Upscaling and rotating

SouriSouri Posts: 13
edited March 2014 in Feature requests
Whoops, should've realise that rotate is already in Pyxel. I'll just leave what I have here on pixel rotation in case it can be useful in some way.

I'd like to put these down as a feature request! These two functions are pretty standard features, but I reckon they'll help encourage more pixel artists into the Pyxel userbase as they'll cover two really useful and time saving pixel art programs out there which are no longer in development. And hey, who wants to open separate programs to do these functions all the time!


Photoshop does a lousy job of rotating pixel art, mainly because it was never made with pixel art in mind, so you'll end up with some pretty messy results that require a whole lot of cleaning work afterwards. Thankfully, clever minds have figured out excellent ways to rotate pixel art and get much better and cleaner results. RotSprite was a program that did this really well!

"The algorithm is dead simple, so I'll just describe it and you can decide: First it scales the image to 8x size, using a "pixel guessing" algorithm to add detail. Then it scales the image to 1/8 size and also rotates it using standard aliased rotation and scaling. That's basically it. To get a big speed  increase for a small penalty in quality, you could use 4x instead of 8x and skip some other optional steps I did, but I wanted high quality above all else."

Unfortunately, RotSprite is PC only, and the last version was made in 2009. Here's some additional discussion on Pixelnation on its implementation (which seem to be unknown in some parts)


Lithander/pixelpracht released a really cool rotate/rescale tool in 2011 called PixelPunch. You can read how the program approaches things here:

Unfortunately, it's PC only and no longer in active development. It can upscale pixel art and uses an algorithm to smooth things out. It's an interesting effect, and while some might say why bother with this kind of processing, there are definite time saving uses for this. Here's one particular example:

Basically, scale your sprites up and then back down to create larger sprites with little cleaning work afterwards. If you have animations needing this, this feature will be a huge time saver. Alonso Martin made a tweet about this useful feature, and Lithander responded here:

Incidently, Alonso is an insanely talented pixel artist (which you can see from his website), and I reckon features like this will get more talented folks like him onboard Pyxel. I've noticed on twitter that Johan Vinet (amazing pixel artist) has recently picked up Pyxel and got a special Skype introduction from another amazing pixel artist and Pyxel user, Simon Bachmann ( - he also frequents this forum), so it's great to see more talented artists finding out about Pyxel.


  • DanikDanik Posts: 899
    Those are definitely interesting algorithms I'd like to implement! As always though since I'm not working on Pyxel Edit full time, I have to choose between which issues to fix and features to focus on. I hope to have more free time this summer (currently very busy with thesis which should be done by then).

    Yeah, it's awesome that such talented artists use Pyxel, Simon has also been very helpful with testing the pre-releases!
  • SimonSimon Posts: 58
    hehe, yes finally got Johan to use Pyxel. While doing the intro to him over Skype I saw that some things are not that obvious as one may think. 

    Maybe I should do an intro on youtube for everyone at some point, as it really helped Johan to get going and took me only an hour or so to run through most features. (Would be a funny WE project :D let see if I find some time if there is some interest for such a thing)

    The scale features of Pixelpunch are looking sweet. -> downloading and looking into it now :D definitely would get a vote from my side :)

  • DanikDanik Posts: 899
    I'm sure a lot of people would appreciate an intro video! I'm also interested in what parts are more and less obvious, you get so used to the program after a while so you become blind to the weird things. :)
  • UbuUbu Posts: 10
    An intro video would be great!
  • SouriSouri Posts: 13
    edited March 2014
    I know Danik's already noticed, but Lithander/pixelpracht has just uploaded the source for PixelPunch up on Github which is phenomenal.

    Put me down as someone eager to check out video tutorials from Simon! I think I've got the basics down - the program is really intuitive and pretty straight forward without needing a manual, but if there's any advanced tips, tricks, and different/faster ways to get things done (or even non-obvious things) etc, I'm always up for that :)
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