JCh values are computed on a pixel-by-pixel basis. Each parameter, J, C, and h, is scaled to 0-255 and represented in the three images. Lighter pixels represent higher values.

Another example.

Matching Experiment Results

Before matching, these two samples have the same RGB values but appear different because of the different intensities of the background.

After matching, the two samples have different RGB values but the same JCH values. Do they appear the same? They should according to the CIECAM97 color model.