EE4206/EE5806 The high and low frequency elements of an image
1. Low frequency parts of images are those where the colors change SLOWLY, while HIGH frequency parts correspond to EDGES and other SHARP changes in color.
2. Low pass filters tend to BLUR images as the high frequency elements are REMOVED, while high pass filters can be used to sharpen EDGES and locate the boundaries of an object in a digital image.
Fundamentals of Digital Signal Processing by Joyce Van de Vegte