Goals and prerequisites

This lesson deals with very basic issues related to digital imaginery like image resolution, sample bit depth, sample value histograms, color sample representation and color spaces. There is no special prerequisite for this lesson that can be easily understood by almost everyone.

Electronic images

Light stimuli may be converted to electric current using photoelectric converters such as semiconductor light-sensitive devices, e.g. popular CCD devices often used in video and photo cameras. This visual information is stored and transmitted as electric signals by use of either analog technology, like in classic analog television systems and analog tape recording systems, or by more modern digital technology. This course obviously deals with the latter kind of electronic images called digital images.

Human visual system

Visual perception is a sophisticated process that obviously is an ultimate stage of a multimedia system. Visual stimuli are perceived by humans by use of eyes with retina, optic nerves and chiasma as well as visual cortex. All mentioned items constitute human visual system that exhibits properties varying between individuals as well changing during lifetime. In order to establish a reference model for human visual systems, a concept of normal observer (standard observer) has been introduced. Normal observer is a hypothetical person with some predefined properties of his visual system that correspond to average features of a healthy adult.