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Wikipedia:Featured picture candidates/pi-unrolled

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Image:Pi-unrolled-720.gif: Animation of the act of unrolling a circle's circumference, illustrating the ratio π.

A previous version of this image was nominated for FP; several objections were raised. A workshop was operated, concerns aired, and a great many changes made.

Some prior objections, with comments:

  • badly needs antialiasing
    • Antialiasing is essentially clever blurring of an image. This is not always wise when presenting a geometric design; it leads to inaccuracy. Antialiasing does not really improve the (generally poor) resolution of your monitor; it just fools your eye into seeing more than there is.
    • Images are always tradeoffs between quality and file size. The latter concern is aggravated by animations, which contain much more information than the equivalently sized static image; this animation contains 45 distinct frames.
    • JPEG photos are handled well by MediaWiki but not animated GIFs. This format depends for small file size on a palette of indexed colors; this particular animation economizes still further by sharing one palette across all frames. The palette is very small: only 8 colors are used, therefore 3 bits are sufficient to specify any pixel. Antialiasing works by blurring the image which creates a range of "in-between" colors. This greatly bloats the color palette. Thus, a fully anti-aliased version might in theory be double in file size. In practice, the penalty is about 50%. This version is already 64 Kb.
  • the box should be removed, simpler to ignore the area question, the rectangle is the culprit Many users objected to the final display of a rectangle in the proportions of π.
    • The final rectangle is gone and with it, an entire sequence of frames. Now, once the wheel has rolled out of sight, the show is over. Having established a linear unit, we now treat π exclusively in terms of position on the number line.
    • For the odd swamp-dweller (me) who liked the rectangle, the entire graphic is now in the rough proportions of π (360px x 114px). Also easter egg in that the final frame is held for a duration of 3.14 seconds.
  • Heart-shaped plumb bob says Pi is for Girls!
    • Given the shortage of women in Mathematics... anyway...
  • A distinguished spoke or marker at the start point on the wheel has long been requested; previously deferred due to workload.
    • The plumb bob is gone in favor of a system of diamond markers. A wheel spoke is so distinguished.
  • better choice of colors, color scheme
    • A proposed palette was edited on workshop. Most of the current palette has had broad exposure and general endorsement. Not everybody agrees on all colors but we have a decent compromise.
  • should look slick and professional
    • Not sure exactly what slickness is desired but if this comment is driven by the usual mass-media, 3D, CGA eye candy, sorry. For one, I have neither the tools nor the time to do advertising-spot-quality animations; for another, the final product would be a gigantic file. Every refinement has a price; this is the "cheapest" version that still works.
    • The frames were all produced in FreeHand and exported as industry-standard EPS files. This is a vector file format and can be scaled to any desired size. So, if you like, we can exchange the frameset and you can convert them to high-resolution video; we can even link to an OGG.
    • I still think for maximum accessibility, the smallest possible file size is best and most professional.

I realize that we all have concerns and I've done my best to address all of them. Inevitably, that means that some editors will not get everything they wished for. Sorry. I've tried to balance all comments made against technical restraints and proven principles of professional graphic design. Hope it's okay now.

  • Nominate and support. - John Reid 02:03, 6 October 2006 (UTC)[reply]
  • Support. Minor quibble: the distance looks more like 3.15 to me. jokeOutriggr § 04:36, 6 October 2006 (UTC)[reply]
    • The original was designed with a unit of 1 inch at the assumed resolution of 72 ppi. The big one's unit is 144px; π is shown at 452px or 3.13888... units. If it makes you feel better about it, anti-aliasing in the big one blurs the line out a smidge to the right so, if you squint, you might say it's exactly at π units. John Reid 09:03, 9 October 2006 (UTC)[reply]
  • Comment. Antialiasing is not blurring: both antialiasing and the unantialiased rasterization you are using are methods for going from some idealized high resolution image to a low resolution pixelization, but antialiasing is a more accurate reflection of the original image, and not the same as blurring an unantialiased image. I still think your unantialiased text is ugly, though I don't care so much about the division lines etc. But I have no strong opinion on whether the improved appearance of antialiasing is worth the file size blowup. —David Eppstein 04:50, 6 October 2006 (UTC)[reply]
  • Support, I think it's awesome. But is there an svg version? I'm sure you've thought of that, which leads me to assume it would be ill-fitting, and I'm curious why. --Masamage 05:54, 6 October 2006 (UTC)[reply]

*STRONG oppose - those are not circles! They are 74 x 65 pixel ovals!!! --Janke | Talk 07:04, 6 October 2006 (UTC)[reply]

Support. The old image needed to be purged. --Janke | Talk 09:14, 6 October 2006 (UTC)[reply]
  • Support, illustrates the concept in a very elegant manner. - Mailer Diablo 10:45, 6 October 2006 (UTC)[reply]
  • Support - excellent. Though I had to purge the page cache twice to get the new version to show, it looks great, and addresses those concerns I had with the previous version. Thanks for making the effort! -- Moondigger 13:46, 6 October 2006 (UTC)[reply]
  • Weak oppose and comment:
    1. MediaWiki handles GIF files just fine, they just can't have optimization of frame animation (it has to store all frames on the whole). Most programs tend to optimize by default, but a good GIF editing program can unoptimize existing optimized files and fix this loslessly (I have done so with several Wikipedia images already).
    2. About the additional colors for anti-aliasing, they wouldn't bring a big difference in file size at all. Compare with my currently FPC on Villarceau circles, which is a full 3D render with lots of shades. It uses a whole color pallete for EACH of the 39 frames, and the full-sized file is only 582 kB in size, and it has 4.2 times more pixels per frame than this one does. That means that, with this resolution and a much simpler and constant color pallete, the file size wouldn't go much beyond 100 kB, and I dare to guess it would stay at the 90 kB mark. I do think anti-aliasing is a must-have here because of clarity and smooth-ness of shapes, and as I just explained, file size would hardly be an issue.
    3. Given this, I'm enamoured with the concept of this animation and I think it's an excellent visual demonstration of pi, but I just think this COULD be a lot better than it is. I just believe the reasons for not making it better don't really make much sense. ? ?i?ff?? 17:04, 6 October 2006 (UTC)[reply]
  • Support Good illustration. HighInBC 19:41, 6 October 2006 (UTC)[reply]


Big and slick

[edit]
Image:Pi-unrolled-720.gif, full size


thumbnail image
  • Support I nominated the first pi image, and it got shot down. I do like this better. Viva La Vie Boheme!
[edit]

Masochists and obsessives can check out a gallery of all uploaded versions of this graphic at Image talk:Pi-unrolled.gif/Gallery. Warning: This page will not just load slowly; it may slow down your whole machine while it's open in your browser. John Reid 21:46, 14 October 2006 (UTC)[reply]

Promoted Image:Pi-unrolled-720.gif

Yay for constructive criticism! --NauticaShades 18:25, 15 October 2006 (UTC)[reply]