Add support for CMYK(16|32|64) encoding

src/encoder/colortype.rs

@@ -100,3 +100,24 @@ impl ColorType for CMYK8 {
     const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
     const BITS_PER_SAMPLE: &'static [u16] = &[8, 8, 8, 8];
 }
+
+pub struct CMYK16;
+impl ColorType for CMYK16 {
+    type Inner = u16;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
+    const BITS_PER_SAMPLE: &'static [u16] = &[16, 16, 16, 16];
+}
+
+pub struct CMYK32;
+impl ColorType for CMYK32 {
+    type Inner = u32;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
+    const BITS_PER_SAMPLE: &'static [u16] = &[32, 32, 32, 32];
+}
+
+pub struct CMYK64;
+impl ColorType for CMYK64 {
+    type Inner = u64;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
+    const BITS_PER_SAMPLE: &'static [u16] = &[64, 64, 64, 64];
+}

tests/encode_images.rs

@@ -105,6 +105,11 @@ fn test_rgb_u8_roundtrip() {
     test_u8_roundtrip::<colortype::RGB8>("rgb-3c-8b.tiff", ColorType::RGB(8));
 }
 
+#[test]
+fn test_cmyk_u8_roundtrip() {
+    test_u8_roundtrip::<colortype::CMYK8>("cmyk-3c-8b.tiff", ColorType::CMYK(8));
+}
+
 #[test]
 fn test_gray_u16_roundtrip() {
     test_u16_roundtrip::<colortype::Gray16>("minisblack-1c-16b.tiff", ColorType::Gray(16));
@@ -115,6 +120,11 @@ fn test_rgb_u16_roundtrip() {
     test_u16_roundtrip::<colortype::RGB16>("rgb-3c-16b.tiff", ColorType::RGB(16));
 }
 
+#[test]
+fn test_cmyk_u16_roundtrip() {
+    test_u16_roundtrip::<colortype::CMYK16>("cmyk-3c-16b.tiff", ColorType::CMYK(16));
+}
+
 #[test]
 fn test_gray_u32_roundtrip() {
     test_u32_roundtrip::<colortype::Gray32>("gradient-1c-32b.tiff", ColorType::Gray(32));