How can transparency be maintained when converting PNG files to thumbnails in PHP?

When converting PNG files to thumbnails in PHP, it is important to maintain transparency in the thumbnail image. To do this, you can use the imagecopyresampled function in PHP to create the thumbnail while preserving transparency. Make sure to set the imagealphablending and imagesavealpha functions to true before creating the thumbnail to maintain transparency. 

// Load the original PNG image
$originalImage = imagecreatefrompng('original.png');

// Create a blank image for the thumbnail with transparency
$thumbnail = imagecreatetruecolor($newWidth, $newHeight);
imagesavealpha($thumbnail, true);
imagealphablending($thumbnail, false);
$transparent = imagecolorallocatealpha($thumbnail, 0, 0, 0, 127);
imagefill($thumbnail, 0, 0, $transparent);

// Copy and resize the original image to the thumbnail while maintaining transparency
imagecopyresampled($thumbnail, $originalImage, 0, 0, 0, 0, $newWidth, $newHeight, $originalWidth, $originalHeight);

// Save the thumbnail image
imagepng($thumbnail, 'thumbnail.png');

// Free up memory
imagedestroy($originalImage);
imagedestroy($thumbnail);

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