diff --git a/src/descriptors/dct.rs b/src/descriptors/dct.rs
index b399554..ab00797 100644
--- a/src/descriptors/dct.rs
+++ b/src/descriptors/dct.rs
@@ -38,7 +38,7 @@ impl DCT {
         self
     }
 
-    fn dct(&self, img: image::DynamicImage) -> [f64; 64] {
+    fn dct(&self, img: &image::DynamicImage) -> [f64; 64] {
         let mut dct_values: [f64; 64] = [0.0; 64];
         for u in 0..8 {
             for v in 0..8 {
@@ -102,8 +102,8 @@ impl DCT {
 
 impl Descriptor for DCT {
     fn describe(&self, img: image::DynamicImage) -> u64 {
-        let img = self.resize(img);
-        let mut dct_values = self.dct(img);
+        let resized = self.resize(img);
+        let mut dct_values = self.dct(&resized);
         debug!("DCT-coefficients:\n {}", print_matrix(dct_values));
 
         // Quantization:
@@ -114,7 +114,7 @@ impl Descriptor for DCT {
         debug!("DCT-coefficients, quantized:\n {}", print_matrix(dct_values));
 
         if log_enabled!(Level::Debug) {
-            img.save("resize.png").expect("Error saving file");
+            resized.save("resize.png").expect("Error saving file");
             // De-quantization:
             for i in 0..64 {
                 dct_values[i] = dct_values[i] * self.quantization_matrix[i] as f64;