Image Hasher

• Create an ImageHasher
  • Using the Constructor
  • Using Static Constructor
  • Using with Driver Constructor
• Modify Existing Hasher
  • Update the Driver
  • Update the Hashing Strategy
• Generate Hashes

Intervention ImageHash offers two ways to generate perceptual image hashes: use the ImageHasher class as a standalone tool, or integrate hashing into an existing Intervention Image workflow using the analyzer interface.

Create an ImageHasher

The ImageHasher class provides several static factory methods for creating instances.

Using the Constructor

public ImageHasher::__construct(string|DriverInterface $driver, StrategyInterface $strategy = new Difference())

The ImageHasher class is your starting point for all hashing operations. You need a driver that matches your PHP image extension (GD, Imagick, or libvips) and a hashing strategy.

Parameters

Name	Type	Description
driver	string or DriverInterface	Image manipulation driver (GD, Imagick, or libvips)
strategy	StrategyInterface	Hashing strategy to use (defaults to Difference)

Example

use Intervention\Image\Drivers\Gd\Driver as GdDriver;
use Intervention\ImageHash\ImageHasher;
use Intervention\ImageHash\Strategies\Difference;

// create hasher with driver and strategy
$hasher = new ImageHasher(new GdDriver(), new Difference());

// generate hash from image path
$hash = $hasher->hash('path/to/image.jpg');

Using Static Constructor

public static ImageHasher::create(string|DriverInterface $driver, StrategyInterface $strategy = new Difference()): ImageHasher

Create a new hasher instance with the given driver and strategy.

use Intervention\Image\Drivers\Imagick\Driver as ImagickDriver;
use Intervention\ImageHash\ImageHasher;
use Intervention\ImageHash\Strategies\Average;

// create hasher using static method
$hasher = ImageHasher::create(ImagickDriver::class, new Average());

Using with Driver Constructor

public static ImageHasher::usingDriver(string|DriverInterface $driver): ImageHasher

Create a hasher instance with the specified driver using the default Difference strategy.

use Intervention\Image\Drivers\Gd\Driver as GdDriver;
use Intervention\ImageHash\ImageHasher;

// create hasher with driver (uses default Difference strategy)
$hasher = ImageHasher::usingDriver(GdDriver::class);

Modify Existing Hasher

You can create new hasher instances from existing ones with modified configuration.

Update the Driver

public ImageHasher::withDriver(string|DriverInterface $driver): ImageHasher

Create a new hasher instance with a different driver, keeping the current strategy.

use Intervention\Image\Drivers\Gd\Driver as GdDriver;
use Intervention\Image\Drivers\Imagick\Driver as ImagickDriver;

$hasher = ImageHasher::usingDriver(GdDriver::class);

// create new hasher with different driver
$imagickHasher = $hasher->withDriver(ImagickDriver::class);

Update the Hashing Strategy

public ImageHasher::withStrategy(StrategyInterface $strategy): ImageHasher

Create a new hasher instance with a different strategy, keeping the current driver.

use Intervention\ImageHash\Strategies\Difference;
use Intervention\ImageHash\Strategies\Perceptual;

$hasher = ImageHasher::usingDriver(GdDriver::class);

// create new hasher with different strategy
$perceptualHasher = $hasher->withStrategy(new Perceptual());

Generate Hashes

public ImageHasher::hash(mixed $image): HashInterface

Generate a perceptual hash from various image sources. This method accepts the same image sources as Intervention Image's decode() method.

Parameters

Name	Type	Description
image	mixed	Image source (path, binary data, SplFileInfo, base64, data URI, stream, ImageInterface, etc.)

Supported Image Sources

The hash() method accepts all image sources supported by Intervention Image:

• Path in filesystem
• Raw binary image data
• SplFileInfo object
• Base64 encoded image data
• Data URI string or instance of DataUriInterface
• Stream resource
• Instance of ImageInterface
• Instance of EncodedImageInterface

Example

use Intervention\Image\Drivers\Gd\Driver as GdDriver;
use Intervention\ImageHash\ImageHasher;
use Intervention\ImageHash\Strategies\Difference;

$hasher = new ImageHasher(new GdDriver(), new Difference());

// hash from file path
$hash1 = $hasher->hash('images/photo.jpg');

// hash from binary data
$hash2 = $hasher->hash(file_get_contents('images/photo.jpg'));

// hash from data URI
$hash3 = $hasher->hash('data:image/png;base64,iVBORw0KG...');

// hash from stream resource
$stream = fopen('images/photo.jpg', 'r');
$hash4 = $hasher->hash($stream);