File talk:Nocover.png

Moved from en:Wikipedia

I've not placed any images on commons before. Please could someone check this is OK? - Alex valavanis 19:12, 2 March 2007 (UTC)

Nocover (12652).png available

Nocover.png is a high-use file in its native un-thumbnailed form on Wikipedia. I've uploaded Image:Nocover (12652).png, which is exactly the same image data, but recompressed from 19832 to 12652 12644 (36%), pretty much guaranteeing a 7kB reduction in data on most Wikipedia album articles with no covers. I'm adding a request on Commons:Requested updates to protected images for 12652 to become the main Nocover.png. For anyone that cares: I used optipng -o7 followed by multiple runs of pngout -k1 -n3 -r and pngout -k1 -b904 -r — and kept the sRGB, gAMA, and cHRM blocks intact in the file because I don't know if they are relevant, though it's worth noting that it was originally converted from GIF which, as far as I know, has no ability to store gamma or chroma hints. I also cleaned up the image description quite a lot. --Closeapple (talk) 01:02, 5 December 2009 (UTC)

Just got another 8 bytes squeezed out by DeflOpt, which I hadn't heard of until tonight. --Closeapple (talk) 07:10, 5 December 2009 (UTC)

Unrelated to the Image:Nocover (12652).png upload directly, but for people who are interested, here are some results with some files I did modify but didn't upload. I can get the compression a little better if I remove the extra blocks and the outliers (pixels that are non-white despite not appearing to be part of the jewel case or shadows). Greyscales are all effectively lossy, because the "current" Nocover.png (as of 2009-12-04), although palletized because it's originally from GIF, is actually a few different blue hues, not monochrome. Results

• 12471 bytes: color with outliers removed; 8-bit 256-entry pallette w/color; multiple runs of pngout -n2 -r (with -c3 -f0 -d8 implied)
• 11111 11110 bytes: greyscale with outliers retained; 8-bit greyscale; multiple runs of pngout -n3 -r (with -c0 -f5 -d8 implied) — 1 more byte saved with DeflOpt.
• 10809 bytes: greyscale with outliers removed; 8-bit greyscale; multiple runs of pngout -b9000 -r (with -c0 -f5 -d8 implied)
• 4757 bytes: greyscale with outliers removed, knocked down to 16 grey levels; 8-bit greyscale (because 4-bit pallette doesn't compress as well); multiple runs of pngout -c0 -f0 -d8 -n1 -r

I don't think the 4757-byte one is very good looking; the transition across the black part of the jewel case is too abrupt. I might be able to solve that with a better choice of grey values though. --Closeapple (talk) 06:48, 5 December 2009 (UTC)

 Done, after just a year and a half. :) —Ilmari Karonen (talk) 19:58, 26 May 2011 (UTC)

Categories

{{edit request}} Please change the category Category:Image placeholders to the more specific Category:Image placeholders in English. --Zundark (talk) 09:09, 17 December 2011 (UTC)

 Done -- Common Good (talk) 19:19, 17 December 2011 (UTC)