医学图像处理-Chapter2_BasicsofImageProcessing_092016.ppt

Many image formats adhere to the simple model shown below (line by line, no breaks between lines). The header contains at least the width and height of the image. Most headers begin with a signature or “magic number” - a short sequence of bytes for identifying the file format. Image file formats Terms CCD: charge-coupled devices电荷耦合器件 Scanning: 扫描 Continuous: 连续的 Discrete: 离散的 Digitization: 数字化 Sampling: 采样 Quantization: 量化 Band-limited function: 带宽有限函数 Terms ADC: analog-to-digital converter 模数转换器 Pixel: picture element 象素 Gray-scale :灰度 Gray level:灰度级 Gray-scale resolution: 灰度分辨率 Resolution: 分辨率(空间与灰度) Sample density: 采样密度 Terms Bit: 比特 Byte: 字节 Pixel spacing: 象素间距 Contrast: 对比度 Noise: 噪声 SNR: signal-to-noise ratio 信噪比 Terms Frame: 帧 Field: 场 Line: 行，线 Interlaced scanning: 隔行扫描 Intensity image/Gray image/ Binary image/ Index image 重要概念与思考题 １.　什么是采样与量化 ２.　对模拟信号采样有什么要求？ ３.　灰度、灰度级、强度、分辨率 ４.　数字(医学)图像是如何表示、存储的？ ５.　DICOM标准 6. 强度图像、灰度图像、二值图像、 索引图像 7. 彩色模型(定义、特点、比较与转换) 8. 直方图概念、意义及编程计算 LISS - III camera provides multispectral data in 4 bands. The spatial resolution for visible (two bands) and near infrared (one band) is 23.5 meters with a ground swath of 141 kms. The fourth band (short wave infrared band) has a spatial resolution of 70.5 meters with a ground swath of 148 kms. The repetitivity of LISS - III is 24 days. * Neighbors of a Pixel p (x+1,y) (x-1,y) (x,y-1) (x,y+1) 4-neighbors of p: N4(p) = (x-1,y) (x+1,y) (x,y-1) (x,y+1) Neighborhood relation is used to tell adjacent pixels. It is useful for analyzing regions. Note: q ? N4(p) implies p ? N4(q) 4-neighborhood relation considers only vertical and horizontal neighbors. p (x+1,y) (x-1,y) (x,y-1) (x,y+1) (x+1,y-1) (x-1,y-1) (x-1,y+1) (x+1,y+1) Neighbors of a Pixel (cont.) 8-neighbors of p: (x-1,y-1) (x,y-1) (x+1,y-1) (x-1,y) (x+1,y) (x-1,y+1) (x,y+1) (x+1,y+1) N8(p) = 8-neighborhood relation considers all neighbor pixels. p (x+1,y-1) (x-1,y-1) (x-1,y+1) (x+1,y+1) Diagonal neighb