Imagick::getImagePixelColor

(PECL imagick 2.0.0)

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

说明

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

Returns the color of the specified pixel.

参数

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

返回值

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

错误／异常

错误时抛出 ImagickException。

User Contributed Notes

sheldon at hyperlinked dot com 19-Jul-2012 08:57


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);


?>