diff --git a/Cargo.toml b/Cargo.toml
index a2813f5..c0d2dd0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,6 +20,3 @@ exclude = ["tests/images/*", "tests/fuzz_images/*"]
 byteorder = "1.2"
 lzw = "0.10"
 miniz_oxide = "0.3"
-
-[dev-dependencies]
-tempfile = "3.0"
diff --git a/src/encoder/mod.rs b/src/encoder/mod.rs
index 9eda804..96e8bfb 100644
--- a/src/encoder/mod.rs
+++ b/src/encoder/mod.rs
@@ -360,10 +360,9 @@ impl<'a, T: TiffValue + ?Sized> TiffValue for &'a T {
 ///
 /// # Examples
 /// ```
-/// # extern crate tempfile;
 /// # extern crate tiff;
 /// # fn main() {
-/// # let mut file = tempfile::tempfile().unwrap();
+/// # let mut file = std::io::Cursor::new(Vec::new());
 /// # let image_data = vec![0; 100*100*3];
 /// use tiff::encoder::*;
 ///
@@ -548,10 +547,9 @@ impl<'a, W: Write + Seek> Drop for DirectoryEncoder<'a, W> {
 ///
 /// # Examples
 /// ```
-/// # extern crate tempfile;
 /// # extern crate tiff;
 /// # fn main() {
-/// # let mut file = tempfile::tempfile().unwrap();
+/// # let mut file = std::io::Cursor::new(Vec::new());
 /// # let image_data = vec![0; 100*100*3];
 /// use tiff::encoder::*;
 ///
diff --git a/tests/decode_images.rs b/tests/decode_images.rs
index 910d43e..7437cb1 100644
--- a/tests/decode_images.rs
+++ b/tests/decode_images.rs
@@ -4,201 +4,113 @@ use tiff::decoder::{ifd, Decoder, DecodingResult};
 use tiff::ColorType;
 
 use std::fs::File;
+use std::path::PathBuf;
 
-#[test]
-fn test_gray_u8() {
-    let img_file =
-        File::open("./tests/images/minisblack-1c-8b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(8));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U8(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
+const TEST_IMAGE_DIR: &str = "./tests/images/";
+
+macro_rules! test_image_sum {
+    ($name:ident, $buffer:ident, $sum_ty:ty) => {
+        fn $name(file: &str, expected_type: ColorType, expected_sum: $sum_ty) {
+            let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
+            let img_file = File::open(path).expect("Cannot find test image!");
+            let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+            assert_eq!(decoder.colortype().unwrap(), expected_type);
+            let img_res = decoder.read_image().unwrap();
+
+            match img_res {
+                DecodingResult::$buffer(res) => {
+                    let sum: $sum_ty = res.into_iter().map(<$sum_ty>::from).sum();
+                    assert_eq!(sum, expected_sum);
+                },
+                _ => panic!("Wrong bit depth"),
+            }
         }
+    };
+}
 
-        assert_eq!(res_sum, 2840893);
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+test_image_sum!(test_image_sum_u8, U8, u64);
+test_image_sum!(test_image_sum_u16, U16, u64);
+test_image_sum!(test_image_sum_u32, U32, u64);
+test_image_sum!(test_image_sum_u64, U64, u64);
+
+/// Tests that a decoder can be constructed for an image and the color type
+/// read from the IFD and is of the appropriate type, but the type is
+/// unsupported.
+fn test_image_color_type_unsupported(file: &str, expected_type: ColorType) {
+    let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
+    let img_file = File::open(path).expect("Cannot find test image!");
+    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+    assert_eq!(decoder.colortype().unwrap(), expected_type);
+    assert!(match decoder.read_image() {
+        Err(tiff::TiffError::UnsupportedError(tiff::TiffUnsupportedError::UnsupportedColorType(_))) => true,
+        _ => false,
+    });
 }
 
 #[test]
-fn test_rgb_u8() {
-    let img_file = File::open("./tests/images/rgb-3c-8b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(8));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U8(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
-        }
-
-        assert_eq!(res_sum, 7842108)
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+fn test_gray_u8() {
+    test_image_sum_u8("minisblack-1c-8b.tiff", ColorType::Gray(8), 2840893);
 }
 
 #[test]
 fn test_gray_u12() {
-    let img_file =
-        File::open("./tests/images/12bit.cropped.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(12));
-    assert!(match decoder.read_image() {
-        Err(tiff::TiffError::UnsupportedError(tiff::TiffUnsupportedError::UnsupportedColorType(_))) => true,
-        _ => false,
-    });
+    test_image_color_type_unsupported("12bit.cropped.tiff", ColorType::Gray(12));
 }
 
 #[test]
 fn test_gray_u16() {
-    let img_file =
-        File::open("./tests/images/minisblack-1c-16b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(16));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U16(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
-        }
-
-        assert_eq!(res_sum, 733126239);
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+    test_image_sum_u16("minisblack-1c-16b.tiff", ColorType::Gray(16), 733126239);
 }
 
 #[test]
 fn test_gray_u32() {
-    let img_file =
-        File::open("./tests/images/gradient-1c-32b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(32));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U32(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
-        }
-
-        assert_eq!(res_sum, 549892913787);
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+    test_image_sum_u32("gradient-1c-32b.tiff", ColorType::Gray(32), 549892913787);
 }
 
 #[test]
 fn test_gray_u64() {
-    let img_file =
-        File::open("./tests/images/gradient-1c-64b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(64));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U64(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
-        }
+    test_image_sum_u64("gradient-1c-64b.tiff", ColorType::Gray(64), 549892913787);
+}
 
-        assert_eq!(res_sum, 549892913787);
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+#[test]
+fn test_rgb_u8() {
+    test_image_sum_u8("rgb-3c-8b.tiff", ColorType::RGB(8), 7842108);
 }
 
 #[test]
 fn test_rgb_u12() {
-    let img_file =
-        File::open("./tests/images/12bit.cropped.rgb.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(12));
-    assert!(match decoder.read_image() {
-        Err(tiff::TiffError::UnsupportedError(tiff::TiffUnsupportedError::UnsupportedColorType(_))) => true,
-        _ => false,
-    });
+    test_image_color_type_unsupported("12bit.cropped.rgb.tiff", ColorType::RGB(12));
 }
 
 #[test]
 fn test_rgb_u16() {
-    let img_file = File::open("./tests/images/rgb-3c-16b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(16));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U16(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
-        }
-
-        assert_eq!(res_sum, 2024349944);
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+    test_image_sum_u16("rgb-3c-16b.tiff", ColorType::RGB(16), 2024349944);
 }
 
 #[test]
 fn test_rgb_u32() {
-    let img_file = File::open("./tests/images/gradient-3c-32b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(32));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U32(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
-        }
-
-        assert_eq!(res_sum, 2030834111716);
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+    test_image_sum_u32("gradient-3c-32b.tiff", ColorType::RGB(32), 2030834111716);
 }
 
 #[test]
 fn test_rgb_u64() {
-    let img_file = File::open("./tests/images/gradient-3c-64b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(64));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U64(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
-        }
-
-        assert_eq!(res_sum, 2030834111716);
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+    test_image_sum_u64("gradient-3c-64b.tiff", ColorType::RGB(64), 2030834111716);
 }
 
 #[test]
 fn test_string_tags() {
     // these files have null-terminated strings for their Software tag. One has extra bytes after
     // the null byte, so we check both to ensure that we're truncating properly
-    let filenames = vec!["minisblack-1c-16b.tiff", "rgb-3c-16b.tiff"];
+    let filenames = ["minisblack-1c-16b.tiff", "rgb-3c-16b.tiff"];
     for filename in filenames.iter() {
-        let path = format!("./tests/images/{}", filename);
-        let img_file = File::open(path).expect("can't open file");
+        let path = PathBuf::from(TEST_IMAGE_DIR).join(filename);
+        let img_file = File::open(path).expect("Cannot find test image!");
         let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
         let software = decoder.get_tag(ifd::Tag::Software).unwrap();
         match software {
             ifd::Value::Ascii(s) => assert_eq!(
-                s,
-                String::from("GraphicsMagick 1.2 unreleased Q16 http://www.GraphicsMagick.org/")
+                &s,
+                "GraphicsMagick 1.2 unreleased Q16 http://www.GraphicsMagick.org/"
             ),
             _ => assert!(false),
         };
diff --git a/tests/encode_images.rs b/tests/encode_images.rs
index f3ca92f..988d386 100644
--- a/tests/encode_images.rs
+++ b/tests/encode_images.rs
@@ -1,4 +1,3 @@
-extern crate tempfile;
 extern crate tiff;
 
 use tiff::decoder::{Decoder, DecodingResult};
@@ -8,6 +7,7 @@ use tiff::ColorType;
 
 use std::fs::File;
 use std::io::{Cursor, Seek, SeekFrom};
+use std::path::PathBuf;
 
 #[test]
 fn encode_decode() {
@@ -20,7 +20,7 @@ fn encode_decode() {
             image_data.push(val);
         }
     }
-    let mut file = tempfile::tempfile().unwrap();
+    let mut file = Cursor::new(Vec::new());
     {
         let mut tiff = TiffEncoder::new(&mut file).unwrap();
 
@@ -54,249 +54,85 @@ fn test_encode_undersized_buffer() {
     }
 }
 
+const TEST_IMAGE_DIR: &str = "./tests/images/";
+
+macro_rules! test_roundtrip {
+    ($name:ident, $buffer:ident, $buffer_ty:ty) => {
+        fn $name<C: colortype::ColorType<Inner=$buffer_ty>>(file: &str, expected_type: ColorType) {
+            let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
+            let img_file = File::open(path).expect("Cannot find test image!");
+            let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+            assert_eq!(decoder.colortype().unwrap(), expected_type);
+
+            let image_data = match decoder.read_image().unwrap() {
+                DecodingResult::$buffer(res) => res,
+                _ => panic!("Wrong data type"),
+            };
+
+            let mut file = Cursor::new(Vec::new());
+            {
+                let mut tiff = TiffEncoder::new(&mut file).unwrap();
+
+                let (width, height) = decoder.dimensions().unwrap();
+                tiff.write_image::<C>(width, height, &image_data)
+                    .unwrap();
+            }
+            file.seek(SeekFrom::Start(0)).unwrap();
+            {
+                let mut decoder = Decoder::new(&mut file).unwrap();
+                if let DecodingResult::$buffer(img_res) = decoder.read_image().unwrap() {
+                    assert_eq!(image_data, img_res);
+                } else {
+                    panic!("Wrong data type");
+                }
+            }
+        }
+    };
+}
+
+test_roundtrip!(test_u8_roundtrip, U8, u8);
+test_roundtrip!(test_u16_roundtrip, U16, u16);
+test_roundtrip!(test_u32_roundtrip, U32, u32);
+test_roundtrip!(test_u64_roundtrip, U64, u64);
 
 #[test]
 fn test_gray_u8_roundtrip() {
-    let img_file =
-        File::open("./tests/images/minisblack-1c-8b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(8));
-
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U8(res) => res,
-        _ => panic!("Wrong data type"),
-    };
-
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::Gray8>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U8(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+    test_u8_roundtrip::<colortype::Gray8>("minisblack-1c-8b.tiff", ColorType::Gray(8));
 }
 
 #[test]
 fn test_rgb_u8_roundtrip() {
-    let img_file = File::open("./tests/images/rgb-3c-8b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(8));
-
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U8(res) => res,
-        _ => panic!("Wrong data type"),
-    };
-
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::RGB8>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U8(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+    test_u8_roundtrip::<colortype::RGB8>("rgb-3c-8b.tiff", ColorType::RGB(8));
 }
 
 #[test]
 fn test_gray_u16_roundtrip() {
-    let img_file =
-        File::open("./tests/images/minisblack-1c-16b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(16));
-
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U16(res) => res,
-        _ => panic!("Wrong data type"),
-    };
-
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::Gray16>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U16(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+    test_u16_roundtrip::<colortype::Gray16>("minisblack-1c-16b.tiff", ColorType::Gray(16));
 }
 
 #[test]
 fn test_rgb_u16_roundtrip() {
-    let img_file = File::open("./tests/images/rgb-3c-16b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(16));
-
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U16(res) => res,
-        _ => panic!("Wrong data type"),
-    };
-
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::RGB16>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U16(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+    test_u16_roundtrip::<colortype::RGB16>("rgb-3c-16b.tiff", ColorType::RGB(16));
 }
 
 #[test]
 fn test_gray_u32_roundtrip() {
-    let img_file =
-        File::open("./tests/images/gradient-1c-32b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(32));
-
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U32(res) => res,
-        _ => panic!("Wrong data type"),
-    };
-
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::Gray32>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U32(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+    test_u32_roundtrip::<colortype::Gray32>("gradient-1c-32b.tiff", ColorType::Gray(32));
 }
 
 #[test]
 fn test_rgb_u32_roundtrip() {
-    let img_file = File::open("./tests/images/gradient-3c-32b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(32));
-
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U32(res) => res,
-        _ => panic!("Wrong data type"),
-    };
-
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::RGB32>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U32(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+    test_u32_roundtrip::<colortype::RGB32>("gradient-3c-32b.tiff", ColorType::RGB(32));
 }
 
 #[test]
 fn test_gray_u64_roundtrip() {
-    let img_file =
-        File::open("./tests/images/gradient-1c-64b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(64));
-
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U64(res) => res,
-        _ => panic!("Wrong data type"),
-    };
-
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::Gray64>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U64(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+    test_u64_roundtrip::<colortype::Gray64>("gradient-1c-64b.tiff", ColorType::Gray(64));
 }
 
 #[test]
 fn test_rgb_u64_roundtrip() {
-    let img_file = File::open("./tests/images/gradient-3c-64b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(64));
-
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U64(res) => res,
-        _ => panic!("Wrong data type"),
-    };
-
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::RGB64>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U64(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+    test_u64_roundtrip::<colortype::RGB64>("gradient-3c-64b.tiff", ColorType::RGB(64));
 }
 
 #[test]