The detection of quasi-periodic patterns, such as those found in clustered-dot halftones, can be efficiently achieved by searching for strong peaks in the frequency domain. In this paper, we quantify four factors that contribute to the attenuation of those characteristic peaks related to mobile hand-held image capture. These include MTF, halftone cluster size, blur, and contrast. We derive the expected theoretical attenuation for each of these factors, and then compare these with experimentally measured results from mobile captured images of test prints.