Saving PNGs

[zeuspaul]

I use PNGs because they are lossless.  I know the compression level with JPGs affects the quality but not so with PNG.  Is the only disadvantage with using the highest compression (9) with a PNG is that it takes longer to save?  What about decompression?  If a PNG is saved at 9 does it affect how another program opens the file?  If one wants to minimize file size is there any reason other than extra saving time not to use the maximum compression?

[Ofnuts]

(10-25-2023, 11:49 PM)zeuspaul Wrote: I use PNGs because they are lossless.  I know the compression level with JPGs affects the quality but not so with PNG.  Is the only disadvantage with using the highest compression (9) with a PNG is that it takes longer to save? 

Yes

(10-25-2023, 11:49 PM)zeuspaul Wrote: What about decompression?  If a PNG is saved at 9 does it affect how another program opens the file? 

Not as far as I know. In practice most

(10-25-2023, 11:49 PM)zeuspaul Wrote: If one wants to minimize file size is there any reason other than extra saving time not to use the maximum compression?

No. But there are other ways to reduce the size. Removing interlacing can make quite a difference. You can also reduce the amount of data (color indexing, removing metadata...).

For instance, the two attached files differ only by the interlacing option: 14.5K vs 21K.