title: Need explanation about Filter Gabor
body: <p>I am studying a finger recognition system.
  There are so many algorithms.
  If I write it with my own words, one of the algorithm (especially about minutiae-based binarized image) will consist of the following steps:</p>
  
  <p>STEP1. Segmentation. This step to separate the foreground from the background. Most done with Thresholding.</p>
  
  <p>STEP2. Normalization. This step to distribute the intensity. Most done with Histogram Equalization.</p>
  
  <p>STEP3. Filtering. This step to fill the gap along the ridge. Also to enhance the contrast between the ridge and the valley. Most done with Gabor Filter.</p>
  
  <p>STEP4. Binarization. This step to binarize the filtered image.</p>
  
  <p>STEP5. Thinning. This step to skeletonize the binarized image.</p>
  
  <p>STEP6. Minutiae Extraction. This step to extract minutiae (ridge ending and ridge bifurcation) from the skeletonized image.</p>
  
  <p>STEP7. Minutiae Matching. This step to match between extracted minutiae template and extracted minutiae input.</p>
  
  <p>I still not understand about STEP3 especially related Gabor Filter.
  I really need step-by-step explanation about Gabor Filter.
  Can you help me?</p>