collect();
+
+        Ok(FaceDetectionOutput {
+            bbox: bboxes,
+            confidence: processed.confidence,
+            landmark: processed.landmarks,
+        })
+    }
+
+    pub fn run_models(&self, image: ndarray::Array3<u8>) -> Result<FaceDetectionModelOutput> {
         #[rustfmt::skip]
         use ::tap::*;
         let output = self
diff --git a/src/main.rs b/src/main.rs
index 56973bb..6fe5ad8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -25,25 +25,15 @@ pub fn main() -> Result<()> {
                 .change_context(errors::Error)
                 .attach_printable("Failed to convert image to ndarray")?;
             let output = model
-                .detect_faces(array.clone())
+                .detect_faces(
+                    array.clone(),
+                    FaceDetectionConfig::default().with_threshold(detect.threshold),
+                )
                 .change_context(errors::Error)
                 .attach_printable("Failed to detect faces")?;
-            // output.print(20);
-            let faces = output
-                .postprocess(FaceDetectionConfig::default().with_threshold(detect.threshold))
-                .change_context(errors::Error)
-                .attach_printable("Failed to attach context")?;
-            for bbox in faces.bbox {
+            for bbox in output.bbox {
                 tracing::info!("Detected face: {:?}", bbox);
                 use bounding_box::draw::*;
-                let bbox = bbox
-                    .denormalize(nalgebra::SVector::<f32, 2>::new(
-                        array.shape()[1] as f32,
-                        array.shape()[0] as f32,
-                    ))
-                    .try_cast()
-                    .ok_or(errors::Error)
-                    .attach_printable("Failed to cast f32 to usize")?;
                 array.draw(bbox, color::palette::css::GREEN_YELLOW.to_rgba8(), 10);
             }
             let v = array.view();