DATA PROCESSING DEVICE AND METHOD, CHARGED PARTICLE ASSESSMENT SYSTEM AND METHOD

A data processing device for detecting defects in sample images generated by a charged particle assessment system, the device comprising: an input module, a filter module, a reference image module and a comparator. The input module is configured to receive a sample image from the charged particle assessment system. The filter module is configured to apply a filter to the sample image to generate a filtered sample image. The reference image module is configured to provide a reference image based on one or more source images. The comparator is configured to compare the filtered sample image to the reference image so as to detect defects in the sample image.