How to remove unwanted objects of smaller than a certain threshold area from a grayscale image?

My algorithm is as follows :- - convert entire image to binary form - remove the objects of the area smaller than required. My problem is to how to work on the object of larger area in its gray scale form. Please suggest any other method if better

Answer 1

[Walter Roberson]

See bwareaopen() but notice that it works on black and white images. So you could convert your grayscale to B&W, run the area open, then use the resulting B&W image as a mask on your grayscale.

[Image Analyst]

To mask (one way of doing it):

grayImage(~binaryImage) = 0; % Set background to zero.

P.S. Richa, you might be interested in my tutorial: http://www.mathworks.com/matlabcentral/fileexchange/25157-image-segmentation-tutorial-blobsdemo

[Richa Nayak]

You BlobsDemo Tutorial has been very helpful till now. dint refer to it for this tho. Thanks a lot!