1. An image-based decision method using a multilevel Chain-And-Tree model comprises the following steps: (a) Input at least one reference CAT model basis selected from the set consisting of inspection specification, learning image, and application knowledge; (b) Create a reference CAT model using at least one reference CAT model basis; (c) Input a new image; (d) Create a result CAT model; (e) Compare the reference CAT model and result CAT model to output a measurement result.