Question: Suppose there is a frame with some image.I want to display only those parts which have pixel intensity above 120 or 130. How can I do that with OpenCv ? Is there any commands to do so?
Then i need to set those parts to some intensity of 190.

Answer: 
This should do the trick for you.

```
$('#dropdownID').val("Value to be selected");

```
I guess there are multiple ways to do it. The easiest way:

```
$("#dropdownID").val("dropdownValue");

```

This will work just fine, but it won't fire the change event if you have in any case. To resolve it, use it like below:

```
$("#dropdownID").val("dropdownValue").change();

```

Other possible ways:

```
$("#dropdownID").attr('selected','selected');

$("#dropdownID").prop('selected', true);

```