‘stitched’ scans

The maximum single scan achievable on the CHD Cruse scanner is 1.5m x 1m. However, larger objects can be imaged by ‘stitching’ several individual images together. In order to do this a large object is scanned in sections with an overlap of at least 20% in each section.

Stitching software works by matching exactly common colour values for pixels. Hence objects where there are lots of colour ‘texture’ in the object stitch better than ones with little variety in tone.

Limits

• If the object is rigid, as with a canvas on a stretcher, then an object with maximum dimensions of 1.8m x 2.0m is possible.

• If it can be rolled then a much larger object can be accommodated.

• If the roll is less than 1m wide, then in theory an infinite length can be scanned. Sections of 1m can be unrolled and scanned with a 20% overlap.

• If the roll is more than than 1m wide and less than 3m long then the limit is the diameter of the roll above the baseboard. A maximum roll diameter of 25cm is the limiting factor.