image
Dart Image Library
Overview
The Dart Image Library provides the ability to load, save, and manipulate images in a variety of image file formats.
The library can be used with both dart:io and dart:html, for command-line, Flutter, and web applications.
NOTE: 4.0 is a major revision from the previous version of the library.
Documentation
Supported Image Formats
Read/Write
- JPG
- PNG / Animated APNG
- GIF / Animated GIF
- BMP
- TIFF
- TGA
- PVR
- ICO
Read Only
- WebP / Animated WebP
- PSD
- EXR
- PNM (PBM, PGM, PPM)
Write Only
- CUR
Examples
Create an image, set pixel values, save it to a PNG.
import 'dart:io';
import 'package:image/image.dart' as img;
void main() async {
// Create a 256x256 8-bit (default) rgb (default) image.
final image = img.Image(width: 256, height: 256);
// Iterate over its pixels
for (var pixel in image) {
// Set the pixels red value to its x position value, creating a gradient.
pixel..r = pixel.x
// Set the pixels green value to its y position value.
..g = pixel.y;
}
// Encode the resulting image to the PNG image format.
final png = img.encodePng(image);
// Write the PNG formatted data to a file.
await File('image.png').writeAsBytes(png);
}
To asynchronously load an image file, resize it, and save it as a thumbnail:
import 'package:image/image.dart' as img;
void main(List<String> args) async {
final path = args.isNotEmpty ? args[0] : 'test.png';
final cmd = img.Command()
// Decode the image file at the given path
..decodeImageFile(path)
// Resize the image to a width of 64 pixels and a height that maintains the aspect ratio of the original.
..copyResize(width: 64)
// Write the image to a PNG file (determined by the suffix of the file path).
..writeToFile('thumbnail.png');
// On platforms that support Isolates, execute the image commands asynchronously on an isolate thread.
// Otherwise, the commands will be executed synchronously.
await cmd.executeThread();
}