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16進数の色をRGBに、またはその逆に変換する

これを行う最も効率的な方法は何ですか?

44
moo

実際の答え:探している16進数の色の値の種類(たとえば、565、555、888、8888など)、アルファビットの量、実際の色分布(rgb vs bgr ...)、および他の変数。

C++テンプレート(ScummVMのストレート)を使用したほとんどのRGB値の一般的なアルゴリズムを次に示します。

template<class T>
uint32 RGBToColor(uint8 r, uint8 g, uint8 b) {
return T::kAlphaMask |
       (((r << T::kRedShift) >> (8 - T::kRedBits)) & T::kRedMask) |
       (((g << T::kGreenShift) >> (8 - T::kGreenBits)) & T::kGreenMask) |
       (((b << T::kBlueShift) >> (8 - T::kBlueBits)) & T::kBlueMask);
}

565のカラー構造体のサンプル(16ビットカラーの標準形式)は次のとおりです。

template<>
struct ColorMasks<565> {
enum {
    highBits    = 0xF7DEF7DE,
    lowBits     = 0x08210821,
    qhighBits   = 0xE79CE79C,
    qlowBits    = 0x18631863,


    kBytesPerPixel = 2,

    kAlphaBits  = 0,
    kRedBits    = 5,
    kGreenBits  = 6,
    kBlueBits   = 5,

    kAlphaShift = kRedBits+kGreenBits+kBlueBits,
    kRedShift   = kGreenBits+kBlueBits,
    kGreenShift = kBlueBits,
    kBlueShift  = 0,

    kAlphaMask = ((1 << kAlphaBits) - 1) << kAlphaShift,
    kRedMask   = ((1 << kRedBits) - 1) << kRedShift,
    kGreenMask = ((1 << kGreenBits) - 1) << kGreenShift,
    kBlueMask  = ((1 << kBlueBits) - 1) << kBlueShift,

    kRedBlueMask = kRedMask | kBlueMask

};
};
10
Vicent Marti

Pythonの場合:

def hex_to_rgb(value):
    """Return (red, green, blue) for the color given as #rrggbb."""
    value = value.lstrip('#')
    lv = len(value)
    return Tuple(int(value[i:i + lv // 3], 16) for i in range(0, lv, lv // 3))

def rgb_to_hex(red, green, blue):
    """Return color as #rrggbb for the given color values."""
    return '#%02x%02x%02x' % (red, green, blue)

hex_to_rgb("#ffffff")           #==> (255, 255, 255)
hex_to_rgb("#ffffffffffff")     #==> (65535, 65535, 65535)
rgb_to_hex(255, 255, 255)       #==> '#ffffff'
rgb_to_hex(65535, 65535, 65535) #==> '#ffffffffffff'
164
Jeremy Cantrell

In python hexと 'rgb'の間の変換も、プロットパッケージmatplotlibに含まれています。

import matplotlib.colors as colors

それから

colors.hex2color('#ffffff')        #==> (1.0, 1.0, 1.0)
colors.rgb2hex((1.0, 1.0, 1.0))    #==> '#ffffff'

注意点は、色のrgb値は0.0〜1.0であると想定されることです。 0から255の間を行きたい場合は、小さな変換を行う必要があります。具体的には、

def hex_to_rgb(hex_string):
    rgb = colors.hex2color(hex_string)
    return Tuple([int(255*x) for x in rgb])

def rgb_to_hex(rgb_Tuple):
    return colors.rgb2hex([1.0*x/255 for x in rgb_Tuple])

もう1つの注意点は、colors.hex2colorは、有効な16進数の色の文字列のみを受け入れます。

37
Chris H.

本当に速い:

int r = ( hexcolor >> 16 ) & 0xFF;

int g = ( hexcolor >> 8 ) & 0xFF;

int b = hexcolor & 0xFF;

int hexcolor = (r << 16) + (g << 8) + b;
18
billjamesdev

Jeremyのpython answerを変更して、0、#999、#fffなどの短いCSS rgb値を処理します(ブラウザは黒、中間の灰色、白としてレンダリングします)):

def hex_to_rgb(value):
    value = value.lstrip('#')
    lv = len(value)
    if lv == 1:
        v = int(value, 16)*17
        return v, v, v
    if lv == 3:
        return Tuple(int(value[i:i+1], 16)*17 for i in range(0, 3))
    return Tuple(int(value[i:i+lv/3], 16) for i in range(0, lv, lv/3))
7
Rick Westera

16進数の値は、16進数で表されたRGB番号です。そのため、16進数の各ペアを取得して、10進数に変換する必要があります。

例:

#FF6400 = RGB(0xFF, 0x64, 0x00) = RGB(255, 100, 0)
2
Jeremy Ruten

値の16進数(一部)を10進数に、またはその逆に変換するだけです。また、16進数のどの値に6文字または3文字が含まれるか(文字「#」なし)を考慮する必要があります。

Python 3.5の実装

"""Utils for working with colors."""

import textwrap


def rgb_to_hex(value1, value2, value3):
    """
    Convert RGB value (as three numbers each ranges from 0 to 255) to hex format.

    >>> rgb_to_hex(235, 244, 66)
    '#EBF442'
    >>> rgb_to_hex(56, 28, 26)
    '#381C1A'
    >>> rgb_to_hex(255, 255, 255)
    '#FFFFFF'
    >>> rgb_to_hex(0, 0, 0)
    '#000000'
    >>> rgb_to_hex(203, 244, 66)
    '#CBF442'
    >>> rgb_to_hex(53, 17, 8)
    '#351108'
    """

    for value in (value1, value2, value3):
        if not 0 <= value <= 255:
            raise ValueError('Value each slider must be ranges from 0 to 255')
    return '#{0:02X}{1:02X}{2:02X}'.format(value1, value2, value3)


def hex_to_rgb(value):
    """
    Convert color`s value in hex format to RGB format.

    >>> hex_to_rgb('fff')
    (255, 255, 255)
    >>> hex_to_rgb('ffffff')
    (255, 255, 255)
    >>> hex_to_rgb('#EBF442')
    (235, 244, 66)
    >>> hex_to_rgb('#000000')
    (0, 0, 0)
    >>> hex_to_rgb('#000')
    (0, 0, 0)
    >>> hex_to_rgb('#54433f')
    (84, 67, 63)
    >>> hex_to_rgb('#f7efed')
    (247, 239, 237)
    >>> hex_to_rgb('#191616')
    (25, 22, 22)
    """

    if value[0] == '#':
        value = value[1:]

    len_value = len(value)

    if len_value not in [3, 6]:
        raise ValueError('Incorect a value hex {}'.format(value))

    if len_value == 3:
        value = ''.join(i * 2 for i in value)
    return Tuple(int(i, 16) for i in textwrap.wrap(value, 2))


if __== '__main__':
    import doctest
    doctest.testmod()

JavaScriptでの実装(ES6をサポートするNodeJSに適応)

const assert = require('assert');

/**
 * Return a color`s value in the hex format by passed the RGB format.
 * @param  {integer} value1 An value in ranges from 0 to 255
 * @param  {integer} value2 An value in ranges from 0 to 255
 * @param  {integer} value3 An value in ranges from 0 to 255
 * @return {string}        A color`s value in the hex format
 */
const RGBtoHex = (value1, value2, value3) => {
    const values = [value1, value2, value3];
    let result = '#';
    for (let i = 0; i < 3; i += 1) {
        // validation input
        if (values[i] < 0 || values[i] > 255) throw new Error('An each value of RGB format must be ranges from 0 to 255');

        // append to result values as hex with at least width 2
        result += (('0' + values[i].toString(16)).slice(-2));
    }
    return result.toUpperCase();
};


/**
 * Convert a value from the hex format to RGB and return as an array
 * @param  {int} value A color`s value in the hex format
 * @return {array}     Array values of the RGB format
 */
const hexToRGB = (value) => {
    let val = value;

    val = (value[0] === '#') ? value.slice(1) : value;

    if ([3, 6].indexOf(val.length) === -1) throw new Error(`Incorect a value of the hex format: ${value}`);

    if (val.length === 3) val = val.split('').map(item => item.repeat(2)).join('');

    return val.match(/.{2}/g).map(item => parseInt(`0x${item}`, 16));
};

assert.deepEqual(hexToRGB('fff'), [255, 255, 255]);
assert.deepEqual(hexToRGB('#fff'), [255, 255, 255]);
assert.deepEqual(hexToRGB('#000000'), [0, 0, 0]);
assert.deepEqual(hexToRGB('000000'), [0, 0, 0]);
assert.deepEqual(hexToRGB('#d7dee8'), [215, 222, 232]);
assert.deepEqual(hexToRGB('#1E2F49'), [30, 47, 73]);
assert.deepEqual(hexToRGB('#030914'), [3, 9, 20]);

assert.equal(RGBtoHex(255, 255, 255), '#FFFFFF');
assert.equal(RGBtoHex(0, 0, 0), '#000000');
assert.equal(RGBtoHex(96, 102, 112), '#606670');
assert.equal(RGBtoHex(199, 204, 214), '#C7CCD6');
assert.equal(RGBtoHex(22, 99, 224), '#1663E0');
assert.equal(RGBtoHex(0, 8, 20), '#000814');


module.exports.RGBtoHex = RGBtoHex;
module.exports.hexToRGB = hexToRGB;

Cでの実装(C11標準用)

// a type for a struct of RGB color
typedef struct _ColorRGB {
    unsigned short int red;
    unsigned short int green;
    unsigned short int blue;
} colorRGB_t;


/*
    Convert a color`s value from the hex format to the RGB.
    Return -1 if a passed value in the hex format is not correct, otherwise - return 0;
 */
static int
convertColorHexToRGB(const char originValue[], colorRGB_t *colorRGB) {

    // a full value of color in hex format must constains 6 charapters
    char completedValue[6];
    size_t lenOriginValue;
    size_t lenCompletedValue;

    // an intermediary variable for keeping value in the hex format
    char hexSingleValue[3];

    // a temp pointer to char, need only to the strtol()
    char *ptr;

    // a variable for keeping a converted number in the hex to the decimal format
    long int number;

    // validation input
    lenOriginValue = strlen(originValue);
    if (lenOriginValue > 7 || lenOriginValue < 3) return -1;

    // copy value without sign '#', if found as first in the string
    (originValue[0] == '#') ? strcpy(completedValue, originValue + 1) : strcpy(completedValue, originValue);

    lenCompletedValue = strlen(completedValue);

    // if the value has only 3 charapters, dublicate an each after itself
    // but if not full version of the hex name of a color (6 charapters), return -1
    if (lenCompletedValue == 3) {
        completedValue[5] = completedValue[2];
        completedValue[4] = completedValue[2];
        completedValue[3] = completedValue[1];
        completedValue[2] = completedValue[1];
        completedValue[1] = completedValue[0];
    } else if (lenCompletedValue != 6) return -1;

    // convert string, by parts, to decimal values and keep it in a struct

    sprintf(hexSingleValue, "%c%c", completedValue[0], completedValue[1]);
    number = strtol(hexSingleValue, &ptr, 16);
    colorRGB->red = number;

    sprintf(hexSingleValue, "%c%c", completedValue[2], completedValue[3]);
    number = strtol(hexSingleValue, &ptr, 16);
    colorRGB->green = number;

    sprintf(hexSingleValue, "%c%c", completedValue[4], completedValue[5]);
    number = strtol(hexSingleValue, &ptr, 16);
    colorRGB->blue = number;

    return 0;
}


/*
    Convert a color`s value from the RGB format to the hex
 */
static int
convertColorRGBToHex(const colorRGB_t *colorRGB, char value[8]) {
    sprintf(value, "#%02X%02X%02X", colorRGB->red, colorRGB->green, colorRGB->blue);
    return 0;
}


/*
    Forming a string representation data in an instance of the structure colorRGB_t
 */
static int
getRGBasString(const colorRGB_t *colorRGB, char str[18]) {
    sprintf(str, "rgb(%d, %d, %d)", colorRGB->red, colorRGB->green, colorRGB->blue);
    return 0;
}


int main (int argv, char **argc)
{
    char str[18];
    char hex[8];

    colorRGB_t *colorRGB_;
    colorRGB_ = (colorRGB_t *)malloc(sizeof(colorRGB_));

    convertColorHexToRGB("fff", colorRGB_);
    getRGBasString(colorRGB_, str);
    printf("Hex 'fff' to RGB %s\n", str);
    convertColorRGBToHex(colorRGB_, hex);
    printf("RGB %s to hex '%s'\n", str, hex);

    convertColorHexToRGB("000000", colorRGB_);
    getRGBasString(colorRGB_, str);
    printf("Hex '000000' to RGB %s\n", str);
    convertColorRGBToHex(colorRGB_, hex);
    printf("RGB %s to hex '%s'\n", str, hex);

    convertColorHexToRGB("#000000", colorRGB_);
    getRGBasString(colorRGB_, str);
    printf("Hex '#000000' to RGB %s\n", str);
    convertColorRGBToHex(colorRGB_, hex);
    printf("RGB %s to hex '%s'\n", str, hex);

    convertColorHexToRGB("#FFF", colorRGB_);
    getRGBasString(colorRGB_, str);
    printf("Hex '#FFF' to RGB %s\n", str);
    convertColorRGBToHex(colorRGB_, hex);
    printf("RGB %s to hex '%s'\n", str, hex);

    free(colorRGB_);
}

コンパイル後の結果(私はGCCを使用しています)

Hex 'fff' to RGB rgb(255, 255, 255)
RGB rgb(255, 255, 255) to hex '#FFFFFF'
Hex '000000' to RGB rgb(0, 0, 0)
RGB rgb(0, 0, 0) to hex '#000000'
Hex '#000000' to RGB rgb(0, 0, 0)
RGB rgb(0, 0, 0) to hex '#000000'
Hex '#FFF' to RGB rgb(255, 255, 255)
RGB rgb(255, 255, 255) to hex '#FFFFFF'
2
Seti Volkylany

これは、c ++ 11で使用するために作成したコードのフラグメントです。 16進値または文字列を送信できます。

    void Color::SetColor(string color) {
    // try catch will be necessary if your string is not sanitized before calling this function.
         SetColor(std::stoul(color, nullptr, 16));
    }

    void Color::SetColor(uint32_t number) {
        B = number & 0xFF;
        number>>= 8;
        G = number & 0xFF;
        number>>= 8;
        R = number & 0xFF;
    }



 // ex:
 SetColor("ffffff");
 SetColor(0xFFFFFF);
1
Patricio Rossi
#!/ usr/bin/env python 
 
 import re 
 import sys 
 
 def hex_to_rgb(value):
 value = value.lstrip( '#')
 lv = len(value)
 return Tuple(int(value [i:i + lv/3]、16)for i範囲内(0、lv、lv/3))
 
 def rgb_to_hex(rgb):
 rgb = eval(rgb)
 r = rgb [0] 
 g = rgb [1] 
 b = rgb [2] 
 return '#%02X%02X%02X'%(r、g、b)
 
 def main():
 color = raw_input( "HEX [#FFFFFF]またはRGB [255、255、255]値(値はプログラムを終了しません):")
 while color:
 if re.search( '\#[a-fA-F0-9] [a-fA-F0-9] [a-fA-F0-9] [a-fA-F0-9 ] [a-fA-F0-9] [a-fA-F0-9] '、色):
 Converted = hex_to_rgb(color)
 print Converted 
 Elif re。 search( '[0-9] {1,3}、[0-9] {1,3}、[0-9] {1,3}'、color):
 Converted = rgb_to_hex(color )
 print変換済み
 Elif color == '':
 sys.exit(0)
 else:
 print 'You did \' t有効な値を入力してくださいe! '
 color = raw_input( "HEX [#FFFFFF]またはRGB [255、255、255]値(値はプログラムを終了しません):")
 
 if __ = = '__main __':
 main()
1
David Borin