Is Turbo-JPEG needed?

[lassoan]

I got a message that turbo-jpeg was not available. After installing (from https://github.com/libjpeg-turbo/libjpeg-turbo/releases), refresh rate seem to have been improved. If turbo-jpeg cannot be bundled it would be good to at least describe it in the installation steps.

[Thibault-Pelletier]

Turbo-JPEG is not needed but provides a nice speed up (x6 compared to VTK JPEG conversion).
Other steps can further improve rendering speed such as disabling V-Sync.

As both optimizations need to be done on the server and cannot be packaged they will need to be properly documented.

[Thibault-Pelletier]

@lassoan for information, a performance fix was pushed to trame-rca which should further improve the performances.

[Thibault-Pelletier]

Just a quick follow up on this issue, VTK also uses lib JPEG Turbo under the hood for JPEG conversion.
The current CI doesn't enable the right compile flags resulting in the performance differences between the two conversions.
Discussions are in progress to properly activate the optimization flags on the CI. Once this is properly done, we will default to VTK's implementation.

[lassoan]

Thanks for the update, this will simplify things!

[Thibault-Pelletier]

Quick follow up on this issue, we are currently looking into integrating VTKStreaming into trame-rca which should improve remote rendering a lot in trame-slicer applications.

We will be making vtkstreaming pip installable first and look at the integration in the next few months

[lassoan]

I've tested again with the default example (that did not install turbo-jpeg) and the rendering quite choppy, considering everything was running local machine. Before I would start advertising slicer-trame widely, we need to have faster streaming with default settings, as I would not want a lot of people trying this and leaving with the disappointment that it is just too slow.