Squirrel Abstract Image Library
The missing fast and easy-to-use image decoding library for humans (not for machines).
SAIL is a format-agnostic cross-platform image decoding library providing rich APIs, from one-liners to complex use cases with custom I/O sources. It enables a client to read and write static, animated, multi-paged images along with their meta data and ICC profiles.
- Image viewers
- Game developers
- Anyone who needs to load or save images in different image formats and who needs a clean and comprehensive API for that
- Easy-to-use thread-safe C and C++ interfaces
- Versatile APIs:
deep diver, and
- Input/output: files, memory, custom I/O streams
- Load by file suffixes, paths, and magic numbers
- Output pixels as close as possible to the source
- Meta data support: text comments, EXIF, ICC profiles
- Access to the image properties w/o decoding pixels (probing)
- Access to the source image properties
- Adding or updating image codecs with ease demonstrated by Intel [*]
- The best MIME icons in the computer industry
Features NOT provided
- Image editing capabilities (filtering, distortion, scaling, etc.)
- Color space conversion functions
- Color management functions (applying ICC profiles etc.)
- EXIF rotation
Supported image formats
See the full list here. Work to add more image formats is ongoing.
Time to load and output default pixels (without explicit conversion) was measured. See BENCHMARKS.
Preferred installation method
- Linux: native packages if available or
SAIL provides four levels of APIs, depending on your needs. Let's have a quick look at the
struct sail_image *image; SAIL_TRY(sail_read_file(path, &image)); /* * Handle the image pixels here. * Use image->width, image->height, image->bytes_per_line, * image->pixel_format, and image->pixels for that. * * In particular, you can convert it to a different pixel format with functions * from libsail-manip. With sail_convert_image(), for example. */ sail_destroy_image(image);
sail::image image(path); // Handle the image and its pixels here. // Use image.width(), image.height(), image.bytes_per_line(), // image.pixel_format(), and image.pixels() for that. // // In particular, you can convert it to a different pixel format with image::convert().
Programming language: C11
Differences from other image decoding libraries
- Easily extensible with new image format plugins
- Easy-to-use API providing expected business entities - images, palettes, pixels etc.
- Access to source pixel data (supported by the most codecs)
- Access to the image properties w/o decoding pixel data (probing)
SAIL is ready for every day use. However, it's still under heavy development. The API can be changed at any time breaking binary and source compatibility. Consider opening a GitHub issue if you have any feature requests or issue reports. Your help (pull requests etc.) is highly welcomed.
Have questions or issues?
Opening a GitHub issue is the preferred way of communicating and solving problems.
See FAQ for more.
SAIL is written in pure C11 w/o using any third-party libraries (except for codecs). It also provides bindings to C++.
SAIL codecs is the deepest level. This is a set of standalone, dynamically loaded codecs (SO on Linux and DLL on Windows). They implement actual decoding and encoding capabilities. End-users never work with codecs directly. They always use abstract, high-level APIs in
libsail for that.
Every codec is accompanied with a so called codec info (description) file which is just a plain text file. It describes what the codec can actually do: what pixel formats it can read and output, what compression types it supports, and more.
By default, SAIL loads codecs on demand. To preload them, use
libsail-common holds common data types (images, pixel formats, I/O abstractions etc.) and a small set of functions shared between SAIL codecs and the high-level APIs in
libsail is a feature-rich, high-level API. It provides comprehensive and lightweight interfaces to decode and encode images. End-users implementing C applications always work with libsail.
libsail-manip is a collection of image manipulation functions. For example, conversion functions from one pixel format to another.
libsail-c++ is a C++ binding to libsail. End-users implementing C++ applications may choose between libsail and libsail-c++. Using libsail-c++ is always recommended, as it's much more simple to use in C++ applications.
Philosophy of SAIL is modularization and simplicity.
Image codecs are architectured to be standalone dynamically loaded files. Any future hypothetical improvements will be implemented as separate client libraries. So a user is always able to choose what to use (i.e. to link against) and what not to use.
If you like the project, please consider starring the repository.
Released under the MIT license.
Copyright (c) 2020 Dmitry Baryshev The MIT License Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.