The Imagick::linearStretchImage() function is an inbuilt function in PHP which is used to stretch with saturation the image intensity. The calculation of Imagick::linearStretchImage() function is carry by pixels multiples with blackPoint and whitePoint simultaneously.
Syntax:
bool Imagick::linearStretchImage( $blackPoint, $whitePoint )
Parameters: This function accepts two parameters as mentioned above and described below:
- $blackPoint: This parameter holds the image black point.
- $whitePoint: This parameter holds the image white point.
Return Value: This function returns TRUE on success FALSE on failure.
Below example illustrates the Imagick::linearStretchImage() function in PHP:
Program: This program uses Imagick::linearStretchImage() function to stretch with saturation the image intensity.
<?php   // Store the image into variable $imagePath=   // Store the value of variables $blackThreshold = 23; $whiteThreshold = 45;   // Declare new Imagick object $imagick = new \Imagick($imagePath);     // Calculate the pixels of image $pixels = $imagick->getImageWidth() * $imagick->getImageHeight();   // Use linearStretchImage() function to stretches with // saturation the image intensity $imagick->linearStretchImage($blackThreshold * $pixels, $whiteThreshold * $pixels);   header("Content-Type: image/jpeg");   // Display the image echo $imagick->getImageBlob();   ?> |
Output:
Reference: https://www.php.net/manual/en/imagick.linearstretchimage.php
