Support 64-bit rgb and rgba decoding

src/decoder/mod.rs

@@ -295,8 +295,8 @@ where
 fn rev_hpredict(image: DecodingBuffer, size: (u32, u32), color_type: ColorType) -> TiffResult<()> {
     let samples = match color_type {
         ColorType::Gray(8) | ColorType::Gray(16) | ColorType::Gray(32) | ColorType::Gray(64) => 1,
-        ColorType::RGB(8) | ColorType::RGB(16) | ColorType::RGB(32) => 3,
-        ColorType::RGBA(8) | ColorType::RGBA(16) | ColorType::RGBA(32) | ColorType::CMYK(8) => 4,
+        ColorType::RGB(8) | ColorType::RGB(16) | ColorType::RGB(32) | ColorType::RGB(64) => 3,
+        ColorType::RGBA(8) | ColorType::RGBA(16) | ColorType::RGBA(32) | ColorType::RGBA(64) | ColorType::CMYK(8) => 4,
         _ => {
             return Err(TiffError::UnsupportedError(
                 TiffUnsupportedError::HorizontalPredictor(color_type),
@@ -370,6 +370,12 @@ impl<R: Read + Seek> Decoder<R> {
             PhotometricInterpretation::RGB if self.bits_per_sample == [32, 32, 32] => {
                 Ok(ColorType::RGB(32))
             }
+            PhotometricInterpretation::RGB if self.bits_per_sample == [64, 64, 64, 64] => {
+                Ok(ColorType::RGBA(64))
+            }
+            PhotometricInterpretation::RGB if self.bits_per_sample == [64, 64, 64] => {
+                Ok(ColorType::RGB(64))
+            }
             PhotometricInterpretation::CMYK if self.bits_per_sample == [8, 8, 8, 8] => {
                 Ok(ColorType::CMYK(8))
             }
@@ -720,6 +726,11 @@ impl<R: Read + Seek> Decoder<R> {
                 reader.read_u32_into(&mut buffer[..bytes / 4])?;
                 bytes / 4
             }
+            (ColorType::RGBA(64), DecodingBuffer::U64(ref mut buffer))
+            | (ColorType::RGB(64), DecodingBuffer::U64(ref mut buffer)) => {
+                reader.read_u64_into(&mut buffer[..bytes / 8])?;
+                bytes / 8
+            }
             (ColorType::Gray(64), DecodingBuffer::U64(ref mut buffer)) => {
                 reader.read_u64_into(&mut buffer[..bytes / 8])?;
                 if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {

tests/decode_images.rs

@@ -142,6 +142,25 @@ fn test_rgb_u32() {
     }
 }
 
+#[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]
 fn test_string_tags() {
     // these files have null-terminated strings for their Software tag. One has extra bytes after