标签：3.2 采样 ati git scale sum point values sign
Continuous Greyscale Image
1 mapping f from a rectangular domain Ω =(0,a1) X (0,a2) to a co-domain R
domain Ω is called image domain or image plane.
co-domain specifies grey value usually low grey values are dark, high grey values bright
2 Sampling
2.1discretization of the domain Ω
2.2 image data are only give on a rectangular point within the image domain Ω
2.3 the grid point is called pixel.
2.4 2D images often have equal pixel distance in both directions.
3 Quantisation
3.1 discretization of the co-domain
3.2 if a grey value is encode with a single byte,the discrete codomain is given by {0,1,...255}
3.3 binary images have the co-domain {0,1}
3.4 Humans can distinguish only about 40 greyscales.
4 Types of image
4.1 m-Dimensional Images
m=1 signals m=2 tow-dimensional images m=3 three-dimensional images
4.2 Scalar-valued Images
co-domain in R, for example, greyscale images
4.3 Vector-valued Images
co-domain in Rn , containing n channels for example: Colour images have three channels R G B. Satellite images：different channels represent different frequency bands
4.4 Matrix-valued Images
co-domain in Rn x m . For example Diffusion Tensor Magnetic Response Imaging.
4.5 Image Sequence
this increases the dimensionality of the domain from m to m+1
summary: Digital images have a discrete domain (sampling) and a discrete co-domain (quantisation)
generalisation of the domain : m-dimensional images , image sequences
generalisation of the co-domain : scalar-valued images, vector-valued images, matrix-valued images.
<数字图像处理1> 数字图像定义(Definition) 类型(Type) 采样 (Sampling) 量化 (Quantisation)
标签：3.2 采样 ati git scale sum point values sign
原文地址：http://www.cnblogs.com/Max-CHENFEI/p/6881134.html
