The probe profile

"Jimmy Volatile" a Lcms user, suggested to incorporate test plots for the regression tests. In this way external apps using lcms could check if all is working as expected. I think this is a good idea, and maybe it is also feasible (all depends on the schedule).

An interesting check would be to use the ICC probe profile. This comes from the ICC site:

"The 'probe profile' (Probev1_ICCv2.icc) is syntactically a v2 ICC output device ('prtr') profile, and can be used in a workflow wherever such a profile is required. The color space of this profile is CMYK, and its PCS is Lab.

Colors processed via this profile are deliberately distorted in a systematic way, to enable visual determination of the rendering intent used when rendering ("BToA" or PCS to device transforms) and when proofing ("AToB" or device to PCS transforms). This is useful, in cases when color-management-aware software does not document the behavior."

Here are some examples