title: How to precisely generate a similarity measure between line charts with similar features
body: <p>I am trying to compare one line chart to a number of other line charts and I would like to find all charts that are similar with regard to their significant markers' positions.</p>
  
  <p><img src="https://i.stack.imgur.com/nwzJ4.png" alt="enter image description here"></p>
  
  <p>I already tried a few solutions that involve correlating the graphs and then getting a distance measure (cost of total similarity between two charts). So the lower the measure, the higher the similarity. </p>
  
  <p><a href="https://stackoverflow.com/questions/27571511/what-is-a-good-way-to-get-a-similarity-measure-of-two-images-that-contain-a-grap">Other SO question</a></p>
  
  <p>The above works quite good but not in all cases. For example, if two charts share 90% percent of features but there is 10% of the features such as strong peaks. Then those two charts are not really similar.</p>
  
  <p>Currently, I am normalizing each graph and then I use a Shi-Tomasi Corner Detector to mark interesting signal points in each graph.</p>
  
  <p>Is there a different approach, that can take "significant" peaks into account?</p>
  
  <p>As requested!</p>
  
  <p><img src="https://i.stack.imgur.com/RFl1i.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/gBvHl.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/cbUFZ.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/nIq8Z.png" alt="enter image description here"></p>