zero value always shown as black even for signed int source

[martinschorb]

Hi,

I have a source (N5) which is normalized signed int data. BDV displays it just fine and also contrast adjustment works. However, the zero value is always mapped to appear as black, even though the minimum selector is set to a negative value. This leads to black contour lines in the displayed data.

[martinschorb]

[tpietzsch]

Can you share a test data set to reproduce? Also, is this in vanilla BDV or MoBIE Viewer or something similar? (It could be that this is some custom source blending code)

[martinschorb]

Hi,

yes, you are right:

• vanilla BDV: manually adjusting levels to -127/+127 gives good results
• BDV-Playground : -- original BDV - correct behaviour, -- BDVPG mixed projector - contour lines -- BDVPG Sum projector - contour lines -- BDVPG Average projector - contour lines
• MoBIE - contour lines

I guess @NicoKiaru , this one's for you then...

[martinschorb]

Test data:

BDV_testzero.zip

supposed to show nice gradients from -20 to +20 intensity.

[NicoKiaru]

Mapping 'zero' as black or actually transparent has been a trick used to enable transparency, but I've now added a way to handle better transparency, and also 'layers', ( see https://github.com/NicoKiaru/bigdataviewer-playground-display). Also, the 'default' bdv used in bdv-playground can now be set by the user. It can be the vanilla one, the mobie one, the 'transparent' one, the biop one. Each of these have different features enabled by default. If @tischi wants to provide a different one, he can also do this on mobie's repo.

All of this is not currently on the update site of bdv-pg. This week I hope to release it, and I think @tischi is ready for it ?

Cheers

[tischi]

This week I hope to release it, and I think @tischi is ready for it ?

I think I tried it and it worked for me.