#icns #icon #image


A library for encoding/decoding Apple Icon Image (.icns) files

6 releases

0.3.1 Jun 5, 2020
0.3.0 Nov 25, 2018
0.2.2 Oct 25, 2017
0.2.1 Mar 4, 2017
0.1.0 May 12, 2016

#9 in Images

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Used in 5 crates (4 directly)

MIT license

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A Rust library for encoding/decoding Apple Icon Image (.icns) files.

Documentation: https://docs.rs/icns


The icns crate implements reading and writing of ICNS files, encoding and decoding images into and out of an ICNS icon family, converting those images to other pixel formats (in case you need to transfer the image data to another library that expects the data in a particular format), and saving/loading those images to/from PNG files.

The crate documentation has more information about how to use the library.

Example usage

extern crate icns;
use icns::{IconFamily, IconType, Image};
use std::fs::File;
use std::io::{BufReader, BufWriter};

fn main() {
    // Load an icon family from an ICNS file.
    let file = BufReader::new(File::open("16.icns").unwrap());
    let mut icon_family = IconFamily::read(file).unwrap();

    // Extract an icon from the family and save it as a PNG.
    let image = icon_family.get_icon_with_type(IconType::RGB24_16x16).unwrap();
    let file = BufWriter::new(File::create("16.png").unwrap());

    // Read in another icon from a PNG file, and add it to the icon family.
    let file = BufReader::new(File::open("32.png").unwrap());
    let image = Image::read_png(file).unwrap();

    // Save the updated icon family to a new ICNS file.
    let file = BufWriter::new(File::create("16-and-32.icns").unwrap());

Supported icon types

ICNS files can contain a number of different icon types. This library supports the most commonly-used types, but some of the older ones are not yet supported. The table below indicates which types are currently supported; see https://en.wikipedia.org/wiki/Apple_Icon_Image_format#Icon_types for more information about each type.

The biggest limitation at this time is that a number of the newer icon types can be encoded with either PNG or JPEG 2000 data, but this library does not yet support JPEG 2000; attempting to decode such an icon will result an an error value being returned (although you can still decode other icons from the same ICNS file). The reason for this is that I don't currently know of any JPEG 2000 libraries for Rust; if one exists, please feel free to file a bug or send a pull request.

OSType Description Supported?
ICON 32×32 1-bit icon No
ICN# 32×32 1-bit icon with 1-bit mask No
icm# 16×12 1-bit icon with 1-bit mask No
icm4 16×12 4-bit icon No
icm8 16×12 8-bit icon No
ics# 16×16 1-bit mask No
ics4 16×16 4-bit icon No
ics8 16x16 8-bit icon No
is32 16×16 24-bit icon Yes
s8mk 16x16 8-bit mask Yes
icl4 32×32 4-bit icon No
icl8 32×32 8-bit icon No
il32 32x32 24-bit icon Yes
l8mk 32×32 8-bit mask Yes
ich# 48×48 1-bit mask No
ich4 48×48 4-bit icon No
ich8 48×48 8-bit icon No
ih32 48×48 24-bit icon Yes
h8mk 48×48 8-bit mask Yes
it32 128×128 24-bit icon Yes
t8mk 128×128 8-bit mask Yes
icp4 16x16 32-bit PNG/JP2 icon PNG only
icp5 32x32 32-bit PNG/JP2 icon PNG only
icp6 64x64 32-bit PNG/JP2 icon PNG only
ic07 128x128 32-bit PNG/JP2 icon PNG only
ic08 256×256 32-bit PNG/JP2 icon PNG only
ic09 512×512 32-bit PNG/JP2 icon PNG only
ic10 512x512@2x "retina" 32-bit PNG/JP2 icon PNG only
ic11 16x16@2x "retina" 32-bit PNG/JP2 icon PNG only
ic12 32x32@2x "retina" 32-bit PNG/JP2 icon PNG only
ic13 128x128@2x "retina" 32-bit PNG/JP2 icon PNG only
ic14 256x256@2x "retina" 32-bit PNG/JP2 icon PNG only


rust-icns is made available under the MIT License.