PHP imagecolorsforindex – Retrieve RGBA Components for a Color Index

The imagecolorsforindex function returns an associative array with keys red, green, blue, and alpha that represent the RGBA components of a specified color index in an image resource.

Parameters

image : The image resource returned by an image creation function such as imagecreatetruecolor().

index : The color index whose RGBA values are to be retrieved.

Return value

On success the function returns an array with the RGBA components; on failure it returns FALSE.

Example

<code><?php
// Open an image
$im = imagecreatefrompng('nexen.png');

// Coordinates of the pixel
$start_x = 40;
$start_y = 50;

// Get the color index at the pixel
$color_index = imagecolorat($im, $start_x, $start_y);

// Convert the index to RGBA components
$color_tran = imagecolorsforindex($im, $color_index);

// Display the color values
echo '<pre>';
print_r($color_tran);
echo '

'; ?>