1. A computer-implemented method for detecting a camera being out-of-focus, the method comprising: receiving a video frame; performing a pyramid image decomposition on the video frame, the pyramid image decomposition being performed using a multi-level wavelet transform; determining sharp edge areas, candidate blurry edge areas, and blurry edge areas in each level of the pyramid image decomposition, wherein the sharp edge areas are areas including edges with either a Dirac or an Astep structure; determining a sharpness value based on at least the sharp edge areas, the sharpness value indicating an overall sharpness of the video frame; determining a blurriness value based on at least the blurry edge areas and the candidate blurry edge areas, the blurriness value indicating an overall blurriness of the video frame; and determining, based on the sharpness value and the blurriness value, whether the video frame is out-of-focus.