Export correct RGB values from Color Map with SaveScreenshot()

ParaView Support
1

Dear Support Team,

I am currently using Paraview 5.6.0 to reconstruct the pressure field from a screenshot of a Slice filter. The screenshot is exported with SaveScreenshot().

The screenshots have been exported with the X Ray colormap, which has the same linear behaviour for all three RGB channels, so it should’t be difficult to read the exported .png pictures and reverse engineer the pressure at that pixel depending on the RGB value interpolation

However, I noticed the following problem: exporting a picture from paraview with the SaveScreenshot() function does not preserve the RGB channels that are set up in the ColorMap. I have also tried with a different Color Map (e.g. jet), and the value that is set for the red channel in the default colormap [0.5, 1, 1] gets somehow converted to another level of red ( I am double checking this by reading the image in different softwares). My guess is that it might be connected to the light rendering.

My questions are 1) if you know why this might be happening, and 2) if there is an alternative way to export the RGB Values on every pixel according to the actual ColorMap??

Thank you in advance for your support, please let me know if there is some missing information,

best regards,

Raffaele

2

Hi @Raffaele_Colombi

Please update to the last release of ParaView, 5.10.1.

Best,

3

What Mathieu said! 5.6.0 is so ancient…

I believe what you are looking for is found on the Properties tab. Click the “Advanced” button, the little gear to the right of the search box. Now, unclick “Map Scalars”.

4

Hello,

thank you for getting back to me so quickly. Unfortunately I cannot update to a newer version because my sample scripting has to be compatible with the version installed on the cluster (why they don’t update is also beyond my understanding).
I later realized that this difference is probably related to the lighting used by the renderer. Are there some settings in lighting that would remove shading or other such effect that can effect the true color of a colored surface according to the ColorMap?