Interpolates colors

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- Interpolates colors

# Imagick::sparseColorImage

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

Imagick::sparseColorImage — Interpolates colors

### Description

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`. This method is available if Imagick has been compiled against ImageMagick version 6.4.5 or newer.

### Parameters

`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. Defaults to `Imagick::CHANNEL_DEFAULT`. Refer to this list of channel constants

### Return Values

Returns `true` on success.

### Errors/Exceptions

Throws ImagickException on error.

### Examples

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()

    <?phpfunction 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;}?>