basic working otsu number binarizer

Cargo.toml

@@ -59,4 +59,7 @@ wasm_support = ["chrono/wasmbind"]
 experimental_features = []
 
 #/// Adds support for serde Serialize and Deserialize for outward facing structs
-serde = ["dep:serde"]
+serde = ["dep:serde"]
+
+#/// Adds otsu binarizer support using imageproc
+otsu_level = ["image"]

src/common/bit_matrix.rs

@@ -709,6 +709,22 @@ impl fmt::Display for BitMatrix {
     }
 }
 
+#[cfg(feature = "image")]
+/// This should only be used if you *know* that the `DynamicImage` is binary.
+impl TryFrom<image::DynamicImage> for BitMatrix {
+    type Error = Exceptions;
+
+    fn try_from(value: image::DynamicImage) -> Result<Self, Self::Error> {
+        let mut new_bitmatrix = BitMatrix::new(value.width(), value.height())?;
+        for (x, y, value) in value.as_luma8().unwrap().enumerate_pixels() {
+            if value.0[0] != u8::MAX {
+                new_bitmatrix.set(x, y)
+            }
+        }
+        Ok(new_bitmatrix)
+    }
+}
+
 #[cfg(feature = "image")]
 impl From<BitMatrix> for image::DynamicImage {
     fn from(value: BitMatrix) -> Self {

src/common/mod.rs

@@ -103,3 +103,8 @@ pub use global_histogram_binarizer::*;
 
 mod hybrid_binarizer;
 pub use hybrid_binarizer::*;
+
+#[cfg(feature = "otsu_level")]
+mod otsu_level_binarizer;
+#[cfg(feature = "otsu_level")]
+pub use otsu_level_binarizer::*;

src/common/otsu_level_binarizer.rs

@@ -0,0 +1,85 @@
+use std::{borrow::Cow, rc::Rc};
+
+use image::{DynamicImage, ImageBuffer, Luma};
+use once_cell::sync::OnceCell;
+
+use crate::{Binarizer, Exceptions, LuminanceSource};
+
+use super::{BitArray, BitMatrix};
+
+pub struct OtsuLevelBinarizer {
+    width: usize,
+    height: usize,
+    source: Box<dyn LuminanceSource>,
+    black_matrix: OnceCell<BitMatrix>,
+    black_row_cache: Vec<OnceCell<BitArray>>,
+}
+
+impl OtsuLevelBinarizer {
+    fn generate_threshold_matrix(source: &dyn LuminanceSource) -> Result<BitMatrix, Exceptions> {
+        let image_buffer = {
+            let Some(buff) : Option<ImageBuffer<Luma<u8>,Vec<u8>>> = ImageBuffer::from_vec(source.getWidth() as u32, source.getHeight() as u32, source.getMatrix()) else {
+                return Err(Exceptions::IllegalArgumentException(None))
+            };
+            buff
+        };
+
+        let otsu_level = imageproc::contrast::otsu_level(&image_buffer);
+
+        let filtered_iamge = imageproc::contrast::threshold(&image_buffer, otsu_level);
+
+        let dynamic_filtered = DynamicImage::from(filtered_iamge);
+
+        dynamic_filtered.try_into()
+    }
+
+    pub fn new(source: Box<dyn LuminanceSource>) -> Self {
+        Self {
+            width: source.getWidth(),
+            height: source.getHeight(),
+            black_row_cache: vec![OnceCell::default(); source.getHeight() as usize],
+            source,
+            black_matrix: OnceCell::new(),
+        }
+    }
+}
+
+impl Binarizer for OtsuLevelBinarizer {
+    fn getLuminanceSource(&self) -> &Box<dyn crate::LuminanceSource> {
+        &self.source
+    }
+
+    fn getBlackRow(
+        &self,
+        y: usize,
+    ) -> Result<std::borrow::Cow<super::BitArray>, crate::Exceptions> {
+        let row = self.black_row_cache[y].get_or_try_init(|| {
+            let matrix = self.getBlackMatrix()?;
+            Ok(matrix.getRow(y as u32))
+        })?;
+
+        Ok(Cow::Borrowed(row))
+    }
+
+    fn getBlackMatrix(&self) -> Result<&super::BitMatrix, crate::Exceptions> {
+        let matrix = self
+            .black_matrix
+            .get_or_try_init(|| Self::generate_threshold_matrix(self.source.as_ref()))?;
+        Ok(matrix)
+    }
+
+    fn createBinarizer(
+        &self,
+        source: Box<dyn crate::LuminanceSource>,
+    ) -> std::rc::Rc<dyn Binarizer> {
+        Rc::new(Self::new(source))
+    }
+
+    fn getWidth(&self) -> usize {
+        self.width
+    }
+
+    fn getHeight(&self) -> usize {
+        self.height
+    }
+}

src/luminance_source.rs

@@ -16,6 +16,8 @@
 
 //package com.google.zxing;
 
+use std::any::Any;
+
 use crate::Exceptions;
 
 /**