How do you calculate threshold of an image?

To calculate the threshold of an image, you can use methods like Otsu's method, which involves finding the intensity value that minimizes the intra-class variance of the pixel intensities. Alternatively, a simple global threshold can be set by choosing a fixed intensity value based on the histogram of the image. Once the threshold is determined, you can convert the image to a binary format by setting pixel values above the threshold to one color (e.g., white) and those below to another (e.g., black). This process helps in segmenting the foreground from the background.