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image.rs
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image.rs
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#![allow(clippy::too_many_arguments)]
use std::ffi::OsStr;
use std::io;
use std::io::Read;
use std::ops::{Deref, DerefMut};
use std::path::Path;
use std::usize;
use crate::color::{ColorType, ExtendedColorType};
use crate::error::{
ImageError, ImageFormatHint, ImageResult, LimitError, LimitErrorKind, ParameterError,
ParameterErrorKind,
};
use crate::math::Rect;
use crate::traits::Pixel;
use crate::ImageBuffer;
use crate::animation::Frames;
#[cfg(feature = "pnm")]
use crate::codecs::pnm::PnmSubtype;
/// An enumeration of supported image formats.
/// Not all formats support both encoding and decoding.
#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
#[non_exhaustive]
pub enum ImageFormat {
/// An Image in PNG Format
Png,
/// An Image in JPEG Format
Jpeg,
/// An Image in GIF Format
Gif,
/// An Image in WEBP Format
WebP,
/// An Image in general PNM Format
Pnm,
/// An Image in TIFF Format
Tiff,
/// An Image in TGA Format
Tga,
/// An Image in DDS Format
Dds,
/// An Image in BMP Format
Bmp,
/// An Image in ICO Format
Ico,
/// An Image in Radiance HDR Format
Hdr,
/// An Image in OpenEXR Format
OpenExr,
/// An Image in farbfeld Format
Farbfeld,
/// An Image in AVIF format.
Avif,
/// An Image in QOI format.
Qoi,
}
impl ImageFormat {
/// Return the image format specified by a path's file extension.
///
/// # Example
///
/// ```
/// use image::ImageFormat;
///
/// let format = ImageFormat::from_extension("jpg");
/// assert_eq!(format, Some(ImageFormat::Jpeg));
/// ```
#[inline]
pub fn from_extension<S>(ext: S) -> Option<Self>
where
S: AsRef<OsStr>,
{
// thin wrapper function to strip generics
fn inner(ext: &OsStr) -> Option<ImageFormat> {
let ext = ext.to_str()?.to_ascii_lowercase();
Some(match ext.as_str() {
"avif" => ImageFormat::Avif,
"jpg" | "jpeg" => ImageFormat::Jpeg,
"png" => ImageFormat::Png,
"gif" => ImageFormat::Gif,
"webp" => ImageFormat::WebP,
"tif" | "tiff" => ImageFormat::Tiff,
"tga" => ImageFormat::Tga,
"dds" => ImageFormat::Dds,
"bmp" => ImageFormat::Bmp,
"ico" => ImageFormat::Ico,
"hdr" => ImageFormat::Hdr,
"exr" => ImageFormat::OpenExr,
"pbm" | "pam" | "ppm" | "pgm" => ImageFormat::Pnm,
"ff" | "farbfeld" => ImageFormat::Farbfeld,
"qoi" => ImageFormat::Qoi,
_ => return None,
})
}
inner(ext.as_ref())
}
/// Return the image format specified by the path's file extension.
///
/// # Example
///
/// ```
/// use image::ImageFormat;
///
/// let format = ImageFormat::from_path("images/ferris.png")?;
/// assert_eq!(format, ImageFormat::Png);
///
/// # Ok::<(), image::error::ImageError>(())
/// ```
#[inline]
pub fn from_path<P>(path: P) -> ImageResult<Self>
where
P: AsRef<Path>,
{
// thin wrapper function to strip generics
fn inner(path: &Path) -> ImageResult<ImageFormat> {
let exact_ext = path.extension();
exact_ext
.and_then(ImageFormat::from_extension)
.ok_or_else(|| {
let format_hint = match exact_ext {
None => ImageFormatHint::Unknown,
Some(os) => ImageFormatHint::PathExtension(os.into()),
};
ImageError::Unsupported(format_hint.into())
})
}
inner(path.as_ref())
}
/// Return the image format specified by a MIME type.
///
/// # Example
///
/// ```
/// use image::ImageFormat;
///
/// let format = ImageFormat::from_mime_type("image/png").unwrap();
/// assert_eq!(format, ImageFormat::Png);
/// ```
pub fn from_mime_type<M>(mime_type: M) -> Option<Self>
where
M: AsRef<str>,
{
match mime_type.as_ref() {
"image/avif" => Some(ImageFormat::Avif),
"image/jpeg" => Some(ImageFormat::Jpeg),
"image/png" => Some(ImageFormat::Png),
"image/gif" => Some(ImageFormat::Gif),
"image/webp" => Some(ImageFormat::WebP),
"image/tiff" => Some(ImageFormat::Tiff),
"image/x-targa" | "image/x-tga" => Some(ImageFormat::Tga),
"image/vnd-ms.dds" => Some(ImageFormat::Dds),
"image/bmp" => Some(ImageFormat::Bmp),
"image/x-icon" => Some(ImageFormat::Ico),
"image/vnd.radiance" => Some(ImageFormat::Hdr),
"image/x-exr" => Some(ImageFormat::OpenExr),
"image/x-portable-bitmap"
| "image/x-portable-graymap"
| "image/x-portable-pixmap"
| "image/x-portable-anymap" => Some(ImageFormat::Pnm),
// Qoi's MIME type is being worked on.
// See: https://github.com/phoboslab/qoi/issues/167
"image/x-qoi" => Some(ImageFormat::Qoi),
_ => None,
}
}
/// Return the MIME type for this image format or "application/octet-stream" if no MIME type
/// exists for the format.
///
/// Some notes on a few of the MIME types:
///
/// - The portable anymap format has a separate MIME type for the pixmap, graymap and bitmap
/// formats, but this method returns the general "image/x-portable-anymap" MIME type.
/// - The Targa format has two common MIME types, "image/x-targa" and "image/x-tga"; this
/// method returns "image/x-targa" for that format.
/// - The QOI MIME type is still a work in progress. This method returns "image/x-qoi" for
/// that format.
///
/// # Example
///
/// ```
/// use image::ImageFormat;
///
/// let mime_type = ImageFormat::Png.to_mime_type();
/// assert_eq!(mime_type, "image/png");
/// ```
pub fn to_mime_type(&self) -> &'static str {
match self {
ImageFormat::Avif => "image/avif",
ImageFormat::Jpeg => "image/jpeg",
ImageFormat::Png => "image/png",
ImageFormat::Gif => "image/gif",
ImageFormat::WebP => "image/webp",
ImageFormat::Tiff => "image/tiff",
// the targa MIME type has two options, but this one seems to be used more
ImageFormat::Tga => "image/x-targa",
ImageFormat::Dds => "image/vnd-ms.dds",
ImageFormat::Bmp => "image/bmp",
ImageFormat::Ico => "image/x-icon",
ImageFormat::Hdr => "image/vnd.radiance",
ImageFormat::OpenExr => "image/x-exr",
// return the most general MIME type
ImageFormat::Pnm => "image/x-portable-anymap",
// Qoi's MIME type is being worked on.
// See: https://github.com/phoboslab/qoi/issues/167
ImageFormat::Qoi => "image/x-qoi",
// farbfield's MIME type taken from https://www.wikidata.org/wiki/Q28206109
ImageFormat::Farbfeld => "application/octet-stream",
}
}
/// Return if the ImageFormat can be decoded by the lib.
#[inline]
pub fn can_read(&self) -> bool {
// Needs to be updated once a new variant's decoder is added to free_functions.rs::load
match self {
ImageFormat::Png => true,
ImageFormat::Gif => true,
ImageFormat::Jpeg => true,
ImageFormat::WebP => true,
ImageFormat::Tiff => true,
ImageFormat::Tga => true,
ImageFormat::Dds => false,
ImageFormat::Bmp => true,
ImageFormat::Ico => true,
ImageFormat::Hdr => true,
ImageFormat::OpenExr => true,
ImageFormat::Pnm => true,
ImageFormat::Farbfeld => true,
ImageFormat::Avif => true,
ImageFormat::Qoi => true,
}
}
/// Return if the ImageFormat can be encoded by the lib.
#[inline]
pub fn can_write(&self) -> bool {
// Needs to be updated once a new variant's encoder is added to free_functions.rs::save_buffer_with_format_impl
match self {
ImageFormat::Gif => true,
ImageFormat::Ico => true,
ImageFormat::Jpeg => true,
ImageFormat::Png => true,
ImageFormat::Bmp => true,
ImageFormat::Tiff => true,
ImageFormat::Tga => true,
ImageFormat::Pnm => true,
ImageFormat::Farbfeld => true,
ImageFormat::Avif => true,
ImageFormat::WebP => true,
ImageFormat::Hdr => false,
ImageFormat::OpenExr => true,
ImageFormat::Dds => false,
ImageFormat::Qoi => true,
}
}
/// Return a list of applicable extensions for this format.
///
/// All currently recognized image formats specify at least on extension but for future
/// compatibility you should not rely on this fact. The list may be empty if the format has no
/// recognized file representation, for example in case it is used as a purely transient memory
/// format.
///
/// The method name `extensions` remains reserved for introducing another method in the future
/// that yields a slice of `OsStr` which is blocked by several features of const evaluation.
pub fn extensions_str(self) -> &'static [&'static str] {
match self {
ImageFormat::Png => &["png"],
ImageFormat::Jpeg => &["jpg", "jpeg"],
ImageFormat::Gif => &["gif"],
ImageFormat::WebP => &["webp"],
ImageFormat::Pnm => &["pbm", "pam", "ppm", "pgm"],
ImageFormat::Tiff => &["tiff", "tif"],
ImageFormat::Tga => &["tga"],
ImageFormat::Dds => &["dds"],
ImageFormat::Bmp => &["bmp"],
ImageFormat::Ico => &["ico"],
ImageFormat::Hdr => &["hdr"],
ImageFormat::OpenExr => &["exr"],
ImageFormat::Farbfeld => &["ff"],
// According to: https://aomediacodec.github.io/av1-avif/#mime-registration
ImageFormat::Avif => &["avif"],
ImageFormat::Qoi => &["qoi"],
}
}
/// Return the ImageFormats which are enabled for reading.
#[inline]
pub fn reading_enabled(&self) -> bool {
match self {
ImageFormat::Png => cfg!(feature = "png"),
ImageFormat::Gif => cfg!(feature = "gif"),
ImageFormat::Jpeg => cfg!(feature = "jpeg"),
ImageFormat::WebP => cfg!(feature = "webp"),
ImageFormat::Tiff => cfg!(feature = "tiff"),
ImageFormat::Tga => cfg!(feature = "tga"),
ImageFormat::Bmp => cfg!(feature = "bmp"),
ImageFormat::Ico => cfg!(feature = "ico"),
ImageFormat::Hdr => cfg!(feature = "hdr"),
ImageFormat::OpenExr => cfg!(feature = "openexr"),
ImageFormat::Pnm => cfg!(feature = "pnm"),
ImageFormat::Farbfeld => cfg!(feature = "farbfeld"),
ImageFormat::Avif => cfg!(feature = "avif"),
ImageFormat::Qoi => cfg!(feature = "qoi"),
ImageFormat::Dds => false,
}
}
/// Return the ImageFormats which are enabled for writing.
#[inline]
pub fn writing_enabled(&self) -> bool {
match self {
ImageFormat::Gif => cfg!(feature = "gif"),
ImageFormat::Ico => cfg!(feature = "ico"),
ImageFormat::Jpeg => cfg!(feature = "jpeg"),
ImageFormat::Png => cfg!(feature = "png"),
ImageFormat::Bmp => cfg!(feature = "bmp"),
ImageFormat::Tiff => cfg!(feature = "tiff"),
ImageFormat::Tga => cfg!(feature = "tga"),
ImageFormat::Pnm => cfg!(feature = "pnm"),
ImageFormat::Farbfeld => cfg!(feature = "farbfeld"),
ImageFormat::Avif => cfg!(feature = "avif"),
ImageFormat::WebP => cfg!(feature = "webp"),
ImageFormat::OpenExr => cfg!(feature = "openexr"),
ImageFormat::Qoi => cfg!(feature = "qoi"),
ImageFormat::Dds => false,
ImageFormat::Hdr => false,
}
}
/// Return all ImageFormats
pub fn all() -> impl Iterator<Item = ImageFormat> {
[
ImageFormat::Gif,
ImageFormat::Ico,
ImageFormat::Jpeg,
ImageFormat::Png,
ImageFormat::Bmp,
ImageFormat::Tiff,
ImageFormat::Tga,
ImageFormat::Pnm,
ImageFormat::Farbfeld,
ImageFormat::Avif,
ImageFormat::WebP,
ImageFormat::OpenExr,
ImageFormat::Qoi,
ImageFormat::Dds,
ImageFormat::Hdr,
]
.iter()
.copied()
}
}
/// An enumeration of supported image formats for encoding.
#[derive(Clone, PartialEq, Eq, Debug)]
#[non_exhaustive]
pub enum ImageOutputFormat {
#[cfg(feature = "png")]
/// An Image in PNG Format
Png,
#[cfg(feature = "jpeg")]
/// An Image in JPEG Format with specified quality, up to 100
Jpeg(u8),
#[cfg(feature = "pnm")]
/// An Image in one of the PNM Formats
Pnm(PnmSubtype),
#[cfg(feature = "gif")]
/// An Image in GIF Format
Gif,
#[cfg(feature = "ico")]
/// An Image in ICO Format
Ico,
#[cfg(feature = "bmp")]
/// An Image in BMP Format
Bmp,
#[cfg(feature = "farbfeld")]
/// An Image in farbfeld Format
Farbfeld,
#[cfg(feature = "tga")]
/// An Image in TGA Format
Tga,
#[cfg(feature = "exr")]
/// An Image in OpenEXR Format
OpenExr,
#[cfg(feature = "tiff")]
/// An Image in TIFF Format
Tiff,
#[cfg(feature = "avif-encoder")]
/// An image in AVIF Format
Avif,
#[cfg(feature = "qoi")]
/// An image in QOI Format
Qoi,
#[cfg(feature = "webp")]
/// An image in WebP Format.
WebP,
/// A value for signalling an error: An unsupported format was requested
// Note: When TryFrom is stabilized, this value should not be needed, and
// a TryInto<ImageOutputFormat> should be used instead of an Into<ImageOutputFormat>.
Unsupported(String),
}
impl From<ImageFormat> for ImageOutputFormat {
fn from(fmt: ImageFormat) -> Self {
match fmt {
#[cfg(feature = "png")]
ImageFormat::Png => ImageOutputFormat::Png,
#[cfg(feature = "jpeg")]
ImageFormat::Jpeg => ImageOutputFormat::Jpeg(75),
#[cfg(feature = "pnm")]
ImageFormat::Pnm => ImageOutputFormat::Pnm(PnmSubtype::ArbitraryMap),
#[cfg(feature = "gif")]
ImageFormat::Gif => ImageOutputFormat::Gif,
#[cfg(feature = "ico")]
ImageFormat::Ico => ImageOutputFormat::Ico,
#[cfg(feature = "bmp")]
ImageFormat::Bmp => ImageOutputFormat::Bmp,
#[cfg(feature = "farbfeld")]
ImageFormat::Farbfeld => ImageOutputFormat::Farbfeld,
#[cfg(feature = "tga")]
ImageFormat::Tga => ImageOutputFormat::Tga,
#[cfg(feature = "exr")]
ImageFormat::OpenExr => ImageOutputFormat::OpenExr,
#[cfg(feature = "tiff")]
ImageFormat::Tiff => ImageOutputFormat::Tiff,
#[cfg(feature = "avif-encoder")]
ImageFormat::Avif => ImageOutputFormat::Avif,
#[cfg(feature = "webp")]
ImageFormat::WebP => ImageOutputFormat::WebP,
#[cfg(feature = "qoi")]
ImageFormat::Qoi => ImageOutputFormat::Qoi,
f => ImageOutputFormat::Unsupported(format!("{:?}", f)),
}
}
}
// This struct manages buffering associated with implementing `Read` and `Seek` on decoders that can
// must decode ranges of bytes at a time.
#[allow(dead_code)]
// When no image formats that use it are enabled
pub(crate) struct ImageReadBuffer {
scanline_bytes: usize,
buffer: Vec<u8>,
consumed: usize,
total_bytes: u64,
offset: u64,
}
impl ImageReadBuffer {
/// Create a new ImageReadBuffer.
///
/// Panics if scanline_bytes doesn't fit into a usize, because that would mean reading anything
/// from the image would take more RAM than the entire virtual address space. In other words,
/// actually using this struct would instantly OOM so just get it out of the way now.
#[allow(dead_code)]
// When no image formats that use it are enabled
pub(crate) fn new(scanline_bytes: u64, total_bytes: u64) -> Self {
Self {
scanline_bytes: usize::try_from(scanline_bytes).unwrap(),
buffer: Vec::new(),
consumed: 0,
total_bytes,
offset: 0,
}
}
#[allow(dead_code)]
// When no image formats that use it are enabled
pub(crate) fn read<F>(&mut self, buf: &mut [u8], mut read_scanline: F) -> io::Result<usize>
where
F: FnMut(&mut [u8]) -> io::Result<usize>,
{
if self.buffer.len() == self.consumed {
if self.offset == self.total_bytes {
return Ok(0);
} else if buf.len() >= self.scanline_bytes {
// If there is nothing buffered and the user requested a full scanline worth of
// data, skip buffering.
let bytes_read = read_scanline(&mut buf[..self.scanline_bytes])?;
self.offset += u64::try_from(bytes_read).unwrap();
return Ok(bytes_read);
} else {
// Lazily allocate buffer the first time that read is called with a buffer smaller
// than the scanline size.
if self.buffer.is_empty() {
self.buffer.resize(self.scanline_bytes, 0);
}
self.consumed = 0;
let bytes_read = read_scanline(&mut self.buffer[..])?;
self.buffer.resize(bytes_read, 0);
self.offset += u64::try_from(bytes_read).unwrap();
assert!(bytes_read == self.scanline_bytes || self.offset == self.total_bytes);
}
}
// Finally, copy bytes into output buffer.
let bytes_buffered = self.buffer.len() - self.consumed;
if bytes_buffered > buf.len() {
buf.copy_from_slice(&self.buffer[self.consumed..][..buf.len()]);
self.consumed += buf.len();
Ok(buf.len())
} else {
buf[..bytes_buffered].copy_from_slice(&self.buffer[self.consumed..][..bytes_buffered]);
self.consumed = self.buffer.len();
Ok(bytes_buffered)
}
}
}
/// Decodes a specific region of the image, represented by the rectangle
/// starting from ```x``` and ```y``` and having ```length``` and ```width```
#[allow(dead_code)]
// When no image formats that use it are enabled
pub(crate) fn load_rect<'a, D, F, F1, F2, E>(
x: u32,
y: u32,
width: u32,
height: u32,
buf: &mut [u8],
progress_callback: F,
decoder: &mut D,
mut seek_scanline: F1,
mut read_scanline: F2,
) -> ImageResult<()>
where
D: ImageDecoder<'a>,
F: Fn(Progress),
F1: FnMut(&mut D, u64) -> io::Result<()>,
F2: FnMut(&mut D, &mut [u8]) -> Result<(), E>,
ImageError: From<E>,
{
let (x, y, width, height) = (
u64::from(x),
u64::from(y),
u64::from(width),
u64::from(height),
);
let dimensions = decoder.dimensions();
let bytes_per_pixel = u64::from(decoder.color_type().bytes_per_pixel());
let row_bytes = bytes_per_pixel * u64::from(dimensions.0);
#[allow(deprecated)]
let scanline_bytes = decoder.scanline_bytes();
let total_bytes = width * height * bytes_per_pixel;
if buf.len() < usize::try_from(total_bytes).unwrap_or(usize::max_value()) {
panic!(
"output buffer too short\n expected `{}`, provided `{}`",
total_bytes,
buf.len()
);
}
let mut bytes_read = 0u64;
let mut current_scanline = 0;
let mut tmp = Vec::new();
let mut tmp_scanline = None;
{
// Read a range of the image starting from byte number `start` and continuing until byte
// number `end`. Updates `current_scanline` and `bytes_read` appropriately.
let mut read_image_range = |mut start: u64, end: u64| -> ImageResult<()> {
// If the first scanline we need is already stored in the temporary buffer, then handle
// it first.
let target_scanline = start / scanline_bytes;
if tmp_scanline == Some(target_scanline) {
let position = target_scanline * scanline_bytes;
let offset = start.saturating_sub(position);
let len = (end - start)
.min(scanline_bytes - offset)
.min(end - position);
buf[(bytes_read as usize)..][..len as usize]
.copy_from_slice(&tmp[offset as usize..][..len as usize]);
bytes_read += len;
start += len;
progress_callback(Progress {
current: bytes_read,
total: total_bytes,
});
if start == end {
return Ok(());
}
}
let target_scanline = start / scanline_bytes;
if target_scanline != current_scanline {
seek_scanline(decoder, target_scanline)?;
current_scanline = target_scanline;
}
let mut position = current_scanline * scanline_bytes;
while position < end {
if position >= start && end - position >= scanline_bytes {
read_scanline(
decoder,
&mut buf[(bytes_read as usize)..][..(scanline_bytes as usize)],
)?;
bytes_read += scanline_bytes;
} else {
tmp.resize(scanline_bytes as usize, 0u8);
read_scanline(decoder, &mut tmp)?;
tmp_scanline = Some(current_scanline);
let offset = start.saturating_sub(position);
let len = (end - start)
.min(scanline_bytes - offset)
.min(end - position);
buf[(bytes_read as usize)..][..len as usize]
.copy_from_slice(&tmp[offset as usize..][..len as usize]);
bytes_read += len;
}
current_scanline += 1;
position += scanline_bytes;
progress_callback(Progress {
current: bytes_read,
total: total_bytes,
});
}
Ok(())
};
if x + width > u64::from(dimensions.0)
|| y + height > u64::from(dimensions.1)
|| width == 0
|| height == 0
{
return Err(ImageError::Parameter(ParameterError::from_kind(
ParameterErrorKind::DimensionMismatch,
)));
}
if scanline_bytes > usize::max_value() as u64 {
return Err(ImageError::Limits(LimitError::from_kind(
LimitErrorKind::InsufficientMemory,
)));
}
progress_callback(Progress {
current: 0,
total: total_bytes,
});
if x == 0 && width == u64::from(dimensions.0) {
let start = x * bytes_per_pixel + y * row_bytes;
let end = (x + width) * bytes_per_pixel + (y + height - 1) * row_bytes;
read_image_range(start, end)?;
} else {
for row in y..(y + height) {
let start = x * bytes_per_pixel + row * row_bytes;
let end = (x + width) * bytes_per_pixel + row * row_bytes;
read_image_range(start, end)?;
}
}
}
// Seek back to the start
Ok(seek_scanline(decoder, 0)?)
}
/// Reads all of the bytes of a decoder into a Vec<T>. No particular alignment
/// of the output buffer is guaranteed.
///
/// Panics if there isn't enough memory to decode the image.
pub(crate) fn decoder_to_vec<'a, T>(decoder: impl ImageDecoder<'a>) -> ImageResult<Vec<T>>
where
T: crate::traits::Primitive + bytemuck::Pod,
{
let total_bytes = usize::try_from(decoder.total_bytes());
if total_bytes.is_err() || total_bytes.unwrap() > isize::max_value() as usize {
return Err(ImageError::Limits(LimitError::from_kind(
LimitErrorKind::InsufficientMemory,
)));
}
let mut buf = vec![num_traits::Zero::zero(); total_bytes.unwrap() / std::mem::size_of::<T>()];
decoder.read_image(bytemuck::cast_slice_mut(buf.as_mut_slice()))?;
Ok(buf)
}
/// Represents the progress of an image operation.
///
/// Note that this is not necessarily accurate and no change to the values passed to the progress
/// function during decoding will be considered breaking. A decoder could in theory report the
/// progress `(0, 0)` if progress is unknown, without violating the interface contract of the type.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct Progress {
current: u64,
total: u64,
}
impl Progress {
/// Create Progress. Result in invalid progress if you provide a greater `current` than `total`.
pub(crate) fn new(current: u64, total: u64) -> Self {
Self { current, total }
}
/// A measure of completed decoding.
pub fn current(self) -> u64 {
self.current
}
/// A measure of all necessary decoding work.
///
/// This is in general greater or equal than `current`.
pub fn total(self) -> u64 {
self.total
}
/// Calculate a measure for remaining decoding work.
pub fn remaining(self) -> u64 {
self.total.max(self.current) - self.current
}
}
/// The trait that all decoders implement
pub trait ImageDecoder<'a>: Sized {
/// The type of reader produced by `into_reader`.
type Reader: Read + 'a;
/// Returns a tuple containing the width and height of the image
fn dimensions(&self) -> (u32, u32);
/// Returns the color type of the image data produced by this decoder
fn color_type(&self) -> ColorType;
/// Returns the color type of the image file before decoding
fn original_color_type(&self) -> ExtendedColorType {
self.color_type().into()
}
/// Returns the ICC color profile embedded in the image
///
/// For formats that don't support embedded profiles this function will always return `None`.
/// This feature is currently only supported for the JPEG, PNG, and AVIF formats.
fn icc_profile(&mut self) -> Option<Vec<u8>> {
None
}
/// Returns a reader that can be used to obtain the bytes of the image. For the best
/// performance, always try to read at least `scanline_bytes` from the reader at a time. Reading
/// fewer bytes will cause the reader to perform internal buffering.
#[deprecated = "Planned for removal. See https://github.com/image-rs/image/issues/1989"]
fn into_reader(self) -> ImageResult<Self::Reader>;
/// Returns the total number of bytes in the decoded image.
///
/// This is the size of the buffer that must be passed to `read_image` or
/// `read_image_with_progress`. The returned value may exceed usize::MAX, in
/// which case it isn't actually possible to construct a buffer to decode all the image data
/// into. If, however, the size does not fit in a u64 then u64::MAX is returned.
fn total_bytes(&self) -> u64 {
let dimensions = self.dimensions();
let total_pixels = u64::from(dimensions.0) * u64::from(dimensions.1);
let bytes_per_pixel = u64::from(self.color_type().bytes_per_pixel());
total_pixels.saturating_mul(bytes_per_pixel)
}
/// Returns the minimum number of bytes that can be efficiently read from this decoder. This may
/// be as few as 1 or as many as `total_bytes()`.
#[deprecated = "Planned for removal. See https://github.com/image-rs/image/issues/1989"]
fn scanline_bytes(&self) -> u64 {
self.total_bytes()
}
/// Returns all the bytes in the image.
///
/// This function takes a slice of bytes and writes the pixel data of the image into it.
/// Although not required, for certain color types callers may want to pass buffers which are
/// aligned to 2 or 4 byte boundaries to the slice can be cast to a [u16] or [u32]. To accommodate
/// such casts, the returned contents will always be in native endian.
///
/// # Panics
///
/// This function panics if buf.len() != self.total_bytes().
///
/// # Examples
///
/// ```no_build
/// use zerocopy::{AsBytes, FromBytes};
/// fn read_16bit_image(decoder: impl ImageDecoder) -> Vec<16> {
/// let mut buf: Vec<u16> = vec![0; decoder.total_bytes()/2];
/// decoder.read_image(buf.as_bytes());
/// buf
/// }
/// ```
fn read_image(self, buf: &mut [u8]) -> ImageResult<()> {
#[allow(deprecated)]
self.read_image_with_progress(buf, |_| {})
}
/// Same as `read_image` but periodically calls the provided callback to give updates on loading
/// progress.
#[deprecated = "Use read_image instead. See https://github.com/image-rs/image/issues/1989"]
fn read_image_with_progress<F: Fn(Progress)>(
self,
buf: &mut [u8],
progress_callback: F,
) -> ImageResult<()> {
assert_eq!(u64::try_from(buf.len()), Ok(self.total_bytes()));
let total_bytes = self.total_bytes() as usize;
#[allow(deprecated)]
let scanline_bytes = self.scanline_bytes() as usize;
let target_read_size = if scanline_bytes < 4096 {
(4096 / scanline_bytes) * scanline_bytes
} else {
scanline_bytes
};
#[allow(deprecated)]
let mut reader = self.into_reader()?;
let mut bytes_read = 0;
while bytes_read < total_bytes {
let read_size = target_read_size.min(total_bytes - bytes_read);
reader.read_exact(&mut buf[bytes_read..][..read_size])?;
bytes_read += read_size;
progress_callback(Progress {
current: bytes_read as u64,
total: total_bytes as u64,
});
}
Ok(())
}
/// Set decoding limits for this decoder. See [`Limits`] for the different kinds of
/// limits that is possible to set.
///
/// Note to implementors: make sure you call [`Limits::check_support`] so that
/// decoding fails if any unsupported strict limits are set. Also make sure
/// you call [`Limits::check_dimensions`] to check the `max_image_width` and
/// `max_image_height` limits.
///
/// [`Limits`]: ./io/struct.Limits.html
/// [`Limits::check_support`]: ./io/struct.Limits.html#method.check_support
/// [`Limits::check_dimensions`]: ./io/struct.Limits.html#method.check_dimensions
fn set_limits(&mut self, limits: crate::io::Limits) -> ImageResult<()> {
limits.check_support(&crate::io::LimitSupport::default())?;
let (width, height) = self.dimensions();
limits.check_dimensions(width, height)?;
Ok(())
}
}
/// Specialized image decoding not be supported by all formats
pub trait ImageDecoderRect<'a>: ImageDecoder<'a> + Sized {
/// Decode a rectangular section of the image; see [`read_rect_with_progress()`](#fn.read_rect_with_progress).
fn read_rect(
&mut self,
x: u32,
y: u32,
width: u32,
height: u32,
buf: &mut [u8],
) -> ImageResult<()> {
#[allow(deprecated)]
self.read_rect_with_progress(x, y, width, height, buf, |_| {})
}
/// Decode a rectangular section of the image, periodically reporting progress.
///
/// The output buffer will be filled with fields specified by
/// [`ImageDecoder::color_type()`](trait.ImageDecoder.html#fn.color_type),
/// in that order, each field represented in native-endian.
///
/// The progress callback will be called at least once at the start and the end of decoding,
/// implementations are encouraged to call this more often,
/// with a frequency meaningful for display to the end-user.
///
/// This function will panic if the output buffer isn't at least
/// `color_type().bytes_per_pixel() * color_type().channel_count() * width * height` bytes long.
#[deprecated = "Use read_image instead. See https://github.com/image-rs/image/issues/1989"]
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<()>;
}
/// AnimationDecoder trait
pub trait AnimationDecoder<'a> {
/// Consume the decoder producing a series of frames.
fn into_frames(self) -> Frames<'a>;
}
/// The trait all encoders implement
pub trait ImageEncoder {
/// Writes all the bytes in an image to the encoder.
///
/// This function takes a slice of bytes of the pixel data of the image
/// and encodes them. Unlike particular format encoders inherent impl encode
/// methods where endianness is not specified, here image data bytes should
/// always be in native endian. The implementor will reorder the endianness
/// as necessary for the target encoding format.
///
/// See also `ImageDecoder::read_image` which reads byte buffers into
/// native endian.
///
/// # Panics
///
/// Panics if `width * height * color_type.bytes_per_pixel() != buf.len()`.
fn write_image(
self,
buf: &[u8],
width: u32,
height: u32,
color_type: ColorType,
) -> ImageResult<()>;
}
/// Immutable pixel iterator
#[derive(Debug)]
pub struct Pixels<'a, I: ?Sized + 'a> {
image: &'a I,
x: u32,
y: u32,
width: u32,
height: u32,
}
impl<'a, I: GenericImageView> Iterator for Pixels<'a, I> {
type Item = (u32, u32, I::Pixel);
fn next(&mut self) -> Option<(u32, u32, I::Pixel)> {
if self.x >= self.width {
self.x = 0;
self.y += 1;
}
if self.y >= self.height {
None
} else {
let pixel = self.image.get_pixel(self.x, self.y);
let p = (self.x, self.y, pixel);
self.x += 1;
Some(p)
}
}
}
impl<I: ?Sized> Clone for Pixels<'_, I> {
fn clone(&self) -> Self {
Pixels { ..*self }
}
}