Crate image

Overview

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 README.md 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:

img.save("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

Implementations of ImageEncoder provides low level control over encoding:

let encoder = JpegEncoder::new_with_quality(&mut writer, 95);
img.write_with_encoder(encoder)?;

While ImageDecoder and ImageDecoderRect give access to more advanced decoding options:

let decoder = PngDecoder::new(&mut reader)?;
let icc = decoder.icc_profile();
let img = DynamicImage::from_decoder(decoder)?;

Re-exports

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

Modules

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

Structs

• Delay
  The delay of a frame relative to the previous one.
• Frame
  A single animation frame
• Frames
  An implementation dependent iterator, reading the frames as requested
• ImageBuffer
  Generic image buffer
• Luma
  Grayscale colors.
• LumaA
  Grayscale colors + alpha channel
• Pixels
  Immutable pixel iterator
• Progress
  Represents the progress of an image operation.
• Rgb
  RGB colors.
• Rgba
  RGB colors + alpha channel
• SubImage
  A View into another image

Enums

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

Traits

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

Functions

• guess_format
  Guess image format from memory block
• image_dimensions
  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.
• load
  Create a new image from a Reader.
• load_from_memory
  Create a new image from a byte slice
• load_from_memory_with_format
  Create a new image from a byte slice
• open
  Open the image located at the path specified. The image’s format is determined from the path’s file extension.
• save_buffer
  Saves the supplied buffer to a file at the path specified.
• save_buffer_with_format
  Saves the supplied buffer to a file at the path specified in the specified format.
• write_buffer_with_format
  Writes the supplied buffer to a writer in the specified format.

Type Aliases

• GrayAlphaImage
  Sendable grayscale + alpha channel image buffer
• GrayImage
  Sendable grayscale image buffer
• Rgb32FImage
  An image buffer for 32-bit float RGB pixels, where the backing container is a flattened vector of floats.
• RgbImage
  Sendable Rgb image buffer
• Rgba32FImage
  An image buffer for 32-bit float RGBA pixels, where the backing container is a flattened vector of floats.
• RgbaImage
  Sendable Rgb + alpha channel image buffer