From PNGs to APNGs

[GeoffreyA]

Originally Posted by poisondeathray

My comments for "pallete optimization" for PNG were "in general" . It's a commonly used lossy technique for web graphics

If you're referring to apngasm specifically , the optimizations used there should be lossless according to the instructions.

Noted. I didn't read the Readme.

[jay123210599]

Here are my test files: https://www.mediafire.com/file/2ooty..._APNGs.7z/file

1-1 and 2-1 uses both color and palette optimization.

1-2 and 2-2 does use color nor palette optimization.

1-3 and 2-3 only uses palette optimization.

1-4 and 2-4 only uses color optimization.

All of them use zlib for compression.

[GeoffreyA]

Originally Posted by jay123210599

Here are my test files: https://www.mediafire.com/file/2ooty..._APNGs.7z/file

1-1 and 2-1 uses both color and palette optimization.

1-2 and 2-2 does use color nor palette optimization.

1-3 and 2-3 only uses palette optimization.

1-4 and 2-4 only uses color optimization.

All of them use zlib for compression.

Good job on the testing, and well organised. Looks like it's of no use turning on those settings because the files are exactly the same size; even the hashes are identical.

I must say, Jay, I couldn't help but smile seeing the second set of APNGs. Thanks for bringing a bit of humour to the evening. What anime is that?

[Z2697]

Keijo, perhaps

[jay123210599]

Originally Posted by GeoffreyA

Good job on the testing, and well organised. Looks like it's of no use turning on those settings because the files are exactly the same size; even the hashes are identical.

You mean the colors? How did you prove they were the same?

[Z2697]

cmp
md5sum
sha1sum
sha256sum
b3sum

Or even just look crc32 already in the 7z archive LOL

[GeoffreyA]

Originally Posted by jay123210599

You mean the colors? How did you prove they were the same?

I didn't test the colours. I just looked at the file sizes and hashes in 7-Zip. Whether they are the same as the PNGs, I do not know, but they, the APNGs, are identical to each other.

[GeoffreyA]

Originally Posted by Z2697

Keijo, perhaps

Okay, I haven't seen that one, or indeed, any of this genre.

[Z2697]

Originally Posted by GeoffreyA

Okay, I haven't seen that one, or indeed, any of this genre.

Me neither
Wait it's a genre?

[GeoffreyA]

Originally Posted by Z2697

Me neither
Wait it's a genre?

Well, I wouldn't be surprised. It's an out-of-the-ordinary concept

[jay123210599]

How do I check the hashes of the APNGs?

[GeoffreyA]

Originally Posted by jay123210599

How do I check the hashes of the APNGs?

For my part, the easiest way is with 7-Zip. Inside its file explorer, right click on a file, then CRC, and select the hash method, or "*" to calculate all methods. Also, in archives, the CRC32 of each file is listed in one of the columns.