653038 - Replacement image for sync-bg.png smaller optimized PNG.

Status: RESOLVED FIXED

(Firefox :: Theme, defect)

Description

[Frédéric Kayser]

User-Agent:       Mozilla/5.0 (Windows NT 6.0; rv:2.0.1) Gecko/20100101 Firefox/4.0.1
Build Identifier: 

File location in source:
mozilla-2.0/browser/themes/gnomestripe/browser/sync-bg.png
mozilla-2.0/browser/themes/pinstripe/browser/sync-bg.png
mozilla-2.0/browser/themes/winstripe/browser/sync-bg.png

Ends up here:
omni.jar!/chrome/browser/skin/classic/browser/sync-bg.png
omni.jar!/chrome/browser/skin/classic/aero/browser/sync-bg.png

Sizes
original:  26756 bytes
optimized: 21309 bytes
saved:      5447 bytes (more than 20%)

Reproducible: Always

Comment 1

[Frédéric Kayser]

Attachment: sync-bg.png optimized

Comment 2

[Charles Chan]

Attachment: Bug 653038 - Patch 1

Update the .png with the optimized version.

Comment 3

[Dão Gottwald [:dao]]

Comment on attachment 606473 [details] [diff] [review]
Bug 653038 - Patch 1

thanks!

Comment 4

[Dão Gottwald [:dao]]

http://hg.mozilla.org/integration/mozilla-inbound/rev/3b09a295bd4e

Comment 5

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

https://hg.mozilla.org/mozilla-central/rev/3b09a295bd4e

Comment 6

[[e-mail]]

Out of interest, which application did you use to optimise this .png file?

Comment 7

[Frédéric Kayser]

(In reply to [e-mail] from comment #6)
> Out of interest, which application did you use to optimise this .png file?

It was probably pngout (ran in random mode dozens of time and trying many different block count).
Pngout is based on Ken Silverman's own deflate engine -kflate- most of the time, if not always, it produces smaller Deflate streams than Zlib and 7-Zip Deflate implementation but it's slow, very slow...

Since I have proposed this file   have written a small tool called Huffmix that is able to pick the smallest Deflate blocks out of different Pngout random runs.
http://encode.ru/threads/1313-Huffmix-a-PNGOUT-r-catalyst
Applied to sync-bg.png it gets even smaller... 21051 bytes.

To have a closer look at what's going on inside Deflate streams found in PNG or GZip files you can try Defdb.
http://encode.ru/threads/1428-defdb-a-tool-to-dump-the-deflate-stream-from-.gz-and-.png-files

PngWolf is also an interesting tool to improve multi-filter (f5) selection:
http:w/encode.ru/threads/1262-pngwolf
Pngwolf output can be recompressed using pngout -f6 (it will keep the filter selected for each scan-line).

State of the art PNG optimization has become a sort of black magic, since it takes 5 or 6 tools and a lot of time to get the best results:
- cryopng (to clear alpha, only for RGB+Alpha files)
- pngwolf (to get the best filters)
- pngout (best deflate engine)
- deflopt & defluff (to reduce Huffman tables)
- huffmix (to get the best out of pngout "random" mode)
(pngout -r, deflopt, defluff, huffmix can be run in a loop hundreds of time)

Comment 8

[Frédéric Kayser]

Attachment: sync-bg.png Huffmix+Pngout+Deflopt+Defluff optimized

I don't know if it's worth reopening the bug, this new file is only 258 bytes smaller.