https://github.com/freshleafmedia/image-compression-finder

Automatic detection of maximum compression without visually changing the image
https://github.com/freshleafmedia/image-compression-finder

automation compression image-compression image-processing

Last synced: 2 months ago
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Automatic detection of maximum compression without visually changing the image

• Host: GitHub
• URL: https://github.com/freshleafmedia/image-compression-finder
• Owner: freshleafmedia
• License: mit
• Created: 2022-12-11T11:21:11.000Z (about 2 years ago)
• Default Branch: master
• Last Pushed: 2022-12-17T20:57:53.000Z (about 2 years ago)
• Last Synced: 2024-10-31T01:49:44.553Z (3 months ago)
• Topics: automation, compression, image-compression, image-processing
• Language: PHP
• Homepage: https://www.freshleafmedia.co.uk/blog/automatically-find-best-image-compression
• Size: 1.44 MB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Image Compression Finder

Automatic detection of maximum compression without visually changing the image.

## Overview

This is a library which attempts to determine the maximum amount of compression which can be applied 

to an image while not introducing any visible changes.

The output is an integer between 0 and 100.

## Installation

```

composer require freshleafmedia/image-compression-finder

```

### DSSIM

A working copy of [kornelski/dssim](https://github.com/kornelski/dssim) must be installed.

To install the latest, at time of writing, on Ubuntu the following one-liner can be used:

```

curl -sSL https://github.com/kornelski/dssim/releases/download/3.2.3/dssim_3.2.3_amd64.deb > /tmp/dssim.deb && apt install /tmp/dssim.deb

```

### Imagick/GD

Either of Imagick or GD extensions are required.

## Usage

```php

use FreshleafMedia\ImageCompressionFinder\ImageCompressionFinder;

$quality = ImageCompressionFinder::make()->run('/path/to/image');

$quality; // 66 (0-100)

```

## How it works

The algorithm uses a binary search to repeatedly compress and test an image until the ideal quality is found

1. Compress the image with a quality setting of 60

2. Analyse the new image using DSSIM

3. If the change is within tolerance the quality is halved, if not it is increased by 50% (aka a binary search)

4. Compress the image again with the new quality

5. GOTO 2

## Options

There are a couple of configuration options:

```php

$quality = ImageCompressionFinder::make()

    ->maxDifference(0.001) // The highest acceptable visual change. 0-∞ where 0 is no change at all

    ->startingQuality(60) // Where to start the search

    ->driver('imagick') // The driver to use to compress images. Eg imagick or gd

    ->run();

```

## Tests

Unit tests can be run via `composer test`

## License

See [LICENSE](LICENSE)