imagecropauto
(PHP 5 >= 5.5.0, PHP 7)
imagecropauto — Crop an image automatically using one of the available modes
Description
$image
[, int $mode = IMG_CROP_DEFAULT
[, float $threshold = .5
[, int $color = -1
]]] ) : resource
Automatically crops an image according to the given
mode.
Parameters
-
image -
An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
-
mode -
One of the following constants:
-
IMG_CROP_DEFAULT -
Same as
IMG_CROP_TRANSPARENT. Before PHP 7.4.0, the bundled libgd fell back toIMG_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
thresholdandcolor.
-
-
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_THRESHOLDmode.Note: Before PHP 7.4.0, the bundled libgd used a somewhat different algorithm, so the same
thresholdyielded different results for system and bundled libgd. -
color -
Either an RGB color value or a palette index.
Used only in
IMG_CROP_THRESHOLDmode.
Return Values
Returns a cropped image resource on success or FALSE on failure.
If the complete image was cropped, imagecrop() returns FALSE.
Changelog
| Version | Description |
|---|---|
| 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.
|
Examples
Example #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 resource
$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 ($cropped !== false) { // in case a new image resource was returned
imagedestroy($im); // we destroy the original image
$im = $cropped; // and assign the cropped image to $im
}
?>
English translation
You have asked to visit this site in English. For now, only the interface is translated, but not all the content yet.If you want to help me in translations, your contribution is welcome. All you need to do is register on the site, and send me a message asking me to add you to the group of translators, which will give you the opportunity to translate the pages you want. A link at the bottom of each translated page indicates that you are the translator, and has a link to your profile.
Thank you in advance.
Document created the 30/01/2003, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/php-rf-function.imagecropauto.html
The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.
References
These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author This site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.
