An approach for fatigue crack detection is described. In one example, a first image of a structure is captured at a first time, and a second image of the structure is captured at a second time. A feature-based image registration is performed to align features of the second image with the first image, and an intensity-based image registration is performed to further align features of the second image with the first image. A registration error map is determined by performing a pixel-by-pixel intensity comparison of the first image and the second image. Additionally, an edge-aware noise reduction process can be performed on the registration error map. The registration error map can be referenced to identify certain fatigue cracks in the structure.