CONTEXT-BASED LOSSLESS IMAGE COMPRESSION SCHEMES USE 180° TYPE MODELING CONTEXTS IN ONE PASS SCANNING AN IMAGE. IN THIS PAPER, A LOSSLESS IMAGE COMPRESSION (LIC) SCHEME IS INTRODUCED AND FOR CAPTURING HIGH-ORDER DEPENDENCIES, STATISTICAL FEATURES AND SPATIAL CONFIGURATION OF AN IMAGE, THREEPASS SCHEME WITH 360° TYPE MODELING CONTEXTS IS PROPOSED. LINEAR AND NONLINEAR RELATIONSHIPS BETWEEN PIXELS IN A CONTEXT ARE USED FOR CONTEXT DETERMINATION. ALSO THE THREE-PASS ALGORITHM IS APPLIED TO JPEG-LS STANDARD, AND FOR CONTEXT DETERMINATION, LOCAL GRADIENTS OF INTENSITY CAPTURING THE LEVEL OF ACTIVITY (SMOOTHNESS, EDGINESS) SURROUNDING A PIXEL, IS EMPLOYED. FOR IMAGES WITH SMALL DIMENSIONS THREE-PASS SCHEMES AND FOR LARGE DIMENSIONS ONE-PASS SCHEMES RESULT IN HIGHER COMPRESSION RATIOS.