Read out short vecs and ascii from ifds

src/decoder/ifd.rs

@@ -10,14 +10,15 @@ use crate::tags::{Tag, Type};
 use crate::{TiffError, TiffFormatError, TiffResult, TiffUnsupportedError};
 
 use self::Value::{
-    Ascii, Byte, Double, Float, List, Rational, RationalBig, SRational, SRationalBig, Signed,
+    Ascii, Byte, Double, Float, List, Rational, RationalBig, SRational, SRationalBig, Short,
-    SignedBig, Unsigned, UnsignedBig,
+    Signed, SignedBig, Unsigned, UnsignedBig,
 };
 
 #[allow(unused_qualifications)]
 #[derive(Debug, Clone, PartialEq)]
 pub enum Value {
     Byte(u8),
+    Short(u16),
     Signed(i32),
     SignedBig(i64),
     Unsigned(u32),
@@ -42,6 +43,17 @@ impl Value {
         }
     }
 
+    pub fn into_u16(self) -> TiffResult<u16> {
+        match self {
+            Short(val) => Ok(val),
+            Unsigned(val) => Ok(u16::try_from(val)?),
+            UnsignedBig(val) => Ok(u16::try_from(val)?),
+            val => Err(TiffError::FormatError(
+                TiffFormatError::UnsignedIntegerExpected(val),
+            )),
+        }
+    }
+
     pub fn into_u32(self) -> TiffResult<u32> {
         match self {
             Unsigned(val) => Ok(val),
@@ -100,6 +112,15 @@ impl Value {
         }
     }
 
+    pub fn into_string(self) -> TiffResult<String> {
+        match self {
+            Ascii(val) => Ok(val),
+            val => Err(TiffError::FormatError(
+                TiffFormatError::SignedIntegerExpected(val),
+            )),
+        }
+    }
+
     pub fn into_u32_vec(self) -> TiffResult<Vec<u32>> {
         match self {
             List(vec) => {
@@ -139,6 +160,22 @@ impl Value {
         }
     }
 
+    pub fn into_u16_vec(self) -> TiffResult<Vec<u16>> {
+        match self {
+            List(vec) => {
+                let mut new_vec = Vec::with_capacity(vec.len());
+                for v in vec {
+                    new_vec.push(v.into_u16()?)
+                }
+                Ok(new_vec)
+            }
+            Short(val) => Ok(vec![val]),
+            val => Err(TiffError::FormatError(
+                TiffFormatError::UnsignedIntegerExpected(val),
+            )),
+        }
+    }
+
     pub fn into_i32_vec(self) -> TiffResult<Vec<i32>> {
         match self {
             List(vec) => {
@@ -400,6 +437,7 @@ impl Entry {
                         Signed(i32::from(r.read_i16()?)),
                     ]))
                 }
+                (Type::SHORT, 16) => Ok(Short(u16::from(decoder.read_short()?))),
                 (Type::SHORT, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
                     Ok(UnsignedBig(u64::from(decoder.read_short()?)))
                 }),

src/decoder/mod.rs

@@ -728,6 +728,10 @@ impl<R: Read + Seek> Decoder<R> {
     pub fn get_tag_u32_vec(&mut self, tag: Tag) -> TiffResult<Vec<u32>> {
         self.get_tag(tag)?.into_u32_vec()
     }
+
+    pub fn get_tag_u16_vec(&mut self, tag: Tag) -> TiffResult<Vec<u16>> {
+        self.get_tag(tag)?.into_u16_vec()
+    }
     pub fn get_tag_u64_vec(&mut self, tag: Tag) -> TiffResult<Vec<u64>> {
         self.get_tag(tag)?.into_u64_vec()
     }
@@ -747,6 +751,11 @@ impl<R: Read + Seek> Decoder<R> {
         self.get_tag(tag)?.into_u8_vec()
     }
 
+    /// Tries to retrieve a tag and convert it to a ascii vector.
+    pub fn get_tag_ascii_string(&mut self, tag: Tag) -> TiffResult<String> {
+        self.get_tag(tag)?.into_string()
+    }
+
     /// Decompresses the strip into the supplied buffer.
     /// Returns the number of bytes read.
     fn expand_strip<'a>(