fix left right icon and canavs center on label annotation

public/self/js/Director/detection.js

@@ -2644,8 +2644,8 @@ function setPage(pageData,pageSize){
  
     canvas = document.getElementById("myCanvas");
     context = canvas.getContext("2d");
-    var maxWidth  = document.getElementById("showPic").offsetWidth;
-    var maxHeight = document.getElementById("showPic").offsetHeight-100;
+    var maxWidth  = document.getElementById("labelwin").offsetWidth;
+    var maxHeight = document.getElementById("labelwin").offsetHeight-100;
     canvas.width = maxWidth;//document.getElementById("tool0").offsetWidth;
     canvas.height = maxHeight;//document.getElementById("tool0").offsetWidth/1280*720;
 
@@ -2657,8 +2657,8 @@ function setPage(pageData,pageSize){
 
     canvas    = document.getElementById("myCanvas");
     context   = canvas.getContext("2d");
-    maxWidth  = document.getElementById("showPic").offsetWidth;
-    maxHeight = document.getElementById("showPic").offsetHeight-100;
+    maxWidth  = document.getElementById("labelwin").offsetWidth;
+    maxHeight = document.getElementById("labelwin").offsetHeight-100;
     canvas.width = maxWidth;
     canvas.height = maxHeight;