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idia-astro / iDaVIE

immersive Data Visualisation Interactive Explorer (iDaVIE). The specific goal of iDaVIE is to enable the interrogation of 3D data using virtual reality technology.
https://idavie.readthedocs.io/
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automatic rescaling after select crop #112

Closed vdhulst closed 1 month ago

vdhulst commented 4 years ago

when I select a region in the data cube and then crop to that selection the data within the selected crop appears to be rescaled. As a result the view of the data is sometimes completely different from the view in the original cube. This is especially annoying after one has carefully selected a min and max display range in the full cube and then starts exploring the selected region. I would prefer to have to set the min/max manually in the selected crop, as it is very easy to do with the voice commands.

veggiesaurus commented 4 years ago

The thresholds aren't actually changing, but what's happening is that the noise and peaks are adjusting because you're going from a downsampled cube (using the mean) to a full resolution cube.

I think the only real way to solve this is to downsample using max instead of mean, at least when using maximum intensity projection rendering (the default).

The current approach is better suited to average intensity projection, since it (somewhat) preserves the mean value of a ray traversing the cube.

vdhulst commented 4 years ago

Yes I noticed the connection width the downsampling and now understand the issue. It is not a problem to rescale manually, especially with the voice commands. Main point was the change in appearance, which by the way depends the range of intensities in the cube one views. Maybe leave for now as other issues are more important.

Pietersielie commented 1 month ago

Closed at some point, see the config options for maxModeDownsampling and the voice commands sampling mode maximum and sampling mode average.