Imagick::sparseColorImage

(PECL imagick 2 >= 2.3.0, PECL imagick 3)

Imagick::sparseColorImage — Interpolates colors

说明

public Imagick::sparseColorImage ( int $SPARSE_METHOD , array $arguments , int $channel = Imagick::CHANNEL_DEFAULT ) : bool

Given the arguments array containing numeric values this method interpolates the colors found at those coordinates across the whole image using sparse_method. 此方法在Imagick基于ImageMagick 6.4.5以上版本编译时可用。

参数

SPARSE_METHOD: Refer to this list of sparse method constants
arguments: An array containing the coordinates. The array is in format array(1,1, 2,45)
channel: Provide any channel constant that is valid for your channel mode. To apply to more than one channel, combine channel constants using bitwise operators. 缺省为Imagick::CHANNEL_DEFAULT. 参考此通道常数列表

返回值

成功时返回 true。

错误／异常

错误时抛出 ImagickException。

范例

Example #1 SPARSECOLORMETHOD_BARYCENTRIC Imagick::sparseColorImage()


<?php
    function renderImageBarycentric2() {
        $points = [
            [0.30, 0.10, 'red'],
            [0.10, 0.80, 'blue'],
            [0.70, 0.60, 'lime'],
            [0.80, 0.20, 'yellow'],
        ];
        $imagick = createGradientImage(
            400, 400,
            $points,
            \Imagick::SPARSECOLORMETHOD_BARYCENTRIC
        );
        header("Content-Type: image/png");
        echo $imagick->getImageBlob();
    }

?>

Example #2 SPARSECOLORMETHOD_BILINEAR Imagick::sparseColorImage()


<?php
    function renderImageBilinear() {
        $points = [[0.30, 0.10, 'red'], [0.10, 0.80, 'blue'], [0.70, 0.60, 'lime'], [0.80, 0.20, 'yellow'],];
        $imagick = createGradientImage(500, 500, $points, \Imagick::SPARSECOLORMETHOD_BILINEAR);
        header("Content-Type: image/png");
        echo $imagick->getImageBlob();
    }

?>

Example #3 SPARSECOLORMETHOD_SPEPARDS Imagick::sparseColorImage()


<?php
    function renderImageShepards() {
        $points = [
            [0.30, 0.10, 'red'],
            [0.10, 0.80, 'blue'],
            [0.70, 0.60, 'lime'],
            [0.80, 0.20, 'yellow'],
        ];
        $imagick = createGradientImage(600, 600, $points, \Imagick::SPARSECOLORMETHOD_SPEPARDS);
        header("Content-Type: image/png");
        echo $imagick->getImageBlob();
    }

?>

Example #4 SPARSECOLORMETHOD_VORONOI Imagick::sparseColorImage()


<?php
    function renderImageVoronoi() {
        $points = [
            [0.30, 0.10, 'red'],
            [0.10, 0.80, 'blue'],
            [0.70, 0.60, 'lime'],
            [0.80, 0.20, 'yellow'],
        ];
        $imagick = createGradientImage(500, 500, $points, \Imagick::SPARSECOLORMETHOD_VORONOI);
        header("Content-Type: image/png");
        echo $imagick->getImageBlob();
    }

?>

Example #5 SPARSECOLORMETHOD_BARYCENTRIC Imagick::sparseColorImage()


<?php
    function renderImageBarycentric() {
        $points = [
            [0, 0, 'skyblue'],
            [-1, 1, 'skyblue'],
            [1, 1, 'black'],
        ];
        $imagick = createGradientImage(600, 200, $points, \Imagick::SPARSECOLORMETHOD_BARYCENTRIC);
        header("Content-Type: image/png");
        echo $imagick->getImageBlob();
    }

?>

Example #6 createGradientImage is used by other examples. Imagick::sparseColorImage()


<?php
function createGradientImage($width, $height, $colorPoints, $sparseMethod, $absolute = false) {

    $imagick = new \Imagick();
    $imagick->newImage($width, $height, "white");
    $imagick->setImageFormat("png");

    $barycentricPoints = array();

    foreach ($colorPoints as $colorPoint) {

        if ($absolute == true) {
            $barycentricPoints[] = $colorPoint[0];
            $barycentricPoints[] = $colorPoint[1];
        }
        else {
            $barycentricPoints[] = $colorPoint[0] * $width;
            $barycentricPoints[] = $colorPoint[1] * $height;
        }

        if (is_string($colorPoint[2])) {
            $imagickPixel = new \ImagickPixel($colorPoint[2]);
        }
        else if ($colorPoint[2] instanceof \ImagickPixel) {
            $imagickPixel = $colorPoint[2];
        }
        else{
            $errorMessage = sprintf(
                "Value %s is neither a string nor an ImagickPixel class. Cannot use as a color.",
                $colorPoint[2]
            );

            throw new \InvalidArgumentException(
                $errorMessage
            );
        }

        $red = $imagickPixel->getColorValue(\Imagick::COLOR_RED);
        $green = $imagickPixel->getColorValue(\Imagick::COLOR_GREEN);
        $blue = $imagickPixel->getColorValue(\Imagick::COLOR_BLUE);
        $alpha = $imagickPixel->getColorValue(\Imagick::COLOR_ALPHA);

        $barycentricPoints[] = $red;
        $barycentricPoints[] = $green;
        $barycentricPoints[] = $blue;
        $barycentricPoints[] = $alpha;
    }

    $imagick->sparseColorImage($sparseMethod, $barycentricPoints);

    return $imagick;
}

?>

User Contributed Notes

aehtyb[]gmail.com 12-May-2016 08:48


For those curious how to use sparseColorImage() directly without the seperate createGradientImage() function.. here is the format of the array used:



Array ( 

[0]  => 0   // X1 (X coordinate value #1)

[1]  => 0   // Y1 (Y coordinate value #1)

[2]  => 1   // R (red value between 0 and 1)

[3]  => 0   // G (green value between 0 and 1)

[4]  => 0   // B (blue value between 0 and 1)

[5]  => 1   // A (alpha value between 0 and 1)

[6]  => 400 // X2 

[7]  => 0   // Y2 

[8]  => 0   // R 

[9]  => 1   // G 

[10] => 0   // B 

[11] => 1   // A

[12] => 0   // X3 

[13] => 400 // Y3 

[14] => 1   // R 

[15] => 1   // G 

[16] => 0   // B 

[17] => 1   // A 

[18] => 400 // X4

[19] => 400 // Y4

[20] => 0   // R 

[21] => 0   // G 

[22] => 1   // B 

[23] => 1   // A 

)



<?php



$imagick = new imagick();

$imagick->newImage(400,400,"white");

$imagick->setImageFormat("png");



$array = Array(0,0,1,0,0,1,400,0,0,1,0,1,0,400,1,1,0,1,400,400,0,0,1,1);

$imagick->sparseColorImage(imagick::SPARSECOLORMETHOD_BILINEAR,$array);

    

header("Content-Type: image/png");

echo $imagick->getImageBlob();



?>