diff --git a/src/png/mod.rs b/src/png/mod.rs
index d8afa106..5d8d432f 100644
--- a/src/png/mod.rs
+++ b/src/png/mod.rs
@@ -295,7 +295,7 @@ impl PngData {
                 }
                 _ => unreachable!(),
             }
-            last_line = line.data;
+            last_line = line.data.to_vec();
             last_pass = line.pass;
         }
         filtered
@@ -322,17 +322,17 @@ impl PngData {
 
         for line in self.scan_lines() {
             reduced.push(line.filter);
-            for (i, byte) in line.data.iter().enumerate() {
+            for (i, &byte) in line.data.iter().enumerate() {
                 if i % 2 == 0 {
                     // High byte
-                    high_byte = *byte;
+                    high_byte = byte;
                 } else {
                     // Low byte
-                    if high_byte != *byte {
+                    if high_byte != byte {
                         // Can't reduce, exit early
                         return false;
                     }
-                    reduced.push(*byte);
+                    reduced.push(byte);
                 }
             }
         }
@@ -406,8 +406,8 @@ impl PngData {
         let mut seen = HashSet::with_capacity(indexed_palette.len());
         for line in self.scan_lines() {
             match self.ihdr_data.bit_depth {
-                BitDepth::Eight => for byte in &line.data {
-                    seen.insert(*byte);
+                BitDepth::Eight => for &byte in line.data {
+                    seen.insert(byte);
                 },
                 BitDepth::Four => {
                     let bitvec = BitVec::from_bytes(&line.data);
@@ -489,52 +489,52 @@ impl PngData {
         for line in self.scan_lines() {
             new_data.push(line.filter);
             match self.ihdr_data.bit_depth {
-                BitDepth::Eight => for byte in &line.data {
-                    if let Some(new_idx) = index_map.get(byte) {
-                        new_data.push(*new_idx);
+                BitDepth::Eight => for &byte in line.data {
+                    if let Some(&new_idx) = index_map.get(&byte) {
+                        new_data.push(new_idx);
                     } else {
-                        new_data.push(*byte);
+                        new_data.push(byte);
                     }
                 },
-                BitDepth::Four => for byte in &line.data {
-                    let upper = *byte & 0b1111_0000;
-                    let lower = *byte & 0b0000_1111;
+                BitDepth::Four => for &byte in line.data {
+                    let upper = byte & 0b1111_0000;
+                    let lower = byte & 0b0000_1111;
                     let mut new_byte = 0u8;
-                    new_byte |= if let Some(new_idx) = index_map.get(&(upper >> 4)) {
-                        *new_idx << 4
+                    new_byte |= if let Some(&new_idx) = index_map.get(&(upper >> 4)) {
+                        new_idx << 4
                     } else {
                         upper
                     };
-                    new_byte |= if let Some(new_idx) = index_map.get(&lower) {
-                        *new_idx
+                    new_byte |= if let Some(&new_idx) = index_map.get(&lower) {
+                        new_idx
                     } else {
                         lower
                     };
                     new_data.push(new_byte);
                 },
-                BitDepth::Two => for byte in &line.data {
-                    let one = *byte & 0b1100_0000;
-                    let two = *byte & 0b0011_0000;
-                    let three = *byte & 0b0000_1100;
-                    let four = *byte & 0b0000_0011;
+                BitDepth::Two => for &byte in line.data {
+                    let one = byte & 0b1100_0000;
+                    let two = byte & 0b0011_0000;
+                    let three = byte & 0b0000_1100;
+                    let four = byte & 0b0000_0011;
                     let mut new_byte = 0u8;
-                    new_byte |= if let Some(new_idx) = index_map.get(&(one >> 6)) {
-                        *new_idx << 6
+                    new_byte |= if let Some(&new_idx) = index_map.get(&(one >> 6)) {
+                        new_idx << 6
                     } else {
                         one
                     };
-                    new_byte |= if let Some(new_idx) = index_map.get(&(two >> 4)) {
-                        *new_idx << 4
+                    new_byte |= if let Some(&new_idx) = index_map.get(&(two >> 4)) {
+                        new_idx << 4
                     } else {
                         two
                     };
-                    new_byte |= if let Some(new_idx) = index_map.get(&(three >> 2)) {
-                        *new_idx << 2
+                    new_byte |= if let Some(&new_idx) = index_map.get(&(three >> 2)) {
+                        new_idx << 2
                     } else {
                         three
                     };
-                    new_byte |= if let Some(new_idx) = index_map.get(&four) {
-                        *new_idx
+                    new_byte |= if let Some(&new_idx) = index_map.get(&four) {
+                        new_idx
                     } else {
                         four
                     };
diff --git a/src/png/scan_lines.rs b/src/png/scan_lines.rs
index a451e14a..bbf36a9d 100644
--- a/src/png/scan_lines.rs
+++ b/src/png/scan_lines.rs
@@ -12,7 +12,7 @@ pub struct ScanLines<'a> {
 }
 
 impl<'a> Iterator for ScanLines<'a> {
-    type Item = ScanLine;
+    type Item = ScanLine<'a>;
     fn next(&mut self) -> Option<Self::Item> {
         if self.end == self.png.raw_data.len() {
             None
@@ -109,7 +109,7 @@ impl<'a> Iterator for ScanLines<'a> {
             }
             Some(ScanLine {
                 filter: self.png.raw_data[self.start],
-                data: self.png.raw_data[(self.start + 1)..self.end].to_owned(),
+                data: &self.png.raw_data[(self.start + 1)..self.end],
                 pass: current_pass,
             })
         } else {
@@ -122,7 +122,7 @@ impl<'a> Iterator for ScanLines<'a> {
             self.end = self.start + bytes_per_line + 1;
             Some(ScanLine {
                 filter: self.png.raw_data[self.start],
-                data: self.png.raw_data[(self.start + 1)..self.end].to_owned(),
+                data: &self.png.raw_data[(self.start + 1)..self.end],
                 pass: None,
             })
         }
@@ -131,11 +131,11 @@ impl<'a> Iterator for ScanLines<'a> {
 
 #[derive(Debug, Clone)]
 /// A scan line in a PNG image
-pub struct ScanLine {
+pub struct ScanLine<'a> {
     /// The filter type used to encode the current scan line (0-4)
     pub filter: u8,
     /// The byte data for the current scan line, encoded with the filter specified in the `filter` field
-    pub data: Vec<u8>,
+    pub data: &'a[u8],
     /// The current pass if the image is interlaced
     pub pass: Option<u8>,
 }