Image scanning apparatus and methods of operating an image scanning apparatus

An image scanning apparatus comprising a line scan detector and configured to:

• image a surface of an object mounted in the image scanning apparatus in a plurality of swathes, wherein each swathe is formed by a group of scan lines, each scan line being acquired using the scan line detector from a respective elongate region of the surface of the object extending in a scan width direction, wherein each group of scan lines is acquired whilst the object is moved relative to the scan line detector in a scan length direction;
• use at least one scan line, acquired from a surface of a first object mounted in the image scanning apparatus using the scan line detector, to obtain at least one measure indicating that the surface of the first object is uneven in the scan width direction relative to an imaging plane of the image scanning apparatus;
• set a swathe width value for use in acquiring at least one swathe from a surface of a second object mounted in the image scanning apparatus, wherein the swathe width value is set based on the at least one measure and configured so as to keep each swathe acquired from the surface of the second object substantially in focus across its width in the scan width direction;
• acquire at least one swathe from the surface of the second object using the scan line detector, wherein the at least one swathe acquired from the surface of the second object has a width in the scan width direction that corresponds to the swathe width value set based on the at least one measure.

A non-transitory computer-readable medium having computer-executable instructions which, when executed by one or more processors, cause an image scanning apparatus to perform a method;

• wherein the image scanning apparatus includes a line scan detector and is configured to image a surface of an object mounted in the image scanning apparatus in a plurality of swathes, wherein each swathe is formed by a group of scan lines, each scan line being acquired using the scan line detector from a respective elongate region of the surface of the object extending in a scan width direction, wherein each group of scan lines is acquired whilst the object is moved relative to the scan line detector in a scan length direction;
• and
• wherein the method includes:
• using at least one scan line, acquired from a surface of a first object mounted in the image scanning apparatus using the scan line detector, to obtain at least one measure indicating that the surface of the first object is uneven or tilted in the scan width direction relative to an imaging plane of the image scanning apparatus,
• setting a swathe width value for use in acquiring at least one swathe from a surface of a second object mounted in the image scanning apparatus, wherein the swathe width value is set based on the at least one measure and configured so as to keep each swathe acquired from the surface of the second object substantially in focus across its width in the scan width direction, and
• acquiring at least one swathe from the surface of the second object using the scan line detector, wherein the at least one swathe acquired from the surface of the second object has a width in the scan width direction that corresponds to the swathe width value set based on the at least one measure.