PHP imageantialias Function: Usage, Parameters, and Example

The imageantialias function in PHP’s GD library enables or disables antialiasing for line and polygon drawing on true‑color images, but it does not support alpha channels, line widths, or styles.

Parameters: $image – an image resource created by functions such as imagecreatetruecolor(); $enabled – a boolean indicating whether antialiasing should be turned on.

Return value: on success the function returns the image resource; on failure it returns FALSE.

Example usage creates two images, enables antialiasing on one, allocates colors, draws lines, merges the images side by side, and outputs the result as a PNG.

<?php
// Setup an anti-aliased image and a normal image
$aa = imagecreatetruecolor(400,100);
$normal = imagecreatetruecolor(200,100);
// Switch antialiasing on for one image
imageantialias($aa, true);
// Allocate colors
$red = imagecolorallocate($normal,255,0,0);
$red_aa = imagecolorallocate($aa,255,0,0);
// Draw two lines, one with AA enabled
imageline($normal,0,0,200,100,$red);
imageline($aa,0,0,200,100,$red_aa);
// Merge the two images side by side for output (AA: left, Normal: Right)
imagecopymerge($aa,$normal,200,0,0,0,200,100,100);
// Output image
header('Content-type: image/png');
imagepng($aa);
imagedestroy($aa);
imagedestroy($normal);
?>