size_ranged_image_compressor

A Dart package for compressing image files to fit within a specified size range, while maintaining the best possible quality. Features

• Compress images to fit within a specified size range (minimum and maximum file size)
• Maintains the highest possible quality while meeting size constraints
• Handles both resizing and quality adjustment for optimal results
• Provides clear error messages if compression fails

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  size_ranged_image_compressor: ^1.0.0

Then run:

$ flutter pub get

Usage

Here's a simple example of how to use the size_ranged_image_compressor:

import 'dart:io';
import 'package:size_ranged_image_compressor/size_ranged_image_compressor.dart';

void main() async {
  File imageFile = File('path/to/your/image.jpg');

  var result = await ImageCompressor.compressSingleFileWithCustomSize(
    imageFile,
    minimum: 50 * 1024,  // 50 KB
    maximum: 200 * 1024, // 200 KB
  );

  result.fold(
    (error) => print('Compression failed: $error'),
    (compressedFile) => print('Compressed file size: ${compressedFile.lengthSync()} bytes'),
  );
}

This example demonstrates how to compress an image file to a size between 50 KB and 200 KB.

API Reference

ImageCompressor.compressSingleFileWithCustomSize

static Future> compressSingleFileWithCustomSize(
  File file, {
  required int minimum,
  required int maximum,
  int qualityStep = 2,
})

Compresses a single image file to fit within a specified size range.

Parameters:

• file: The original image file to be compressed. Must be a valid image file.
• minimum: The minimum allowed file size in bytes. Must be greater than 0 and less than or equal to maximum.
• maximum: The maximum allowed file size in bytes. Must be greater than or equal to minimum.
• qualityStep: The step size for reducing quality during compression. Default is 2. Lower values result in more gradual quality reduction.

Returns:

An Either containing either an error message (String) if compression fails, or the compressed File if successful.

Throws:

ArgumentError if maximum is less than minimum.

Error Handling

The package uses the Either type for error handling. If compression fails, it will return a Left with an error message. If successful, it will return a Right with the compressed File.

Common error messages include:

• "File is smaller than the minimum size requirement"
• "Compression failed"
• "Unable to compress file to desired size range"

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the BSD 2-Clause License - see the LICENSE file for details.