added round trip test

fixed ci
added colortype

src/decoder/image.rs

@@ -313,10 +313,9 @@ impl Image {
                         self.bits_per_sample.clone(),
                     ),
                 )),
-            }
-            ,
+            },
             PhotometricInterpretation::YCbCr => match self.bits_per_sample[..] {
-                [y, cb, cr] if [y, y] == [cb, cr]=> Ok(ColorType::YCbCr(y)),
+                [y, cb, cr] if [y, y] == [cb, cr] => Ok(ColorType::YCbCr(y)),
                 _ => Err(TiffError::UnsupportedError(
                     TiffUnsupportedError::InterpretationWithBits(
                         self.photometric_interpretation,

src/encoder/colortype.rs

@@ -235,3 +235,11 @@ impl ColorType for CMYK64Float {
     const BITS_PER_SAMPLE: &'static [u16] = &[64, 64, 64, 64];
     const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::IEEEFP; 4];
 }
+
+pub struct YCbCr8;
+impl ColorType for YCbCr8 {
+    type Inner = u8;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::YCbCr;
+    const BITS_PER_SAMPLE: &'static [u16] = &[8, 8, 8];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 3];
+}

tests/encode_images.rs

@@ -264,6 +264,11 @@ fn test_gray_f64_roundtrip() {
     test_f64_roundtrip::<colortype::Gray64Float>("gradient-1c-64b-float.tiff", ColorType::Gray(64));
 }
 
+#[test]
+fn test_ycbcr_u8_roundtrip() {
+    test_u8_roundtrip::<colortype::YCbCr8>("tiled-jpeg-ycbcr.tif", ColorType::YCbCr(8));
+}
+
 trait AssertDecode {
     fn assert_tag_u32(&mut self, tag: u16) -> u32;
     fn assert_tag_u32_vec(&mut self, tag: u16) -> Vec<u32>;