Funções da GD
PHP Manual

imagelayereffect

(PHP 4 >= 4.3.0, PHP 5, PHP 7)

imagelayereffectSet the alpha blending flag to use layering effects

Descrição

bool imagelayereffect ( resource $image , int $effect )

Set the alpha blending flag to use layering effects.

Parâmetros

image

Um resource de imagem, retornado por funções de criação de imagens, como imagecreatetruecolor().

effect

One of the following constants:

IMG_EFFECT_REPLACE
Use pixel replacement (equivalent of passing TRUE to imagealphablending())
IMG_EFFECT_ALPHABLEND
Use normal pixel blending (equivalent of passing FALSE to imagealphablending())
IMG_EFFECT_NORMAL
Same as IMG_EFFECT_ALPHABLEND.
IMG_EFFECT_OVERLAY
Overlay has the effect that black background pixels will remain black, white background pixels will remain white, but grey background pixels will take the colour of the foreground pixel.
IMG_EFFECT_MULTIPLY
Overlays with a multiply effect.

Valor Retornado

Retorna TRUE em caso de sucesso ou FALSE em caso de falha.

Changelog

Versão Descrição
7.2.0 Added IMG_EFFECT_MULTIPLY (requires system libgd >= 2.1.1 or the bundled libgd).

Exemplos

Exemplo #1 imagelayereffect() example

<?php
// Setup an image
$im imagecreatetruecolor(100100);

// Set a background
imagefilledrectangle($im00100100imagecolorallocate($im220220220));

// Apply the overlay alpha blending flag
imagelayereffect($imIMG_EFFECT_OVERLAY);

// Draw two grey ellipses
imagefilledellipse($im50504040imagecolorallocate($im100255100));
imagefilledellipse($im50505080imagecolorallocate($im100100255));
imagefilledellipse($im50508050imagecolorallocate($im255100100));

// Output
header('Content-type: image/png');

imagepng($im);
imagedestroy($im);
?>

O exemplo acima irá imprimir algo similar à:

Output of example : imagelayereffect()

Notas

Before PHP 5.5.0, this function is only available if PHP is compiled with the bundled version of the GD library.


Funções da GD
PHP Manual