Image processing

• Usage
  • Image information
  • Image manipulation
  • Image metadata
    • XMP
      • Reading

The pixel library allows you to manipulate images through a consistent API using either GD or ImageMagick.

Usage

First you'll have to decide whether to use GD or ImageMagick. In this example we'll use the ImageMagick processor.

$image = new Gd('image.png');

Image information

The getHeight method returns the height of your image.

$height = $image->getHeight();

The getWidth method returns the width of your image.

$width = $image->getWidth();

The getDimensions method returns an array containing both the height and width of your image.

$dimensions = $image->getDimensions();

The getTopColors method returns an array of the top n colors in an image, represented as Color class instances. By default, it returns the top five colors, but you can specify a custom number of colors to return.

$topColors = $image->getTopColors();

foreach ($topColors as $color) {
    var_dump($color->toHexString());
}

The following methods are available on the Color class:

Note: If you want the best color accuracy then you should use the ImageMagick class.

Image manipulation

The snapshot method allows you to create a snapshot of your image.

$image->snapshot();

The restore method allows you to restore an image snapshot.

$image->restore();

The apply method allows you to apply an image operation to your image.

$image->apply(new Sharpen);
$image->apply(new Border(new Color(0, 0, 0, 127), width: 10));

Here are all of the included image operations:

You can also create your own custom image operations by implementing the OperationInterface.

class MyOperation implements OperationInterface
{
    #[Override]
	public function apply(object &$imageResource): void
	{
        // Do your custom image operations here
    }
}

The getImageBlob method returns the raw binary image data.

$image = $image->getImageBlob();

// You can also tell it to return a different image type

$image = $image->getImageBlob('jpg');

// You can also adjust the image quality in percent (default is 95%)

$image = $image->getImageBlob('jpg', 70);

As the name suggests the save method will save your edited image to disk.

// Override original file

$image->save();

// Create a new file

$image->save('edited_image.png');

// You can also adjust the image quality in percent (default is 95%)

$image->save('edited_image.png', 70);

Image metadata

The library also includes functionality for working with embedded image metadata.

XMP

Reading

The XmpReader class allows you to extract XMP metadata from the image file.

Note: The XMP reader relies on FFI and libexempi. The reader will attempt to auto-detect the shared library, but depending on your setup, you may need to specify it manually.

$reader = new XmpReader('image.tif');

// You can specify the shared library if needed

$reader = new XmpReader('image.tif', 'libexempi.so.8');

The getXml method returns all the XMP data as XML.

$xml = $reader->getXml();

// You can also cast the reader object to a string

$xml = (string) $reader;

The getProperties method returns all the XMP properties as objects.

$properties = $reader->getProperties();

// You can also select the properties from a specific namespace

$properties = $reader->getProperties('http://purl.org/dc/elements/1.1/');

The getProperty method allows you to get a specific property. The first parameter is the property namespace and the second is the property name.

$property = $reader->getProperty('http://purl.org/dc/elements/1.1/', 'title');

echo $property->value;