The GmagickPixel::getcolorvalue() function is an inbuilt function in PHP which is used to get the normalized value of the provided color channel for a given GmagickPixel color. The normalized value is a floating-point number between 0 and 1.
Syntax:
float GmagickPixel::getcolorvalue( int $color )
Parameters: This function accepts a single parameter $color which holds an integer value corresponding to one of the COLOR constants.
List of all COLOR constants are given below:
- imagick::COLOR_BLACK (11)
- imagick::COLOR_BLUE (12)
- imagick::COLOR_CYAN (13)
- imagick::COLOR_GREEN (14)
- imagick::COLOR_RED (15)
- imagick::COLOR_YELLOW (16)
- imagick::COLOR_MAGENTA (17)
- imagick::COLOR_OPACITY (18)
- imagick::COLOR_ALPHA (19)
- imagick::COLOR_FUZZ (20)
Return Value: This function returns the value of the color channel specified as a floating-point number between 0 and 1.
Exceptions: This function throws GmagickPixelException on error.
Below given programs illustrate the GmagickPixel::getcolorvalue() function in PHP:
Program 1:
<?php   // Create a new gmagickPixel object $gmagickPixel = new GmagickPixel('#ad4c45');     // Get the Color value with imagick::COLOR_RED $colorValue = $gmagickPixel->getcolorvalue(gmagick::COLOR_RED); echo $colorValue; ?> |
Output:
0.67843137254902
Used Image:
Program 2:
<?php   // Create a new Gmagick object $gmagick = new Gmagick('neveropen.png');   // Get the image histogram $histogramElements = $gmagick->getimagehistogram();      // Get the 301th pixel $getPixel = $histogramElements[300];     // Get the Color value with gmagick::COLOR_GREEN $colorValue = $getPixel->getcolorvalue(gmagick::COLOR_GREEN);     echo $colorValue; ?> |
Output:
0.29803921568627
Reference: https://www.php.net/manual/en/gmagickpixel.getcolorvalue.php
