(PHP 7 >= 7.2.0, PHP 8)
imageresolution — Get or set the resolution of the image
imageresolution() allows to set and get the resolution of
an image in DPI (dots per inch). If the optional parameters are null,
the current resolution is returned as an indexed array. If only
resolution_x is not null, the horizontal and vertical resolution
are set to this value. If none of the optional parameters are null, 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.
image由圖象創(chuàng )建函數(例如imagecreatetruecolor())返回的 GdImage 對象。
resolution_xThe horizontal resolution in DPI.
resolution_yThe vertical resolution in DPI.
When used as getter,
it returns an indexed array of the horizontal and vertical resolution on
success, 或者在失敗時(shí)返回 false.
When used as setter, it returns
true on success, 或者在失敗時(shí)返回 false.
| 版本 | 說(shuō)明 |
|---|---|
| 8.0.0 |
resolution_x and resolution_y are now nullable.
|
示例 #1 Setting and getting the resolution of an image
<?php
$im = imagecreatetruecolor(100, 100);
imageresolution($im, 200);
print_r(imageresolution($im));
imageresolution($im, 300, 72);
print_r(imageresolution($im));
?>
以上例程會(huì )輸出：
Array
(
[0] => 200
[1] => 200
)
Array
(
[0] => 300
[1] => 72
)