Upscaling and rotating
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!
RotatingPhotoshop 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." http://forums.sonicretro.org/index.php?showtopic=8848&st=15&p=159754&#entry159754
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:
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 (https://twitter.com/sibachmann - he also frequents this forum), so it's great to see more talented artists finding out about Pyxel.