A function to parse EXIF metadata from NIKON devices and NIKKOR lenses

read_meta_from_exif.func.php

<?php


/*
 * Reads metadata from EXIF data in a JPEG file.
 * 
 * @param string $file_path Path to the JPEG file.
 * @return array Associative array of metadata.
 */
function read_meta_from_exif($path){

    $exif = exif_read_data($path);
    $data = array();

    // Get DateTime
    if(!isset($exif['DateTimeOriginal'])){
        $data['date_time'] = null;
    }else{
        // save as unix
        $data['date_time'] = strtotime($exif['DateTimeOriginal']);
    }

    // Get camera manufacturer
    if(!isset($exif['Make'])){
        $data['make'] = null;
    }else{
        $data['make'] = $exif['Make'];
    }

    // Get camera model
    if(!isset($exif['Model'])){
        $data['model'] = null;
    }else{
        $data['model'] = $exif['Model'];
    }
        // handle Xiaomi models
        if($data['make'] == "Xiaomi"){
            if(isset($exif['UndefinedTag:0x9A00'])){
                $data['model'] = $exif['UndefinedTag:0x9A00'];
            }
        }

    // Get lens manufacturer and model
    if($data['make'] == "NIKON CORPORATION"){
        if(!isset($exif['UndefinedTag:0xA434'])){
            $data['lens'] = null;
        }else{
            $data['lens'] = $exif['UndefinedTag:0xA434'];
        }
    }else{
        $data['lens'] = null;
    }

    // Get focal length
    if(isset($exif['FocalLength'])){
        if(is_numeric($exif['FocalLength'])){
            $data['focal_length'] = $exif['FocalLength'];
        }elseif(count(explode("/", $exif['FocalLength'])) == 2){
            $parts = explode("/", $exif['FocalLength']);
            if(is_numeric($parts[0]) && is_numeric($parts[1])){
                $data['focal_length'] = $parts[0] / $parts[1];
            }else{
                $data['focal_length'] = null;
            }
        }else{
            $data['focal_length'] = null;
        }
    }elseif(isset($exif['FocalLengthIn35mmFilm'])){
        if(is_numeric($exif['FocalLengthIn35mmFilm'])){
            $data['focal_length'] = $exif['FocalLengthIn35mmFilm'];
        }elseif(count(explode("/", $exif['FocalLengthIn35mmFilm'])) == 2){
            $parts = explode("/", $exif['FocalLengthIn35mmFilm']);
            if(is_numeric($parts[0]) && is_numeric($parts[1])){
                $data['focal_length'] = $parts[0] / $parts[1];
            }else{
                $data['focal_length'] = null;
            }
        }else{
            $data['focal_length'] = null;
        }
    }else{
        $data['focal_length'] = null;
    }

    // Get exposure time
    if(!isset($exif['ExposureTime'])){
        $data['exposure_time'] = null;
    }else{
        $data['exposure_time'] = $exif['ExposureTime'];
    }
    // Format exposure time so that if it was e.g. 10/32000, it becomes 1/3200
    if($data['exposure_time'] !== null){
        $exposure_parts = explode("/", $data['exposure_time']);
        if(count($exposure_parts) == 2 && is_numeric($exposure_parts[0]) && is_numeric($exposure_parts[1])){
            $exposure_parts[0] = intval($exposure_parts[0]);
            $exposure_parts[1] = intval($exposure_parts[1]);
            while($exposure_parts[0] % 10 == 0 && $exposure_parts[1] % 10 == 0){
                $exposure_parts[0] /= 10;
                $exposure_parts[1] /= 10;
            }
            while($exposure_parts[0] % 5 == 0 && $exposure_parts[1] % 5 == 0){
                $exposure_parts[0] /= 5;
                $exposure_parts[1] /= 5;
            }
            while($exposure_parts[0] % 2 == 0 && $exposure_parts[1] % 2 == 0){
                $exposure_parts[0] /= 2;
                $exposure_parts[1] /= 2;
            }
            $data['exposure_time'] = $exposure_parts[0] . "/" . $exposure_parts[1];
        }
    }

    // Get aperture
    if(!isset($exif['COMPUTED']) || !isset($exif['COMPUTED']['ApertureFNumber'])){
        $data['aperture'] = null;
    }else{
        $data['aperture'] = $exif['COMPUTED']['ApertureFNumber'];
    }

    // Get ISO
    if(!isset($exif['ISOSpeedRatings'])){
        $data['iso'] = null;
    }else{
        $data['iso'] = $exif['ISOSpeedRatings'];
    }

    // Get flash status
    if(!isset($exif['Flash'])){
        $data['flash'] = null;
    }else{
        if(is_numeric($exif['Flash'])){
            $data['flash'] = $exif['Flash'] > 0;
        }else{
            if(is_bool($exif['Flash'])){
                $data['flash'] = $exif['Flash'];
            }else{
                $data['flash'] = null;
            }
        }
    }

    return $data;

}