README

Automatic image focal point detection.

Overview

Autofocus is an image analysis library which attempts to determine where the focal point of an image is.

Installation

composer require freshleafmedia/autofocus

Usage

use FreshleafMedia\Autofocus\FocalPointDetector;

$focalPointDetector = new FocalPointDetector();

$point = $focalPointDetector->getPoint(new Imagick('/path/to/image'));

$point->x; // 283
$point->y; // 157

How it works

The algorithm works by picking the busiest area of the image:

1. Detect edges
2. Apply a vignette. This pushes the focus towards the centre
3. Split the image into segments
4. Calculate the average brightness within each segment
5. Pick the segment with the highest brightness

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Options

The FocalPointDetector constructor takes a number of options:

new FocalPointDetector(
 segmentSize: 20, // The size of the Segments in pixels
);

Debugging

You can get access to the processed image to see how the focus was determined:

use FreshleafMedia\Autofocus\FocalPointDetector;

$focalPointDetector = new FocalPointDetector();

$focalPointDetector
 ->debug(new Imagick('/path/to/image'))
 ->drawHeatMap()
 ->drawGrid()
 ->getRawImage()
 ->writeImage(__DIR__ . '/debug.jpg');

Tests

Unit tests can be run via composer test

Credits

This library is essentially a PHP port of https://github.com/sylvainjule/kirby-autofocus.

License

See LICENSE