PHP/Graphics Image/JPG Image

Load jpg image file

<?php
$myImage = imagecreatefromjpeg("jpgFile.jpg");
header("Content-type: image/jpeg");
imagejpeg($myImage);
imagedestroy($myImage);
?>

Paint on a jpg image file

<?php
$mainImage = imagecreatefromjpeg("jpgFile.jpg");   
$mainWidth = imagesx($mainImage);
$mainHeight = imagesy($mainImage);
$thumbWidth = intval($mainWidth / 4);
$thumbHeight = intval($mainHeight / 4);
$myThumbnail = imagecreatetruecolor($thumbWidth, $thumbHeight);
imagecopyresampled($myThumbnail, $mainImage, 0, 0, 0, 0, $thumbWidth, $thumbHeight, $mainWidth, $mainHeight);
header("Content-type: image/jpeg");
imagejpeg($myThumbnail);
imagedestroy($myThumbnail);
imagedestroy($mainImage);
?>