A system and a method include a display and a control unit including one or more processors configured to create a filter, and apply the filter to spectrum graphs of digital images to create modified spectrum graphs of the digital images. The digital images being digital charts including grid lines and data lines. The control unit is configured to convert the modified spectrum graphs to modified digital images. The modified digital images being modified digital charts that include the data lines, and at least some of the grid lines are removed from the digital charts of the digital images.