Here is an example on how to compose two images into a single one. The Imagick class utilises the exception handling model introduced in PHP5 and thus we will do that as well. Let's presume, that we have a directory in our filesystem, which contains our program and the two images we want to operate on.
<?php
try
{
// Let's check whether we can perform the magick.
if (TRUE !== extension_loaded('imagick'))
{
throw new Exception('Imagick extension is not loaded.');
}
// This check is an alternative to the previous one.
// Use the one that suits you better.
if (TRUE !== class_exists('Imagick'))
{
throw new Exception('Imagick class does not exist.');
}
// Let's find out where we are.
$dir = dirname(__FILE__);
// Let's read the images.
$glasses = new Imagick();
if (FALSE === $glasses->readImage($dir . '/glasses.png'))
{
throw new Exception();
}
$face = new Imagick();
if (FALSE === $face->readImage($dir . '/face.jpg'))
{
throw new Exception();
}
// Let's put the glasses on (10 pixels from left, 20 pixels from top of face).
$face->compositeImage($glasses, Imagick::COMPOSITE_DEFAULT, 10, 20);
// Let's merge all layers (it is not mandatory).
$face->flattenImages();
// We do not want to overwrite face.jpg.
$face->setImageFileName($dir . '/face_and_glasses.jpg');
// Let's write the image.
if (FALSE == $face->writeImage())
{
throw new Exception();
}
}
catch (Exception $e)
{
echo 'Caught exception: ' . $e->getMessage() . "\n";
}
exit(0);
?>
Also a couple more words on the Imagick::COMPOSITE_DEFAULT argument. The images we are composing together are separate layers. Not only can we put them in specific order, but we can also choose the way we want them to interfere with each other. And here comes the second argument of the compositeImage method. It can be given either as a constant or as the integer value of that constant. You can use the reflection API of PHP5 to get the list of them.
<?php
Reflection::export(new ReflectionClass('Imagick'));
?>
Just look for COMPOSITE_* constants in the "Constants" section.
Imagick::compositeImage
(PECL imagick 2, PECL imagick 3)
Imagick::compositeImage — Composite one image onto another
Descrição
public Imagick::compositeImage(
Imagick
int
int
int
int
): bool
Imagick
$composite_object,int
$composite,int
$x,int
$y,int
$channel = Imagick::CHANNEL_DEFAULT): bool
Composite one image onto another at the specified offset. Any extra arguments needed for the compose algorithm should passed to setImageArtifact with 'compose:args' as the first parameter and the data as the second parameter.
Parâmetros
-
composite_object -
Imagick object which holds the composite image
-
compose -
Composite operator. See Composite Operator Constants
-
x -
The column offset of the composited image
-
y -
The row offset of the composited image
-
channel -
Provide any channel constant that is valid for your channel mode. To apply to more than one channel, combine channeltype constants using bitwise operators. Refer to this list of channel constants.
Valor Retornado
Retorna true em caso de sucesso.
Exemplos
Exemplo #1 Using Imagick::compositeImage():
Composite two images with the 'mathematics' compose method
<?php
// Equivalent to running the command
// convert src1.png src2.png -compose mathematics -define compose:args="1,0,-0.5,0.5" -composite output.png
$src1 = new \Imagick("./src1.png");
$src2 = new \Imagick("./src2.png");
$src1->setImageVirtualPixelMethod(Imagick::VIRTUALPIXELMETHOD_TRANSPARENT);
$src1->setImageArtifact('compose:args', "1,0,-0.5,0.5");
$src1->compositeImage($src2, Imagick::COMPOSITE_MATHEMATICS, 0, 0);
$src1->writeImage("./output.png");
?>
add a note
User Contributed Notes 4 notes
m dot roszka at textend dot net ¶
16 years ago
elizapinchley at google dot com ¶
3 years ago
There has been changes to Imagick constants in new version. Please read new list of constants like this.
<?php
$img = new \Imagick();
$reflection_class = new ReflectionClass($img);
die(var_dump($reflection_class->getConstants()));
?>
Iddles ¶
13 years ago
To copy the alpha channel from one image to another, you can do the following:
<?php
$img1 = new Imagick( "image1.png" );
$img2 = new Imagick( "image2.png" );
$img1->compositeImage( $img2, imagick::COMPOSITE_COPYOPACITY, 0, 0 );
header('Content-type: image/png');
echo $img1;
?>
giso at connectholland dot nl ¶
14 years ago
You might need to set the colorspace the same when composing two images over each other
<?php
//Creating two Imagick object
$first = new Imagick('first.jpg');
$second = new Imagick('second.jpg');
// Set the colorspace to the same value
$first->setImageColorspace($second->getImageColorspace() );
//Second image is put on top of the first
$first->compositeImage($second, $second->getImageCompose(), 5, 5);
//new image is saved as final.jpg
$first->writeImage('final.jpg');
?>
