PHP 8.1.0 Beta 1 available for testing

imageresolution

(PHP 7 >= 7.2.0)

imageresolutionGet or set the resolution of the image

Descrierea

imageresolution ( resource $image ) : mixed
imageresolution ( resource $image , int $res_x , int $res_y = $res_x ) : mixed

imageresolution() allows to set and get the resolution of an image in DPI (dots per inch). If none of the optional parameters is given, the current resolution is returned as indexed array. If only res_x is given, the horizontal and vertical resolution are set to this value. If both optional parameters are given, the horizontal and vertical resolution are set to these values, respectively.

The resolution is only used as meta information when images are read from and written to formats supporting this kind of information (curently PNG and JPEG). It does not affect any drawing operations. The default resolution for new images is 96 DPI.

Parametri

image

O resursă - imagine, întoarsă de una din funcțiile de creare a imaginilor, cum ar fi imagecreatetruecolor().

res_x

The horizontal resolution in DPI.

res_y

The vertical resolution in DPI.

Valorile întoarse

When used as getter (first signature), it returns an indexed array of the horizontal and vertical resolution on success, sau false în cazul eșecului. When used as setter (second signature), it returns true on success, sau false în cazul eșecului.

Exemple

Example #1 Setting and getting the resolution of an image

<?php
$im 
imagecreatetruecolor(100100);
imageresolution($im200);
print_r(imageresolution($im));
imageresolution($im30072);
print_r(imageresolution($im));
?>

Exemplul de mai sus va afișa:

Array
(
    [0] => 200
    [1] => 200
)
Array
(
    [0] => 300
    [1] => 72
)
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User Contributed Notes 1 note

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1
fernando dot fonseca at afteryou dot pt
28 days ago
It should be clear that the set version of the function doesn't change the image it self, just the resource in memory, which probably is fine if you didn't save the image yet. If your use case is for an image that is already on disk,  image you should always do something like:

imageresolution($img, 300, 300);
imagepng($img, $filname, $quality);
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