The Imagick::getImageAphaChannel() function is an inbuilt function in PHP which is used to get the image alpha channel. The returned value is one of the ALPHACHANNEL constants.
Syntax:
int Imagick::getImageAlphaChannel( void )
Parameters: This function does not accept any parameters.
Exceptions: This function throws ImagickException on error.
Return Value: This function returns an integer value on success.
List of ALPHACHANNEL constants are given below:
- imagick::ALPHACHANNEL_ACTIVATE (0)
- imagick::ALPHACHANNEL_DEACTIVATE (1)
- imagick::ALPHACHANNEL_RESET (2)
- imagick::ALPHACHANNEL_SET (3)
- imagick::ALPHACHANNEL_UNDEFINED (4)
- imagick::ALPHACHANNEL_COPY (5)
- imagick::ALPHACHANNEL_EXTRACT (6)
- imagick::ALPHACHANNEL_OPAQUE (7)
- imagick::ALPHACHANNEL_SHAPE (8)
- imagick::ALPHACHANNEL_TRANSPARENT (9)
Below programs illustrate the Imagick::getImageAlphaChannel() function in PHP:
Program 1:
<?php // Create a new imagick object with a PNG image $imagick = new Imagick( // Get the Alpha Channel $alphaChannel = $imagick ->getImageAlphaChannel(); echo $alphaChannel ; ?> |
Output:
1 ( which corresponds to imagick::ALPHACHANNEL_DEACTIVATE. )
Program 2:
<?php // Create a new imagick object with a PNG image $imagick = new Imagick( // Get the Alpha Channel $alphaChannel = $imagick ->getImageAlphaChannel(); echo $alphaChannel . "<br>" ; // Set the alpha channel $alphaChannel = $imagick ->setImageAlphaChannel(imagick::ALPHACHANNEL_RESET ); // Get the Alpha Channel $alphaChannel = $imagick ->getImageAlphaChannel(); echo $alphaChannel ; ?> |
Output:
0 1
Reference: https://www.php.net/manual/en/imagick.getimagealphachannel.php