1. A method to facilitate auto-alignment of images for defect inspection and defect analysis, comprising: receiving a reference image and a test image; creating a horizontal cut line across the reference image; choosing a vertical feature on the reference image with a specified width along the horizontal cut line; determining that the vertical feature substantially maintains the specified width over a specified range above and below the horizontal cut line; locating a corresponding vertical feature on the test image; creating a vertical cut line across the reference image; choosing a horizontal feature on the reference image with the specified width along the vertical cut line; determining that the horizontal feature substantially maintains the specified width over a specified range left and right of the vertical cut line; locating a corresponding horizontal feature on the test image; and aligning the reference image and the test image by aligning the vertical feature on the reference image with the corresponding vertical feature on the test image and aligning the horizontal feature on the reference image with the corresponding horizontal feature on the test image.