imageinterlace() is an inbuilt PHP function that is used to enable or disable interlace in an image. It is a method of encoding a bitmap image such that a person who has partially received it sees a degraded copy of the entire image.
Interlacing an image lets users see portions of it as it loads, and it takes different forms depending on the image type. The non-interlaced JPEGs appear line-by-line. To enable interlacing on picture, we can simply call this function with the second parameter set to 1, or set to 0 (zero) to disable it.
Syntax
int imageinterlace(resource $image, int $interlace)
Parameters
imageinterlace() takes two parameters: $image and $interlace.
$image − Specifies the image to be interlaced.
$interlace − Specifies whether to enable or disable interlacing.
Return Values
imageinterlace() returns 1 if the interlace bit is set for the image, else it returns 0.
Example 1
<?php
//load an image by using imagecreatefromjpeg() function
$img = imagecreatefromjpeg('C:\xampp\htdocs\test\30.jpg');
// Enable interlacing by using one
imageinterlace($img, 1);
// View the output image
header('Content-type: image/jpeg');
imagejpeg($img);
imagedestroy($img);
?>
Example 2
In this example, we have disabled interlacing.
<?php
//load an image by using imagecreatefromjpeg() function
$img = imagecreatefromjpeg('C:\xampp\htdocs\test\30.jpg');
// Disable interlacing by using zero
imageinterlace($img, 0);
// View the output image
header('Content-type: image/jpeg');
imagejpeg($img);
imagedestroy($img);
?>Output
