What are the functions imagealphablending() and imagesavealpha() used for in PHP image manipulation?

The functions imagealphablending() and imagesavealpha() are used in PHP image manipulation to enable or disable alpha channel blending and save alpha channel information in PNG images, respectively. Alpha channel blending allows for transparent pixels to blend with the background, while imagesavealpha() ensures that the transparency information is preserved when saving the image in PNG format.

// Enable alpha blending
imagealphablending($image_resource, true);

// Save alpha channel information in PNG images
imagesavealpha($image_resource, true);