A system and method for determining high frequency content in an analog image source. A method comprises creating a histogram of the image, and selecting a portion of the image based on the histogram. The histogram comprises a first number of horizontal bins and a second number of vertical bins, with each bin having an associated counter for maintaining a count of pixel differences of pixels in a portion of the image corresponding to the bin that exceed a threshold. The portion of the image selected corresponds to a portion of the histogram having a high pixel difference count relative to other portions of the histogram.