Set a range to the spectral axis to generate a pv image (backend)

[kswang1029]

user feedback from v3 beta test

With v3 release, a PV image is generated using the entire spectral axis along the pv cut. The enhancement is to be able to set a spectral range to generate a pv image. This is helpful to focus on a certain line feature in the cube.

The companion frontend feature is CARTAvis/carta-frontend#1952

[pford]

Added spectral_range (channel min and max IntBounds) to PvRequest message, as in MomentRequest message.
carta-protobuf branch pv_spectral_range

[kswang1029]

@pford regarding #1175 do you think we can also modify the PvRequest message to include the axes definition too? Users would like to have the freedom to set x as spatial and y as spectral or x as spectral and y as spatial.

[pford]

@pford regarding #1175 do you think we can also modify the PvRequest message to include the axes definition too? Users would like to have the freedom to set x as spatial and y as spectral or x as spectral and y as spatial.

Yes, if that would be easier for the frontend development and testing.

[kswang1029]

@pford regarding #1175 do you think we can also modify the PvRequest message to include the axes definition too? Users would like to have the freedom to set x as spatial and y as spectral or x as spectral and y as spatial.

Yes, if that would be easier for the frontend development and testing.

@pford ok let's do this. @crocka needs it for CARTAvis/carta-frontend#1950

[crocka]

@pford regarding #1175 do you think we can also modify the PvRequest message to include the axes definition too? Users would like to have the freedom to set x as spatial and y as spectral or x as spectral and y as spatial.

Yes, if that would be easier for the frontend development and testing.

@pford ok let's do this. @crocka needs it for CARTAvis/carta-frontend#1950

We have three options for x and y axis (spectral, spatial, distance). Do we add two fields to the PvRequest message (string xAxis and string yAxis)?

[kswang1029]

@pford regarding #1175 do you think we can also modify the PvRequest message to include the axes definition too? Users would like to have the freedom to set x as spatial and y as spectral or x as spectral and y as spatial.

Yes, if that would be easier for the frontend development and testing.

@pford ok let's do this. @crocka needs it for CARTAvis/carta-frontend#1950

We have three options for x and y axis (spectral, spatial, distance). Do we add two fields to the PvRequest message (string xAxis and string yAxis)?

@crocka we should just use spatial and spectral for users. As the spatial is offset or distance you will be able tell from the image header provided from the backend.