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

Question

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!

Answer 1

Chris and Idothings:
Here's a quick example that explains what I am talking about:
Download this 32bit png, and open in Photoshop:
http://www.estructor.biz/testje/heading.psd
In Photoshop, the only options in the save for web dialog I have for png are these:
and
Since I require the alpha channel to remain intact, I am forced to export to a 32bit png (png-24 with transparency checked). Png-8 would be a much better choice, since this image could be optimized with a limited colour palette, but Photoshop does not allow a full alpha channel to be included in that case. In short, a pixel's transparency is either on or off in 8bit png mode.
In Photoline I can choose a png with 32768 colours and full alpha transparency. This reduces the file size while I retain full visual quality.
Fireworks offers us an additional option:
Png 8 bit with Alpha Transparency. This gives us the power of full transparency and a limited index-based colour pallette. It also results in a much reduced file size.
Unfortunately, Fireworks' colour reduction algoritms are quite old, and you cannot really choose 128 colours: it wrecks the quality (in this case, at least). With manual colour choices this could be improved, but the time this would take kinda defeats the purpose of having a web optimization tool.
One other disadvantage to Fireworks: no further development. Adobe killed it.
Often 256 indexed colours are not enough. Color Quantize goes one step further, and allows for a limited colour palette of 512, 1024, 2048 and 4096:
This gives a web front end developer an incredible control over a limited colour palette, and yields the best balance between file size and visual quality, while retaining a full alpha channel. Color Quantizer also includes a very simple quality mask brush tool to paint over areas that must remain identical in quality.  The colour reduction algoritms are top-notch, so with the sample image even 128 colours are visually quite acceptable.
Final results:
Photoshop: full 32bit png - 254kb
Photoline: 32768 colours 32bit png - 207kb
Photoline: 256 colours 32bit png - 170kb
Fireworks: 256 colour 8bit png + 8bit alpha channel - 54kb
Color Quantizer: 256 colour 8bit png + 8bit alpha channel: 50kb
Color Quantizer: 128 colour 8bit png+ 8bit alpha channel: 41kb
Do I really have to explain any further? You'd have to be mad as a hatter to continue to use Photoshop for png optimization once you start to realize how limited its png output options are. Luckily, Color Quantizer (and ImageAlpha for mac) is completely free: so export to a 32bit png, and optimize in those.It will save a LOT of bandwidth.
Chris, you are correct in stating the png export options have not changed since v5.5 - it shows. Photoshop is stuck in the nineties as far as web export is concerned.
Oh, and one more thing: Photoline, Color Quantizer and ImageAlpha offer a wealth of dithering algoritms. While Photoshop users are limited to diffusion, pattern and noise, in Color Quantizer I have six different options plus other options to control the final colour reduction.
PS I could not check ImageAlpha for the mac, since I work on a WIndows machine at home. In my classes I do demonstrate ImageAlpha to the students, and it gives comparable results to Color Quantizer (since both use, I believe, the same colour reduction algoritms) at a low 128 colours. I recall a file size of around 46kb.