Lossless compression of bi-level images based on context selection and hierarchical enumerative coding

We propose a lossless compression algorithm for bi-level images based on context selection and hierarchical enumerative coding. To exploit inter-pixel correlation in an image, a context that is calculated from coded pixels is obtained to rearrange a 2-D image to a 1-D binary string, and the resulting 1-D sequence undergoes hierarchical enumerative coding. The proposed method attains performance similar or superior to existing state-of-the-art schemes. Also, since the required operations are only addition and comparison, its computational complexity is substantially low.