Hi Gayathri,
It would have been easier for me to help you out with this task if you would've provided a code you are using. But I will try my best to guide you through the process.
As you want to perform an erosion and dilation task, you need to first generate a "structuring element" using the "strel"/"offsetstrel" function. Post that, you can simply erode or dilate using the "imerode" or "imdilate" respectively. Following is the code you can use:
frame = rgb2gray(imread('example.jpg'));
se = strel('square', 3);
minFrame = imerode(frame, se);
maxFrame = imdilate(frame, se);
You need to make sure that the image is grayscale before you perform the erosion or dilation.
Now, to the second part of you question, examples for the same are here"
Feel free to follow up, in case you have any doubts!
