mox wrote: ↑21 Jun 2023, 10:03
For PNGs in TVP, you can choose a compression ratio from 1 to 10 (5 by default I guess): the picture will be always lossless but the file size will be different (and it will impact a lot when decompressing for memory/cpu).
Yes, this is true and it has a significant impact on the file sizes of the exported PNGs.
I usually compress my PNGs exported from TVPaint at the default setting of
5.
- TVPaint PNG_export_settings.png (38.39 KiB) Viewed 13907 times
I know you know this , mox, but for the benefit of anyone on this forum who is reading this discussion in the future, when exporting PNGs from TVPaint the export setting of
1 is the
fastest export speed , but the file sizes are
larger. The PNG export setting of
10 is slowest for export , but the file sizes are much
smaller. The middle setting of
5 is a reasonably fast export time and and the file sizes are not too large, so I usually just leave it set on 5. One would expect that using the middle setting of
5 would mean that the file size would be half-way between the size of the fastest setting of
1 and the slowest setting of
10 , but in my experience 5 tends to be closer to 10 in file size , while the PNG export setting of 1 makes a significantly larger file size. For example, I just now made a test of exporting a single image: at the setting of 1 (fastest export) the file size is
33.2 MB . At the setting of 10 (slowest export) the file size is only
3.5 MB (9.5x smaller ). At the export setting of 5 the file size is
4.3 MB. (about 7.7x smaller than the largest size of 33.2 MB).
So, PNGs exported at the fastest export setting of
1 will be 9x - to - 10x larger than PNGs exported at the slowest export setting of
10 .
mox wrote: ↑21 Jun 2023, 10:03
Does the guy say at one point what kind of compression he uses for PNGs? I don't see any info about it in the video.
That is a question worth asking . I plan to email him to ask about that.
This is why until this point I have continued to use PNGs because if I export PNGs from TVPaint at the setting of 5 (medium) or 10 (slow) the file sizes are smaller than uncompressed LZW (lossless) TIFF files. In comparison to the PNG file sizes for my test export , the TIFF file is
6.3 MB compared to 3.5 MB (PNG export setting 10) or 4.3 MB (PNG export setting of 5). The same image exported as TGA was
12.3 MB.
But now that I am delving into this a bit deeper by carefully reading the articles by Chris Zwar, I wonder if even with the smaller file sizes if perhaps the PNG file format is not optimal for use in After Effects ? If using TIFF files speeds up the rendering process in After Effects as Chris Zwar suggests, then maybe better to switch to TIFF.
However, overall image quality is an important factor, so if lossless PNGs result in a sharper image quality and better color fidelity , I would tend to stick with using PNGs even if render times are slower. But if TIFF (which is also lossless) gets the same results as PNG and has faster render times from After Effects, I will switch to TIFF. (or perhaps EXR , if TVPaint adds EXR as an export option). Chris Zwar's tests indicate that using MOV files with Apple ProRes 4444 compression are even faster than using TIFF image sequences, but as I mentioned in my previous post I have experienced some odd behavior from MOV files exported from TVPaint using FFMpeg ProRes codec. Often I have noticed animated elements with transparent edges such as soft shadows, glows, or gradients will tend to have a visible "edge" around the transparent area when they are imported into After Effects. That ugly, visible edge is not visible if the same elements are imported as transparent PNGs. Animated elements that have a hard, opaque edge seem to do fine as MOV files exported with ProRes compression codec.
