How to convert HEX2 to RGBA?

Question

The world of art is full of colour, but the world of the network is even fuller than the world of art of diferent colours and it's renderings. That's why we need to know how to convert one type of colour format to another.

The challenge is self-evident:

Write a program / function than converts an given HEX code (#00ff0080, for instance) to RGBA (like rgba(0, 255, 0, 0.5)).

Rules:

• External libraries/ built-ins for converting HEX to RGBA are disallowed. However, jQuery and syntax replacers like that are acceptable.
• Standard Input/Output rules apply.
• Format of the alpha can be between (1 == 100%) or the other (100 == 100%) that's not really important.
• The output is flexible, as long as it returns the 4 converted values (as a String, Array, List, your choice).
• You may choose to take the input without the # in the beginning. Hence, you can take input as either #RRGGBBAA or RRGGBBAA. You can assume that the hex code (excluding the #) will always be 8 characters long.
• You should divide all the values by 255, including the alpha. The minimum decimal precision (for the alpha will be 2 decimal places).

Test Cases

Input:  00ff0080
Output: 0, 255, 0, 0.5

Scoring

code-golf, the code with the least amount of bytes wins.

Answer 1

JavaScript (ES6), 73 54 50 bytes

(Saved some bytes thanks to @LeakyNun, the edited challenge, and @CraigAyre.)

s=>s.match(/../g).map((c,i)=>('0x'+c)/(i-3?1:255))

let f=

s=>s.match(/../g).map((c,i)=>('0x'+c)/(i-3?1:255))

console.log(f('00ff0080'));

Answer 2

Japt, 13 bytes

Takes input as a string, without the leading #. Outputs the rgba value as an array.

ò ®nG
pUo /#ÿ

Test it

---

Explanation

We implicitly take the string as input via variable U.
"00ff0080"

ò

Split the string into an array of elements of length 2.
["00","ff","00","80"]

®nG

Map over the array and convert each element from a base 16 string to a decimal number. Because of the following newline, that array is implicitly assigned to variable U.
[0,255,0,128]

Uo

Pop the last element from the array.
128

/#ÿ

Divide it by 255.
0.5019607843137255

p

Push the result back into U then implicitly output the final array.
[0,255,0,0.5019607843137255]

Answer 3

05AB1E, 9 bytes

2ôH`255/)

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At least we have supporters like Emigna to often use some common sense...(that's what you get for golfing all day and then you start producing stuff like 2ô16öRć255/¸ìR ಠ_ಠ)

Answer 4

PHP, 63 bytes

Output as array

$h=array_map(hexdec,str_split($argn,2));$h[3]/=255;print_r($h);

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PHP, 80 bytes

Output as rgba value, Input without #

$h=array_map(hexdec,str_split($argn,2));$h[3]/=255;echo"rgba(",join(",",$h),")";

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PHP, 88 bytes

Output as rgba value, Input with #

for(;$i<7;)$h[]=hexdec($argn[++$i].$argn[++$i]);$h[3]/=255;echo"rgba(",join(",",$h),")";

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Answer 5

C (gcc), 139 bytes

C(x){x=x>57?x-87:x-48;}
#define Z C(h[i])*16+C(h[++i]))
i;f(char*h){printf("rgba(");for(i=0;i<6;i++)printf("%i, ",Z;printf("%g)",(Z/256.);}

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My other attempt clocked in at 145 bytes. I'm not much of a C golfer, so this could probably be shorter.

Answer 6

Jelly, 15 14 bytes

Øhi$€’s2ḅ⁴÷4¦⁹

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How it Works

Øhi$€’s2ḅ⁴÷4¦⁹ - main link, takes input without # and all lowercase
   $€             - to each input character:
  i               - return its 1-based index in
Øh                - the string "0123456789abcdef"
     ’            - decrement (otherwise 0 is mapped to 1 and f to 16)
      s2          - split the characters into groups of two
        ḅ⁴        - convert from base 16 to decimal
           4¦     - on the fourth element:
          ÷       - divide by
             ⁹    - 256

-1 byte thanks to @EricTheOutgolfer

Answer 7

PHP, 72 bytes

Jörg´s array output version is unbeatable; but there are other options:

<?=($a=hexdec($argn))>>24,",",255&$a>>16,",",255&$a>>8,",",(255&$a)>256;

Run as pipe with -F. # does not matter, plain csv output

or 73 bytes (run with -R):

for($a=hexdec($argn);$i++<4;)echo(255&$a>>32-8*$i)/($i<4?:256),","[$i>3];

74 bytes with the spaces:

<?=($a=hexdec($argn))>>24,$c=", ",255&$a>>16,$c,255&$a>>8,$c,(255&$a)>256;

not so plain, 81 bytes:

rgba(<?=($a=hexdec($argn))>>24,$c=", ",255&$a>>16,$c,255&$a>>8,$c,(255&$a)/256?>)

Answer 8

Stacked, 47 45 41 bytes

[2#<$unhexmap(1::256)/', '#`'rgba(@id)'!]

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Answer 9

Excel, 99 bytes

=HEX2DEC(LEFT(A1,2))&","&HEX2DEC(MID(A1,3,2))&","&HEX2DEC(MID(A1,5,2))&","&HEX2DEC(RIGHT(A1,2))/256

Answer 10

SmileBASIC, 50 bytes

INPUT H$RGBREAD VAL("&H"+H$)OUT R,G,B,A?R,G,B,A/#L

The hexadecimal string is converted to a number using VAL(), then RGBREAD extracts each byte. #L is a constant with the value 256.

RGBREAD is designed to extract the channels from an ARGB color, but really it just splits a 4 byte integer into 4 separate bytes, so the order doesn't matter.

Answer 11

Perl 6, 42 bytes

{m:g/../.map({:16(~$_)}) »/«(1,1,1,255)}

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Answer 12

JS ES2015, 84 bytes

$=>{a=[1,3,5,7].map(b=>eval("0x"+$.substr(b,2)));a[3]=(a[3]/256);return a.join(",")}

this is a function. Run it using

( CODE )("#00ff0080")

Answer 13

Python 3, 62 bytes

lambda h:[int(h[x:x+2],16)for x in(0,2,4)]+[int(h[6:],16)/255]

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Answer 14

q/kdb+, 43 bytes

Solution:

{(16 sv'(.Q.n,6#.Q.a)?/:2 cut x)%1 1 1 256}

Example:

q){(16 sv'(.Q.n,6#.Q.a)?/:2 cut x)%1 1 1 256}"00ff0080"
0 255 0 0.5

Explanation:

{                                         } / anonymous lambda function
                        2 cut x             / split input into 2-char length lists
                     ?/:                    / returns index where (each-right) item is found in 'the list'
        (           )                       / 'the list'
              6#.Q.a                        / Q.a is lowercase alphabet, 6# takes first 6 chars
         .Q.n,                              / Q.n is "012..89", so prepend this onto the "abcdef"                         
  16 sv'                                    / converts each index from base 16 to base 10
 (                            )%1 1 1 256   / divide this output by 1,1,1,256 to get alpha in 0..1 range 

Answer 15

APL (Dyalog), 24 bytes

Requires ⎕IO←0 which is default on many systems. Prompts for input as uppercase without #.

256÷⍨@3⊢16⊥⍉4 2⍴⍞⍳⍨⎕D,⎕A

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⎕D,⎕A Digits followed by Alphabet

⍞⍳⍨ prompt for text input (mnemonic: console with quote) and find the ɩndex of each letter in that

4 2⍴ reshape as four row two column matrix

⍉ transpose (because base conversion works columnwise)

16⊥ evaluate as base sixteen

⊢ yield (serves to separate 3 and 16)

256÷⍨@3 divide the 4^th element by 256

Answer 16

Python 2, 54 bytes

lambda h:[int(h[i-2:i],16)/2.**(8&i)for i in(2,4,6,8)]

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Answer 17

Yabasic, 96 bytes

Yet another basic answer; Takes input as string and outputs to the console.

Input""a$
For i=1To 7Step 2
?Dec(Mid$(a$,i,2))/(j+1);
If i=5Then j=255Fi
If i<7Then?", ";Fi
Next

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Answer 18

Excel VBA, 90 bytes

An anonymous VBE immediate window function that takes input from the range [A1] and outputs to the VBE immediate window.

For i=1To 7Step 2:[B1]=i:?[Hex2Dec(Mid(A1,B1,2))]/IIf(i=7,256,1)&""+IIf(i<7,", ","");:Next

Answer 19

Vim, 46 bytes

:s/../$((16#&)) /g␊iecho ␛$hhi*100/255␛:w !sh␊

Takes input without the # and returns by printing on the screen.