imagecolorclosest

(PHP 4, PHP 5, PHP 7)

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

설명

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.

이미지를 파일에서 생성하였을 경우, 이미지에서 사용한 색만 해석됩니다. 팔레트에 존재하는 색은 해석되지 않습니다.

인수

image: imagecreatetruecolor() 등의 이미지 생성 함수에서 반환한 이미지 자원.
red: Red 컴포넌트 값.
green: Green 컴포넌트 값.
blue: Blue 컴포넌트 값.

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

반환값

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

예제

Example #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);
?>

위 예제의 출력 예시:

#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).

참고

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