Some trouble removing small objects from an image in Simulink

Hello I understand the question I'm posing can be answered in numerous way's so let me give some detail. The image I'm working with is that of two objects(A cloud and the sun). I want to remove the noise so that are only 2 objects instead of the 9 currently. To give an idea here is the image(sorry about media fire)

http://www.mediafire.com/?lca414xp9w8mbw3

If this were being processed in MATLAB the command that would be ideal is bwareaopen which removes small objects based on their area. But since this isn't matlab I've been attempting to use the opening block from the Computer Vision Systems object which relies on the morphological operation from MATLAB; strel. However, the structuring elements don't ever give me the ideal image I want. Please see if you can give me a simple way to get rid of all the small objects and keep the two large ones. If no notable solution can be found I could also just setup embedded MATLAB function with the systems object for blob anlysis, but I really don't want to do that. So thank you for your time if you read this, and please offer any help you can.