diff --git a/src/bin/dctfilename.rs b/src/bin/dctfilename.rs
index 4c42190..931ced6 100644
--- a/src/bin/dctfilename.rs
+++ b/src/bin/dctfilename.rs
@@ -31,7 +31,7 @@ fn main() {
 
     let img = image::open(cfg.path)
         .expect("Unable to open file");
-    let phash: u64 = desc.describe(img);
+    let phash: u64 = desc.describe(&img);
     debug!("Phash integer:\n{phash}");
     debug!("Phash binary:\n{phash:b}");
     let output = URL_SAFE_NO_PAD.encode(phash.to_be_bytes());
diff --git a/src/descriptors/dct.rs b/src/descriptors/dct.rs
index ab00797..1244af9 100644
--- a/src/descriptors/dct.rs
+++ b/src/descriptors/dct.rs
@@ -101,7 +101,7 @@ impl DCT {
 }
 
 impl Descriptor for DCT {
-    fn describe(&self, img: image::DynamicImage) -> u64 {
+    fn describe(&self, img: &image::DynamicImage) -> u64 {
         let resized = self.resize(img);
         let mut dct_values = self.dct(&resized);
         debug!("DCT-coefficients:\n {}", print_matrix(dct_values));
diff --git a/src/descriptors/mod.rs b/src/descriptors/mod.rs
index 0c54c9d..fe0690f 100644
--- a/src/descriptors/mod.rs
+++ b/src/descriptors/mod.rs
@@ -2,10 +2,10 @@ pub trait Descriptor {
     fn info(&self) -> String {
         "Descriptor".to_string()
     }
-    fn resize(&self, img: image::DynamicImage) -> image::DynamicImage {
+    fn resize(&self, img: &image::DynamicImage) -> image::DynamicImage {
         img.grayscale().thumbnail_exact(8, 8)
     }
-    fn describe(&self, img: image::DynamicImage) -> u64;
+    fn describe(&self, img: &image::DynamicImage) -> u64;
     fn distance(&self, a: u64, b: u64) -> u64 {
         (a^b).count_ones().into()
     }
diff --git a/src/store.rs b/src/store.rs
index 63ae6dc..04a6029 100644
--- a/src/store.rs
+++ b/src/store.rs
@@ -75,7 +75,7 @@ impl DescriptorStore {
 						continue
 					}
 				};
-				let phash = desc.describe(img);
+				let phash = desc.describe(&img);
 				self.map.insert(name, phash);
 			} else {
 				debug!("{} already known, skipping.", name);