imagecreatefrompng

(PHP 4, PHP 5)

imagecreatefrompng — Create a new image from file or URL

說明

resource imagecreatefrompng ( string $filename )

imagecreatefrompng() returns an image identifier representing the image obtained from the given filename.

imagecreatefrompng() returns an empty string on failure. It also outputs an error message, which unfortunately displays as a broken link in a browser. To ease debugging the following example will produce an error PNG:

Example#1 Example to handle an error during creation


<?php
function LoadPNG($imgname)
{
    $im = @imagecreatefrompng($imgname); /* Attempt to open */
    if (!$im) { /* See if it failed */
        $im  = imagecreatetruecolor(150, 30); /* Create a blank image */
        $bgc = imagecolorallocate($im, 255, 255, 255);
        $tc  = imagecolorallocate($im, 0, 0, 0);
        imagefilledrectangle($im, 0, 0, 150, 30, $bgc);
        /* Output an errmsg */
        imagestring($im, 1, 5, 5, "Error loading $imgname", $tc);
    }
    return $im;
}
header("Content-Type: image/png");
$img = LoadPNG("bogus.image");
imagepng($img);
?>