Tile rotation not noticeable in thumbnails
February 11th, 2007 in Developer Diary · By Markus WeichselbaumSince the inception of TheBroth, we wanted to be able to rotate the tiles. This would make artworks possible that look like real mosaics, instead of the somewhat computerish, pixelated artworks that are the result of upright square tiles. Interestingly, tile rotation has no effect on the thumbnails, by which many artworks are rated.
How straight up tiles used to look
Rotation of tiles in 5 degree steps. Star-like and disk-like objects can be created by placing tiles in the same position but with different rotation.
For the longest time, tile rotation remained elusive, caused by the implementation of TheBroth using Javascript that provides only limited means for advanced graphical effects. We thought it would be REALLY worth having tile rotation though, so we eventually decided to reprogram TheBroth core functionality in Flash. We’re making good progress, and hopefully it is only a matter of weeks until the potential of artworks on TheBroth is GREATLY improved.
I can hardly contain myself, so enormous is the excitement, but in a nutshell: It rocks. :-)
Rotation in artwork thumbnails - it’s not visible!
Anyway, this post isn’t really about tile rotation and all the other nifty things that are possible thanks to moving TheBroth to Flash. In fact, it’s about the interesting effect that tile rotation is simply not noticable at all when looking at thumbnails.
Without further ado, let’s jump straight to the proof. The following are thumbnails of the exact same room, shown with rotation of tiles and without.
The first one is a little birdy. It’s a very nice piece of art. I took the liberty to import this snapshot into a private room with an early alpha of Flash-enabled tile rotation. I am not exactly a gifted artist, but it was a breeze to smoothen out the image by rotating some of the tiles.
Here’s the result (all images saved as JPEG with 45% quality setting):
With tile rotation, 146×90 px
Original image, 146×90 px
While the above images are actually different on a pixel level, the point is: They LOOK the same.
Needless to say, using our current thumbnail size that’s even smaller (130×80 px), there’s even less of a difference - if that makes any sense, since there is no visible difference at the larger 146×90 px resolution either.
To really see any noticable difference, we would have to make the thumbnails a lot larger. Here are the same images, this time at 219×135 px resolution (click to see the full 730×450 px versions):
The images above clearly show the difference. The right one is very jaggy and pixelated.
For the mathematically inclined, the observation of “missing” rotation in the small thumbnails doesn’t come as a surprise. Rotating a tile at 45 degrees creates an object that extends the original square area by only 2 pixels at most; less so at wider angles. The tile size is 10 pixels. A thumbnail of 146×90 is exactly 20% in dimension of the original size (730×450), which corresponds to a 10x smaller area. In the thumbnail, each tile is at best reflected as 2×2 pixels, and the tiny 20% extension that the tile may experience at some angles is simply above the sampling frequency and thus won’t show up in the thumbnail.
Many people rate images in the gallery view, before even (or ever) looking at the full size artwork. The question will be, is the absence of rotation in the thumbnails a good thing, does it matter at all, or is it a bad thing?
I look forward to your input!
