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• These items can be purchased for reasonable prices, and will become standard computer components in the near future.
14.6 IMAGE PREPROCESSING
•Images are basically a set of pixels that are often less than a perfect image representation. By preprocessing, some unwanted variations/noise can be reduced, and desired features enhanced.
•Some sources of image variation/noise,
-electronic noise - this can be reduced by designing for a higher Signal to Noise Ratio (SNR).
-lighting variations cause inconsistent lighting across an image.
-equipment defects - these cause artifacts that are always present, such as stripes, or pixels stuck off or on.
14.7 FILTERING
•Filtering techniques can be applied,
-thresholding
-laplace filtering
-fourier filters
-convolution
-histograms
-neighborhood averaging