how to convert input type file into an icon

1<div class="image-upload">
2      <label for="file-input">
3        <img id="previewImg" src="https://icon-library.net/images/upload-photo-icon/upload-photo-icon-21.jpg" style="width: 100px; height: 100px;" />
4      </label>
5
6      <input id="file-input" type="file" onchange="previewFile(this);" style="display: none;" />
7    </div>
8
9
10
11
12<script>
13        function previewFile(input){
14            var file = $("input[type=file]").get(0).files[0];
15
16            if(file){
17              var reader = new FileReader();
18
19              reader.onload = function(){
20                  $("#previewImg").attr("src", reader.result);
21              }
22
23              reader.readAsDataURL(file);
24            }
25        }
26    </script>
27