Image-to-design alignment for images with color or other variations suitable for real time applications

A non-transitory computer-readable medium, storing program instructions executable on a computer system for performing a computer-implemented method for determining information for a specimen, wherein the computer-implemented method comprises:

• acquiring images of the specimen generated by an imaging subsystem;
• modifying one or more parameters of a model based on one or more of variation in one or more parameters of the imaging subsystem and variation in one or more process conditions used to fabricate the specimen, wherein the model is configured for generating a rendered image for an alignment target on the specimen from information for a design of the alignment target, and wherein the rendered image is a simulation of the images of the alignment target on the specimen generated by the imaging subsystem;
• subsequent to said modifying, generating an additional rendered image for the alignment target by inputting the information for the design of the alignment target into the model;
• aligning the additional rendered image to at least one of the images of the alignment target generated by the imaging subsystem;
• and
• determining information for the specimen based on results of said aligning, wherein said acquiring, modifying, generating, aligning, and determining are performed by the computer system.

A method for determining information for a specimen, comprising:

• acquiring images of the specimen generated by an imaging subsystem;
• modifying one or more parameters of a model based on one or more of variation in one or more parameters of the imaging subsystem and variation in one or more process conditions used to fabricate the specimen, wherein the model is configured for generating a rendered image for an alignment target on the specimen from information for a design of the alignment target, and wherein the rendered image is a simulation of the images of the alignment target on the specimen generated by the imaging subsystem;
• subsequent to said modifying, generating an additional rendered image for the alignment target by inputting the information for the design of the alignment target into the model;
• aligning the additional rendered image to at least one of the images of the alignment target generated by the imaging subsystem;
• and
• determining information for the specimen based on results of said aligning, wherein said acquiring, modifying, generating, aligning, and determining are performed by a computer subsystem coupled to the imaging subsystem.