test camera capabilities

modules/input/video

@@ -204,6 +204,8 @@ function start_video() {
          mod.video.srcObject = stream
          mod.video.onloadedmetadata = function(e) {
             mod.video.play()
+            var track = stream.getVideoTracks()[0]
+            console.log(track.getCapabilities())
             capture_video()
             }
          })

modules/processes/scan/line

@@ -84,14 +84,26 @@ var interface = function(div){
       div.appendChild(input)
       mod.width = input
    //
-   // start scan button
+   // background scan button
    //
    div.appendChild(document.createElement('br'))
    div.appendChild(document.createTextNode(' '))
    var btn = document.createElement('button')
       btn.style.padding = mods.ui.padding
       btn.style.margin = 1
-      btn.appendChild(document.createTextNode('start scan'))
+      btn.appendChild(document.createTextNode('background scan'))
+      btn.addEventListener('click',function(){
+         linescan()
+         })
+      div.appendChild(btn)
+   //
+   // object scan button
+   //
+   div.appendChild(document.createTextNode(' '))
+   var btn = document.createElement('button')
+      btn.style.padding = mods.ui.padding
+      btn.style.margin = 1
+      btn.appendChild(document.createTextNode('object scan'))
       btn.addEventListener('click',function(){
          linescan()
          })