Since last month, or maybe earlier, I've been recompressing all the .PNGs using PNGGauntlet's "brute force optimization" option, shrinking the images which make up the bulk of the site to reduce bandwidth usage. As you know, the site has funked out near the end of each month because of bandwidth issues, and though I've asked for an increase from 50 GB to 75 GB, I thought it really couldn't hurt to be able to deliver the same maps, unaltered in visual quality, using less bandwidth on my end and less time loading on your end.
All sections except for the top five sections (NES, Super NES, GB/GBC, GBA, and PC) take up only 10% of the site (based on numbers of maps), so I didn't record the differences in them. But you might be interested in the size reductions of the major sections.
NES:
83.6 MB to 55.0 MB
-difference of 28.6 MB, or reduction of 34.21%
-biggest change (in bytes, not percentage) in a single map: EarthBound Zero's whole world map, from 7.00 MB to 3.42 MB
PC:
120 MB to 113 MB
-difference of 7 MB, or reduction of 5.83%
GB/GBC:
52.1 MB to 39.8 MB
-difference of 12.3 MB, or reduction of 23.61%
-new sizes not noted on file listing yet
GBA:
92.4 MB to 65.0 MB
-difference of 27.4 MB, or reduction of 29.65%
-new sizes not noted on file listing yet
Super NES
188 MB to 124 MB
-difference of 64 MB, or reduction of 34.04%
-new sizes not noted on file listing yet
-biggest change in a single game I've seen so far: The 7th Saga maps by KingKuros alone took up 36 MB (30.5% of all of the Super NES atlas's size!), but shrunk to 16 MB (a difference of 20 MB, a size comparable to the total change of the other major sections!)
Neat stuff, huh?
Other things:
-greyscale images can actually be visually altered by PNGGauntlet if "preserve gamma information" isn't checked. Greys can be darkened or lightened, and I didn't want that. However, they don't seem to be altered if they've already been run through PNGGauntlet once before. So I did a double pass with the Game Boy maps...once with that option checked, and then a second time with it unchecked. The second time most images didn't shrink at all, but some still managed to shrink some more. Overall, though, I'm kind of surprised that they didn't shrink a lot, the maps with colour shrank more.
-unanimated .GIFs on this site have been or will be replaced by .PNGs. I will have to change all title images which are currently all .GIFs for whatever reason. The only .GIFs that should remain are the animated ones.
-currently, all maps in the DS section are all less than 1 kB each. Of course, they're all Mario Kart DS in-game maps as transcribed by osrevad and Revned, but it's still worth noting as having some of the smallest maps.
-I think the smallest map used to be "ResidentEvil(PC)-Laboratory-B2.png" in the PC section. Now the honour goes to "ResidentEvil-Survivor(PC)-Arcade-1F.png", which compressed better, and is now at 170 B.
-one of the smallest NES maps is an anomaly. "Bonk'sAdventure-Round4-Area5.png" has less than 16 colours, but PNGGauntlet only reduced it to a 256-colour palette. (I love PNGGauntlet's ability to reduce images to a palette to only as small as it has to be (except in this case), shrinking many maps to a 16- or 256-colour palette, and some even to 4 colours!) When using other programs to reduce the palette to 16 colours and using PNGGauntlet on that, the image comes out to being larger than when sticking to a 256-colour palette. So I left it, but I don't get why.
- >_> don't take this the wrong way, but the most inefficient images (largest before compression) seem to come from KingKuros. Also, Revned and TerraEsperZ have had some pretty overly large maps. (If I haven't changed the file listing yet, compare the sizes of their GBC Legend Of Zelda: Oracle maps' listed size and actual size.) Unless you have trouble sending maps to me, there's really no point to encourage people to use PNGGauntlet 'cause I'm going to do it anyway. Plus, I hear that some people can't for whatever reason. To put a more positive spin on it, that means their maps are the most compressible, and based on what I know about colour pattern recognition in .PNGs, it probably means their maps are accurate with everything all lined up.
-despite my love of PNGGauntlet and the incredible amount of space it's saving me, I fear it may not be the most efficient method of saving .PNGs. When it's unable to compress a .PNG smaller than its original size, it makes a copy of the original. Which is fine, because then I'm guaranteed that files won't get larger. Only thing is, what if some maps (like the GBA Banjo-Kazooie maps) are MUCH smaller than PNGGauntlet can attempt to compress them? There must be some secret to that! Maps can never be, say, 1 byte each, but it seems like I haven't yet hit the minimum size possible yet. I want to squeeze every unnecessary byte out of them if I can do it without altering the images!
-first maps compressed: Mega Man III
-last maps compressed: Mega Man X 3
-last maps compressed including April Fools' maps: Mega Man Solid X: Guns Of The Mavericks