What are some alternative approaches to achieving the same result of making specific areas of an image transparent in PHP?

When working with images in PHP, one common task is to make specific areas of an image transparent. One way to achieve this is by using the `imagecolortransparent()` function in combination with the `imagecopymerge()` function. Another approach is to use the `imagecolorallocatealpha()` function to create a transparent color and then use the `imagefill()` function to fill the desired areas with this transparent color. 

// Method 1: Using imagecolortransparent() and imagecopymerge()
$sourceImage = imagecreatefrompng('source.png');
$transparentColor = imagecolorallocate($sourceImage, 255, 255, 255);
imagecolortransparent($sourceImage, $transparentColor);

$overlayImage = imagecreatefrompng('overlay.png');
imagecopymerge($sourceImage, $overlayImage, 0, 0, 0, 0, imagesx($overlayImage), imagesy($overlayImage), 100);

header('Content-Type: image/png');
imagepng($sourceImage);
imagedestroy($sourceImage);
imagedestroy($overlayImage);

// Method 2: Using imagecolorallocatealpha() and imagefill()
$sourceImage = imagecreatefrompng('source.png');
$transparentColor = imagecolorallocatealpha($sourceImage, 255, 255, 255, 127);

imagefill($sourceImage, 0, 0, $transparentColor);

header('Content-Type: image/png');
imagepng($sourceImage);
imagedestroy($sourceImage);

Keywords

image manipulation transparency GD library imagecolorallocatealpha imagecopymerge.

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