PNG Crush Plus

Community Forums/Developer Stations/PNG Crush Plus

jhocking(Posted 2003) [#1]
I'm sure a lot of you already know about PNG Crush (I first found out about it here.) It is a small app to compress PNG images; it routinely shaves around 20% off the filesize off PNG images saved from Photoshop.

The trouble with PNG Crush is that it is only available in Linux and DOS versions, neither of which is terribly useful for Windows users. Well to get around this I wrote a Windows GUI for the DOS version. Basically the GUI has buttons to control the process and select files, and then it automatically launches the DOS version to do the compressing.

I call my GUI "PNG Crush Plus" (since it was written in BlitzPlus.) You can download it from:

Note that it includes the DOS version (which is required.) To use it just double-click on pngcrush_plus.exe and click the appropriate buttons. Note that all PNG files you intend to compress must be in the same directory as the exe files, and you must not disturb while PNG Crush is compressing (there will be a console window open.) The compressed images will be saved with the same name as the original but with "c_" added to the front.

WendellM(Posted 2003) [#2]
That sounds useful, Joe. I haven't tried PNG Crush before - do the files it produces contain the exact same information (including any alpha) as the original PNGs, just better compressed? Any difference in loading speeds in Blitz? (I'd test these myself, but I'm in the middle of rendering a lightmap and thus have few CPU cycles to spare at the moment <g>).

jhocking(Posted 2003) [#3]
Yes, PNG Crush-ed png files are visually identical to before. I would certainly hang on to the pre-crushed versions just in case but they always look fine to me.

Beaker(Posted 2003) [#4]
Are you aware of the other PNG crusher, called PNGOUT, that crushes even better than PNG Crush (allegedly)? Get it here.

PNGOUT website here.

jhocking(Posted 2003) [#5]
No, I wasn't aware. Doh, did I just waste my afternoon writing a GUI for PNG Crush?

ADDITION: I just tested pngout and it actually INCREASED the filesize of PNG images saved from Photoshop. So the hell with that. Note that all four images I tested with had alpha transparency; I should have tested without but that's the main reason I use PNG file format (JPG compresses better, before and after zipping the files for distributing my games, for most images without alpha.)

Beaker(Posted 2003) [#6]
Nah. It's probably minimal difference.
There's another one called OptiPNG

big10p(Posted 2003) [#7]
Another one? FlipPNG 'ell! :)

Russell(Posted 2003) [#8]
What about png images NOT saved from Photoshop?

And, I thought png was supposed to be really good at compressing?

Are any special programs needed to uncompress these png images, or does it just re-arrange the data more logically in a compressed png image? In other words, will BB be able to load these newly re-compressed images without any trouble?


jhocking(Posted 2003) [#9]
PNG images from any source will work in PNG Crush.

Your second question is misguided; PNG is not a tool to do the compressing, png is simply a file format with which you can compress the data in an image. How well a given png file is compressed depends on the tool the image is saved from.

The recompressed images are still normal PNG images, just with the data rearranged more compactly.