Typical diamond anvil cell data for multigrain XRD has to be pre-processed and cleaned.

Elements that should be addressed are:

• shadows from the tungsten carbide diamond seats,
• single-crystal diffraction spots from the diamond anvils,
• additional diffraction from very small grains (powder rings), pressure media, etc.

Processing of the single-crystal diffraction spots from the diamond anvils is performed using the timelessDiamondSpotRemoval script, which is part of the TIMEleSS tools.

The idea is that diamond diffraction is

• very intense (often saturate the detector),
• extends over many pixels (in X and Y) and in ω.

The timelessDiamondSpotRemoval script does the following - reduce the resolution of the image, to make it blur and get rid of the small features, - apply a median filter on the reduced image to clear out small diffraction spots, which are probably originating from the sample, - detect diamond diffraction spots based on a threshold in intensity, - create a mask based on the detected diamond diffraction spots, - expand the mask in X, Y, and ω to account for the fact that the real diamond diffraction spots are wider and appear over wider omega ranges than detected by the above steps.

In addition, you can define a disk, at the center of the image, in which nothing should be removed. This option is for samples with very intense diffraction spots on the inner rings which could be confused with diamond spots based on intensity criteria.