# imagecropauto

(PHP 5 >= 5.5.0, PHP 7)

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

### Description

imagecropauto ( resource `$image` [, int `$mode` = `IMG_CROP_DEFAULT` [, float `$threshold` = .5 [, int `$color` = -1 ]]] ) : resource|false

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 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.

  > 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.

### 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
}
?>`

### See Also

- imagecrop() - Crop an image to the given rectangle