Imagick::getImagePixelColor

(PECL imagick 2.0.0)

Imagick::getImagePixelColor — Returns the color of the specified pixel

Description

ImagickPixel Imagick::getImagePixelColor ( int $x , int $y )

Returns the color of the specified pixel.

Parameters

x: The x-coordinate of the pixel
y: The y-coordinate of the pixel

Return Values

Returns an ImagickPixel instance for the color at the coordinates given.

Errors/Exceptions

Throws ImagickException on error.

Коментарии

Jul 19

Автор: sheldon at hyperlinked dot com


I'm sure there are a lot of people like me who have been wondering, "How you manage to produce a human readable output of this operation?"



<?php

$image = new Imagick('testimage.jpg');



$x = 1; 

$y = 1;

$pixel = $image->getImagePixelColor($x, $y);

?>



If you try to print an output of the $pixel object, you get nothing. You have to use one of the ImagickPixel operations to get back a value.



You can do either of the following:



<?php

$colors = $pixel->getColor();

print_r($colors); // produces Array([r]=>255,[g]=>255,[b]=>255,[a]=>1);



$pixel->getColorAsString(); // produces rgb(255,255,255);

?>



The place where I was getting hung up was how to get the data that was captured in the Imagick::getImagePixelColor operation into an ImagickPixel object. I was trying to find ways of passing the value to a newly instantiated ImagickPixel object. Well, it appears that once you've captured your color data using Imagick::getImagePixelColor, what's returned IS an ImagickPixel object!



As a further note, you do not need to convert this to a human readable format if you just want to take a color sample at a single point on your image to plug into another operation. 



For example, if you wanted to perform a flood fill effect on a certain color you could plug in the instance of the ImagickPixel object directly. 



The following fill perform a flood fill effect at coordinates 1,1 on your image using Green as the fill color and the color sampled at 1,1 as the target color to fill.



<?php

$hexcolor = '#00ff00';

$fuzz = '4000';

$x = 1;

$y = 1;

$pixel = $image->getImagePixelColor($x, $y);

$image->floodfillPaintImage($hexcolor, $fuzz, $pixel, $x, $y, false);

?>