imageresolution

(PHP 7 >= 7.2.0)

imageresolution — Get or set the resolution of the image

説明

mixed imageresolution ( resource $image [, int $res_x [, int $res_y ]] )

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.

パラメータ

image: imagecreatetruecolor() のような画像作成関数が返す画像リソース。
res_x: The horizontal resolution in DPI.
res_y: The vertical resolution in DPI.

返り値

When used as getter (that is without the optional parameters), it returns TRUE on success, 失敗した場合に FALSE を返します. When used as setter (that is with one or both optional parameters given), it returns an indexed array of the horizontal and vertical resolution on success, 失敗した場合に FALSE を返します.

例

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));
?>

上の例の出力は以下となります。

Array
(
    [0] => 200
    [1] => 200
)
Array
(
    [0] => 300
    [1] => 72
)