Files
image-tiff/src/decoder/ifd.rs
T
2019-08-29 19:10:27 +09:00

334 lines
11 KiB
Rust

//! Function for reading TIFF tags
use std::collections::HashMap;
use std::io::{self, Read, Seek};
use std::mem;
use super::stream::{ByteOrder, EndianReader, SmartReader};
use {TiffError, TiffFormatError, TiffResult, TiffUnsupportedError};
use self::Value::{Ascii, List, Rational, Unsigned, Signed, SRational};
macro_rules! tags {
{$(
$tag:ident
$val:expr;
)*} => {
/// TIFF tag
#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
pub enum Tag {
$($tag,)*
Unknown(u16)
}
impl Tag {
pub fn from_u16(n: u16) -> Tag {
$(if n == $val { Tag::$tag } else)* {
Tag::Unknown(n)
}
}
pub fn to_u16(&self) -> u16 {
match *self {
$( Tag::$tag => $val, )*
Tag::Unknown(n) => n,
}
}
}
}
}
// Note: These tags appear in the order they are mentioned in the TIFF reference
tags! {
// Baseline tags:
Artist 315;
// grayscale images PhotometricInterpretation 1 or 3
BitsPerSample 258;
CellLength 265; // TODO add support
CellWidth 264; // TODO add support
// palette-color images (PhotometricInterpretation 3)
ColorMap 320; // TODO add support
Compression 259; // TODO add support for 2 and 32773
Copyright 33_432;
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;
ImageDescription 270;
ImageLength 257;
ImageWidth 256;
Make 271;
MaxSampleValue 281; // TODO add support
MinSampleValue 280; // TODO add support
Model 272;
NewSubfileType 254; // TODO add support
Orientation 274; // TODO add support
PhotometricInterpretation 262;
PlanarConfiguration 284;
ResolutionUnit 296; // TODO add support
RowsPerStrip 278;
SamplesPerPixel 277;
Software 305;
StripByteCounts 279;
StripOffsets 273;
SubfileType 255; // TODO add support
Threshholding 263; // TODO add support
XResolution 282;
YResolution 283;
// Advanced tags
Predictor 317;
}
#[derive(Clone, Copy, Debug, FromPrimitive)]
pub enum Type {
BYTE = 1,
ASCII = 2,
SHORT = 3,
LONG = 4,
RATIONAL = 5,
SBYTE = 6,
SSHORT = 8,
SLONG = 9,
SRATIONAL = 10,
}
#[allow(unused_qualifications)]
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum Value {
Signed(i32),
Unsigned(u32),
List(Vec<Value>),
Rational(u32, u32),
SRational(i32, i32),
Ascii(String),
}
impl Value {
pub fn into_u32(self) -> TiffResult<u32> {
match self {
Unsigned(val) => Ok(val),
val => Err(TiffError::FormatError(
TiffFormatError::UnsignedIntegerExpected(val),
)),
}
}
pub fn into_i32(self) -> TiffResult<i32> {
match self {
Signed(val) => Ok(val),
val => Err(TiffError::FormatError(
TiffFormatError::SignedIntegerExpected(val),
)),
}
}
pub fn into_u32_vec(self) -> TiffResult<Vec<u32>> {
match self {
List(vec) => {
let mut new_vec = Vec::with_capacity(vec.len());
for v in vec {
new_vec.push(v.into_u32()?)
}
Ok(new_vec)
}
Unsigned(val) => Ok(vec![val]),
Rational(numerator, denominator) => Ok(vec![numerator, denominator]),
Ascii(val) => Ok(val.chars().map(|x| x as u32).collect()),
val => Err(TiffError::FormatError(
TiffFormatError::UnsignedIntegerExpected(val),
)),
}
}
pub fn into_i32_vec(self) -> TiffResult<Vec<i32>> {
match self {
List(vec) => {
let mut new_vec = Vec::with_capacity(vec.len());
for v in vec {
match v {
SRational(numerator, denominator) => {
new_vec.push(numerator);
new_vec.push(denominator);
}
_ => new_vec.push(v.into_i32()?)
}
}
Ok(new_vec)
}
Signed(val) => Ok(vec![val]),
SRational(numerator, denominator) => Ok(vec![numerator, denominator]),
val => Err(TiffError::FormatError(
TiffFormatError::SignedIntegerExpected(val),
)),
}
}
}
#[derive(Clone)]
pub struct Entry {
type_: Type,
count: u32,
offset: [u8; 4],
}
impl ::std::fmt::Debug for Entry {
fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
fmt.write_str(&format!(
"Entry {{ type_: {:?}, count: {:?}, offset: {:?} }}",
self.type_, self.count, &self.offset
))
}
}
impl Entry {
pub fn new(type_: Type, count: u32, offset: [u8; 4]) -> Entry {
Entry {
type_,
count,
offset,
}
}
/// Returns a mem_reader for the offset/value field
fn r(&self, byte_order: ByteOrder) -> SmartReader<io::Cursor<Vec<u8>>> {
SmartReader::wrap(io::Cursor::new(self.offset.to_vec()), byte_order)
}
pub fn val<R: Read + Seek>(
&self,
limits: &super::Limits,
decoder: &mut super::Decoder<R>,
) -> TiffResult<Value> {
let bo = decoder.byte_order();
match (self.type_, self.count) {
// TODO check if this could give wrong results
// at a different endianess of file/computer.
(Type::BYTE, 1) => Ok(Unsigned(u32::from(self.offset[0]))),
(Type::BYTE, 2) => offset_to_bytes(2, self),
(Type::BYTE, 3) => offset_to_bytes(3, self),
(Type::BYTE, 4) => offset_to_bytes(4, self),
(Type::BYTE, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
Ok(Unsigned(u32::from(decoder.read_byte()?)))
}),
(Type::SBYTE, 1) => Ok(Signed(i32::from(self.offset[0] as i8))),
(Type::SBYTE, 2) => offset_to_sbytes(2, self),
(Type::SBYTE, 3) => offset_to_sbytes(3, self),
(Type::SBYTE, 4) => offset_to_sbytes(4, self),
(Type::SBYTE, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
Ok(Signed(i32::from(decoder.read_byte()? as i8)))
}),
(Type::SHORT, 1) => Ok(Unsigned(u32::from(self.r(bo).read_u16()?))),
(Type::SSHORT, 1) => Ok(Signed(i32::from(self.r(bo).read_i16()?))),
(Type::SHORT, 2) => {
let mut r = self.r(bo);
Ok(List(vec![
Unsigned(u32::from(r.read_u16()?)),
Unsigned(u32::from(r.read_u16()?)),
]))
}
(Type::SSHORT, 2) => {
let mut r = self.r(bo);
Ok(List(vec![
Signed(i32::from(r.read_i16()?)),
Signed(i32::from(r.read_i16()?)),
]))
}
(Type::SHORT, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
Ok(Unsigned(u32::from(decoder.read_short()?)))
}),
(Type::SSHORT, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
Ok(Signed(i32::from(decoder.read_sshort()?)))
}),
(Type::LONG, 1) => Ok(Unsigned(self.r(bo).read_u32()?)),
(Type::SLONG, 1) => Ok(Signed(self.r(bo).read_i32()?)),
(Type::LONG, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
Ok(Unsigned(decoder.read_long()?))
}),
(Type::SLONG, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
Ok(Signed(decoder.read_slong()?))
}),
(Type::RATIONAL, 1) => {
decoder.goto_offset(self.r(bo).read_u32()?)?;
let numerator = decoder.read_long()?;
let denominator = decoder.read_long()?;
Ok(Rational(numerator, denominator))
}
(Type::SRATIONAL, 1) => {
decoder.goto_offset(self.r(bo).read_u32()?)?;
let numerator = decoder.read_slong()?;
let denominator = decoder.read_slong()?;
Ok(SRational(numerator, denominator))
}
(Type::RATIONAL, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
Ok(Rational(
decoder.read_long()?,
decoder.read_long()?,
))
}),
(Type::SRATIONAL, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
Ok(SRational(
decoder.read_slong()?,
decoder.read_slong()?,
))
}),
(Type::ASCII, n) => {
if n as usize > limits.decoding_buffer_size {
return Err(TiffError::LimitsExceeded);
}
decoder.goto_offset(self.r(bo).read_u32()?)?;
let string = decoder.read_string(n as usize)?;
Ok(Ascii(string))
}
_ => Err(TiffError::UnsupportedError(
TiffUnsupportedError::UnsupportedDataType,
)),
}
}
#[inline]
fn decode_offset<R, F>(&self, value_count: u32, bo: ByteOrder, limits: &super::Limits, decoder: &mut super::Decoder<R>, decode_fn: F) -> TiffResult<Value>
where
R: Read + Seek,
F: Fn(&mut super::Decoder<R>) -> TiffResult<Value>,
{
if value_count as usize > limits.decoding_buffer_size / mem::size_of::<Value>() {
return Err(TiffError::LimitsExceeded);
}
let mut v = Vec::with_capacity(value_count as usize);
decoder.goto_offset(self.r(bo).read_u32()?)?;
for _ in 0..value_count {
v.push(decode_fn(decoder)?)
}
Ok(List(v))
}
}
/// Extracts a list of BYTE tags stored in an offset
#[inline]
fn offset_to_bytes(n: usize, entry: &Entry) -> TiffResult<Value> {
Ok(List(
entry.offset[0..n]
.iter()
.map(|&e| Unsigned(u32::from(e)))
.collect()
))
}
/// Extracts a list of SBYTE tags stored in an offset
#[inline]
fn offset_to_sbytes(n: usize, entry: &Entry) -> TiffResult<Value> {
Ok(List(
entry.offset[0..n]
.iter()
.map(|&e| Signed(i32::from(e as i8)))
.collect()
))
}
/// Type representing an Image File Directory
pub type Directory = HashMap<Tag, Entry>;