Metadata

Imagine 0.6 comes with an abstraction to read Image metadata.

Access image metadata

Metadata are read with a Imagine\Image\Metadata\MetadataReaderInterface and accessible through Imagine\Image\ImageInterface::metadata method that returns a Imagine\Image\Metadata\MetadataBag object:

<?php

use Imagine\Image\Metadata\ExifMetadataReader;

$image = $imagine->open('/path/to/image.jpg');
$metadata = $image->metadata();

// prints '/path/to/image.jpg'
print($metadata['filename']);

Change the metadata reader

Imagine comes bundled with two metadata readers: Imagine\Image\Metadata\DefaultMetadataReader and Imagine\Image\Metadata\ExifMetadataReader.

Imagine uses the default metadata reader by default. You can easily switch to the one you want using Imagine\Image\ImagineInterface::setMetadataReader method.

<?php

use Imagine\Image\Metadata\ExifMetadataReader;

$imagine->setMetadataReader(new ExifMetadataReader());

Default Metadata Reader

The default metadata reader is a basic reader that stores original information about the resource.

<?php

use Imagine\Image\Metadata\DefaultMetadataReader;

$image = $imagine
    ->setMetadataReader(new DefaultMetadataReader())
    ->open('chenille.jpg');
$metadata = $image->metadata();

var_dump($metadata->toArray());

The previous code might produce such output:

array(2) {
  'filepath' =>
  string(60) "/Users/romainneutron/Documents/workspace/Imagine/chenille.jpg"
  'uri' =>
  string(12) "chenille.jpg"
}

Exif Metadata Reader

Exif Metadata Reader gives the same base information as the default metadata reader and adds exif data provided by the Exif extension.

Note

Using the exif metadata reader adds a significant overhead to image processing.

<?php

use Imagine\Image\Metadata\ExifMetadataReader;

$image = $imagine
    ->setMetadataReader(new ExifMetadataReader())
    ->open('chenille.jpg');
$metadata = $image->metadata();

var_dump($metadata->toArray());

The previous code should produce this output:

array(37) {
  'filepath' =>
  string(60) "/Users/romainneutron/Documents/workspace/Imagine/chenille.jpg"
  'uri' =>
  string(12) "chenille.jpg"
  'exif.ExposureTime' =>
  string(5) "1/120"
  'exif.FNumber' =>
  string(4) "11/5"
  'exif.ExposureProgram' =>
  int(2)
  'exif.ISOSpeedRatings' =>
  int(40)
  'exif.ExifVersion' =>
  string(4) "0221"
  'exif.DateTimeOriginal' =>
  string(19) "2014:04:06 16:11:59"
  'exif.DateTimeDigitized' =>
  string(19) "2014:04:06 16:11:59"
  'exif.ComponentsConfiguration' =>
  string(4) "\000"
  'exif.ShutterSpeedValue' =>
  string(9) "9488/1373"
  'exif.ApertureValue' =>
  string(9) "7801/3429"
  'exif.BrightnessValue' =>
  string(8) "4457/710"
  'exif.MeteringMode' =>
  int(3)
  'exif.Flash' =>
  int(16)
  'exif.FocalLength' =>
  string(6) "103/25"
  'exif.ColorSpace' =>
  int(1)
  'exif.ExifImageWidth' =>
  int(2048)
  'exif.ExifImageLength' =>
  int(1536)
  'exif.SensingMethod' =>
  int(2)
  'exif.ExposureMode' =>
  int(0)
  'exif.WhiteBalance' =>
  int(0)
  'exif.FocalLengthIn35mmFilm' =>
  int(30)
  'exif.SceneCaptureType' =>
  int(0)
  'exif.UndefinedTag:0xA433' =>
  string(5) "Apple"
  'exif.UndefinedTag:0xA434' =>
  string(34) "iPhone 5s back camera 4.12mm f/2.2"
  'ifd0.Make' =>
  string(5) "Apple"
  'ifd0.Model' =>
  string(9) "iPhone 5s"
  'ifd0.XResolution' =>
  string(4) "72/1"
  'ifd0.YResolution' =>
  string(4) "72/1"
  'ifd0.ResolutionUnit' =>
  int(2)
  'ifd0.Software' =>
  string(5) "7.0.4"
  'ifd0.DateTime' =>
  string(19) "2014:04:06 16:11:59"
  'ifd0.YCbCrPositioning' =>
  int(1)
  'ifd0.Exif_IFD_Pointer' =>
  int(192)
  'ifd0.GPS_IFD_Pointer' =>
  int(1486)
}

Create your own metadata reader

Any metadata reader must implement Imagine\Image\Metadata\MetadataReaderInterface. However it’s easier to extend Imagine\Image\Metadata\AbstractMetadataReader to avoid missing things and focus on the purpose of the reader.

Here’s an example of a metadata reader that retrieves posix access information from a file:

<?php

use Imagine\Image\Metadata\AbstractMetadataReader;

class PosixMetadataReader extends AbstractMetadataReader
{
    /**
     * {@inheritdoc}
     */
    protected function extractFromFile($file)
    {
        // if file is not local, forget it
        if (!stream_is_local($file)) {
            return array();
        }

        return array(
            'access' => posix_access($file),
        );
    }

    /**
     * {@inheritdoc}
     */
    protected function extractFromData($data)
    {
        // posix informations about raw data in non-sense
        return array();
    }

    /**
     * {@inheritdoc}
     */
    protected function extractFromStream($resource)
    {
        if (!stream_is_local($file)) {
            return array();
        }

        if (false !== $data = @stream_get_meta_data($resource)) {
            return array(
                'access' => posix_access($data['uri']),
            );
        }

        return array();
    }
}

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