# Stained Glass

The stained glass monogram on the Basics page to which we subjected various effects does not particularly invoke the feeling of stained glass. It belies its origins: an export bitmap from a Structured Vector Graphics original, Reeking of Perfection, its lines are too clean, the colors too unvarying throughout. Compare it to an original example, the 15th Century specimen on the left from Chartres Cathedral. Color is hardly uniform. Indeed, it is deliberately otherwise. There are bits of dirt. The glass itself has uneven thickness. the soldering on the lead cames forms blobs and soft curves. Up close, there are no sharp angles.

Here, we filter our CGI-clean monogram, borrowing heavily from the -bandpass command as it extracts very low frequency image components. The effect is liquid-like, aping the uneven thickness of a hand-shaped viscous liquid.

We harness the -bandpass command for two purposes, one to manufacture a vector field to warp the artwork, invoking a handmade look, and another to introduce color and luminance variations. Details follow.

## Pipeline

In the following, we have broken the overall command into segments and indicate continuance with ellipses (...). These markers are not operational parts of the command, so if one is copying these into command shells, the ellipses should be left behind.