imagecropauto() is an inbuilt function in PHP that is used to crop an image automatically using one of the available modes.
Syntax
resource imagecropauto(resource $image, int $mode, float $threshold, int $color)
Parameters
imagecropauto() takes four different parameters − $image, $mode, $threshold and $color.
$image − Specifies the image resource to be cropped.
$mode − It is an optional parameter and it is used to specify an integer corresponding to a crop mode, below is the list of crop modes.
IMG_CROP_DEFAULT − The IMG_CROP_DEFAULT works just like the IMG_CROP_TRANSPARENT mode.
IMG_CROP_TRANSPARENT − This mode is used to crop out a transparent background.
IMG_CROP_BLACK − This mode is used to crop out a black background.
IMG_CROP_WHITE − This mode is used to crop out a white background.
IMG_CROP_SIDES − This mode uses the four corners of the image to attempt to detect the background to crop.
IMG_CROP_THRESHOLD − This mode is used to crop an image using the given threshold and color.
$threshold − Optional parameter, it is used to specify the tolerance in percent to be used while comparing the image color and the color to crop.
$color − Optional parameter, it is used to specify either an RGB (Red, Green, and Blue) color value or a palette index.
Return Values
imagecropauto() returns a cropped image resource on success or false on failure. The imagecrop() function returns false if the complete image is the crop.
Example 1
<?php
// Load the png image from the local drive folder
$img = imagecreatefromjpeg('C:\xampp\htdocs\Images\img33.jpg');
// Crop the extra white area of an image
$cropped = imagecropauto($img,IMG_CROP_WHITE);
// Convert it to a gif file
header('Content-type: image/gif');
imagepng($cropped);
?>Output
Image with white side area before using the IMG_CROP_WHITE mode parameter.
Crop white color area from the side after using IMG_CROP_WHITE mode of the parameter.
Note − We can use the different given modes of parameters to crop an image. For example, we can use IMG_CROP_BLACK, which will crop the black part of the image.