Photoshop CC saves PNG files bigger than some PNG-specific tools

[name2941]

Hey,

as a web-developer i'm working with PNG files alot. Since the release of Photoshop CC i always need to go back to CS6 for saving what i did in CC. I thought maybe it's just an early bug which will be fixed soon but still nothing and annoying. Maybe i missed something and there is a benefit in this bigger files? So here is a short discription...

When saving a PNG file

( file > save as > PNG > Compression: Smallest/Slow and Interlaced: None )

the files saved in Photoshop CC are about 17kb bigger compared to the saving in Photoshop CS6

A former 0,3kb PNG file gets saved with 17kb in Photoshop CC.

I use the English Windows 64bit Version of Photoshop CS6 and CC.

A fix would be very appreciated.

Screenshot of both files:

Thanks,

Bye!

[Herbert2001]

Are you certain that is a legit site?

[Herbert2001]

Oops, sorry Noel, I though your were responding to my post. Did you compare my versions?

[Noel Carboni]

Yes, thanks.  It's clear that there are sophisticated ways to compress PNGs that Adobe doesn't presently use.  What I don't know, not being a graphics file format expert, is whether the 3rd party software is taking liberties with the standards.  Clearly Adobe is very standards-oriented.

But yes, I agree that Adobe should take a good look at the PNG compression algorithms again.  They did this not too many years ago and the PNG saves got a lot better, but clearly there's still room to improve.

-Noel

[Herbert2001]

The other tools take no liberties with the standards, I believe. The main difference is that Adobe's png web export does not support saving png images with full transparency and a limited indexed colour palette - that is the simple reason why Photoshop generates transparent png files that are on average four times bigger in file size.

Quality-wise Photoshop's transparent png web export also does not allow for any regional quality control either.

So, yes, lots of room to improve. Unfortunately, I have been rocking this boat for years and years now, and so far nothing has been done about it. Fireworks has had support for 8bit png export with full transparency since at least a decade. I still wonder why such a basic fundamental export option never made it into Photoshop's web export.

Perhaps one of the developers can let us in on their secret why they have been so reluctant?

[IHICAP]

Well, there is plenty of good evidence and some examples in here of why Photoshop's handling and output of .PNG files is not as good as it ought to be for anyone who creating images for the web. All we can do is hit "like" at the top right of this page and hope that a page with a few likes gets noticed by the development team.

...Unless anyone here happens to know of a writer for a popular computer arts or web design publication? I imagine that the headline "How Adobe Could Make the Internet 4x Faster" would be pretty interesting reading for a lot of web designers! Not strictly true perhaps, but it piques interest and gets discussion going.

[Herbert2001]

To be fair, there are a number of optimization techniques that will also work quite well in Photoshop:

http://www.smashingmagazine.com/2009/07/15/clever-png-optimization-techniques/

Btw, you do not need a plugin to convert transparency to a layer mask (the above article tells us to install a special plugin, but there is a "transparency to layer mask" option in the layer menu of Photoshop).

Having said that, CQ still does a better job. And is quicker and easier to use. And Photoshop's save for web function does not support full transparency for indexed png images - and that is the main concern here.