diff --git a/src/binarizer.rs b/src/binarizer.rs
index fe8fb6f..791a3e0 100644
--- a/src/binarizer.rs
+++ b/src/binarizer.rs
@@ -16,7 +16,7 @@
 
 //package com.google.zxing;
 
-use std::{cell::RefCell, rc::Rc, borrow::Cow};
+use std::{rc::Rc, borrow::Cow};
 
 use crate::{
     common::{BitArray, BitMatrix},
diff --git a/src/binary_bitmap.rs b/src/binary_bitmap.rs
index b035452..5a92b95 100644
--- a/src/binary_bitmap.rs
+++ b/src/binary_bitmap.rs
@@ -16,7 +16,7 @@
 
 //package com.google.zxing;
 
-use std::{cell::RefCell, fmt, rc::Rc, borrow::Cow};
+use std::{fmt, rc::Rc, borrow::Cow};
 
 use crate::{
     common::{BitArray, BitMatrix},
@@ -47,14 +47,14 @@ impl BinaryBitmap {
      * @return The width of the bitmap.
      */
     pub fn getWidth(&self) -> usize {
-        return self.binarizer.getWidth();
+        self.binarizer.getWidth()
     }
 
     /**
      * @return The height of the bitmap.
      */
     pub fn getHeight(&self) -> usize {
-        return self.binarizer.getHeight();
+        self.binarizer.getHeight()
     }
 
     /**
diff --git a/src/common/global_histogram_binarizer.rs b/src/common/global_histogram_binarizer.rs
index baf134c..92330b3 100644
--- a/src/common/global_histogram_binarizer.rs
+++ b/src/common/global_histogram_binarizer.rs
@@ -20,7 +20,7 @@
 // import com.google.zxing.LuminanceSource;
 // import com.google.zxing.NotFoundException;
 
-use std::{cell::RefCell, rc::Rc, borrow::Cow};
+use std::{rc::Rc, borrow::Cow};
 
 use once_cell::unsync::OnceCell;
 
diff --git a/src/common/hybrid_binarizer.rs b/src/common/hybrid_binarizer.rs
index d4d89bf..58370b8 100644
--- a/src/common/hybrid_binarizer.rs
+++ b/src/common/hybrid_binarizer.rs
@@ -20,7 +20,7 @@
 // import com.google.zxing.LuminanceSource;
 // import com.google.zxing.NotFoundException;
 
-use std::{cell::RefCell, rc::Rc, borrow::Cow};
+use std::{rc::Rc, borrow::Cow};
 
 use once_cell::unsync::OnceCell;
 
diff --git a/src/helpers.rs b/src/helpers.rs
index 742f427..9553758 100644
--- a/src/helpers.rs
+++ b/src/helpers.rs
@@ -1,5 +1,4 @@
 use std::{
-    cell::RefCell,
     collections::{HashMap, HashSet},
     rc::Rc,
 };
diff --git a/src/multi/multi_test_case.rs b/src/multi/multi_test_case.rs
index 4e5e2a4..409d8a3 100644
--- a/src/multi/multi_test_case.rs
+++ b/src/multi/multi_test_case.rs
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-use std::{cell::RefCell, collections::HashSet, path::PathBuf, rc::Rc};
+use std::{collections::HashSet, path::PathBuf, rc::Rc};
 
 use crate::{
     common::HybridBinarizer, BarcodeFormat, BinaryBitmap, BufferedImageLuminanceSource,
diff --git a/src/multi/qrcode/qr_code_multi_reader.rs b/src/multi/qrcode/qr_code_multi_reader.rs
index 7fcb668..d97c345 100644
--- a/src/multi/qrcode/qr_code_multi_reader.rs
+++ b/src/multi/qrcode/qr_code_multi_reader.rs
@@ -222,7 +222,7 @@ mod multi_qr_code_test_case {
      * limitations under the License.
      */
 
-    use std::{cell::RefCell, collections::HashSet, path::PathBuf, rc::Rc};
+    use std::{collections::HashSet, path::PathBuf, rc::Rc};
 
     use image;
 
diff --git a/src/oned/rss/expanded/rss_expanded_image_2_binary_test_tase.rs b/src/oned/rss/expanded/rss_expanded_image_2_binary_test_tase.rs
index d637c0d..18e1a77 100644
--- a/src/oned/rss/expanded/rss_expanded_image_2_binary_test_tase.rs
+++ b/src/oned/rss/expanded/rss_expanded_image_2_binary_test_tase.rs
@@ -24,7 +24,7 @@
  *   http://www.piramidepse.com/
  */
 
-use std::{cell::RefCell, rc::Rc};
+use std::{rc::Rc};
 
 /**
  * @author Pablo Orduña, University of Deusto (pablo.orduna@deusto.es)
@@ -174,7 +174,7 @@ fn assertCorrectImage2binary(fileName: &str, expected: &str) {
     let path = format!("test_resources/blackbox/rssexpanded-1/{}", fileName);
 
     let image = image::open(path).expect("file exists");
-    let mut binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
+    let binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
         Box::new(BufferedImageLuminanceSource::new(image)),
     )));
     let rowNumber = binaryMap.getHeight() / 2;
diff --git a/src/oned/rss/expanded/rss_expanded_image_2_result_test_case.rs b/src/oned/rss/expanded/rss_expanded_image_2_result_test_case.rs
index 31c84ec..43a6e40 100644
--- a/src/oned/rss/expanded/rss_expanded_image_2_result_test_case.rs
+++ b/src/oned/rss/expanded/rss_expanded_image_2_result_test_case.rs
@@ -29,7 +29,7 @@
  *
  */
 
-use std::{cell::RefCell, collections::HashMap, rc::Rc};
+use std::{collections::HashMap, rc::Rc};
 
 use crate::{
     client::result::{ExpandedProductParsedRXingResult, ParsedClientResult},
@@ -71,7 +71,7 @@ fn assertCorrectImage2result(fileName: &str, expected: ExpandedProductParsedRXin
     let path = format!("test_resources/blackbox/rssexpanded-1/{}", fileName);
 
     let image = image::open(path).expect("image must exist");
-    let mut binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
+    let binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
         Box::new(BufferedImageLuminanceSource::new(image)),
     )));
     let rowNumber = binaryMap.getHeight() / 2;
diff --git a/src/oned/rss/expanded/rss_expanded_image_2_string_test_case.rs b/src/oned/rss/expanded/rss_expanded_image_2_string_test_case.rs
index 9e338fe..8a50910 100644
--- a/src/oned/rss/expanded/rss_expanded_image_2_string_test_case.rs
+++ b/src/oned/rss/expanded/rss_expanded_image_2_string_test_case.rs
@@ -24,7 +24,7 @@
  *   http://www.piramidepse.com/
  */
 
-use std::{cell::RefCell, collections::HashMap, rc::Rc};
+use std::{collections::HashMap, rc::Rc};
 
 use crate::{
     common::GlobalHistogramBinarizer,
@@ -184,7 +184,7 @@ fn assertCorrectImage2string(fileName: &str, expected: &str) {
     let path = format!("test_resources/blackbox/rssexpanded-1/{}", fileName);
 
     let image = image::open(path).expect("load image");
-    let mut binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
+    let binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
         Box::new(BufferedImageLuminanceSource::new(image)),
     )));
     let rowNumber = binaryMap.getHeight() / 2;
diff --git a/src/oned/rss/expanded/rss_expanded_internal_test_case.rs b/src/oned/rss/expanded/rss_expanded_internal_test_case.rs
index fa6ea83..45351e0 100644
--- a/src/oned/rss/expanded/rss_expanded_internal_test_case.rs
+++ b/src/oned/rss/expanded/rss_expanded_internal_test_case.rs
@@ -24,7 +24,7 @@
  *   http://www.piramidepse.com/
  */
 
-use std::{cell::RefCell, rc::Rc};
+use std::{rc::Rc};
 
 use crate::{
     common::GlobalHistogramBinarizer,
@@ -42,7 +42,7 @@ use super::RSSExpandedReader;
 #[test]
 fn testFindFinderPatterns() {
     let image = readImage("2.png");
-    let mut binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
+    let binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
         Box::new(BufferedImageLuminanceSource::new(image)),
     )));
     let rowNumber = binaryMap.getHeight() as u32 / 2;
@@ -88,7 +88,7 @@ fn testFindFinderPatterns() {
 #[test]
 fn testRetrieveNextPairPatterns() {
     let image = readImage("3.png");
-    let mut binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
+    let binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
         Box::new(BufferedImageLuminanceSource::new(image)),
     )));
     let rowNumber = binaryMap.getHeight() as u32 / 2;
@@ -116,7 +116,7 @@ fn testRetrieveNextPairPatterns() {
 #[test]
 fn testDecodeCheckCharacter() {
     let image = readImage("3.png");
-    let mut binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
+    let binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
         Box::new(BufferedImageLuminanceSource::new(image.clone())),
     )));
     let row = binaryMap
@@ -144,7 +144,7 @@ fn testDecodeCheckCharacter() {
 #[test]
 fn testDecodeDataCharacter() {
     let image = readImage("3.png");
-    let mut binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
+    let binaryMap = BinaryBitmap::new(Rc::new(GlobalHistogramBinarizer::new(
         Box::new(BufferedImageLuminanceSource::new(image.clone())),
     )));
     let row = binaryMap
diff --git a/src/oned/rss/expanded/rss_expanded_stacked_internal_test_case.rs b/src/oned/rss/expanded/rss_expanded_stacked_internal_test_case.rs
index ef304fd..4f0c756 100644
--- a/src/oned/rss/expanded/rss_expanded_stacked_internal_test_case.rs
+++ b/src/oned/rss/expanded/rss_expanded_stacked_internal_test_case.rs
@@ -36,7 +36,7 @@ use super::{test_case_util, RSSExpandedReader};
 fn testDecodingRowByRow() {
     let mut rssExpandedReader = RSSExpandedReader::new();
 
-    let mut binaryMap = test_case_util::getBinaryBitmap("1000.png");
+    let binaryMap = test_case_util::getBinaryBitmap("1000.png");
 
     let firstRowNumber = binaryMap.getHeight() / 3;
     let firstRow = binaryMap.getBlackRow(firstRowNumber).expect("get row");
diff --git a/src/oned/rss/expanded/test_case_util.rs b/src/oned/rss/expanded/test_case_util.rs
index 472d231..57cb248 100644
--- a/src/oned/rss/expanded/test_case_util.rs
+++ b/src/oned/rss/expanded/test_case_util.rs
@@ -24,7 +24,7 @@
  *   http://www.piramidepse.com/
  */
 
-use std::{cell::RefCell, rc::Rc};
+use std::{rc::Rc};
 
 use image::DynamicImage;
 
diff --git a/tests/common/abstract_black_box_test_case.rs b/tests/common/abstract_black_box_test_case.rs
index 9e8134e..8e3a2c7 100644
--- a/tests/common/abstract_black_box_test_case.rs
+++ b/tests/common/abstract_black_box_test_case.rs
@@ -16,7 +16,6 @@
  */
 
 use std::{
-    cell::RefCell,
     collections::HashMap,
     fs::{read_dir, read_to_string, File},
     io::Read,
diff --git a/tests/common/pdf_417_multiimage_span.rs b/tests/common/pdf_417_multiimage_span.rs
index 89c97e7..80bb9de 100644
--- a/tests/common/pdf_417_multiimage_span.rs
+++ b/tests/common/pdf_417_multiimage_span.rs
@@ -16,7 +16,6 @@
  */
 
 use std::{
-    cell::RefCell,
     collections::HashMap,
     fs::{read_dir, read_to_string, File},
     io::Read,