array ( 0 => 'index.php', 1 => 'PHP Manual', ), 'head' => array ( 0 => 'UTF-8', 1 => 'de', ), 'this' => array ( 0 => 'function.imagecropauto.php', 1 => 'imagecropauto', 2 => 'Crop an image automatically using one of the available modes', ), 'up' => array ( 0 => 'ref.image.php', 1 => 'GD- und Image-Funktionen', ), 'prev' => array ( 0 => 'function.imagecrop.php', 1 => 'imagecrop', ), 'next' => array ( 0 => 'function.imagedashedline.php', 1 => 'imagedashedline', ), 'alternatives' => array ( ), 'source' => array ( 'lang' => 'en', 'path' => 'reference/image/functions/imagecropauto.xml', ), 'history' => array ( ), ); $setup["toc"] = $TOC; $setup["toc_deprecated"] = $TOC_DEPRECATED; $setup["parents"] = $PARENTS; manual_setup($setup); contributors($setup); ?>

imagecropauto

(PHP 5 >= 5.5.0, PHP 7, PHP 8)

imagecropauto — Crop an image automatically using one of the available modes

Beschreibung

imagecropauto(
    GdImage $image,
    int $mode = IMG_CROP_DEFAULT,
    float $threshold = 0.5,
    int $color = -1
): GdImage|false

Automatically crops an image according to the given mode.

Parameter-Liste

image

Ein GdImage-Objekt, das von einer der Funktionen zur Bilderzeugung, z. B. imagecreatetruecolor(), zurückgegeben wurde.

mode

One of the following constants:

IMG_CROP_DEFAULT
Same as IMG_CROP_TRANSPARENT. Before PHP 7.4.0, the bundled libgd fell back to IMG_CROP_SIDES, if the image had no transparent color.
IMG_CROP_TRANSPARENT
Crops out a transparent background.
IMG_CROP_BLACK
Crops out a black background.
IMG_CROP_WHITE
Crops out a white background.
IMG_CROP_SIDES
Uses the 4 corners of the image to attempt to detect the background to crop.
IMG_CROP_THRESHOLD
Crops an image using the given threshold and color.
threshold

Specifies the tolerance in percent to be used while comparing the image color and the color to crop. The method used to calculate the color difference is based on the color distance in the RGB(a) cube.

Used only in IMG_CROP_THRESHOLD mode.

Hinweis: Before PHP 7.4.0, the bundled libgd used a somewhat different algorithm, so the same threshold yielded different results for system and bundled libgd.

color

Either an RGB color value or a palette index.

Used only in IMG_CROP_THRESHOLD mode.

Rückgabewerte

Returns a cropped image object on successBei einem Fehler wird false zurückgegeben.. false is also returned if the whole image was cropped.

Changelog

Version Beschreibung
8.0.0 image erwartet nun eine GdImage-Instanz; vorher wurde eine gültige gd-Ressource erwartet.
8.0.0 On success, this function returns a GDImage instance now; previously, a resource was returned.
7.4.0 The behavior of imagecropauto() in the bundled libgd has been synced with that of system libgd: IMG_CROP_DEFAULT no longer falls back to IMG_CROP_SIDES and threshold-cropping now uses the same algorithm as system libgd.
7.4.0 The default value of mode has been changed to IMG_CROP_AUTO. Formerly, the default value has been -1 which corresponds to IMG_CROP_DEFAULT, but passing -1 is now deprecated.

Beispiele

Beispiel #1 Proper handling of auto-cropping

As noted in the return value section, imagecropauto() returns false if the whole image was cropped. In this example we have an image object $im which should be automatically cropped only if there is something to crop; otherwise we want to proceed with the original image.

<?php
$cropped = imagecropauto($im, IMG_CROP_DEFAULT);
if ($cropped !== false) { // in case a new image object was returned
$im = $cropped; // assign the cropped image to $im
}
?>

Siehe auch