Imagick::paintTransparentImage

(PECL imagick 2, PECL imagick 3)

Imagick::paintTransparentImage — 色にマッチするピクセルを塗りつぶし色に変更する

警告

この関数は Imagick 3.4.4 以降では 非推奨 になりました。この関数に依存したコードを書くのはやめましょう。

説明

public Imagick::paintTransparentImage(mixed $target, float $alpha, float $fuzz): bool

塗りつぶし色に指定した色にマッチするピクセルを変更します。

パラメータ

target: この対象色を変更して、画像の不透明度を指定します。
alpha: 不透明度レベル。1.0 は完全な不透明、0.0 は完全な透明を表します。
fuzz: 画像の fuzz 値。どの程度の色を「同じ色」とみなすかを表します。

戻り値

成功した場合に true を返します。

エラー / 例外

エラー時に ImagickException をスローします。

変更履歴

バージョン	説明
PECL imagick 2.1.0	色を表す文字列を最初のパラメータとして指定できるようになりました。これまでのバージョンでは ImagickPixel オブジェクトしか指定できませんでした。

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User Contributed Notes 3 notes

down

Anonymous ¶

15 years ago

Actually it does seem to work just not the way expected perhaps.

Looking at the fuzz option on ImageMagick's site (http://www.imagemagick.org/script/command-line-options.php#fuzz), "The distance can be in absolute intensity units or, by appending % as a percentage of the maximum possible intensity (255, 65535, or 4294967295)."

As it requires a float, the percentage value won't work so it actually one of the max intensity values.  In my case, the images I was working with seemed to have max intensity values of 65535.  So a fuzz of 6500, for roughly 10%, seemed to do the trick.

The part that might be problematic though is how do you determine the max intensity of a color/image?  Using a static 6500 would be fine until I would have to convert an image with a max intensity other than 65535.  If it's 255 it would wipe the entire image.  Or fall far short on the fuzz with the larger value.

down

quickshiftin at gmail dot com ¶

10 years ago

Have a look at this thread on Stackoverflow for the answer regarding how to determine the max intensity of an image.

http://stackoverflow.com/questions/26239130/determine-max-possible-intensity-of-image/26240656#26240656

In short here is the code to make the $fuzz parameter behave more like you would expect (it now represents a percentage between 0-100). The $fuzz value should now be a float between 0 and 1.

class SaneImagick extends Imagick
{
    public function paintTransparentImage($target, $alpha, $fuzz)
    {
        $iQuantumDepth = pow(2, $this->getQuantumDepth()['quantumDepthLong']);
        return parent::paintTransparentImage($target, $alpha, $fuzz * $iQuantumDepth);
    }
}

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alain at ocarina dot fr ¶

13 years ago

The fuzz is just working well in a range of 0 to 65535.

I suggest you to try to move fuzz on a color spectrum image.

1/ Get a color spectrum ( Google Image has a lot )

2/ Try this code :

<?php

    function fuzzTest($source, $target, $fuzz) {

        // Loads image
        $im = new Imagick($source);

        // Resizes images to make them easily comparable
        $im->resizeImage(320, 240, Imagick::FILTER_LANCZOS, 1, true);
        
        // Apply fuzz
        $im->paintTransparentImage($im->getImagePixelColor(0, 0), 0, $fuzz);
        
         // Writes image
        $im->setImageFormat('png');
        $im->writeImage($target);
        $im->destroy();
         
        return true;
     }

     for ($i = 0; ($i <= 10); $i++) {
         fuzzTest('spectrum.png', "test_{$i}.png", (6553.5 * $i));
         echo '<img src="test_' . $i . '.png" />&nbsp;';
     }
 
 ?>

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