(PHP 5 >= 5.5.0, PHP 7)
imagecropauto — Crop an image automatically using one of the available modes
$image
[, int $mode
= IMG_CROP_DEFAULT
[, float $threshold
= .5
[, int $color
= -1
]]] ) : resource
Automatically crops an image according to the given
mode
.
image
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mode
One of the following constants:
IMG_CROP_DEFAULT
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
IMG_CROP_BLACK
IMG_CROP_WHITE
IMG_CROP_SIDES
IMG_CROP_THRESHOLD
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.
Note: 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.
Returns a cropped image resource on success ������ʧ��ʱ���� FALSE
.
If the complete image was cropped, imagecrop() returns FALSE
.
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---|---|
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.
|
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
}
?>