imagecolorclosest

(PHP 4, PHP 5)

imagecolorclosest — Get the index of the closest color to the specified color

Описание

int imagecolorclosest ( resource $image , int $red , int $green , int $blue )

Returns the index of the color in the palette of the image which is "closest" to the specified RGB value.

The "distance" between the desired color and each color in the palette is calculated as if the RGB values represented points in three-dimensional space.

If you created the image from a file, only colors used in the image are resolved. Colors present only in the palette are not resolved.

Список параметров

image: An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
red: Value of red component.
green: Value of green component.
blue: Value of blue component.

The colors parameters are integers between 0 and 255 or hexadecimals between 0x00 and 0xFF.

Возвращаемые значения

Returns the index of the closest color, in the palette of the image, to the specified one

Примеры

Пример #1 Search for a set of colors in an image


<?php
// Start with an image and convert it to a palette-based image
$im = imagecreatefrompng('figures/imagecolorclosest.png');
imagetruecolortopalette($im, false, 255);

// Search colors (RGB)
$colors = array(
    array(254, 145, 154),
    array(153, 145, 188),
    array(153, 90, 145),
    array(255, 137, 92)
);

// Loop through each search and find the closest color in the palette.
// Return the search number, the search RGB and the converted RGB match
foreach($colors as $id => $rgb)
{
    $result = imagecolorclosest($im, $rgb[0], $rgb[1], $rgb[2]);
    $result = imagecolorsforindex($im, $result);
    $result = "({$result['red']}, {$result['green']}, {$result['blue']})";

    echo "#$id: Search ($rgb[0], $rgb[1], $rgb[2]); Closest match: $result.\n";
}

imagedestroy($im);
?>

Результатом выполнения данного примера будет что-то подобное:

#0: Search (254, 145, 154); Closest match: (252, 150, 148).
#1: Search (153, 145, 188); Closest match: (148, 150, 196).
#2: Search (153, 90, 145); Closest match: (148, 90, 156).
#3: Search (255, 137, 92); Closest match: (252, 150, 92).

Смотрите также

imagecolorexact() - Get the index of the specified color
imagecolorclosestalpha() - Get the index of the closest color to the specified color + alpha
imagecolorclosesthwb() - Get the index of the color which has the hue, white and blackness