Friendly request: please optimze your PNG images

[PooshhMao]

Hi,

I've been taking some mods apart to see what makes them tick.
I've noticed that pretty much all of them come with unoptimized PNG images (I'm going to refrain naming names at the moment).

In most cases, it doesn't make a large difference, but in some, it does - sometimes I can reduce the image to less than half their original file size.

There's a number of ways to do this. If you're on Linux, pngcrush is the most straightforward. If you're on anything resembling Debian, it should be in the repositories. Windows users can choose between crushpng or tinypng AFAIK.

There's a bunch of reasons why you'd want to do this. Your mod will be smaller, it will load faster, and it'll use less memory.

Thank you for considering!

[Accensus]

Converting PNGs to paletted colors in SLADE or changing them to Index in Photoshop works too, but for the most part makes the quality crap. Some soft gradient spots start to look at lot less pleasant to the eye.

[PooshhMao]

That's something else altogether. Reducing the color palette obviously makes the image smaller too, but if the image contains more than 255 unique colors (+ transparency), and you change it to have indexed color, then obviously you're going to see reduced color depth.

But that's not what crushpng does. It retains the original color depth, it just saves the image in an optimized fashion. There's no perceivable difference at all, the end result is identical.

[Graf Zahl]

and it'll use less memory.

No, it won't. PNGs are always decompressed before being used. It doesn't even make a difference if the source is a true color or paletted image - internally all PNGs will be turned into a32 bit flat image for hardware rendering and an 8 bit flat image for software rendering.

[DaMan]

Plugging File Optimizer. For extra convenience put in the send to menu.

[The Zombie Killer]

Plugging File Optimizer. For extra convenience put in the send to menu.

unless that tool lets you tell it not to strip specific custom chunks (specifically, grAb), then it's useless for ZDoom modding (I haven't looked at it, so I don't know if it can do that)

[Dark-Assassin]

Still helpful to those who have really crappy download speeds.
Same goes for music and other audio files.

I personally am turned off from downloading large mods because of this shitty Australianet

[Gez]

That's why I made it so that you can call pngout, pngcrush, and deflopt from within SLADE 3 to optimize PNGs though without losing important lumps (like grAb, which contains the offset information for sprites) that these tools don't know should be kept.

[PooshhMao]

No, it won't. PNGs are always decompressed before being used. It doesn't even make a difference if the source is a true color or paletted image - internally all PNGs will be turned into a32 bit flat image for hardware rendering and an 8 bit flat image for software rendering.

Alright. Still, that leaves two good reasons why you'd want to optimize your PNG's.

[NeuralStunner]

I made a batch program to run pngcrush on numerous files. With options to keep/strip chunks like tRNS and grAb. (Also works from backup files just in case something goes bad.) That was torturous.