imagecolortransparent

(PHP 4, PHP 5, PHP 7)

imagecolortransparent — Define a color as transparent

Descrierea

int imagecolortransparent ( resource $image [, int $color ] )

Sets the transparent color in the given image.

Parametri

image: O resursă - imagine, întoarsă de una din funcțiile de creare a imaginilor, cum ar fi imagecreatetruecolor().
color: A color identifier created with imagecolorallocate().

Valorile întoarse

The identifier of the new (or current, if none is specified) transparent color is returned. If color is not specified, and the image has no transparent color, the returned identifier will be -1.

Exemple

Example #1 imagecolortransparent() example


<?php
// Create a 55x30 image
$im = imagecreatetruecolor(55, 30);
$red = imagecolorallocate($im, 255, 0, 0);
$black = imagecolorallocate($im, 0, 0, 0);

// Make the background transparent
imagecolortransparent($im, $black);

// Draw a red rectangle
imagefilledrectangle($im, 4, 4, 50, 25, $red);

// Save the image
imagepng($im, './imagecolortransparent.png');
imagedestroy($im);
?>

Exemplul de mai sus va afișa ceva similar cu:

Note

Notă:
Transparency is copied only with imagecopymerge() and true color images, not with imagecopy() or pallete images.

Notă:
The transparent color is a property of the image, transparency is not a property of the color. Once you have set a color to be the transparent color, any regions of the image in that color that were drawn previously will be transparent.