$variable=imagecreatefromgif(original image)
Generate a new gif image from the source image
$variable=imagecreatefromjpeg(original image)
Generate a new jpeg image from the original
$variable=imagecreatefrompng(original image)
Generate a new png image from the source image
round(number or variable)
Rounding values to the nearest whole number
imagecreatetruecolor(horizontal size, vertical size)
Create a new image frame. Note that the background will be black.
imagecopyresampled(copy destination, copy source)
After the new image frame is created, copy information is written.