How do I resize an image with SwiftGD?

Use the resizedTo methods: resizedTo(width:height:) for exact dimensions, or resizedTo(width:) / resizedTo(height:) to maintain aspect ratio. An optional applySmoothing parameter controls bilinear filtering for smoother results.

SwiftGD or Core Graphics for Linux Swift?

SwiftGD is the only viable option for server-side Swift on Linux since Core Graphics isn't available. For macOS or iOS, Core Graphics is more powerful, but SwiftGD bridges the gap for cross-platform server code.

Does SwiftGD support WebP images?

No, SwiftGD only supports PNG and JPEG formats because it wraps libgd, which has limited format support. For WebP, you'd need to use additional libraries or convert images first.

How to install SwiftGD on an Ubuntu server?

First, install libgd-dev with sudo apt-get install libgd-dev. Then, add SwiftGD as a dependency in your Package.swift file with the URL and version from the README, and include it in your target dependencies.

Is SwiftGD thread-safe for concurrent image processing?

The README doesn't address thread-safety. Since it wraps libgd, which may not be thread-safe, it's recommended to handle concurrency carefully, such as using serial queues or isolating image operations to avoid issues.

How to apply a Gaussian blur effect in SwiftGD?

Call the blur(radius:) method on an Image instance, specifying the radius for blur intensity. For example, image.blur(radius: 10) applies a strong blur, as shown in the concentric rectangles example code.

Open-Awesome

SwiftGD

MITSwift2.0.0

A Swift wrapper for libgd enabling server-side image manipulation without Core Graphics.

GitHub

473 stars75 forks0 contributors

What is SwiftGD?

SwiftGD is a Swift wrapper for the libgd graphics library that enables image manipulation in server-side Swift environments. It provides functionality for loading, creating, drawing, and processing images where Apple's Core Graphics framework is not available, such as on Linux servers. The library handles common tasks like resizing, cropping, applying filters, and drawing shapes through a Swift-native API.

Target Audience

Server-side Swift developers who need to perform image processing tasks like generating thumbnails, applying watermarks, or creating dynamic graphics without access to Core Graphics. It's also useful for anyone writing cross-platform Swift code that includes image manipulation on Linux.

Value Proposition

Developers choose SwiftGD because it brings essential image manipulation capabilities to server-side Swift with a clean, Swifty API that automatically manages memory. It's specifically designed for environments where Core Graphics isn't available, making it the go-to solution for image processing in Linux-based Swift deployments.

Overview

A simple Swift wrapper for libgd

Use Cases

Best For

Generating dynamic images or thumbnails in server-side Swift applications
Applying watermarks, filters, or effects to images on Linux servers
Creating charts, graphics, or visualizations in backend Swift code
Processing user-uploaded images in Vapor or other Swift web frameworks
Building image manipulation tools or utilities with Swift on multiple platforms
Converting between image formats or performing batch image operations server-side

Not Ideal For

Applications requiring GPU-accelerated image processing or real-time video effects
Projects that need to handle modern image formats like WebP, AVIF, or HEIC
iOS or macOS client apps where Core Graphics is available and more feature-rich

Pros & Cons

Pros

Swift-Native API

Wraps libgd in Swift classes like Image and Color, providing an intuitive, memory-safe interface that simplifies common graphics tasks compared to direct C usage.

Automatic Memory Management

Uses Swift's deinitializers to automatically release GD resources, preventing memory leaks without manual intervention, as highlighted in the README.

Server-Side Focus

Specifically designed for environments where Apple's Core Graphics is unavailable, making it essential for image manipulation on Linux-based Swift servers.

Comprehensive Basic Operations

Offers methods for loading, saving, resizing, cropping, drawing shapes, and applying filters like blur and colorize, all demonstrated in the example code.

Cons

Limited Image Format Support

Only supports PNG and JPEG formats, missing modern alternatives like WebP or HEIC, which can be a significant drawback for web or mobile applications.

Basic Drawing Capabilities

Provides only simple shapes and filters; lacks advanced features such as gradients, text rendering, or layer-based compositing, limiting creative use cases.

External Library Dependency

Requires manual installation of the libgd library via system package managers (e.g., brew on macOS, apt-get on Linux), adding setup complexity and potential deployment hurdles.

Frequently Asked Questions

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