Rotate an Image

Question

This challenge is simple: Take a path to an png image file as input and overwrite that file with a copy of itself rotated 90 degrees clockwise. You may assume that the file has dimensions of 128x128 pixels. You may not use image metadata modifications (like Exif) to rotate the image; the pixels themselves must be transformed.

Examples

Input:

A cat

Output:

A weird cat

This is code-golf, so shortest answer wins.

• noodle person: Can the program take in the PNG as a file or buffer instead of a path, and output a modified file?
• EzioMercer: @Jacob I think this suggestion ignores one of the main part of competition "overwrite the file"
• qarz: Is a HTTP PUT an acceptable method of "overwriting"?
• Ginger: @qarz That depends on the behavior of the server; if the server actually overwrites the file then yes, it does.

Answer 1

Bash/ImageMagick, 21 bytes

mogrify -rotate 90 1ドル

Conveniently this command overwrites the source file, and does not need the image to be of any specific dimensions.

Answer 2

AutoHotkey + MSPaint, 77 Bytes

f(s){
run mspaint %s%
sleep 999
click 189,116
sleep 200
click 26,13
send ^s
}

Autohotkey is not a language that lends itself to golfing very well, though it is uniquely very good at pretending to be a user.

This simply opens paint with the target image, clicks the Rotate, then 90 degrees buttons, then presses CTRL+S to save the image.

Video of it Running

• tsh: You can send keys instead of clicking, send !hror^s
• qarz: I love this. This is one of those things that would probably be a new standard loophole if it were more space-efficient, but it's not, so it remains a fun novelty that occasionally shows up and is occasionally surprisingly small.

Answer 3

Python + Pillow, (削除) 64 (削除ここまで) 59 bytes

from PIL.Image import*
open(p:=input()).rotate(-90).save(p)

-5 thanks to @tsh

Commented

from PIL.Image import* # Import module
open( # Open an image
 p:=input() # Input the filename and store in p
).rotate( # Rotate the image
 -90 # -90 degrees anti-clockwise
 # (= 90 degrees clockwise)
).save(p) # And save it back in the original file

• tsh: Maybe you can from PIL.Image import* and then open(p:=...
• The Thonnu: @tsh yes, you're right! Thanks.

Answer 4

MATL, 8 bytes

YiIX!GYG

Unfortunately the online compilers cannot load/save images so here is a demo that uses an image defined within the interpreter itself.

Explanation

 % Implicitly grab the first input (the file path) as a string
Yi % Read in the image
IX! % Rotate 270 degrees counter-clockwise
G % Grab the file path again
YG % Write the rotated image to this file

Answer 5

NodeJS + JIMP, 74 bytes

require('jimp').read(n=process.argv[2]).then(x=>x.rotate(270,!1).write(n))

The path to image must be passed as third arg:

node filename.js imageSrc.png

UPD 87 -> 84

Thanks to Arnauld for the tip to reduce bytes count

UPD 84 -> 74

Thanks to Jacob for the tip to reduce bytes count

• The Thonnu: Aren't you supposed to take input rather than just hard-coding it as c.png?
• EzioMercer: @TheThonnu Yes, you are right!
• noodle person: You can get rid of the (async()=>{...})() if you use Node16 or newer (top-level await)
• noodle person: When I get the chance I will, busy at the moment
• noodle person: require("jimp").read(n=process.argv[2]).then(x=>x.rotate(270,!1).write(n)) is 74 bytes (regular .js file)

Answer 6

MacOS zsh + sips, 13

sips -r 90 1ドル

sips (Scriptable Image Processing System) is a lesser-known built-in command-line utility for image manipulation. Confusingly, nothing to do with SIP (System Integrity Protection).

---

MacOS zsh alias + sips, 10

sips -r 90

Create the alias with alias r=sips -r 90, then run with r test.png.

• Dominic van Essen: Do you actually need the 1ドル? If the input is given as a command-line argument, isn't the 'program' just sips -r 90 (10 bytes)?
• Digital Trauma: @DominicvanEssen To my knowledge, there is no way to implicitly do this without providing a positional parameter. In some CG asnwers, a script can read from STDIN - the stream gets piped to the first command in the script that reads it. But in this case the input is the filename, as we need to both read from and write to the input filename. Also, sips doesn't appear to read from STDIN
• Dominic van Essen: I'm not sure that I understood your explanation: typing sips -r 90 2iORu.png on my Mac seems to rotate the image file "2iORu.png" and overwrite the original (without using zsh). Isn't that the objective?
• Digital Trauma: If you're typing sips -r 90 2iORu.png (presumably into the terminal), then you are using the shell, which zsh by default on modern MacOS. Thus my answer is a zsh shell script (that could be saved as a script file). Am I missing something? If I create a zsh script file with the content sips -r 90, it doesn't do what is required.
• Digital Trauma: @DominicvanEssen I suppose one could submit an answer in the form of a shell alias alias r='sips -r 90', which may be run as r test.png then claim that the alias is only 10 bytes long... hmm, not a bad idea for this challenge actually

Answer 7

APL (Dyalog Unicode), 64 bytes

Anonymous prefix lambda.

{b.MakePNG⎕NREPLACE,⍨⍵⎕NTIE-≡b.CBits←⌽⍉'CBits'⍎⍨'b'⎕WC'Bitmap'⍵}

{...} "dfn"; argument is denoted ⍵:

'b'⎕WC'Bitmap'⍵ create a Bitmap b from the file

'CBits'⍎⍨ extract the Colour Bits from that

⍉ transpose

⌽ mirror

b.CBits← update b's Colour Bits to that value

≡ get the array nesting depth of that (returns 1)

- negate (returns −1)

⍵⎕NTIE use that as file handle to tie the file (returns −1)

,⍨ self-concatenate (we need a list of file handle and start position, where −1 means current position, i.e. at the start of the file)

b.MakePNG⎕NREPLACE replace the file contents with a render of b to PNG file contents

Answer 8

Factor + image.processing.rotation, 52 bytes

[ dup load-image 90 rotate swap save-graphic-image ]

Testing the function in Factor's REPL:

enter image description here

Answer 9

Python + opencv-python, (削除) 84 (削除ここまで) 62 bytes

import cv2
cv2.imwrite(p:=input(),cv2.rotate(cv2.imread(p),0))

Screenshot

-22 thanks to @Stef

Unfortunately for some reason when I do from cv2 import* it just doesn't work:

Screenshot

Commented

import cv2 # Import module
cv2.imwrite( # Write to a file:
 p:=input() # Get the filename as input and store in p
 cv2.rotate( # A rotated version of:
 cv2.imread(p), # The contents of p
 0 # Rotated 90 degrees clockwise
)) # Close the parentheses

• Stef: It looks like cv2.ROTATE_90_CLOCKWISE is just an enum with value 0. So you could just do cv2.imwrite(p:=input(),cv2.rotate(cv2.imread(p),0))
• Stef: BTW the from cv2 import* version works for me. Have you tried with a linebreak instead of a ;?
• The Thonnu: @Stef yeah I did, it still didn't work. I'll update it with the 0 later.

Answer 10

Python + Pygame, 77 bytes

from pygame import*
image.save(transform.rotate(image.load(a:=input()),90),a)

Guess in terms of golfiness PIL/Pillow > Pygame > OpenCV

• The Thonnu: Now Pillow > OpenCV > Pygame

Answer 11

Julia, 46 bytes

using Images
~f=save(f,imrotate(load(f),π/2))

Answer 12

PowerShell Core, 58 bytes

%{$p=[Drawing.Image]::FromFile($_);$p|% Ro* 1;$p.Save($_)}

Input comes from the pipeline.

TIO won't work, what with the file, so the following assumes the cat above was downloaded to C:\Temp.

Try it in a PS 7 Console:

$path = 'C:\Temp2円iORu.png'
$path |
%{$p=[Drawing.Image]::FromFile($_);$p|% Ro* 1;$p.Save($_)}
Invoke-Item $path

Windows PowerShell, 78 bytes

The System.Drawing assembly must be loaded, which costs 20 bytes as compared to Core.

%{Add-Type -A *.*wing;$p=[Drawing.Image]::FromFile($_);$p|% Ro* 1;$p.Save($_)}

Try it in a Windows PowerShell console:

$path = 'C:\Temp2円iORu.png'
$path |
%{Add-Type -A *.*wing;$p=[Drawing.Image]::FromFile($_);$p|% Ro* 1;$p.Save($_)}
Invoke-Item $path

Pretty straightforward: Starts the % cmdlet (alias for ForEach-Object)
Adds the assembly System.Drawing (not required in PS Core).
Loads the image file from the pipeline (in $_) into $p.
Then a bit of golfing can take place: $p|% Ro* 1 pipes the image to % (ForEach-Object) and calls the image's method RotateFlip(RotateFlipType), with 1 being Rotate90FlipNone.
Then the image gets saved to the original location.
Invoke-Item shows the image in the default app for .png. You can of course leave out that line and open it with your favorite viewer.

Answer 13

MATLAB/Octave, 33 bytes

@(x)imwrite(rot90(imread(x),3),x)

Answer 14

PHP 7.4.33 + WideImage 11.02.09 - 88 bytes

This relies on the WideImage library, which is an old library to manipulate images.

<?php include($x=WideImage)."/$x.php";$x::load($a=$argv[1])->rotate(90)->saveToFile($a);

You can use from PHP 5.2.0 to 7.4.33, but I've confirmed it works in 7.4.33 and 5.6.44.

This is meant to be executed from a command line/shell.

It does exactly what the code says: loads an image, rotates by 90o and overwrites the file.

How to test this

Just follow these simple steps:

• Install PHP 7.4.33
• Create a PHP file somewhere convenient
• Put the code in that file
• Download WideImage - DO NOT DOWNLOAD THE GITHUB VERSION
• Extract the lib folder
• Rename it to WideImage

To run it, just execute something like php -f file.php image.png.

Answer 15

feh image viewer, 1

feh is an image viewer for the Unix X window system, first developed in 1999.

>

From linux.com:

Type > to rotate an image 90 degrees clockwise, and < to rotate it 90 degrees counterclockwise. Your changes are immediately saved to the file.