No option for interpolation in Rotate and Scale filter

[radzo73]

What is your operating system?
Windows 10

What is your Shotcut version?
20.09.13, 64-bit

Can you repeat the problem? If so, what are the steps?

1. Create a generic, video project (720p is fine), and load in an image.
2. Resize the image so that it’s aspect ratio is 1:1 (in my case, 690 x 690)
3. Export the video (in my case, as a .webm for transparency), and set Export>Advanced>Interpolation to Nearest Neighbor
4. Cry that your image that you basically moved around now has a bunch of artifacts instead of crisp lines that you would get from Nearest Neighbor

[shotcut]

Rotate and Scale is discontinued, but the new Size, Position & Rotate uses the same functions in the engine. But this bug is not be accepted since it is about a filter that is no longer supported. The new filter’s interpolation does follow the interpolation setting in Export.

Step 2 is confusing because it already a 1:1 aspect ratio when you open the image. Are you simply changing the size to 690x690 as I have shown below?

Another option is to simply set Size mode to Fit. This will not upscale the image to fill the rectangle (only downscale if needed).

Here is a frame exported from the webm image, and I do not see a lot of artifacts.

Here it is zoomed in compared to the original:

If you want it to be sharper then you can change export to not output with subsampled chroma, but it will not be perfect. This filter does not offer pixel grid fitting.

[radzo73]

Firstly, thanks for the help!
Secondly, you would think that a 690 x 690 image basically translated would look the same as it was when imported into the project.
Thirdly, even when exporting and viewing with Nearest Neighbor (described in the docs as “no interpolation”), I’m still getting some interpolation. Why?

[shotcut]

Here is the result of Size, Position & Rotate with Size mode = Fit exported using Quicktime Animation, played in VLC, snapshot frame:

and zoomed in in GIMP

[shotcut]

@radzo73

Why?

subsampled chroma in the export; VPx only offers YUV 4:2:0. Sub-sampled chroma forces the viewer/player to upscale the chroma planes, and that is typically interpolated.
See related Color on edges of text/masks/etc

Here it is with Size mode = Fill, Export > Quicktime Animation > Interpolation = Nearest Neighbor:

Here it is when I do upscale it with the filter and export without interpolation as ARGB: