Image Number 5 for United States Patent #8495525.
A library of waivable images with corresponding waiver constraints is generated. Each of the waivable images is an image of a region of a reference design layout including a raw error as determined by an optical rule checks (ORC) program and does not require a correction for printability on a photoresist layer. A list of raw errors is generated by running the ORC program on a target design layout. Error region images corresponding to the list of raw errors are generated by selecting a region of the target design layout around points corresponding to the raw errors. A list of matches between the library of waivable images and the error region images is generated. By removing a subset of raw errors that correspond to a subset of the list of matches from the list of raw errors, a list of real errors is generated.