A computer-implemented method for determining striation properties of fatigue striations on a sample surface of a part, the method comprising: 1.1 with a scanning microscope device, imaging the sample surface so as to obtain a sample image potentially containing the fatigue striations; 1.2 with an image patch selecting device, selecting a sample image patch potentially containing the fatigue striations from the sample image for further processing; 1.3 with a pre-processing device, normalizing the sample image patch by performing any of the following operations on the sample image patch: - a Gaussian filter operation; and/or - a histogram equalization; and/or - an image binarization and subsequent morphological operation, such as erosion, dilation or skeleton-operations; and/or - a frequency domain self-filtering operation; and/or - a window operation; and/or - a normalization operation to normalize intensity values to a fixed range; and enhancing line-like regular structures contained in the sample image patch so as to obtain a normalized image patch; 1.4 with an autocorrelation device, determining the autocorrelation of the normalized image patch so as to obtain an autocorrelation image patch; 1.5 with a Radon transform device, performing a Radon transform of the autocorrelation image patch so as to obtain a transformed image patch; 1.6 with a frequency analysis device, performing a spectral analysis of the transformed image patch and determining a power spectrum of the transformed image patch; 1.7 with a striation property determining device, determining, from the power spectrum, at least one striation property that is suitable to indicate the presence of fatigue striations in the sample image patch. 1.1 with a scanning microscope device, imaging the sample surface so as to obtain a sample image potentially containing the fatigue striations; 1.2 with an image patch selecting device, selecting a sample image patch potentially containing the fatigue striations from the sample image for further processing; 1.3 with a pre-processing device, normalizing the sample image patch by performing any of the following operations on the sample image patch: - a Gaussian filter operation; and/or - a histogram equalization; and/or - an image binarization and subsequent morphological operation, such as erosion, dilation or skeleton-operations; and/or - a frequency domain self-filtering operation; and/or - a window operation; and/or - a normalization operation to normalize intensity values to a fixed range; and enhancing line-like regular structures contained in the sample image patch so as to obtain a normalized image patch; - a Gaussian filter operation; and/or - a histogram equalization; and/or - an image binarization and subsequent morphological operation, such as erosion, dilation or skeleton-operations; and/or - a frequency domain self-filtering operation; and/or - a window operation; and/or - a normalization operation to normalize intensity values to a fixed range; 1.4 with an autocorrelation device, determining the autocorrelation of the normalized image patch so as to obtain an autocorrelation image patch; 1.5 with a Radon transform device, performing a Radon transform of the autocorrelation image patch so as to obtain a transformed image patch; 1.6 with a frequency analysis device, performing a spectral analysis of the transformed image patch and determining a power spectrum of the transformed image patch; 1.7 with a striation property determining device, determining, from the power spectrum, at least one striation property that is suitable to indicate the presence of fatigue striations in the sample image patch.