Conversion de la couleur hexadécimale en RVB et vice-versa

Réponse réelle: dépend du type de valeur de couleur hexadécimale que vous recherchez (par exemple, 565, 555, 888, 8888, etc.), de la quantité de bits alpha, de la dissortingbution de couleurs réelle (RVB vs bgr …) et d’une tonne de autres variables.

Voici un algorithme générique pour la plupart des valeurs RVB utilisant des modèles C ++ (directement à partir de ScummVM).

template 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); } 

Voici un exemple de structure de couleur pour 565 (le format standard pour les couleurs 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 }; }; 

En python:

 def hex_to_rgb(value): """Return (red, green, blue) for the color given as #rrggbb.""" value = value.lssortingp('#') 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' 

En python, la conversion entre hex et rgb est également incluse dans le package matplotlib . À savoir

 import matplotlib.colors as colors 

alors

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

La mise en garde est que les valeurs RVB en couleurs sont supposées être entre 0.0 et 1.0. Si vous voulez aller entre 0 et 255, vous devez faire une petite conversion. Plus précisément,

 def hex_to_rgb(hex_ssortingng): rgb = colors.hex2color(hex_ssortingng) 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]) 

L’autre remarque est que colors.hex2color accepte uniquement les chaînes de couleurs hexadécimales valides.

juste très vite:

 int r = ( hexcolor >> 16 ) & 0xFF; int g = ( hexcolor >> 8 ) & 0xFF; int b = hexcolor & 0xFF; int hexcolor = (r << 16) + (g << 8) + b; 

Modification de la réponse python de Jeremy pour gérer les valeurs CSS rg courtes telles que 0, # 999 et #fff (que les navigateurs afficheraient en noir, gris moyen et blanc):

 def hex_to_rgb(value): value = value.lssortingp('#') 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)) 

Une valeur hexadécimale correspond uniquement aux nombres RVB représentés en hexadécimal. Il suffit donc de prendre chaque paire de chiffres hexadécimaux et de les convertir en décimal.

Exemple:

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

 #! / usr / bin / env python

 import re
 import sys

 def hex_to_rgb (valeur):
   value = value.lssortingp ('#')
   lv = len (valeur)
   return tuple (int (valeur [i: i + lv / 3], 16) pour i dans la plage (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 (valeur "HEX [#FFFFFF] ou RGB [255, 255, 255] (aucune valeur ne quitte le programme):")
   en couleur:
     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] ', couleur):
       converti = hex_to_rgb (couleur)
       imprimer converti
     elif re.search ('[0-9] {1,3}, [0-9] {1,3}, [0-9] {1,3}', couleur):
       converti = rgb_to_hex (couleur)
       imprimer converti
     elif color == '':
       sys.exit (0)
     autre:
       print 'Vous n'avez pas entré de valeur valide!'
     color = raw_input (valeur "HEX [#FFFFFF] ou RGB [255, 255, 255] (aucune valeur ne quitte le programme):")

 si __name__ == '__main__':
   principale()

Ceci est un fragment de code que j’ai créé pour mon propre usage dans c ++ 11. vous pouvez envoyer des valeurs hexadécimales ou des chaînes:

  void Color::SetColor(ssortingng color) { // try catch will be necessary if your ssortingng 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); 

Vous devez uniquement convertir un hex de valeur (en parties) en décimal et vice-versa. Aussi besoin de considérer, quelle valeur en hex peut contenir 6 ou 3 caractères (sans le caractère ‘#’).

Implémentation sur le 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() 

Implémentation sur le JavaScript (adapté au NodeJS avec un support 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 {ssortingng} 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].toSsortingng(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; 

Implémentation sur le C (destiné au standart 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 ssortingng representation data in an instance of the structure colorRGB_t */ static int getRGBasSsortingng(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_); getRGBasSsortingng(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_); getRGBasSsortingng(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_); getRGBasSsortingng(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_); getRGBasSsortingng(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 résultat après compilation (je suis habitué au 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'