This document discusses techniques for image coding and compression, including predicting pixel values from neighboring pixels, encoding differences between actual and predicted values (DPCM), and adapting the mapping of bits to differences over time (ADPCM). DPCM removes redundancy by transmitting only differences between samples, which are normally small. ADPCM varies this mapping dynamically so more bits can be used for rapid changes and fewer for slow changes. Overall the document focuses on prediction-based approaches to reduce image data by exploiting spatial and temporal correlations between pixels.