What is phpmlkit/opal?

phpmlkit/opal is a high-performance image processing library for PHP. It's an alternative to GD and Imagick — faster, more memory-efficient, and designed for modern workflows.

use PhpMlKit\Opal\Image;

$img = Image::fromFile('photo.jpg')
    ->resize(1200, 800)
    ->sharpen()
    ->toFile('output.jpg');

Why Opal?

GD is limited and slow. Imagick is powerful but memory-hungry. Opal is built on libvips — a C engine that processes images faster than both while using a fraction of the memory.

Load → resize → rotate 45° → sharpen (full pipeline):

Image	GD	Imagick	Opal
640×480	8.48 ms	128.55 ms	1.56 ms
1920×1080	49.67 ms	721.97 ms	5.36 ms
4000×2670	152.74 ms	2,039.15 ms	15.47 ms
6000×4000	299.43 ms	3,538.47 ms	33.17 ms

Apple M1, macOS. 5–30 iterations per cell. Run: php benchmarks/opal-vs-gd-vs-imagick.php

Opal is 5–10× faster than GD and 50–105× faster than Imagick.

What you get

• Immutable API — every transform returns a new Image. No mutation, no surprises.
• Lazy pipelines — build a chain of operations; nothing executes until you save or export. VIPS fuses and optimises the pipeline automatically.
• Full format support — JPEG, PNG, WebP, AVIF, TIFF, HEIF, BMP, GIF. Load from files, buffers, or raw memory.
• Drawing & compositing — rectangles, circles, text, image overlays with blend modes. No separate graphics library needed.
• ML-ready — export images as NDArrays for PyTorch (CHW) or TensorFlow (HWC) format. Preprocessing pipelines compose directly with phpmlkit/ndarray.
• Type-safe — PHP 8.2+ with strict types, enums, and immutable value objects throughout.

When to use it

• Resizing, cropping, rotating, filtering, and colour conversions
• ML preprocessing — resize → normalize → tensor export
• Thumbnail generation at scale (libvips shrink-on-load)
• Drawing annotations — bounding boxes, labels, heatmaps
• Compositing — overlays, watermarks, text with blend modes
• Format conversion with quality control

Requirements

• PHP 8.2+
• ext-ffi

Everything else — including the libvips binary — is installed automatically by Composer.