Can someone help me create a binary image in C#

I am making a C# project in which I have to count the number of sheep in the given image.

Its algorithm works by first converting an image into greyscale then converting it into a binary image by setting Minimum white distance threshold = 0.1 the applying area threshold and  then plotting centroids. Can someone guide me in this?

I have converted image into grey scale now I have to convert it into binary image .