php zoom image code

// Specify the file path and scaling ratio
$filename = 'test.jpg';
$percent = 0.5;
// Specify the header file Content type value
header('Content-type: image/jpeg');
// Get the width and height of the image
list($width, $height) = getimagesize($filename);
$newwidth = $width * $percent;
$newheight = $height * $percent;
// Create an image. The received parameters are width and height respectively, and the generated resource handle is returned.
$thumb = imagecreatetruecolor($newwidth, $newheight);
//Get the source file resource handle. The received parameter is the image path and the handle is returned
$source = imagecreatefromjpeg($filename);
// Cut all fields of the source file and reduce it to the target image. The first two are resource handles
imagecopyresampled($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
// Output to the browser
imagejpeg($thumb);
?>

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