Read out byte-sized arrays

src/decoder/ifd.rs

@@ -10,13 +10,14 @@ use tags::{Tag, Type};
 use {TiffError, TiffFormatError, TiffResult, TiffUnsupportedError};
 
 use self::Value::{
-    Ascii, Double, Float, List, Rational, RationalBig, SRational, SRationalBig, Signed, SignedBig,
+    Ascii, Byte, Double, Float, List, Rational, RationalBig, SRational, SRationalBig, Signed, SignedBig,
     Unsigned, UnsignedBig,
 };
 
 #[allow(unused_qualifications)]
 #[derive(Debug, Clone, PartialEq)]
 pub enum Value {
+    Byte(u8),
     Signed(i32),
     SignedBig(i64),
     Unsigned(u32),
@@ -34,6 +35,16 @@ pub enum Value {
 }
 
 impl Value {
+
+    pub fn into_u8(self) -> TiffResult<u8> {
+        match self {
+            Byte(val) => Ok(val),
+            val => Err(TiffError::FormatError(
+                TiffFormatError::UnsignedIntegerExpected(val),
+            )),
+        }
+    }
+
     pub fn into_u32(self) -> TiffResult<u32> {
         match self {
             Unsigned(val) => Ok(val),
@@ -114,6 +125,23 @@ impl Value {
         }
     }
 
+    pub fn into_u8_vec(self) -> TiffResult<Vec<u8>> {
+        match self {
+            List(vec) => {
+                let mut new_vec = Vec::with_capacity(vec.len());
+                for v in vec {
+                    new_vec.push(v.into_u8()?)
+                }
+                Ok(new_vec)
+            }
+            Byte(val) => Ok(vec![val]),
+
+            val => Err(TiffError::FormatError(
+                TiffFormatError::UnsignedIntegerExpected(val),
+            )),
+        }
+    }
+
     pub fn into_i32_vec(self) -> TiffResult<Vec<i32>> {
         match self {
             List(vec) => {

src/decoder/mod.rs

@@ -746,6 +746,11 @@ impl<R: Read + Seek> Decoder<R> {
         self.get_tag(tag)?.into_f64_vec()
     }
 
+    /// Tries to retrieve a tag and convert it to a 8bit vector.
+    pub fn get_tag_u8_vec(&mut self, tag: Tag) -> TiffResult<Vec<u8>> {
+        self.get_tag(tag)?.into_u8_vec()
+    }
+
     /// Decompresses the strip into the supplied buffer.
     /// Returns the number of bytes read.
     fn expand_strip<'a>(