Crate image

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This crate provides native rust implementations of image encoding and decoding as well as some basic image manipulation functions. Additional documentation can currently also be found in the file which is most easily viewed on github.

There are two core problems for which this library provides solutions: a unified interface for image encodings and simple generic buffers for their content. It’s possible to use either feature without the other. The focus is on a small and stable set of common operations that can be supplemented by other specialized crates. The library also prefers safe solutions with few dependencies.

High level API

Load images using io::Reader:

use std::io::Cursor;
use image::io::Reader as ImageReader;

let img = ImageReader::open("myimage.png")?.decode()?;
let img2 = ImageReader::new(Cursor::new(bytes)).with_guessed_format()?.decode()?;

And save them using save or write_to methods:"empty.jpg")?;

let mut bytes: Vec<u8> = Vec::new();
img2.write_to(&mut Cursor::new(&mut bytes), image::ImageOutputFormat::Png)?;

With default features, the crate includes support for many common image formats.

Image buffers

The two main types for storing images:

  • ImageBuffer which holds statically typed image contents.
  • DynamicImage which is an enum over the supported ImageBuffer formats and supports conversions between them.

As well as a few more specialized options:

  • GenericImage trait for a mutable image buffer.
  • GenericImageView trait for read only references to a GenericImage.
  • flat module containing types for interoperability with generic channel matrices and foreign interfaces.

Low level encoding/decoding API

The ImageDecoder and ImageDecoderRect traits are implemented for many image file formats. They decode image data by directly on raw byte slices. Given an ImageDecoder, you can produce a DynamicImage via DynamicImage::from_decoder.

ImageEncoder provides the analogous functionality for encoding image data.


pub use crate::error::ImageError;
pub use crate::error::ImageResult;
pub use crate::flat::FlatSamples;


Iterators and other auxiliary structure for the ImageBuffer type.
Encoding and decoding for various image file formats.
Contains detailed error representation.
Image representations for ffi.
Image Processing Functions
Input and output of images.
Mathematical helper functions and types.


The delay of a frame relative to the previous one.
A single animation frame
An implementation dependent iterator, reading the frames as requested
Generic image buffer
Grayscale colors.
Grayscale colors + alpha channel
Immutable pixel iterator
Represents the progress of an image operation.
RGB colors.
RGB colors + alpha channel
A View into another image


An enumeration over supported color types and bit depths
A Dynamic Image
An enumeration of color types encountered in image formats.
An enumeration of supported image formats. Not all formats support both encoding and decoding.
An enumeration of supported image formats for encoding.


AnimationDecoder trait
Types which are safe to treat as an immutable byte slice in a pixel layout for image encoding.
A trait for manipulating images.
Trait to inspect an image.
The trait that all decoders implement
Specialized image decoding not be supported by all formats
The trait all encoders implement
A generalized pixel.
The pixel with an associated ColorType. Not all possible pixels represent one of the predefined ColorTypes.
The type of each channel in a pixel. For example, this can be u8, u16, f32.


Guess image format from memory block
Read a tuple containing the (width, height) of the image located at the specified path. This is faster than fully loading the image and then getting its dimensions.
Create a new image from a Reader.
Create a new image from a byte slice
Create a new image from a byte slice
Open the image located at the path specified. The image’s format is determined from the path’s file extension.
Saves the supplied buffer to a file at the path specified.
Saves the supplied buffer to a file at the path specified in the specified format.
Writes the supplied buffer to a writer in the specified format.

Type Definitions

Sendable grayscale + alpha channel image buffer
Sendable grayscale image buffer
An image buffer for 32-bit float RGB pixels, where the backing container is a flattened vector of floats.
Sendable Rgb image buffer
An image buffer for 32-bit float RGBA pixels, where the backing container is a flattened vector of floats.
Sendable Rgb + alpha channel image buffer