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fparkan/vendor/image/src/codecs/bmp/decoder.rs

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Initial vendor packages Signed-off-by: Valentin Popov <valentin@popov.link>
2024-01-08 01:21:28 +04:00
use std::cmp::{self, Ordering};
use std::convert::TryFrom;
use std::io::{self, Cursor, Read, Seek, SeekFrom};
use std::iter::{repeat, Iterator, Rev};
use std::marker::PhantomData;
use std::slice::ChunksMut;
use std::{error, fmt, mem};
use byteorder::{LittleEndian, ReadBytesExt};
use crate::color::ColorType;
use crate::error::{
DecodingError, ImageError, ImageResult, UnsupportedError, UnsupportedErrorKind,
};
use crate::image::{self, ImageDecoder, ImageDecoderRect, ImageFormat, Progress};
const BITMAPCOREHEADER_SIZE: u32 = 12;
const BITMAPINFOHEADER_SIZE: u32 = 40;
const BITMAPV2HEADER_SIZE: u32 = 52;
const BITMAPV3HEADER_SIZE: u32 = 56;
const BITMAPV4HEADER_SIZE: u32 = 108;
const BITMAPV5HEADER_SIZE: u32 = 124;
static LOOKUP_TABLE_3_BIT_TO_8_BIT: [u8; 8] = [0, 36, 73, 109, 146, 182, 219, 255];
static LOOKUP_TABLE_4_BIT_TO_8_BIT: [u8; 16] = [
0, 17, 34, 51, 68, 85, 102, 119, 136, 153, 170, 187, 204, 221, 238, 255,
];
static LOOKUP_TABLE_5_BIT_TO_8_BIT: [u8; 32] = [
0, 8, 16, 25, 33, 41, 49, 58, 66, 74, 82, 90, 99, 107, 115, 123, 132, 140, 148, 156, 165, 173,
181, 189, 197, 206, 214, 222, 230, 239, 247, 255,
];
static LOOKUP_TABLE_6_BIT_TO_8_BIT: [u8; 64] = [
0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93,
97, 101, 105, 109, 113, 117, 121, 125, 130, 134, 138, 142, 146, 150, 154, 158, 162, 166, 170,
174, 178, 182, 186, 190, 194, 198, 202, 206, 210, 215, 219, 223, 227, 231, 235, 239, 243, 247,
251, 255,
];
static R5_G5_B5_COLOR_MASK: Bitfields = Bitfields {
r: Bitfield { len: 5, shift: 10 },
g: Bitfield { len: 5, shift: 5 },
b: Bitfield { len: 5, shift: 0 },
a: Bitfield { len: 0, shift: 0 },
};
const R8_G8_B8_COLOR_MASK: Bitfields = Bitfields {
r: Bitfield { len: 8, shift: 24 },
g: Bitfield { len: 8, shift: 16 },
b: Bitfield { len: 8, shift: 8 },
a: Bitfield { len: 0, shift: 0 },
};
const R8_G8_B8_A8_COLOR_MASK: Bitfields = Bitfields {
r: Bitfield { len: 8, shift: 16 },
g: Bitfield { len: 8, shift: 8 },
b: Bitfield { len: 8, shift: 0 },
a: Bitfield { len: 8, shift: 24 },
};
const RLE_ESCAPE: u8 = 0;
const RLE_ESCAPE_EOL: u8 = 0;
const RLE_ESCAPE_EOF: u8 = 1;
const RLE_ESCAPE_DELTA: u8 = 2;
/// The maximum width/height the decoder will process.
const MAX_WIDTH_HEIGHT: i32 = 0xFFFF;
#[derive(PartialEq, Copy, Clone)]
enum ImageType {
Palette,
RGB16,
RGB24,
RGB32,
RGBA32,
RLE8,
RLE4,
Bitfields16,
Bitfields32,
}
#[derive(PartialEq)]
enum BMPHeaderType {
Core,
Info,
V2,
V3,
V4,
V5,
}
#[derive(PartialEq)]
enum FormatFullBytes {
RGB24,
RGB32,
RGBA32,
Format888,
}
enum Chunker<'a> {
FromTop(ChunksMut<'a, u8>),
FromBottom(Rev<ChunksMut<'a, u8>>),
}
pub(crate) struct RowIterator<'a> {
chunks: Chunker<'a>,
}
impl<'a> Iterator for RowIterator<'a> {
type Item = &'a mut [u8];
#[inline(always)]
fn next(&mut self) -> Option<&'a mut [u8]> {
match self.chunks {
Chunker::FromTop(ref mut chunks) => chunks.next(),
Chunker::FromBottom(ref mut chunks) => chunks.next(),
}
}
}
/// All errors that can occur when attempting to parse a BMP
#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
enum DecoderError {
// Failed to decompress RLE data.
CorruptRleData,
/// The bitfield mask interleaves set and unset bits
BitfieldMaskNonContiguous,
/// Bitfield mask invalid (e.g. too long for specified type)
BitfieldMaskInvalid,
/// Bitfield (of the specified width – 16- or 32-bit) mask not present
BitfieldMaskMissing(u32),
/// Bitfield (of the specified width – 16- or 32-bit) masks not present
BitfieldMasksMissing(u32),
/// BMP's "BM" signature wrong or missing
BmpSignatureInvalid,
/// More than the exactly one allowed plane specified by the format
MoreThanOnePlane,
/// Invalid amount of bits per channel for the specified image type
InvalidChannelWidth(ChannelWidthError, u16),
/// The width is negative
NegativeWidth(i32),
/// One of the dimensions is larger than a soft limit
ImageTooLarge(i32, i32),
/// The height is `i32::min_value()`
///
/// General negative heights specify top-down DIBs
InvalidHeight,
/// Specified image type is invalid for top-down BMPs (i.e. is compressed)
ImageTypeInvalidForTopDown(u32),
/// Image type not currently recognized by the decoder
ImageTypeUnknown(u32),
/// Bitmap header smaller than the core header
HeaderTooSmall(u32),
/// The palette is bigger than allowed by the bit count of the BMP
PaletteSizeExceeded {
colors_used: u32,
bit_count: u16,
},
}
impl fmt::Display for DecoderError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
DecoderError::CorruptRleData => f.write_str("Corrupt RLE data"),
DecoderError::BitfieldMaskNonContiguous => f.write_str("Non-contiguous bitfield mask"),
DecoderError::BitfieldMaskInvalid => f.write_str("Invalid bitfield mask"),
DecoderError::BitfieldMaskMissing(bb) => {
f.write_fmt(format_args!("Missing {}-bit bitfield mask", bb))
}
DecoderError::BitfieldMasksMissing(bb) => {
f.write_fmt(format_args!("Missing {}-bit bitfield masks", bb))
}
DecoderError::BmpSignatureInvalid => f.write_str("BMP signature not found"),
DecoderError::MoreThanOnePlane => f.write_str("More than one plane"),
DecoderError::InvalidChannelWidth(tp, n) => {
f.write_fmt(format_args!("Invalid channel bit count for {}: {}", tp, n))
}
DecoderError::NegativeWidth(w) => f.write_fmt(format_args!("Negative width ({})", w)),
DecoderError::ImageTooLarge(w, h) => f.write_fmt(format_args!(
"Image too large (one of ({}, {}) > soft limit of {})",
w, h, MAX_WIDTH_HEIGHT
)),
DecoderError::InvalidHeight => f.write_str("Invalid height"),
DecoderError::ImageTypeInvalidForTopDown(tp) => f.write_fmt(format_args!(
"Invalid image type {} for top-down image.",
tp
)),
DecoderError::ImageTypeUnknown(tp) => {
f.write_fmt(format_args!("Unknown image compression type {}", tp))
}
DecoderError::HeaderTooSmall(s) => {
f.write_fmt(format_args!("Bitmap header too small ({} bytes)", s))
}
DecoderError::PaletteSizeExceeded {
colors_used,
bit_count,
} => f.write_fmt(format_args!(
"Palette size {} exceeds maximum size for BMP with bit count of {}",
colors_used, bit_count
)),
}
}
}
impl From<DecoderError> for ImageError {
fn from(e: DecoderError) -> ImageError {
ImageError::Decoding(DecodingError::new(ImageFormat::Bmp.into(), e))
}
}
impl error::Error for DecoderError {}
/// Distinct image types whose saved channel width can be invalid
#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
enum ChannelWidthError {
/// RGB
Rgb,
/// 8-bit run length encoding
Rle8,
/// 4-bit run length encoding
Rle4,
/// Bitfields (16- or 32-bit)
Bitfields,
}
impl fmt::Display for ChannelWidthError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str(match self {
ChannelWidthError::Rgb => "RGB",
ChannelWidthError::Rle8 => "RLE8",
ChannelWidthError::Rle4 => "RLE4",
ChannelWidthError::Bitfields => "bitfields",
})
}
}
/// Convenience function to check if the combination of width, length and number of
/// channels would result in a buffer that would overflow.
fn check_for_overflow(width: i32, length: i32, channels: usize) -> ImageResult<()> {
num_bytes(width, length, channels)
.map(|_| ())
.ok_or_else(|| {
ImageError::Unsupported(UnsupportedError::from_format_and_kind(
ImageFormat::Bmp.into(),
UnsupportedErrorKind::GenericFeature(format!(
"Image dimensions ({}x{} w/{} channels) are too large",
width, length, channels
)),
))
})
}
/// Calculate how many many bytes a buffer holding a decoded image with these properties would
/// require. Returns `None` if the buffer size would overflow or if one of the sizes are negative.
fn num_bytes(width: i32, length: i32, channels: usize) -> Option<usize> {
if width <= 0 || length <= 0 {
None
} else {
match channels.checked_mul(width as usize) {
Some(n) => n.checked_mul(length as usize),
None => None,
}
}
}
/// Call the provided function on each row of the provided buffer, returning Err if the provided
/// function returns an error, extends the buffer if it's not large enough.
fn with_rows<F>(
buffer: &mut [u8],
width: i32,
height: i32,
channels: usize,
top_down: bool,
mut func: F,
) -> io::Result<()>
where
F: FnMut(&mut [u8]) -> io::Result<()>,
{
// An overflow should already have been checked for when this is called,
// though we check anyhow, as it somehow seems to increase performance slightly.
let row_width = channels.checked_mul(width as usize).unwrap();
let full_image_size = row_width.checked_mul(height as usize).unwrap();
assert_eq!(buffer.len(), full_image_size);
if !top_down {
for row in buffer.chunks_mut(row_width).rev() {
func(row)?;
}
} else {
for row in buffer.chunks_mut(row_width) {
func(row)?;
}
}
Ok(())
}
fn set_8bit_pixel_run<'a, T: Iterator<Item = &'a u8>>(
pixel_iter: &mut ChunksMut<u8>,
palette: &[[u8; 3]],
indices: T,
n_pixels: usize,
) -> bool {
for idx in indices.take(n_pixels) {
if let Some(pixel) = pixel_iter.next() {
let rgb = palette[*idx as usize];
pixel[0] = rgb[0];
pixel[1] = rgb[1];
pixel[2] = rgb[2];
} else {
return false;
}
}
true
}
fn set_4bit_pixel_run<'a, T: Iterator<Item = &'a u8>>(
pixel_iter: &mut ChunksMut<u8>,
palette: &[[u8; 3]],
indices: T,
mut n_pixels: usize,
) -> bool {
for idx in indices {
macro_rules! set_pixel {
($i:expr) => {
if n_pixels == 0 {
break;
}
if let Some(pixel) = pixel_iter.next() {
let rgb = palette[$i as usize];
pixel[0] = rgb[0];
pixel[1] = rgb[1];
pixel[2] = rgb[2];
} else {
return false;
}
n_pixels -= 1;
};
}
set_pixel!(idx >> 4);
set_pixel!(idx & 0xf);
}
true
}
#[rustfmt::skip]
fn set_2bit_pixel_run<'a, T: Iterator<Item = &'a u8>>(
pixel_iter: &mut ChunksMut<u8>,
palette: &[[u8; 3]],
indices: T,
mut n_pixels: usize,
) -> bool {
for idx in indices {
macro_rules! set_pixel {
($i:expr) => {
if n_pixels == 0 {
break;
}
if let Some(pixel) = pixel_iter.next() {
let rgb = palette[$i as usize];
pixel[0] = rgb[0];
pixel[1] = rgb[1];
pixel[2] = rgb[2];
} else {
return false;
}
n_pixels -= 1;
};
}
set_pixel!((idx >> 6) & 0x3u8);
set_pixel!((idx >> 4) & 0x3u8);
set_pixel!((idx >> 2) & 0x3u8);
set_pixel!( idx & 0x3u8);
}
true
}
fn set_1bit_pixel_run<'a, T: Iterator<Item = &'a u8>>(
pixel_iter: &mut ChunksMut<u8>,
palette: &[[u8; 3]],
indices: T,
) {
for idx in indices {
let mut bit = 0x80;
loop {
if let Some(pixel) = pixel_iter.next() {
let rgb = palette[((idx & bit) != 0) as usize];
pixel[0] = rgb[0];
pixel[1] = rgb[1];
pixel[2] = rgb[2];
} else {
return;
}
bit >>= 1;
if bit == 0 {
break;
}
}
}
}
#[derive(PartialEq, Eq)]
struct Bitfield {
shift: u32,
len: u32,
}
impl Bitfield {
fn from_mask(mask: u32, max_len: u32) -> ImageResult<Bitfield> {
if mask == 0 {
return Ok(Bitfield { shift: 0, len: 0 });
}
let mut shift = mask.trailing_zeros();
let mut len = (!(mask >> shift)).trailing_zeros();
if len != mask.count_ones() {
return Err(DecoderError::BitfieldMaskNonContiguous.into());
}
if len + shift > max_len {
return Err(DecoderError::BitfieldMaskInvalid.into());
}
if len > 8 {
shift += len - 8;
len = 8;
}
Ok(Bitfield { shift, len })
}
fn read(&self, data: u32) -> u8 {
let data = data >> self.shift;
match self.len {
1 => ((data & 0b1) * 0xff) as u8,
2 => ((data & 0b11) * 0x55) as u8,
3 => LOOKUP_TABLE_3_BIT_TO_8_BIT[(data & 0b00_0111) as usize],
4 => LOOKUP_TABLE_4_BIT_TO_8_BIT[(data & 0b00_1111) as usize],
5 => LOOKUP_TABLE_5_BIT_TO_8_BIT[(data & 0b01_1111) as usize],
6 => LOOKUP_TABLE_6_BIT_TO_8_BIT[(data & 0b11_1111) as usize],
7 => ((data & 0x7f) << 1 | (data & 0x7f) >> 6) as u8,
8 => (data & 0xff) as u8,
_ => panic!(),
}
}
}
#[derive(PartialEq, Eq)]
struct Bitfields {
r: Bitfield,
g: Bitfield,
b: Bitfield,
a: Bitfield,
}
impl Bitfields {
fn from_mask(
r_mask: u32,
g_mask: u32,
b_mask: u32,
a_mask: u32,
max_len: u32,
) -> ImageResult<Bitfields> {
let bitfields = Bitfields {
r: Bitfield::from_mask(r_mask, max_len)?,
g: Bitfield::from_mask(g_mask, max_len)?,
b: Bitfield::from_mask(b_mask, max_len)?,
a: Bitfield::from_mask(a_mask, max_len)?,
};
if bitfields.r.len == 0 || bitfields.g.len == 0 || bitfields.b.len == 0 {
return Err(DecoderError::BitfieldMaskMissing(max_len).into());
}
Ok(bitfields)
}
}
/// A bmp decoder
pub struct BmpDecoder<R> {
reader: R,
bmp_header_type: BMPHeaderType,
indexed_color: bool,
width: i32,
height: i32,
data_offset: u64,
top_down: bool,
no_file_header: bool,
add_alpha_channel: bool,
has_loaded_metadata: bool,
image_type: ImageType,
bit_count: u16,
colors_used: u32,
palette: Option<Vec<[u8; 3]>>,
bitfields: Option<Bitfields>,
}
enum RLEInsn {
EndOfFile,
EndOfRow,
Delta(u8, u8),
Absolute(u8, Vec<u8>),
PixelRun(u8, u8),
}
impl<R: Read + Seek> BmpDecoder<R> {
fn new_decoder(reader: R) -> BmpDecoder<R> {
BmpDecoder {
reader,
bmp_header_type: BMPHeaderType::Info,
indexed_color: false,
width: 0,
height: 0,
data_offset: 0,
top_down: false,
no_file_header: false,
add_alpha_channel: false,
has_loaded_metadata: false,
image_type: ImageType::Palette,
bit_count: 0,
colors_used: 0,
palette: None,
bitfields: None,
}
}
/// Create a new decoder that decodes from the stream ```r```
pub fn new(reader: R) -> ImageResult<BmpDecoder<R>> {
let mut decoder = Self::new_decoder(reader);
decoder.read_metadata()?;
Ok(decoder)
}
/// Create a new decoder that decodes from the stream ```r``` without first
/// reading a BITMAPFILEHEADER. This is useful for decoding the CF_DIB format
/// directly from the Windows clipboard.
pub fn new_without_file_header(reader: R) -> ImageResult<BmpDecoder<R>> {
let mut decoder = Self::new_decoder(reader);
decoder.no_file_header = true;
decoder.read_metadata()?;
Ok(decoder)
}
#[cfg(feature = "ico")]
pub(crate) fn new_with_ico_format(reader: R) -> ImageResult<BmpDecoder<R>> {
let mut decoder = Self::new_decoder(reader);
decoder.read_metadata_in_ico_format()?;
Ok(decoder)
}
/// If true, the palette in BMP does not apply to the image even if it is found.
/// In other words, the output image is the indexed color.
pub fn set_indexed_color(&mut self, indexed_color: bool) {
self.indexed_color = indexed_color;
}
#[cfg(feature = "ico")]
pub(crate) fn reader(&mut self) -> &mut R {
&mut self.reader
}
fn read_file_header(&mut self) -> ImageResult<()> {
if self.no_file_header {
return Ok(());
}
let mut signature = [0; 2];
self.reader.read_exact(&mut signature)?;
if signature != b"BM"[..] {
return Err(DecoderError::BmpSignatureInvalid.into());
}
// The next 8 bytes represent file size, followed the 4 reserved bytes
// We're not interesting these values
self.reader.read_u32::<LittleEndian>()?;
self.reader.read_u32::<LittleEndian>()?;
self.data_offset = u64::from(self.reader.read_u32::<LittleEndian>()?);
Ok(())
}
/// Read BITMAPCOREHEADER https://msdn.microsoft.com/en-us/library/vs/alm/dd183372(v=vs.85).aspx
///
/// returns Err if any of the values are invalid.
fn read_bitmap_core_header(&mut self) -> ImageResult<()> {
// As height/width values in BMP files with core headers are only 16 bits long,
// they won't be larger than `MAX_WIDTH_HEIGHT`.
self.width = i32::from(self.reader.read_u16::<LittleEndian>()?);
self.height = i32::from(self.reader.read_u16::<LittleEndian>()?);
check_for_overflow(self.width, self.height, self.num_channels())?;
// Number of planes (format specifies that this should be 1).
if self.reader.read_u16::<LittleEndian>()? != 1 {
return Err(DecoderError::MoreThanOnePlane.into());
}
self.bit_count = self.reader.read_u16::<LittleEndian>()?;
self.image_type = match self.bit_count {
1 | 4 | 8 => ImageType::Palette,
24 => ImageType::RGB24,
_ => {
return Err(DecoderError::InvalidChannelWidth(
ChannelWidthError::Rgb,
self.bit_count,
)
.into())
}
};
Ok(())
}
/// Read BITMAPINFOHEADER https://msdn.microsoft.com/en-us/library/vs/alm/dd183376(v=vs.85).aspx
/// or BITMAPV{2|3|4|5}HEADER.
///
/// returns Err if any of the values are invalid.
fn read_bitmap_info_header(&mut self) -> ImageResult<()> {
self.width = self.reader.read_i32::<LittleEndian>()?;
self.height = self.reader.read_i32::<LittleEndian>()?;
// Width can not be negative
if self.width < 0 {
return Err(DecoderError::NegativeWidth(self.width).into());
} else if self.width > MAX_WIDTH_HEIGHT || self.height > MAX_WIDTH_HEIGHT {
// Limit very large image sizes to avoid OOM issues. Images with these sizes are
// unlikely to be valid anyhow.
return Err(DecoderError::ImageTooLarge(self.width, self.height).into());
}
if self.height == i32::min_value() {
return Err(DecoderError::InvalidHeight.into());
}
// A negative height indicates a top-down DIB.
if self.height < 0 {
self.height *= -1;
self.top_down = true;
}
check_for_overflow(self.width, self.height, self.num_channels())?;
// Number of planes (format specifies that this should be 1).
if self.reader.read_u16::<LittleEndian>()? != 1 {
return Err(DecoderError::MoreThanOnePlane.into());
}
self.bit_count = self.reader.read_u16::<LittleEndian>()?;
let image_type_u32 = self.reader.read_u32::<LittleEndian>()?;
// Top-down dibs can not be compressed.
if self.top_down && image_type_u32 != 0 && image_type_u32 != 3 {
return Err(DecoderError::ImageTypeInvalidForTopDown(image_type_u32).into());
}
self.image_type = match image_type_u32 {
0 => match self.bit_count {
1 | 2 | 4 | 8 => ImageType::Palette,
16 => ImageType::RGB16,
24 => ImageType::RGB24,
32 if self.add_alpha_channel => ImageType::RGBA32,
32 => ImageType::RGB32,
_ => {
return Err(DecoderError::InvalidChannelWidth(
ChannelWidthError::Rgb,
self.bit_count,
)
.into())
}
},
1 => match self.bit_count {
8 => ImageType::RLE8,
_ => {
return Err(DecoderError::InvalidChannelWidth(
ChannelWidthError::Rle8,
self.bit_count,
)
.into())
}
},
2 => match self.bit_count {
4 => ImageType::RLE4,
_ => {
return Err(DecoderError::InvalidChannelWidth(
ChannelWidthError::Rle4,
self.bit_count,
)
.into())
}
},
3 => match self.bit_count {
16 => ImageType::Bitfields16,
32 => ImageType::Bitfields32,
_ => {
return Err(DecoderError::InvalidChannelWidth(
ChannelWidthError::Bitfields,
self.bit_count,
)
.into())
}
},
4 => {
// JPEG compression is not implemented yet.
return Err(ImageError::Unsupported(
UnsupportedError::from_format_and_kind(
ImageFormat::Bmp.into(),
UnsupportedErrorKind::GenericFeature("JPEG compression".to_owned()),
),
));
}
5 => {
// PNG compression is not implemented yet.
return Err(ImageError::Unsupported(
UnsupportedError::from_format_and_kind(
ImageFormat::Bmp.into(),
UnsupportedErrorKind::GenericFeature("PNG compression".to_owned()),
),
));
}
11 | 12 | 13 => {
// CMYK types are not implemented yet.
return Err(ImageError::Unsupported(
UnsupportedError::from_format_and_kind(
ImageFormat::Bmp.into(),
UnsupportedErrorKind::GenericFeature("CMYK format".to_owned()),
),
));
}
_ => {
// Unknown compression type.
return Err(DecoderError::ImageTypeUnknown(image_type_u32).into());
}
};
// The next 12 bytes represent data array size in bytes,
// followed the horizontal and vertical printing resolutions
// We will calculate the pixel array size using width & height of image
// We're not interesting the horz or vert printing resolutions
self.reader.read_u32::<LittleEndian>()?;
self.reader.read_u32::<LittleEndian>()?;
self.reader.read_u32::<LittleEndian>()?;
self.colors_used = self.reader.read_u32::<LittleEndian>()?;
// The next 4 bytes represent number of "important" colors
// We're not interested in this value, so we'll skip it
self.reader.read_u32::<LittleEndian>()?;
Ok(())
}
fn read_bitmasks(&mut self) -> ImageResult<()> {
let r_mask = self.reader.read_u32::<LittleEndian>()?;
let g_mask = self.reader.read_u32::<LittleEndian>()?;
let b_mask = self.reader.read_u32::<LittleEndian>()?;
let a_mask = match self.bmp_header_type {
BMPHeaderType::V3 | BMPHeaderType::V4 | BMPHeaderType::V5 => {
self.reader.read_u32::<LittleEndian>()?
}
_ => 0,
};
self.bitfields = match self.image_type {
ImageType::Bitfields16 => {
Some(Bitfields::from_mask(r_mask, g_mask, b_mask, a_mask, 16)?)
}
ImageType::Bitfields32 => {
Some(Bitfields::from_mask(r_mask, g_mask, b_mask, a_mask, 32)?)
}
_ => None,
};
if self.bitfields.is_some() && a_mask != 0 {
self.add_alpha_channel = true;
}
Ok(())
}
fn read_metadata(&mut self) -> ImageResult<()> {
if !self.has_loaded_metadata {
self.read_file_header()?;
let bmp_header_offset = self.reader.stream_position()?;
let bmp_header_size = self.reader.read_u32::<LittleEndian>()?;
let bmp_header_end = bmp_header_offset + u64::from(bmp_header_size);
self.bmp_header_type = match bmp_header_size {
BITMAPCOREHEADER_SIZE => BMPHeaderType::Core,
BITMAPINFOHEADER_SIZE => BMPHeaderType::Info,
BITMAPV2HEADER_SIZE => BMPHeaderType::V2,
BITMAPV3HEADER_SIZE => BMPHeaderType::V3,
BITMAPV4HEADER_SIZE => BMPHeaderType::V4,
BITMAPV5HEADER_SIZE => BMPHeaderType::V5,
_ if bmp_header_size < BITMAPCOREHEADER_SIZE => {
// Size of any valid header types won't be smaller than core header type.
return Err(DecoderError::HeaderTooSmall(bmp_header_size).into());
}
_ => {
return Err(ImageError::Unsupported(
UnsupportedError::from_format_and_kind(
ImageFormat::Bmp.into(),
UnsupportedErrorKind::GenericFeature(format!(
"Unknown bitmap header type (size={})",
bmp_header_size
)),
),
))
}
};
match self.bmp_header_type {
BMPHeaderType::Core => {
self.read_bitmap_core_header()?;
}
BMPHeaderType::Info
| BMPHeaderType::V2
| BMPHeaderType::V3
| BMPHeaderType::V4
| BMPHeaderType::V5 => {
self.read_bitmap_info_header()?;
}
};
match self.image_type {
ImageType::Bitfields16 | ImageType::Bitfields32 => self.read_bitmasks()?,
_ => {}
};
self.reader.seek(SeekFrom::Start(bmp_header_end))?;
match self.image_type {
ImageType::Palette | ImageType::RLE4 | ImageType::RLE8 => self.read_palette()?,
_ => {}
};
if self.no_file_header {
// Use the offset of the end of metadata instead of reading a BMP file header.
self.data_offset = self.reader.stream_position()?;
}
self.has_loaded_metadata = true;
}
Ok(())
}
#[cfg(feature = "ico")]
#[doc(hidden)]
pub fn read_metadata_in_ico_format(&mut self) -> ImageResult<()> {
self.no_file_header = true;
self.add_alpha_channel = true;
self.read_metadata()?;
// The height field in an ICO file is doubled to account for the AND mask
// (whether or not an AND mask is actually present).
self.height /= 2;
Ok(())
}
fn get_palette_size(&mut self) -> ImageResult<usize> {
match self.colors_used {
0 => Ok(1 << self.bit_count),
_ => {
if self.colors_used > 1 << self.bit_count {
return Err(DecoderError::PaletteSizeExceeded {
colors_used: self.colors_used,
bit_count: self.bit_count,
}
.into());
}
Ok(self.colors_used as usize)
}
}
}
fn bytes_per_color(&self) -> usize {
match self.bmp_header_type {
BMPHeaderType::Core => 3,
_ => 4,
}
}
fn read_palette(&mut self) -> ImageResult<()> {
const MAX_PALETTE_SIZE: usize = 256; // Palette indices are u8.
let bytes_per_color = self.bytes_per_color();
let palette_size = self.get_palette_size()?;
let max_length = MAX_PALETTE_SIZE * bytes_per_color;
let length = palette_size * bytes_per_color;
let mut buf = Vec::with_capacity(max_length);
// Resize and read the palette entries to the buffer.
// We limit the buffer to at most 256 colours to avoid any oom issues as
// 8-bit images can't reference more than 256 indexes anyhow.
buf.resize(cmp::min(length, max_length), 0);
self.reader.by_ref().read_exact(&mut buf)?;
// Allocate 256 entries even if palette_size is smaller, to prevent corrupt files from
// causing an out-of-bounds array access.
match length.cmp(&max_length) {
Ordering::Greater => {
self.reader
.seek(SeekFrom::Current((length - max_length) as i64))?;
}
Ordering::Less => buf.resize(max_length, 0),
Ordering::Equal => (),
}
let p: Vec<[u8; 3]> = (0..MAX_PALETTE_SIZE)
.map(|i| {
let b = buf[bytes_per_color * i];
let g = buf[bytes_per_color * i + 1];
let r = buf[bytes_per_color * i + 2];
[r, g, b]
})
.collect();
self.palette = Some(p);
Ok(())
}
/// Get the palette that is embedded in the BMP image, if any.
pub fn get_palette(&self) -> Option<&[[u8; 3]]> {
self.palette.as_ref().map(|vec| &vec[..])
}
fn num_channels(&self) -> usize {
if self.indexed_color {
1
} else if self.add_alpha_channel {
4
} else {
3
}
}
fn rows<'a>(&self, pixel_data: &'a mut [u8]) -> RowIterator<'a> {
let stride = self.width as usize * self.num_channels();
if self.top_down {
RowIterator {
chunks: Chunker::FromTop(pixel_data.chunks_mut(stride)),
}
} else {
RowIterator {
chunks: Chunker::FromBottom(pixel_data.chunks_mut(stride).rev()),
}
}
}
fn read_palettized_pixel_data(&mut self, buf: &mut [u8]) -> ImageResult<()> {
let num_channels = self.num_channels();
let row_byte_length = ((i32::from(self.bit_count) * self.width + 31) / 32 * 4) as usize;
let mut indices = vec![0; row_byte_length];
let palette = self.palette.as_ref().unwrap();
let bit_count = self.bit_count;
let reader = &mut self.reader;
let width = self.width as usize;
let skip_palette = self.indexed_color;
reader.seek(SeekFrom::Start(self.data_offset))?;
if num_channels == 4 {
buf.chunks_exact_mut(4).for_each(|c| c[3] = 0xFF);
}
with_rows(
buf,
self.width,
self.height,
num_channels,
self.top_down,
|row| {
reader.read_exact(&mut indices)?;
if skip_palette {
row.clone_from_slice(&indices[0..width]);
} else {
let mut pixel_iter = row.chunks_mut(num_channels);
match bit_count {
1 => {
set_1bit_pixel_run(&mut pixel_iter, palette, indices.iter());
}
2 => {
set_2bit_pixel_run(&mut pixel_iter, palette, indices.iter(), width);
}
4 => {
set_4bit_pixel_run(&mut pixel_iter, palette, indices.iter(), width);
}
8 => {
set_8bit_pixel_run(&mut pixel_iter, palette, indices.iter(), width);
}
_ => panic!(),
};
}
Ok(())
},
)?;
Ok(())
}
fn read_16_bit_pixel_data(
&mut self,
buf: &mut [u8],
bitfields: Option<&Bitfields>,
) -> ImageResult<()> {
let num_channels = self.num_channels();
let row_padding_len = self.width as usize % 2 * 2;
let row_padding = &mut [0; 2][..row_padding_len];
let bitfields = match bitfields {
Some(b) => b,
None => self.bitfields.as_ref().unwrap(),
};
let reader = &mut self.reader;
reader.seek(SeekFrom::Start(self.data_offset))?;
with_rows(
buf,
self.width,
self.height,
num_channels,
self.top_down,
|row| {
for pixel in row.chunks_mut(num_channels) {
let data = u32::from(reader.read_u16::<LittleEndian>()?);
pixel[0] = bitfields.r.read(data);
pixel[1] = bitfields.g.read(data);
pixel[2] = bitfields.b.read(data);
if num_channels == 4 {
if bitfields.a.len != 0 {
pixel[3] = bitfields.a.read(data);
} else {
pixel[3] = 0xFF;
}
}
}
reader.read_exact(row_padding)
},
)?;
Ok(())
}
/// Read image data from a reader in 32-bit formats that use bitfields.
fn read_32_bit_pixel_data(&mut self, buf: &mut [u8]) -> ImageResult<()> {
let num_channels = self.num_channels();
let bitfields = self.bitfields.as_ref().unwrap();
let reader = &mut self.reader;
reader.seek(SeekFrom::Start(self.data_offset))?;
with_rows(
buf,
self.width,
self.height,
num_channels,
self.top_down,
|row| {
for pixel in row.chunks_mut(num_channels) {
let data = reader.read_u32::<LittleEndian>()?;
pixel[0] = bitfields.r.read(data);
pixel[1] = bitfields.g.read(data);
pixel[2] = bitfields.b.read(data);
if num_channels == 4 {
if bitfields.a.len != 0 {
pixel[3] = bitfields.a.read(data);
} else {
pixel[3] = 0xff;
}
}
}
Ok(())
},
)?;
Ok(())
}
/// Read image data from a reader where the colours are stored as 8-bit values (24 or 32-bit).
fn read_full_byte_pixel_data(
&mut self,
buf: &mut [u8],
format: &FormatFullBytes,
) -> ImageResult<()> {
let num_channels = self.num_channels();
let row_padding_len = match *format {
FormatFullBytes::RGB24 => (4 - (self.width as usize * 3) % 4) % 4,
_ => 0,
};
let row_padding = &mut [0; 4][..row_padding_len];
self.reader.seek(SeekFrom::Start(self.data_offset))?;
let reader = &mut self.reader;
with_rows(
buf,
self.width,
self.height,
num_channels,
self.top_down,
|row| {
for pixel in row.chunks_mut(num_channels) {
if *format == FormatFullBytes::Format888 {
reader.read_u8()?;
}
// Read the colour values (b, g, r).
// Reading 3 bytes and reversing them is significantly faster than reading one
// at a time.
reader.read_exact(&mut pixel[0..3])?;
pixel[0..3].reverse();
if *format == FormatFullBytes::RGB32 {
reader.read_u8()?;
}
// Read the alpha channel if present
if *format == FormatFullBytes::RGBA32 {
reader.read_exact(&mut pixel[3..4])?;
} else if num_channels == 4 {
pixel[3] = 0xFF;
}
}
reader.read_exact(row_padding)
},
)?;
Ok(())
}
fn read_rle_data(&mut self, buf: &mut [u8], image_type: ImageType) -> ImageResult<()> {
// Seek to the start of the actual image data.
self.reader.seek(SeekFrom::Start(self.data_offset))?;
let num_channels = self.num_channels();
let p = self.palette.as_ref().unwrap();
// Handling deltas in the RLE scheme means that we need to manually
// iterate through rows and pixels. Even if we didn't have to handle
// deltas, we have to ensure that a single runlength doesn't straddle
// two rows.
let mut row_iter = self.rows(buf);
while let Some(row) = row_iter.next() {
let mut pixel_iter = row.chunks_mut(num_channels);
let mut x = 0;
loop {
let instruction = {
let control_byte = self.reader.read_u8()?;
match control_byte {
RLE_ESCAPE => {
let op = self.reader.read_u8()?;
match op {
RLE_ESCAPE_EOL => RLEInsn::EndOfRow,
RLE_ESCAPE_EOF => RLEInsn::EndOfFile,
RLE_ESCAPE_DELTA => {
let xdelta = self.reader.read_u8()?;
let ydelta = self.reader.read_u8()?;
RLEInsn::Delta(xdelta, ydelta)
}
_ => {
let mut length = op as usize;
if self.image_type == ImageType::RLE4 {
length = (length + 1) / 2;
}
length += length & 1;
let mut buffer = vec![0; length];
self.reader.read_exact(&mut buffer)?;
RLEInsn::Absolute(op, buffer)
}
}
}
_ => {
let palette_index = self.reader.read_u8()?;
RLEInsn::PixelRun(control_byte, palette_index)
}
}
};
match instruction {
RLEInsn::EndOfFile => {
pixel_iter.for_each(|p| p.fill(0));
row_iter.for_each(|r| r.fill(0));
return Ok(());
}
RLEInsn::EndOfRow => {
pixel_iter.for_each(|p| p.fill(0));
break;
}
RLEInsn::Delta(x_delta, y_delta) => {
// The msdn site on bitmap compression doesn't specify
// what happens to the values skipped when encountering
// a delta code, however IE and the windows image
// preview seems to replace them with black pixels,
// so we stick to that.
if y_delta > 0 {
// Zero out the remainder of the current row.
pixel_iter.for_each(|p| p.fill(0));
// If any full rows are skipped, zero them out.
for _ in 1..y_delta {
let row = row_iter.next().ok_or(DecoderError::CorruptRleData)?;
row.fill(0);
}
// Set the pixel iterator to the start of the next row.
pixel_iter = row_iter
.next()
.ok_or(DecoderError::CorruptRleData)?
.chunks_mut(num_channels);
// Zero out the pixels up to the current point in the row.
for _ in 0..x {
pixel_iter
.next()
.ok_or(DecoderError::CorruptRleData)?
.fill(0);
}
}
for _ in 0..x_delta {
let pixel = pixel_iter.next().ok_or(DecoderError::CorruptRleData)?;
pixel.fill(0);
}
x += x_delta as usize;
}
RLEInsn::Absolute(length, indices) => {
// Absolute mode cannot span rows, so if we run
// out of pixels to process, we should stop
// processing the image.
match image_type {
ImageType::RLE8 => {
if !set_8bit_pixel_run(
&mut pixel_iter,
p,
indices.iter(),
length as usize,
) {
return Err(DecoderError::CorruptRleData.into());
}
}
ImageType::RLE4 => {
if !set_4bit_pixel_run(
&mut pixel_iter,
p,
indices.iter(),
length as usize,
) {
return Err(DecoderError::CorruptRleData.into());
}
}
_ => unreachable!(),
}
x += length as usize;
}
RLEInsn::PixelRun(n_pixels, palette_index) => {
// A pixel run isn't allowed to span rows, but we
// simply continue on to the next row if we run
// out of pixels to set.
match image_type {
ImageType::RLE8 => {
if !set_8bit_pixel_run(
&mut pixel_iter,
p,
repeat(&palette_index),
n_pixels as usize,
) {
return Err(DecoderError::CorruptRleData.into());
}
}
ImageType::RLE4 => {
if !set_4bit_pixel_run(
&mut pixel_iter,
p,
repeat(&palette_index),
n_pixels as usize,
) {
return Err(DecoderError::CorruptRleData.into());
}
}
_ => unreachable!(),
}
x += n_pixels as usize;
}
}
}
}
Ok(())
}
/// Read the actual data of the image. This function is deliberately not public because it
/// cannot be called multiple times without seeking back the underlying reader in between.
pub(crate) fn read_image_data(&mut self, buf: &mut [u8]) -> ImageResult<()> {
match self.image_type {
ImageType::Palette => self.read_palettized_pixel_data(buf),
ImageType::RGB16 => self.read_16_bit_pixel_data(buf, Some(&R5_G5_B5_COLOR_MASK)),
ImageType::RGB24 => self.read_full_byte_pixel_data(buf, &FormatFullBytes::RGB24),
ImageType::RGB32 => self.read_full_byte_pixel_data(buf, &FormatFullBytes::RGB32),
ImageType::RGBA32 => self.read_full_byte_pixel_data(buf, &FormatFullBytes::RGBA32),
ImageType::RLE8 => self.read_rle_data(buf, ImageType::RLE8),
ImageType::RLE4 => self.read_rle_data(buf, ImageType::RLE4),
ImageType::Bitfields16 => match self.bitfields {
Some(_) => self.read_16_bit_pixel_data(buf, None),
None => Err(DecoderError::BitfieldMasksMissing(16).into()),
},
ImageType::Bitfields32 => match self.bitfields {
Some(R8_G8_B8_COLOR_MASK) => {
self.read_full_byte_pixel_data(buf, &FormatFullBytes::Format888)
}
Some(R8_G8_B8_A8_COLOR_MASK) => {
self.read_full_byte_pixel_data(buf, &FormatFullBytes::RGBA32)
}
Some(_) => self.read_32_bit_pixel_data(buf),
None => Err(DecoderError::BitfieldMasksMissing(32).into()),
},
}
}
}
/// Wrapper struct around a `Cursor<Vec<u8>>`
pub struct BmpReader<R>(Cursor<Vec<u8>>, PhantomData<R>);
impl<R> Read for BmpReader<R> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.0.read(buf)
}
fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
if self.0.position() == 0 && buf.is_empty() {
mem::swap(buf, self.0.get_mut());
Ok(buf.len())
} else {
self.0.read_to_end(buf)
}
}
}
impl<'a, R: 'a + Read + Seek> ImageDecoder<'a> for BmpDecoder<R> {
type Reader = BmpReader<R>;
fn dimensions(&self) -> (u32, u32) {
(self.width as u32, self.height as u32)
}
fn color_type(&self) -> ColorType {
if self.indexed_color {
ColorType::L8
} else if self.add_alpha_channel {
ColorType::Rgba8
} else {
ColorType::Rgb8
}
}
fn into_reader(self) -> ImageResult<Self::Reader> {
Ok(BmpReader(
Cursor::new(image::decoder_to_vec(self)?),
PhantomData,
))
}
fn read_image(mut self, buf: &mut [u8]) -> ImageResult<()> {
assert_eq!(u64::try_from(buf.len()), Ok(self.total_bytes()));
self.read_image_data(buf)
}
}
impl<'a, R: 'a + Read + Seek> ImageDecoderRect<'a> for BmpDecoder<R> {
fn read_rect_with_progress<F: Fn(Progress)>(
&mut self,
x: u32,
y: u32,
width: u32,
height: u32,
buf: &mut [u8],
progress_callback: F,
) -> ImageResult<()> {
let start = self.reader.stream_position()?;
image::load_rect(
x,
y,
width,
height,
buf,
progress_callback,
self,
|_, _| Ok(()),
|s, buf| s.read_image_data(buf),
)?;
self.reader.seek(SeekFrom::Start(start))?;
Ok(())
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_bitfield_len() {
for len in 1..9 {
let bitfield = Bitfield { shift: 0, len };
for i in 0..(1 << len) {
let read = bitfield.read(i);
let calc = (i as f64 / ((1 << len) - 1) as f64 * 255f64).round() as u8;
if read != calc {
println!("len:{} i:{} read:{} calc:{}", len, i, read, calc);
}
assert_eq!(read, calc);
}
}
}
#[test]
fn read_rect() {
let f = std::fs::File::open("tests/images/bmp/images/Core_8_Bit.bmp").unwrap();
let mut decoder = super::BmpDecoder::new(f).unwrap();
let mut buf: Vec<u8> = vec![0; 8 * 8 * 3];
decoder.read_rect(0, 0, 8, 8, &mut *buf).unwrap();
}
#[test]
fn read_rle_too_short() {
let data = vec![
0x42, 0x4d, 0x04, 0xee, 0xfe, 0xff, 0xff, 0x10, 0xff, 0x00, 0x04, 0x00, 0x00, 0x00,
0x7c, 0x00, 0x00, 0x00, 0x0c, 0x41, 0x00, 0x00, 0x07, 0x10, 0x00, 0x00, 0x01, 0x00,
0x04, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0d, 0x00, 0x00, 0x00,
0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xfe, 0x21,
0xff, 0x00, 0x66, 0x61, 0x72, 0x62, 0x66, 0x65, 0x6c, 0x64, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0xff, 0xd8, 0xff, 0x00, 0x00, 0x19, 0x51, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfa, 0xff, 0x00, 0x00, 0x00,
0x00, 0x01, 0x00, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0f, 0x00,
0x00, 0x00, 0x00, 0x2d, 0x31, 0x31, 0x35, 0x36, 0x00, 0xff, 0x00, 0x00, 0x52, 0x3a,
0x37, 0x30, 0x7e, 0x71, 0x63, 0x91, 0x5a, 0x04, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00,
0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x2d, 0x35, 0x37, 0x00, 0xff, 0x00, 0x00, 0x52,
0x3a, 0x37, 0x30, 0x7e, 0x71, 0x63, 0x91, 0x5a, 0x04, 0x05, 0x3c, 0x00, 0x00, 0x11,
0x00, 0x5d, 0x7a, 0x82, 0xb7, 0xca, 0x2d, 0x31, 0xff, 0xff, 0xc7, 0x95, 0x33, 0x2e,
0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7c, 0x00,
0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0x66, 0x00, 0x4d,
0x4d, 0x00, 0x2a, 0x00,
];
let decoder = BmpDecoder::new(Cursor::new(&data)).unwrap();
let mut buf = vec![0; usize::try_from(decoder.total_bytes()).unwrap()];
assert!(decoder.read_image(&mut buf).is_ok());
}
#[test]
fn test_no_header() {
let tests = [
"Info_R8_G8_B8.bmp",
"Info_A8_R8_G8_B8.bmp",
"Info_8_Bit.bmp",
"Info_4_Bit.bmp",
"Info_1_Bit.bmp",
];
for name in &tests {
let path = format!("tests/images/bmp/images/{name}");
let ref_img = crate::open(&path).unwrap();
let mut data = std::fs::read(&path).unwrap();
// skip the BITMAPFILEHEADER
let slice = &mut data[14..];
let decoder = BmpDecoder::new_without_file_header(Cursor::new(slice)).unwrap();
let no_hdr_img = crate::DynamicImage::from_decoder(decoder).unwrap();
assert_eq!(ref_img, no_hdr_img);
}
}
}
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