PHP | GmagickPixel getcolorvalue() Function

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('geeksforgeeks.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