PHP - 从具有十六进制颜色的数组中获取最亮的十六进制颜色

Question

现在我一直在网上搜索如何做到这一点，但似乎没有一个问题/答案。

我正在使用脚本从给定图像中获取 6 种主要颜色。

function detectColors($image, $num, $level = 5)
{
    $level   = (int) $level;
    $palette = array();
    $size    = getimagesize($image);
    if (!$size) {
        return FALSE;
    }
    switch ($size['mime']) {
        case 'image/jpeg':
            $img = imagecreatefromjpeg($image);
            break;
        case 'image/png':
            $img = imagecreatefrompng($image);
            break;
        case 'image/gif':
            $img = imagecreatefromgif($image);
            break;
        default:
            return FALSE;
    }
    if (!$img) {
        return FALSE;
    }
    for ($i = 0; $i < $size[0]; $i += $level) {
        for ($j = 0; $j < $size[1]; $j += $level) {
            $thisColor       = imagecolorat($img, $i, $j);
            $rgb             = imagecolorsforindex($img, $thisColor);
            $color           = sprintf('%02X%02X%02X', (round(round(($rgb['red'] / 0x33)) * 0x33)), round(round(($rgb['green'] / 0x33)) * 0x33), round(round(($rgb['blue'] / 0x33)) * 0x33));
            $palette[$color] = isset($palette[$color]) ? ++$palette[$color] : 1;
        }
    }
    arsort($palette);
    return array_slice(array_keys($palette), 0, $num);
}

$img = 'https://gs2-sec.ww.prod.dl.playstation.net/gs2-sec/appkgo/prod/CUSA03041_00/15/i_2efe1b71a037233f60cec3b41a18d69c02bcff5fd0c895c212d44f37883dbaf8/i/icon0.png';
$palette = detectColors($img, 6, 5);
echo '<img src="' . $img . '" />';
echo '<table>';
foreach($palette as $color) {
  echo '<tr><td style="background:#' . $color . '; width:36px;"></td><td>#' . $color . '</td></tr>';
}
echo '</table>';

这将输出一个调色板:



我想用这些颜色做的是找出哪个是最亮的，也就是主色，在这种情况下是第二种颜色“CC0000”。当然不包括白色#FFFFFF 和黑色#000000。

我的问题是， 如何从 PHP 中的一系列颜色中获得最亮的颜色？

Answer 1

如果我理解正确，那么也许您可以像这样解决问题？

function detectColors( $image, $num, $level = 5 ) {
    $level   = (int)$level;
    $palette = array();
    $details = array();# store the count of non black or white colours here ( see $exclusions )

    list( $width, $height, $type, $attr )=getimagesize( $image );
    if( !$type ) return FALSE;

    switch ( image_type_to_mime_type( $type ) ) {
        case 'image/jpeg':
            $img = imagecreatefromjpeg( $image );
        break;
        case 'image/png':
            $img = imagecreatefrompng( $image );
        break;
        case 'image/gif':
            $img = imagecreatefromgif( $image );
        break;
        default: return FALSE;
    }
    if( !$img ) return FALSE;

    /* Colours to not factor into dominance statistics */
    $exclusions=['000000','FFFFFF'];

    for( $i = 0; $i < $width; $i += $level ) {
        for( $j = 0; $j < $height; $j += $level ) {
            $colour             = imagecolorat( $img, $i, $j );
            $rgb                = imagecolorsforindex( $img, $colour );
            $key                = sprintf('%02X%02X%02X', ( round( round( ( $rgb['red'] / 0x33 ) ) * 0x33 ) ), round(round(($rgb['green'] / 0x33)) * 0x33), round(round(($rgb['blue'] / 0x33)) * 0x33));
            $palette[ $key ]    = isset( $palette[ $key ] ) ? ++$palette[ $key ] : 1;

            if( !in_array( $key, $exclusions ) ){
                /* add count of any non excluded colours */
                $details[ $key ] = isset( $details[ $key ] ) ? ++$details[ $key ] : 1;
            }
        }
    }
    arsort( $palette );

    /* prepare statistics for output */
    $output=new stdclass;
    $output->data=array_slice( array_keys( $palette ), 0, $num );
    $output->highest=max( $details );
    $output->lowest=min( $details );
    $output->dominant=array_search( $output->highest, $details );
    $output->recessive=array_search( $output->lowest, $details );


    return $output;
}



$img = 'https://gs2-sec.ww.prod.dl.playstation.net/gs2-sec/appkgo/prod/CUSA03041_00/15/i_2efe1b71a037233f60cec3b41a18d69c02bcff5fd0c895c212d44f37883dbaf8/i/icon0.png';
$palette = detectColors( $img, 6, 5 );


$html=[];
foreach( $palette->data as $colour ) $html[]=sprintf( '<tr><td style="background:#%1$s; width:200px; height:1rem; " >#%1$s</td></tr>', $colour );

printf('
    <p>Analysing: %1$s</p>
    <img src="%1$s" />
    <table>%2$s</table>
    <ul>
        <li>Dominant colour: %3$s - count: %4$d</li>
        <li>Recessive colour: %5$s - count: %6$d</li>
    </ul>',
    $img,
    implode( PHP_EOL, $html ),
    $palette->dominant,
    $palette->highest,
    $palette->recessive,
    $palette->lowest
);

输出:

Dominant colour: CC0000 - count: 3032
Recessive colour: 333366 - count: 1

这或多或少是你问的吗？