Download the PHP package intervention/imagehash without Composer
On this page you can find all versions of the php package intervention/imagehash. It is possible to download/install these versions without Composer. Possible dependencies are resolved automatically.
Download intervention/imagehash
More information about intervention/imagehash
Files in intervention/imagehash
Package imagehash
Short Description Perceptual image hashing for PHP
License MIT
Homepage https://github.com/Intervention/imagehash
FAQ
Example:
In general, it is recommended to use always a project to download your libraries. In an application normally there is more than one library needed.
- Some hosting areas are not accessible by a terminal or SSH. Then it is not possible to use Composer.
- To use Composer is sometimes complicated. Especially for beginners.
- Composer needs much resources. Sometimes they are not available on a simple webspace.
- If you are using private repositories you don't need to share your credentials. You can set up everything on our site and then you provide a simple download link to your team member.
- Simplify your Composer build process. Use our own command line tool to download the vendor folder as binary. This makes your build process faster and you don't need to expose your credentials for private repositories.
Informations about the package imagehash
Intervention ImageHash
Perceptual image hashing for PHP
Intervention ImageHash is an extension library to Intervention Image and provides perceptual image hashing with different strategies.
A perceptual hash is a fingerprint of a multimedia file derived from various features from its content. Unlike cryptographic hash functions which rely on the avalanche effect of small changes in input leading to drastic changes in the output, perceptual hashes are "close" to one another if the features are similar.
Installation
Install this library using Composer. Add the package with the following command:
Usage
Building Hashes
Using ImageHasher
The ImageHasher serves as the central starting point for all hashing operations. Depending on the PHP environment, a driver must be passed to it that matches the image extension (GD, Imagick or libvips) being used. Here is also the hashing strategy defined.
The library comes with four built-in hashing strategies:
Intervention\ImageHash\Strategies\Average- Hash based the average image colorIntervention\ImageHash\Strategies\Difference- Hash based on the previous pixelIntervention\ImageHash\Strategies\Block- Hash based on blockhash.ioIntervention\ImageHash\Strategies\Perceptual- The original pHash
Choose one of these strategies. If you don't know which one to use, try the Difference strategy. Some strategies allow configuration, be sure to check the constructors.
To generate hashes, the hash() method is used, which can read from various image sources like paths, raw image data and more.
Using AnalyzerInterface
Alternatively, you can choose to use Image::analyze() method instead of the ImageHasher. This integrates more seamlessly into an existing Intervention Image processing pipeline, if you already have instances of Intervention\Image\Interfaces\ImageInterface - the results remain the same.
Comparing Hashes
The resulting Hash object, is a hexadecimal image fingerprint that can be stored once calculated. Two fingerprints can be compared by the hamming distance for similarities. Low distance values will indicate that the images are similar or the same, high distance values indicate that the images are different. Use the following methods for comparisons:
Perceptual hashes are a different concept compared to cryptographic hash functions like MD5 and SHA1. With cryptographic hashes, the hash values are random. Comparing two SHA1 hash values really only tells you two things. If the hashes are different, then the data is different. In contrast, perceptual hashes can be compared - giving you a sense of similarity between the two data sets.
A perceptual hash is a compact summary of visual features. Because of that, the hashes are influenced by the input images, the processing strategy and the processing pipeline and may vary with its distance to other hashes depending on these factors.
Converting Hashes
The Hash object can be converted to a couple of different formats:
Parsing Hashes
If you want to reconstruct a Hash object from a previous calculated value, use:
Requirements
- PHP 8.3 or higher
- The GD, Imagick or libvips extension
- Optionally, install the GMP extension for faster fingerprint comparisons
Demo
These images are similar:
Image 1 hash: 8f9e9d8b0f0f1f07 (1000111110011110100111011000101100001111000011110001111100000111)
Image 2 hash: 8e9e958b0f2f1f07 (1000111010011110100101011000101100001111001011110001111100000111)
Hamming distance: 3These images are different:
Image 1 hash: 6c2b58432011e38e (0110110000101011010110000100001100100000000100011110001110001110)
Image 2 hash: 8f9e9d8b0f0f1f07 (1000111110011110100111011000101100001111000011110001111100000111)
Hamming distance: 35Security
If you discover any security related issues, please email [email protected] directly.
Authors
This project is based on work originally developed by Jens Segers and released under the MIT License. Many thanks to him for sharing his code with the community, which made this fork possible.
This version is maintained by Oliver Vogel including modifications and improvements, but it builds directly on the solid foundation Jens created.
License
Intervention ImageHash is licensed under the MIT License.
