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imagecreatefrompng

(PHP 4, PHP 5)

imagecreatefrompng — Create a new image from file or URL

Description

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);
?>

The above example will output something similar to:

Tip

如果 fopen wrappers 已啟動,則可藉此函數把檔名當成URL使用。參考 fopen() 有更多關於如何指定檔名的細節和List of Supported Protocols/Wrappers支援URL協定的列表。

Parameters

filename

Path to the PNG image

Return Values

Returns an image resource identifier on success, FALSE on errors.

Notes

Warning

PHP 4.3.0 之前的 Windows PHP版本不支援由此函數存取遠端檔案,即使啟動allow_url_fopen選項。