Image processing is a method of converting an image into digital form to extract some useful information from it. It is a type of signal dispensation in which input is image or video frame, and output may be image or characteristics associated with that image.
Natural Language Processing (NLP) is a sub-set of artificial intelligence that focuses on system development that allows computers to communicate with people using everyday language.
Voice or speaker recognition is the ability of a machine or program to receive and interpret dictation or to understand and carry out spoken commands. Voice recognition has gained prominence and use with the rise of AI and intelligent assistants, such as Amazon's Alexa, Apple's Siri and Microsoft's Cortana.