Popular lossless image compression techniques used today belong to the Lempel-Ziv family of encoders. These techniques are generic in nature and do not take full advantage of the two-dimensional correlation of digital image data. They process a one-dimensional stream of data replacing repetitions with smaller codes. Techniques for Lossless Image Compression introduces a new model for lossless image compression that consists of two stages: transformation and encoDing Transformation takes advantage of the correlative properties of the data, modifying it in order to maximize the use of encoding techniques. Encoding can be described as replacing data symbols that occur frequently or in repeated groups with codes that are represented in a smaller number of bits. Techniques presented in this thesis include descriptions of Lempel-Ziv encoders in use today as well as several new techniques involving the model of transformation and encoding mentioned previously. Example compression ratios achieved by each technique when applied to a sample set of gray-scale cardiac images are provided for compariSon