Gets EXIF GPS data from an image #php #gps

gps.php

<?php
/**
 * GPS helper class.
 *
 * @package   Gps
 *
 * @author    Beau Hastings <[email protected]>
 * @copyright 2019 Beau Hastings
 * @license   GNU GPL v2
 *
 * @link      https://gist.github.com/hastinbe/6ba47b243da1adcd063ce64a25ca1c0c
 */

namespace hastinbe\Gps;

class Gps
{
    /**
     * EXIF data.
     *
     * @var array
     */
    protected $exifData = [];

    /**
     * Image path.
     *
     * @var string
     */
    protected $path = '';

    /**
     * Create a new instance.
     *
     * @param string $path  Path to image.
     * @param bool $read    Read EXIF data on instance creation
     */
    public function __construct(string $path, $read = false)
    {
        $this->path = $path;

        if ($read) {
            $this->readExifData();
        }
    }

    /**
     * Get EXIF data.
     *
     * @return mixed
     * @throws \Exception
     */
    public function getExifData($attribute = null)
    {
        if ($attribute === null) {
            return $this->exifData;
        }

        if (!isset($this->exifData[$attribute])) {
            throw new \Exception("EXIF attribute '$attribute' is undefined");
        }

        return $this->exifData[$attribute];
    }

    /**
     * Set EXIF data.
     *
     * @param array $exif
     * @return Gps
     */
    public function setExifData(array $exifData)
    {
        $this->exifData = $exifData;

        return $this;
    }

    /**
     * Get path to image.
     *
     * @return string
     */
    public function getPath(): string
    {
        return $this->path;
    }

    /**
     * Set path to image.
     *
     * @param string $path
     * @return Gps
     */
    public function setPath(string $path)
    {
        $this->path = $path;

        return $this;
    }

    /**
     * Read EXIF data.
     *
     * @return Gps
     */
    public function readExifData()
    {
        $this->setExifData(exif_read_data($this->getPath()));

        return $this;
    }

    /**
     * Get coordinate in degrees.
     *
     * @param array $coordinate
     * @param string $hemisphere  For latitude, N or S; for longitude, E or W
     * @return float
     */
    public function getCoordDegrees($coordinate, $hemisphere): float
    {
        for ($i = 0; $i < 3; $i++) {
            $part = explode('/', $coordinate[$i]);

            if (count($part) == 1) {
                $coordinate[$i] = $part[0];
            }
            elseif (count($part) == 2) {
                $coordinate[$i] = floatval($part[0]) / floatval($part[1]);
            }
            else {
                $coordinate[$i] = 0;
            }
        }

        list($degrees, $minutes, $seconds) = $coordinate;
        $sign = ($hemisphere == 'W' || $hemisphere == 'S') ? -1 : 1;

        return $sign * ($degrees + $minutes / 60 + $seconds / 3600);
    }

    /**
     * Get the latitude and longitude.
     *
     * @return array
     */
    public function getLatLong(): array
    {
        $latitude = $this->getCoordDegrees(
            $this->getExifData('GPSLatitude'),
            $this->getExifData('GPSLatitudeRef')
        );

        $longitude = $this->getCoordDegrees(
            $this->getExifData('GPSLongitude'),
            $this->getExifData('GPSLongitudeRef')
        );

        return [$latitude, $longitude];
    }
}