colors - google - Conversión de color hexadecimal a RGB y viceversa

hex to rgba

Question

¿Cuál es la forma más eficiente de hacer esto?

Answer 1

En Python:

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''

Answer 2

En python, la conversión entre hex y ''rgb'' también se incluye en el paquete de trazado matplotlib . A saber

import matplotlib.colors as colors

Entonces

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

La advertencia es que se supone que los valores de rgb en colores están entre 0.0 y 1.0. Si quiere ir entre 0 y 255, necesita hacer una pequeña conversión. Específicamente,

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])

La otra nota es que colors.hex2color solo acepta cadenas de colores hexagonales válidas.

Answer 3

Este es un fragmento de código que creé para mi propio uso en c ++ 11. puede enviar valores hexadecimales o cadenas:

    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);

Answer 4

Modificando la respuesta pitón de Jeremy para manejar valores cortos de rgb de CSS como 0, # 999 y #fff (que los navegadores representarían como negro, gris medio y blanco):

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))

Answer 5

Respuesta real: Depende del tipo de valor de color hexadecimal que esté buscando (por ejemplo, 565, 555, 888, 8888, etc.), la cantidad de bits alfabéticos, la distribución de color real (rgb vs bgr ...) y una tonelada de otras variables

Aquí hay un algoritmo genérico para la mayoría de los valores RGB usando plantillas C ++ (directamente de ScummVM).

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);
}

Aquí hay una estructura de color de muestra para 565 (el formato estándar para colores de 16 bits):

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

};
};

Answer 6

Solo necesita convertir un valor hexadecimal (en partes) a decimal y viceversa. También se necesita considerar, qué valor en hex puede contener 6 o 3 caracteres (sin el carácter ''#'').

Implementación en Python 3.5

"""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 __name__ == ''__main__'':
    import doctest
    doctest.testmod()

Implementación en JavaScript (adaptado a NodeJS con soporte ES6)

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;

Implementación en la C (prevista para el estándar C11)

// 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_);
}

Un resultado después de la compilación (me utilizan los GCC)

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''

Answer 7

Un valor hexadecimal es solo números RGB representados en hexadecimal. Entonces solo tienes que tomar cada par de dígitos hexadecimales y convertirlos a decimal.

Ejemplo:

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

Answer 8

simplemente muy rápido:

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

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

int b = hexcolor & 0xFF;

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

Answer 9

#!/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 in range(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] or RGB [255, 255, 255] value (no value quits program): ") 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]'', color): 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 converted elif color == '''': sys.exit(0) else: print ''You didn/'t enter a valid value!'' color = raw_input("HEX [#FFFFFF] or RGB [255, 255, 255] value (no value quits program): ") if __name__ == ''__main__'': main()