The embodiments of the present invention provide for methods, devices, and systems adapted to perform adaptive quantization processes. The adaptive quantization processes of the present invention are adapted to provide one or more adaptive quantization modes based on one or more previous pixels and their associated coding modes. The output of an adaptive quantization process may include coded data and a coding mode, indicating whether the coded data is pulse code modulation (PCM) data or differential pulse code modulation (DPCM) data.