How to remove unwanted object from an image?

In my attached image, I want to remove all the black dots on the right side of the image. I want to keep the object on the left side (long filament object.) How could I do without changing the threshold value? Changing threshold values I am actually loosing some pixel from the long object. Please help, I am new in Image analysis.

Thank you

Answer 1

[Image Analyst]

Assuming you have a binary image

mask = bwareafilt(~mask, 1); % Take largest blob only.

[Animesh Biswas]

Thank you.

Following question, in some situation the object I am tracking is touching the unwanted object. In that case what to do?

[Image Analyst]

Somehow you have to identify what makes an object desired or unwanted. I can't tell that from the binary image you posted. Perhaps your segmentation is no good. What does your original gray scale or color image look like?

[Animesh Biswas]

Hi, thanks again for your reply I am attaching oringinal and thresholded images. I want to track the object inside the boundary. Moreover, I have many images like that.

[Image Analyst]

Can I assume you have a professionally designed image capture setup? It looks like you have a petri dish with a worm in it. So to get the dish in the same position every time, a good imaging person would put the camera on a rigid mount atop the light booth, and have an L-shaped block on the floor of the light booth such that when you put the dish in, it will be in exactly the same place in the image every time. Then, you can just make a fixed mask that you will use to blacken or whiten your image outside that mask. Like

grayImage(mask) = 0; % Blacken

[Animesh Biswas]

Yes all the images are same. The object and and the boudary have same color (black in this case). According to you, I can mask only the boarder to make it white right? Could you please help how to mask diffeent parts of the image with different colors? Thanks

[Image Analyst]

To whiten:

backgroundMask = imread('mask.png') > 128;
grayImage(backgroundMask) = 255; % Whiten