第5章 数字图像处理及其在交通中的应用

灰度图像（单色图像）：

单色图像(lena)
单色图像的局部放大图







125,153,158,157,127, 70,103,120,129,144,144,150,150,147,150,160,165,160,164,165,167,175,175,166,133, 133,154,158,100,116,120, 97, 74, 54, 74,118,146,148,150,145,157,164,157,158,162,165,171,155,115, 88, 155,163, 95,112,123,101,137,108, 81, 71, 63, 81,137,142,146,152,159,161,159,154,138, 81, 78, 84,114, 167, 69, 85, 59, 65, 43, 85, 34, 69, 78,104,101,117,132,134,149,160,165,158,143,114, 99, 57, 45, 51, 54, 46, 38, 44, 38, 36, 44, 36, 25, 48,115,113,114,124,135,152,168,169,156, 75, 43, 39, 41, 38, 42, 58, 30, 44, 35, 28, 69,144,147, 57, 60, 93,106,119,124,131,144,175,177, 63, 30, 30,124,139, 65, 31, 61, 35, 75, 51, 66, 58,167,177,153, 58, 80, 95,108,120,133,155,182,137, 84, 74, 54, 61,149, 96, 36, 115, 71, 84,105, 86,136,172,175,128,126,114,106,109,115,127,169,187,105,102, 95, 66,135,145, 87, 38, 124,120,106, 93, 95,117,120,131,148,144,113,112,109,115,128,162,193,143,132,124,110,131, 97, 53, 66, 129,123,128,114,108,115,102,121,129,125,113,112,111,111,127,162,192,150,129,117,112,107, 64, 67, 73, 133,139,132,127,128,134,136,144,140,141,113,120,114,115,122,154,188,159,143,131,125,112,105, 95, 88, 136,138,143,145,138,143,143,141,144,129,118,119,115,112,120,152,186,165,150,139,128,117,109,104, 93, 140,146,147,145,150,154,147,149,143,132,127,124,117,112,117,142,184,171,144,139,129,119,114,112,100, 135,143,145,151,150,143,146,142,139,131,131,127,119,115,114,140,190,177,141,135,133,121,120,115,102, 128,137,141,149,150,148,143,141,136,128,120,122,116,109,116,136,182,182,140,135,130,124,116,109,100, 131,132,141,143,148,147,143,140,134,125,116,117,108,109,120,130,171,185,133,132,127,120,117,110, 90, 136,131,139,136,140,141,140,136,132,121,114,117,109,106,112,130,163,192,130,131,127,119,116,110, 81, 126,131,132,132,136,140,134,135,128,117,110,113,111,110,112,129,151,196,155,130,127,120,115,103, 64, 127,132,130,128,134,134,140,132,126,110,102,117,118,114,112,121,152,195,165,123,128,117,115, 96, 36, 123,131,127,129,132,133,134,131,127,112,109,117,114,116,107,116,145,172,136,123,122,116,107, 72, 27, 127,128,129,130,133,135,132,134,130,120,108,110, 48, 79, 76,103,128,165,137,127,118,115,105, 34, 31, 123,124,127,128,132,129,134,131,131,124,114,109,115,117,106,120,151,149,134,126,118,114, 85, 30, 36, 122,122,123,128,132,133,134,133,132,127,128,125,120,138,130,158,162,149,130,123,115,106, 36, 34, 29, 124,124,122,124,129,130,126,134,130,130,124,123,127,164,155,162,163,144,128,128,117, 97, 37, 29, 29, ……………..
（续） (e)~(h) 以16， 8，4和2 灰度 级显示的图像
4. 常用图像格式



BMP、JPEG、TIFF、GIF…… 特点：以像素为单位的矩形区域。（位图） 颜色深度：1,2,4,8,16,24bits/pixel 编码方式：无压缩、无损压缩、有损压缩 压缩方式：LZW、RLE、JPEG 、CCITT3 、 CCITT4 、JPEG2000
不同空间分辨率图像（灰度级为8比特） (a) 1024×1024；(b)~(f)的原始空间分辨率依次为512 × 512， 256 × 256，128 × 128，64 × 64，32×32像素。
(a) 453 ×374， 256灰度级图像； (b)~(d) 保持空 间分辨率不变， 以灰度级为128， 64和32显示的 图像
第5章 数字图像处理技术

数字图像基础概念 主要图像处理技术 图像处理及其实例
一、数字图像基础概念
1. 什么是数字图像？

离散化的图像，亮度和坐标均为有限、离散 的数值 。 每个像素的亮度用一个数值来表示，通常数 值范围在0到255之间（一个字节），0表示 黑、255表示白，而其它表示灰度。
蓝
品红 白 绿 黑 红 黄 归一化的RGB颜色立方图 青
彩色图像(lena)及其局部放大图





(207,137,130) (220,179,163) (215,169,161) (210,179,172) (210,179,172) (207,154,146) (217,124,121) (226,144,133) (226,144,133) (224,137,124) (227,151,136) (227,151,136) (226,159,142) (227,151,136) (230,170,154) (231,178,163) (231,178,163) (231,178,163) (236,187,171) (236,187,171) (239,195,176) (239,195,176) (240,205,187) (239,195,176) (231,138,123) (217,124,121) (215,169,161) (216,179,170) (216,179,170) (207,137,120) (159, 51, 71) (189, 89,101) (216,111,110) (217,124,121) (227,151,136) (227,151,136) (226,159,142) (226,159,142) (237,159,135) (237,159,135) (231,178,163) (236,187,171) (231,178,163) (236,187,171) (236,187,171) (236,187,171) (239,195,176) (239,195,176) (236,187,171) (227,133,118) (213,142,135) (216,179,170) (221,184,170) (190, 89, 89) (204,109,113) (204,115,118) (189, 85, 97) (159, 60, 78) (136, 38, 65) (160, 56, 75) (204,109,113) (227,151,136) (226,159,142) (237,159,135) (227,151,136) (230,170,154) (231,178,163) (230,170,154) (231,178,163) (231,178,163) (236,187,171) (239,195,176) (230,170,154) (204,109,113) (178, 73, 83) (216,179,170) (220,188,176) (190, 77, 84) (206, 95, 97) (217,113,113) (189, 85, 97) (226,144,133) (207, 91, 94) (170, 56, 72) (159, 51, 71) (150, 47, 67) (172, 63, 78) (226,144,133) (226,144,133) (227,151,136) (226,159,142) (230,170,154) (231,178,163) (230,170,154) (230,170,154) (226,144,133) (172, 63, 78) (155, 75,101) (155, 75,101) (204,109,113) ………………………………………………………………………………………

数字图像的重要指标。500万像素 —— 数码相机主流 像素，可以放大到24寸而看不出颗粒。
3. 空间和灰度级分辨率

空间分辨率——图像中可辨别的最小细节。

主要由取样值决定。 M×N 像素

灰度分辨率——在灰度级别中可分辨的最小变 化。

由量化级数决定。 一般取灰度分辨率为8比特——灰度为256级
60, 49, 95, 57, 41, 39, 29, 38, 47, 48, 52, 58, 58, 48, 45, 42, 26, 28, 28, 28, 28, 29, 29, 41,
局部放大图在计算机中的实际存在形式 ——二维矩阵

彩色图像：


利用人眼感光的三原色原理，用红、绿、 蓝(RGB)三元组的二维矩阵来表示。 如(255, 0, 0)表示纯粹的红色，(255, 255, 255)表示白色。
彩色图像局部放大图在计算机中的实际存在形式 （给出前四行）
2. 数字图像获取过程
光源
相机
输出的数字化图像
CCD平面上的像 实际物体
光学 成像
CCD光电 转换
A/D转换 输出图像
像素
Leabharlann Baidu
连续图像

数字图像
像素：组成数字图像的元素。每一个像素的坐标对应
特定的图像网格位置。像素的数值反映图像中对应位置 的亮度。