dqoi ('dart_qoi') #

A Dart implementation of the "Quite OK Image Format", with a command line interface for console use and a library for use in applications.

Based off of the official C implementation and other implementations.

Command Line Interface #

Currently only Windows is supported for the CLI, as I cannot test on other operating systems. When I release the full version, there should be at least a Linux CLI.

Setup #

Very little setup is required. If you want to clone the source from GitHub you can. Then you can build and start using the 'bin/dqoi.exe' executable on Windows.
Alternatively, you can just install the package as normal, as use dqoi from the command line once activated. See the installation instructions on pub-web.flutter-io.cn for more information.

CLI Usage #

You can list the available options by just running the executable with no arguments or with '--help'.
dqoi-test.bat is designed to test the CLI on Windows, by comparing the files with official samples.

Application Library #

Installation #

There are two included libraries, each of which are very similar. Flutter applications should use the standard package:dqoi/dqoi.dart import. The other dqoi_pure.dart file excludes some useful extensions.
When this documentation refers to the singular "library", it means either library.

Library Usage #

The QOI class provides conversions between binary, PNG, and QOI formats. When extended by FlutterQOIExts, it also provides an easy way to render a QOI image in a Flutter app efficiently.
Note that neither library uses 'dart:io', so both are fully compatible with Web construction.

Examples #

You can build and install the example application, found in the 'example/' directory. However, below are some quick useful snippets to get you started.

Here's a way to convert PNG to QOI:

await outputFile.writeAsBytes(QOI.fromPNG(await inputFile.readAsBytes()).toQOI());

Here's the way to render a QOI image without converting to any other formats first:

QOI.fromQOI(await inputFile.readAsBytes()).toImageWidget(loadingWidget: loadingWidget);

FAQ #

• How do I pronounce the name of this library?
  It's up to you, but I like "decoy" best.
• Is this a good implementation?
  The outputted QOI files perfectly match the official C implementation's outputs. The re-encoded PNGs don't always match byte-for-byte, but the pixels are always correct
• Why wasn't this ported to Dart sooner?
  I'm not sure either. You can see all the other available ports on the official README.