(PHP 4 >= 4.0.6, PHP 5)
imagecolorclosestalpha -- Get the index of the closest color to the specified color + alpha
Returns the index of the color in the palette of the image which
is "closest" to the specified RGB value and
alpha
level.
image
An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
red
Value of red component
green
Value of green component
blue
Value of blue component
alpha
A value between 0 and 127. 0 indicates completely opaque while 127 indicates completely transparent.