SwiftImageCompressor

A lightweight, high-performance Swift library for resizing and compressing UIImage to a specific file size (in megabytes). Supports JPEG and PNG formats, with both synchronous and asynchronous APIs.

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✅ Features

• Resize images to fit within a max dimension while preserving aspect ratio
• Compress images to target file size (JPEG: binary search; PNG: lossless check)
• UIImage extensions included for ease of use
• async/await, completion handler, and sync APIs
• Written in pure Swift with no dependencies
• Supports iOS 14+

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📦 Installation

Swift Package Manager (SPM)

Add this to your Package.swift dependencies:

.package(url: "https://github.com/your-username/SwiftImageCompressor.git", from: "0.0.2")

Then include it in your target dependencies:

.target(
    name: "YourApp",
    dependencies: ["SwiftImageCompressor"]
)

Usage

Resize and Compress (Async)

import SwiftImageCompressor
import UIKit

let image = UIImage(named: "largeImage")!

let data = await image.reSizeWithCompressImage(
    type: .jpeg,
    targetMB: 1.5,
    maxDimension: 2048
)

print("Compressed size: \(Double(data?.count ?? 0) / 1024 / 1024) MB")

Completion Handler

image.resizeAndCompress(type: .jpeg, targetMB: 1.0) { data in
    if let data = data {
        print("Compressed image is \(Double(data.count) / 1024 / 1024) MB")
    }
}

Synchronous

let data = image.reSizeWithCompressImage(type: .jpeg, targetMB: 2.0)

Resize Only

let resized = image.resizeImage(maxDimension: 1024)

Compress Only

let compressed = await image.onlyCompressImage(image, type: .jpeg, targetMB: want)

    --- or ---
    
let compressed = image.onlyCompressImage(image, type: .jpeg, targetMB: want) { data in
    if let data {
        print(data)
    }
}

📌 PNG Support Notes

PNG compression is lossless, so file size cannot be controlled The library will return nil if the PNG image still exceeds the size after resizing For smaller PNGs, just use .png type — no compression quality parameter is used

📄 License

MIT License © 2025 Jae hyung Kim

Feel free to contribute or open issues!