[auojznlt] QR ink bleed compensation

Modify a digital image of a QR code, yet to be printed, to compensate for an expectation that ink from dark areas will bleed into white areas.

First, divide a black block into 9 regions sort of like Android NinePatch.  Color the center subblock black.  The orthogonal side subblocks are colored the same color as the center of the neighboring block.  The corner subblocks are colored black only if both neighboring subblocks within this block are also black.  For example, the southwest subblock is black only if the south and west subblocks are black.

Two black blocks touching only at a corner will become disconnected (but reconnect after ink bleed).

Previous work on halftoning might be applicable.