Add image format pattern.

("borrowed" from RenderImage)

src/core/operations/ParseQRCode.mjs

@@ -33,6 +33,14 @@ class ParseQRCode extends Operation {
                 "value": false
             }
         ];
+        this.patterns = [
+            {
+                "match": "^(?:\\xff\\xd8\\xff|\\x89\\x50\\x4e\\x47|\\x47\\x49\\x46|.{8}\\x57\\x45\\x42\\x50|\\x42\\x4d)",
+                "flags": "",
+                "args": [false],
+                "useful": true
+            }
+        ];
     }
 
     /**