PHP | imageconvolution() Function

The imageconvolution() function is an inbuilt function in PHP which is used to modify the image content. It applies a 3 x 3 convolution matrix in the image, using the given coefficient and offset. This function returns true on success or false on failure.

Syntax:

bool imageconvolution ( $image, $matrix, $div, $offset )

Parameters: This function accepts four parameter as mentioned above and described below:

  • $image: It is returned by one of the image creation functions, such as imagecreatetruecolor(). It is used to create size of image.
  • $matrix: It contains an array of 3 x 3 (3 x 3 matrix) of floats.
  • $div: It is divisor of result of the convolution, used for normalization.
  • $offset: It is used to set the color offset.

Return Value: This function returns True on success or False on failure.

Below programs illustrate the imageconvolution() function in PHP:

Program 1:

filter_none

edit
close

play_arrow

link
brightness_4
code

<?php
  
// Create a gif image 
$image = imagecreatefromgif(
'https://cdncontribute.geeksforgeeks.org/wp-content/uploads/animateImages.gif');
   
// Declare a 3X3 matrix
$matrix = array(
        array(2, 0, 0), 
        array(0, -1, 0), 
        array(0, 0, -1)
);
   
// imageconvolution function to modify image elements
imageconvolution($image, $matrix, 1, 127);
   
// Output of image content
header('Content-Type: image/png');
imagepng($image, null, 9);
?>

chevron_right






                        filter_none










Output:

image


Program 2:













                                    filter_none




                                    edit

                                    close




                                    play_arrow




                                    link

                                    brightness_4

                                    code
                                




















<?php 


  


// Create a gif image  


$image = imagecreatefrompng( 


'https://cdncontribute.geeksforgeeks.org/wp-content/uploads/geeksforgeeks-9.png'); 


   


// Declare a 3X3 matrix 


$emboss = array(         


        array(0, -1, 2),  


        array(2, 0, 0), 


        array(2, 0, -2) 


); 


   


// imageconvolution function to modify image elements 


imageconvolution($image, $emboss, 1, 127); 


  


// Output of image content 


header('Content-Type: image/png'); 


imagepng($image, null, 9); 


?> 



















                        chevron_right







                        filter_none










Output:

image


Related Articles:



Reference: http://php.net/manual/en/function.imageconvolution.php



          
          
          
          

            

    

        My Personal Notes
        arrow_drop_up
    

    

        
        

            
            
        

    


Recommended Posts:
Image
Mahadev99
Check out this Author's contributed articles.
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on  the "Improve Article" button below.