I assume that you are using MATLAB's built-in “huffmandict” function to create a Huffman dictionary based on the symbol probabilities and using MATLAB's “huffmanenco” function for generating the encoded image.
You can calculate the size of compressed data in bits by simply finding the length of the encoded data using the "length" function. Divide the same by 8 to get the size of compressed data in bytes.
Now, to find the size of your Huffman dictionary, it will depend upon how you have implemented or stored it. For example, if you save it to a file, you can use “<filename>.bytes” to get the size of your Huffman dictionary.
Finally, to calculate the compression ratio, add the compressed file size and the dictionary size and divide the answer by the file size of the original image.
You can find an example in the file that I have attached.
