Now that we know how to read images and webcam streams, we are going to explain some more basic image processing functions and how to create basic controls to change their parameters. In this section, we are going to create a web page that allows users to choose a filter to apply to a loaded image. The filters that we are going to apply are threshold, Gaussian blur, canny, and histogram equalization. Each filter or algorithm takes different input parameters, which we are going to add to user interfaces to control each one.
First, we are going to generate the required elements to create our application. As the user has the ability to choose the algorithm/filter to apply, we are going to add a select HTML element with the possible options to choose from:
<select class="form-control" id="filter">
<option value...
