Method of printing foreground and background images with overlapping printhead segments

Summary

A pagewide inkjet that stitches two printheads together never produces a perfect join. The seam-carving approach in 10,293,622 finds a wandering path that hides through low-density pixels — which works well on photographs but treats every layer of an image the same way. Real print jobs mix layers: a piece of black text sitting on top of a continuous-tone background. Those layers have different stitching needs.

For continuous-tone backgrounds the soft fade of older feathering approaches still has the right physics — the eye averages adjacent pixels and a gentle blend hides best. For sharp typography or graphics, that same fade is a disaster: alternating tiny segments of a letter between two slightly misaligned heads turns the edge ragged.

This patent extends seam carving with a layered stitching strategy. The image is decomposed into foreground (text, graphics, sharp content) and background (photographic, contone) layers, and each layer is stitched the way it should be: a carved butt-seam through the foreground keeps each character whole under a single head, while a soft feathered transition handles the background where blending works well. The combination is targeted at the real workload of labels, brochures, and packaging — text laid over photographic backgrounds — where neither stitching method alone gives an acceptable result.