How does size work with PNG-8 and PNG-24 images?


I am desperately trying to save a psd file as a high res png.

I found some relevant setting when I click Save for Web in photoshop but then I got confused about size vs resolution. I found this explanation:

"Png -8 has less size and low resolution, on the other hand png-24 has more size with high resolution. But these two formats are of less size than normal png file."

I need to crank an image up to 300 px per inch but if I save as png-24 will that do the trick or reduce the size instead of increasing it?

Probably sounds like a silly question for those who know but help would be much appreciated. Thanks.

7/31/2014 12:41:00 PM

PNG-8 means 8 bits, so 256 colors maximum. PNG-24 means 24 bits, so 16,7 million colors max. Resolution is not an inherent factor of any format, so saying a PNG-8 is "low resolution" does not make sense, it only has low number of colors. You/the image you're saving determine the resolution. It is true though that PNG-24 has a larger file size (i e in kilobytes/megabytes) than a PNG-8 which contains fewer colors.

The DPI setting is just a print setting, you probably don't need to worry about it. Only the number of pixels matter when your destination is digital.

7/31/2014 12:21:00 PM