2.Digital image fundamentals

2.1 Elements of visual perception

2.1.1 Structure of the human eye -choroid // lens // retina // fovea

2.1.2 Image formation in the eye

• optical cental -the retinal image is focused primarily on the region of the fovea

2.1.3 Brightness adaptation and discrimination -Perceiving brightness , Mach bands & simultaneous contrast

2.2 Light and the Electromagnetic spectrum

-Electromagnetic waves can be visualized as propagating sinusoidal waves with wavelength

-Each bundle of energy is called a photon

-The colors that humans perceive in a object are determined by the nature of the light reflected from the object

-Light that is void of color is called monochromatic light

2.3 Image sensing and acquisition

2.3.1 Image acquisition using a single sensor -Energy -> filter -> sensing material - voltage waveform out 2.3.2 Image acquisition using sensor strips

• Microdensitometers 2.3.3 Image acquisition using sensor arrays -MRI , X-ray 2.3.4 A simple image formation mode -Illumination source(energy) -> Scene element -> (Internal) image plane -> output image( digitized)

2.4 image sampling and quantization

2.4.1 Basic concepts in sampling and quantization -Sampling is digitizing the coordinate values, Digitizing the amplitude values is called quantization 2.4.2 Representing digital images -Spatial domain is the section of the real plane spanned by the coordinates of an image -We define the dynamic range of an imaging system to be the ratio of the maximum measurable intensity(saturation) to minimum detectable intensity(noise) level in the system 2.4.3 Spatial and intensity resolution -Dpi is Dots per unit distance which is a measure of image resolution used commonly in the printing and publishing industry -False contouring is the effect caused by the used of an insufficient number of intensity levels in smooth areas of a digital image -Isopreference curves is the generated results in the Nk-plane by varying N and k which are ranked them according to photo’s subjective quality 2.4.4 Image interpolation -Interploation is a basic tool used extensively in task such as zooming, shrinking,rotating ,geometric corrections, and the process of using known data to estimated values at unknown location -Bilinear interpolation -Bicubic interpolation

2.5 Some basic relationships between pixels

2.5.1 Neighbors of a pixe -A pixel p at coordinates has four horizontal and vertical neighbors - 4-neighbors, 8-neighbors of p 2.5.2 Adjacency, Connectivity, Regions, and Boundaries -Inner border , outer border - R be called region of the image . If R is a connected set, they be said to be Adjacent -Edge is found frequently in discussions dealing with regions a boundaries 2.5.3 Distance Measures - p and q is defined in the Euclidean distance depends on m-Neighbors

2.6 An Introduction to the mathematical tools used in digital image processing

2.6.1 array versus matrix operations - matrix [ , ] 2.6.2 linear versus nonlinear operations - y = ax 2.6.3 Arithmetic operations - + , - , * , / 2.6.4 Set and Logical operations - Union, intersection ,OR , Xor etc 2.6.5 Spatial operations - rotating 2.6.6 Vector and Matrix operations