Merge branch 'master' into 16bit-performance

src/decoder/ifd.rs

@@ -4,9 +4,9 @@ use std::io::{self, Read, Seek};
 use std::collections::{HashMap};
 
 use super::stream::{ByteOrder, SmartReader, EndianReader};
-use ::{TiffError, TiffResult};
+use ::{TiffError, TiffFormatError, TiffUnsupportedError, TiffResult};
 
-use self::Value::{Unsigned, List, Rational};
+use self::Value::{Unsigned, List, Rational, Ascii};
 
 macro_rules! tags {
     {$(
@@ -33,7 +33,7 @@ macro_rules! tags {
 // Note: These tags appear in the order they are mentioned in the TIFF reference
 tags!{
     // Baseline tags:
-    Artist 315; // TODO add support
+    Artist 315;
     // grayscale images PhotometricInterpretation 1 or 3
     BitsPerSample 258;
     CellLength 265; // TODO add support
@@ -41,22 +41,22 @@ tags!{
     // palette-color images (PhotometricInterpretation 3)
     ColorMap 320; // TODO add support
     Compression 259; // TODO add support for 2 and 32773
-    Copyright 33_432; // TODO add support
+    Copyright 33_432;
-    DateTime 306; // TODO add support
+    DateTime 306;
     ExtraSamples 338; // TODO add support
     FillOrder 266; // TODO add support
     FreeByteCounts 289; // TODO add support
     FreeOffsets 288; // TODO add support
     GrayResponseCurve 291; // TODO add support
     GrayResponseUnit 290; // TODO add support
-    HostComputer 316; // TODO add support
+    HostComputer 316;
-    ImageDescription 270; // TODO add support
+    ImageDescription 270;
     ImageLength 257;
     ImageWidth 256;
-    Make 271; // TODO add support
+    Make 271;
     MaxSampleValue 281; // TODO add support
     MinSampleValue 280; // TODO add support
-    Model 272; // TODO add support
+    Model 272;
     NewSubfileType 254; // TODO add support
     Orientation 274; // TODO add support
     PhotometricInterpretation 262;
@@ -86,21 +86,20 @@ pub enum Type {
 
 
 #[allow(unused_qualifications)]
-#[derive(Debug)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum Value {
     //Signed(i32),
     Unsigned(u32),
     List(Vec<Value>),
-    Rational(u32, u32)
+    Rational(u32, u32),
+    Ascii(String)
 }
 
 impl Value {
     pub fn into_u32(self) -> TiffResult<u32> {
         match self {
             Unsigned(val) => Ok(val),
-            val => Err(TiffError::FormatError(format!(
+            val => Err(TiffError::FormatError(TiffFormatError::UnsignedIntegerExpected(val))),
-                "Expected unsigned integer, {:?} found.", val
-            )))
         }
     }
     pub fn into_u32_vec(self) -> TiffResult<Vec<u32>> {
@@ -113,8 +112,8 @@ impl Value {
                 Ok(new_vec)
             },
             Unsigned(val) => Ok(vec![val]),
-            Rational(numerator, denominator) => Ok(vec![numerator, denominator])
+            Rational(numerator, denominator) => Ok(vec![numerator, denominator]),
-            //_ => Err(::image::FormatError("Tag data malformed.".to_string()))
+            Ascii(val) => Ok(val.chars().map(|x| x as u32).collect())
         }
     }
 }
@@ -196,7 +195,12 @@ impl Entry {
                 }
                 Ok(List(v))
             },
-            _ => Err(TiffError::UnsupportedError("Unsupported data type.".to_string()))
+            (Type::ASCII, n) => {
+                try!(decoder.goto_offset(try!(self.r(bo).read_u32())));
+                let string = try!(decoder.read_string(n as usize));
+                Ok(Ascii(string))
+            }
+            _ => Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedDataType))
         }
     }
 }

src/decoder/mod.rs

@@ -2,8 +2,9 @@ use std::io::{self, Read, Seek};
 use std::mem;
 use num_traits::{FromPrimitive, Num};
 use std::collections::HashMap;
+use std::string::FromUtf8Error;
 
-use ::{ColorType, TiffError, TiffResult};
+use ::{ColorType, TiffError, TiffFormatError, TiffUnsupportedError, TiffResult};
 
 use self::ifd::Directory;
 
@@ -35,8 +36,8 @@ enum DecodingBuffer<'a> {
     U16(&'a mut [u16])
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, FromPrimitive)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, FromPrimitive)]
-enum PhotometricInterpretation {
+pub enum PhotometricInterpretation {
     WhiteIsZero = 0,
     BlackIsZero = 1,
     RGB = 2,
@@ -47,8 +48,8 @@ enum PhotometricInterpretation {
     CIELab = 8,
 }
 
-#[derive(Clone, Copy, Debug, FromPrimitive)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, FromPrimitive)]
-enum CompressionMethod {
+pub enum CompressionMethod {
     None = 1,
     Huffman = 2,
     Fax3 = 3,
@@ -58,13 +59,13 @@ enum CompressionMethod {
     PackBits = 0x8005
 }
 
-#[derive(Clone, Copy, Debug, FromPrimitive)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, FromPrimitive)]
-enum PlanarConfiguration {
+pub enum PlanarConfiguration {
     Chunky = 1,
     Planar = 2
 }
 
-#[derive(Clone, Copy, Debug, FromPrimitive)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, FromPrimitive)]
 enum Predictor {
     None = 1,
     Horizontal = 2
@@ -125,9 +126,7 @@ fn rev_hpredict(image: DecodingResult, size: (u32, u32), color_type: ColorType)
         ColorType::Gray(8) | ColorType::Gray(16) => 1,
         ColorType::RGB(8) | ColorType::RGB(16) => 3,
         ColorType::RGBA(8) | ColorType::RGBA(16) | ColorType::CMYK(8) => 4,
-        _ => return Err(TiffError::UnsupportedError(format!(
+        _ => return Err(TiffError::UnsupportedError(TiffUnsupportedError::HorizontalPredictor(color_type)))
-            "Horizontal predictor for {:?} is unsupported.", color_type
-        )))
     };
     Ok(match image {
         DecodingResult::U8(buf) => {
@@ -171,9 +170,8 @@ impl<R: Read + Seek> Decoder<R> {
             PhotometricInterpretation::BlackIsZero | PhotometricInterpretation::WhiteIsZero
                                            if self.bits_per_sample.len() == 1 => Ok(ColorType::Gray(self.bits_per_sample[0])),
 
-            _ => Err(TiffError::UnsupportedError(format!(
+            // TODO: this is bad we should not fail at this point
-                "{:?} with {:?} bits per sample is unsupported", self.photometric_interpretation, self.bits_per_sample
+            _ => Err(TiffError::UnsupportedError(TiffUnsupportedError::InterpretationWithBits(self.photometric_interpretation, self.bits_per_sample.clone())))
-            ))) // TODO: this is bad we should not fail at this point}
         }
     }
 
@@ -187,12 +185,10 @@ impl<R: Read + Seek> Decoder<R> {
             b"MM" => {
                 self.byte_order = ByteOrder::BigEndian;
                 self.reader.byte_order = ByteOrder::BigEndian;  },
-            _ => return Err(TiffError::FormatError(
+            _ => return Err(TiffError::FormatError(TiffFormatError::TiffSignatureNotFound))
-                "TIFF signature not found.".to_string()
-            ))
         }
         if try!(self.read_short()) != 42 {
-            return Err(TiffError::FormatError("TIFF signature invalid.".to_string()))
+            return Err(TiffError::FormatError(TiffFormatError::TiffSignatureInvalid))
         }
         self.next_ifd = match try!(self.read_long()) {
             0 => None,
@@ -218,18 +214,14 @@ impl<R: Read + Seek> Decoder<R> {
             try!(self.get_tag_u32(ifd::Tag::PhotometricInterpretation))
         ) {
             Some(val) => val,
-            None => return Err(TiffError::UnsupportedError(
+            None => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnknownInterpretation))
-                "The image is using an unknown photometric interpretation.".to_string()
-            ))
         };
         if let Some(val) = try!(self.find_tag_u32(ifd::Tag::Compression)) {
             match FromPrimitive::from_u32(val) {
                 Some(method) =>  {
                     self.compression_method = method
                 },
-                None => return Err(TiffError::UnsupportedError(
+                None => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnknownCompressionMethod))
-                    "Unknown compression method.".to_string()
-                ))
             }
         }
         if let Some(val) = try!(self.find_tag_u32(ifd::Tag::SamplesPerPixel)) {
@@ -247,9 +239,7 @@ impl<R: Read + Seek> Decoder<R> {
                 }
 
             }
-            _ => return Err(TiffError::UnsupportedError(
+            _ => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedSampleDepth(self.samples)))
-                format!("{} samples per pixel is supported.", self.samples)
-            ))
         }
         Ok(self)
     }
@@ -279,6 +269,16 @@ impl<R: Read + Seek> Decoder<R> {
         self.reader.read_u32()
     }
 
+    /// Reads a string
+    #[inline]
+    pub fn read_string(&mut self, length: usize) -> Result<String, FromUtf8Error> {
+        let mut out = String::with_capacity(length);
+        self.reader.read_to_string(&mut out);
+        // Strings may be null-terminated, so we trim anything downstream of the null byte
+        let trimmed = out.bytes().take_while(|&n| n != 0).collect::<Vec<u8>>();
+        String::from_utf8(trimmed)
+    }
+
     /// Reads a TIFF IFA offset/value field
     #[inline]
     pub fn read_offset(&mut self) -> Result<[u8; 4], io::Error> {
@@ -323,9 +323,7 @@ impl<R: Read + Seek> Decoder<R> {
     fn read_ifd(&mut self) -> TiffResult<Directory> {
         let mut dir: Directory = HashMap::new();
         match self.next_ifd {
-            None => return Err(TiffError::FormatError(
+            None => return Err(TiffError::FormatError(TiffFormatError::ImageFileDirectoryNotFound)),
-                "Image file directory not found.".to_string())
-            ),
             Some(offset) => try!(self.goto_offset(offset))
         }
         for _ in 0..try!(self.read_short()) {
@@ -379,9 +377,7 @@ impl<R: Read + Seek> Decoder<R> {
     pub fn get_tag(&mut self, tag: ifd::Tag) -> TiffResult<ifd::Value> {
         match try!(self.find_tag(tag)) {
             Some(val) => Ok(val),
-            None => Err(TiffError::FormatError(format!(
+            None => Err(TiffError::FormatError(TiffFormatError::RequiredTagNotFound(tag))),
-                "Required tag `{:?}` not found.", tag
-            )))
         }
     }
 
@@ -414,13 +410,11 @@ impl<R: Read + Seek> Decoder<R> {
                 let (bytes, reader) = try!(PackBitsReader::new(&mut self.reader, order, length as usize));
                 (bytes, Box::new(reader))
             },
-            method => return Err(TiffError::UnsupportedError(format!(
+            method => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedCompressionMethod(method)))
-                "Compression method {:?} is unsupported", method
-            )))
         };
         Ok(match (color_type, buffer) {
             (ColorType:: RGB(8), DecodingBuffer::U8(ref mut buffer)) |
-            (ColorType::RGBA(8), DecodingBuffer::U8(ref mut buffer)) | 
+            (ColorType::RGBA(8), DecodingBuffer::U8(ref mut buffer)) |
             (ColorType::CMYK(8), DecodingBuffer::U8(ref mut buffer)) => {
                 try!(reader.read_exact(&mut buffer[..bytes]));
                 bytes
@@ -448,9 +442,7 @@ impl<R: Read + Seek> Decoder<R> {
                 }
                 bytes
             }
-            (type_, _) => return Err(TiffError::UnsupportedError(format!(
+            (type_, _) => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedColorType(type_))),
-                "Color type {:?} is unsupported", type_
-            )))
         })
     }
 
@@ -468,18 +460,12 @@ impl<R: Read + Seek> Decoder<R> {
         let mut result = match self.bits_per_sample.iter().cloned().max().unwrap_or(8) {
             n if n <= 8 => DecodingResult::U8(vec![0; buffer_size]),
             n if n <= 16 => DecodingResult::U16(vec![0; buffer_size]),
-            n => return Err(
+            n => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedBitsPerChannel(n))),
-                TiffError::UnsupportedError(
-                    format!("{} bits per channel not supported", n)
-                )
-            )
         };
         if let Ok(config) = self.get_tag_u32(ifd::Tag::PlanarConfiguration) {
             match FromPrimitive::from_u32(config) {
                 Some(PlanarConfiguration::Chunky) => {},
-                config => return Err(TiffError::UnsupportedError(
+                config => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedPlanarConfig(config)))
-                    format!("Unsupported planar configuration “{:?}”.", config)
-                ))
             }
         }
         let mut units_read = 0;
@@ -519,9 +505,7 @@ impl<R: Read + Seek> Decoder<R> {
                         try!(self.colortype())
                     ))
                 },
-                None => return Err(TiffError::FormatError(
+                None => return Err(TiffError::FormatError(TiffFormatError::UnknownPredictor(predictor))),
-                    format!("Unknown predictor “{}” encountered", predictor)
-                ))
             }
         }
         Ok(result)

src/error.rs

@@ -1,20 +1,83 @@
 use std::error::Error;
 use std::fmt;
 use std::io;
+use std::string;
+
+use decoder::ifd::{Tag, Value};
+use decoder::{PhotometricInterpretation, CompressionMethod, PlanarConfiguration};
+use ColorType;
 
 /// Tiff error kinds.
 #[derive(Debug)]
 pub enum TiffError {
     /// The Image is not formatted properly
-    FormatError(String),
+    FormatError(TiffFormatError),
 
     /// The Decoder does not support this image format
-    UnsupportedError(String),
+    UnsupportedError(TiffUnsupportedError),
 
     /// An I/O Error occurred while decoding the image
     IoError(io::Error),
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum TiffFormatError {
+    TiffSignatureNotFound,
+    TiffSignatureInvalid,
+    ImageFileDirectoryNotFound,
+    RequiredTagNotFound(Tag),
+    UnknownPredictor(u32),
+    UnsignedIntegerExpected(Value),
+}
+
+impl fmt::Display for TiffFormatError {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        use self::TiffFormatError::*;
+        match *self {
+            TiffSignatureNotFound => write!(fmt, "TIFF signature not found."),
+            TiffSignatureInvalid => write!(fmt, "TIFF signature invalid."),
+            ImageFileDirectoryNotFound => write!(fmt, "Image file directory not found."),
+            RequiredTagNotFound(ref tag) => write!(fmt, "Required tag `{:?}` not found.", tag),
+            UnknownPredictor(ref predictor) => write!(fmt, "Unknown predictor “{}” encountered", predictor),
+            UnsignedIntegerExpected(ref val) => write!(fmt,  "Expected unsigned integer, {:?} found.", val),
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum TiffUnsupportedError {
+    HorizontalPredictor(ColorType),
+    InterpretationWithBits(PhotometricInterpretation, Vec<u8>),
+    UnknownInterpretation,
+    UnknownCompressionMethod,
+    UnsupportedCompressionMethod(CompressionMethod),
+    UnsupportedSampleDepth(u8),
+    UnsupportedColorType(ColorType),
+    UnsupportedBitsPerChannel(u8),
+    UnsupportedPlanarConfig(Option<PlanarConfiguration>),
+    UnsupportedDataType,
+}
+
+impl fmt::Display for TiffUnsupportedError {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        use self::TiffUnsupportedError::*;
+        match *self {
+            HorizontalPredictor(color_type) => write!(fmt, "Horizontal predictor for {:?} is unsupported.", color_type),
+            InterpretationWithBits(ref photometric_interpretation, ref bits_per_sample) => {
+                write!(fmt, "{:?} with {:?} bits per sample is unsupported", photometric_interpretation, bits_per_sample)
+            },
+            UnknownInterpretation => write!(fmt, "The image is using an unknown photometric interpretation."),
+            UnknownCompressionMethod => write!(fmt, "Unknown compression method."),
+            UnsupportedCompressionMethod(method) => write!(fmt, "Compression method {:?} is unsupported", method),
+            UnsupportedSampleDepth(samples) => write!(fmt, "{} samples per pixel is supported.", samples),
+            UnsupportedColorType(color_type) => write!(fmt, "Color type {:?} is unsupported", color_type),
+            UnsupportedBitsPerChannel(bits) => write!(fmt, "{} bits per channel not supported", bits),
+            UnsupportedPlanarConfig(config) => write!(fmt, "Unsupported planar configuration “{:?}”.", config),
+            UnsupportedDataType => write!(fmt, "Unsupported data type."),
+        }
+    }
+}
+
 impl fmt::Display for TiffError {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
         match *self {
@@ -49,5 +112,11 @@ impl From<io::Error> for TiffError {
     }
 }
 
+impl From<string::FromUtf8Error> for TiffError {
+    fn from(err: string::FromUtf8Error) -> TiffError {
+        TiffError::FormatError(String::from("Image contains invalid tag."))
+    }
+}
+
 /// Result of an image decoding/encoding process
 pub type TiffResult<T> = Result<T, TiffError>;

src/lib.rs

@@ -14,7 +14,7 @@ extern crate num_traits;
 pub mod decoder;
 mod error;
 
-pub use self::error::{TiffError, TiffResult};
+pub use self::error::{TiffError, TiffFormatError, TiffUnsupportedError, TiffResult};
 
 /// An enumeration over supported color types and their bit depths
 #[derive(Copy, PartialEq, Eq, Debug, Clone, Hash)]

tests/decode_images.rs

@@ -1,7 +1,7 @@
 extern crate tiff;
 
 use tiff::ColorType;
-use tiff::decoder::{Decoder, DecodingResult};
+use tiff::decoder::{Decoder, DecodingResult, ifd::Tag, ifd::Value};
 
 use std::fs::File;
 
@@ -45,6 +45,24 @@ fn test_rgb_u16()
     assert!(img_res.is_ok());
 }
 
+#[test]
+fn test_string_tags()
+{
+    // these files have null-terminated strings for their Software tag. One has extra bytes after
+    // the null byte, so we check both to ensure that we're truncating properly
+    let filenames = vec!["minisblack-1c-16b.tiff", "rgb-3c-16b.tiff"];
+    for filename in filenames.iter() {
+        let path = format!("./tests/images/{}", filename);
+        let img_file = File::open(path).expect("can't open file");
+        let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+        let software= decoder.get_tag(Tag::Software).unwrap();
+        match software {
+            Value::Ascii(s) => assert_eq!(s, String::from("GraphicsMagick 1.2 unreleased Q16 http://www.GraphicsMagick.org/")),
+            _ => assert!(false)
+        };
+    }
+}
+
 // TODO: GrayA support
 //#[test]
 //fn test_gray_alpha_u8()