摘要随着红外热成像技术的发展,红外热像仪及测温仪在军事和民用等诸多的领域得到广泛应用。现代高性能红外探测器的输出为 12-16 位的宽动态范围图像,超过了正常显示要求。为此,本文提出一种针对宽动态范围的红外图像的处理算法:数字图像细节增强。
本文提出基于分层处理的方法对红外图像进行处理,在分析现有算法的基础上,提出改进方法,并在 FPGA上实现。本文处理思想如下:将输入的原始图像进行滤波平滑处理,得到图像的基本层;再将基本层和原始图像数据作差,得到细节层;然后分别对基本层进行对比度调整和动态范围压缩,对细节层进行自适应增强;最后将基本层和细节层合并得到输出图像。
考虑到算法的可行性和对图像质量的影响,本文提出了将简易的高斯滤波代替自适应高斯滤波的处理方法,使得该算法在工程上易于实现。另外,提出了改进的直方图投影技术,采用两个参数控制直方图投影的灰度范围,避免在和细节层合并时产生溢出,影响图像质量。实验结果表明,该算法工程适用性较强,对图像对比度的改善,细节的增强,噪声的抑制均具有较好效果。
关键词 宽动态范围图像 细节增强 FPGA 高斯滤波 直方图投影 19277
Title Research On The Detail Enhancement Algorithm For Infrared Image And Its Implementation On FPGA
Abstract
With the development of infrared imaging technology, the infrared thermal
imager has been widely used in many fields of military and civilian. In
view of this, the author proposed a algorithm for the wide dynamic range
infrared image: digital image detail enhancement.
This paper proposes a framework to deal infrared image. Based on analyzing
extant algorithm, proposing a new method and implement it on FPGA. The
framework of this paper is as follows: First, we use a filter to smooth
the input raw data, obtaining the base layer; secondly, we make the base
layer sub the raw data, obtaining the detail layer. Then controlling the
contrast of the base layer, and compressing it to a proper dynamic range
for display. Except that, the detail is enhanced. Finally, combining the
processed detail layer and base layer, and then getting the output image.
Considering the implementation of this algorithm and the influence on
image, this paper proposes that using the simple Gaussian filter to replace
the self-adaption Gaussian filter, making this algorithm realized easily.
Except that, this paper proposes a new histogram projection to control the
range of gray level by using two parameters. It can avoid the overflow when
combining the detail layer and the base layer. According the consequence
of the experiment, this algorithm is suitable for engineering
applications, and it can improve the overall contrast and improve the
detail, suppress background noises.
Keywords high dynamic range image, detail enhancement, FPGA, noise
suppression,Gaussian filter,Histogram Equalization
目 次
1 绪论 . 1
1.1 课题研究背景 1
1.2 红外图像增强发展现状 3
1.3 本论文的主要工作和安排 4
2 基本算法介绍 . 5
2.1 基于直方图的图像处理技术 5
2.2 双边滤波算法 8
2.3 自适应高斯滤波 9
3 基于 FPGA的数字图像细节增强算法 . 12
3.1 DDE 原理 12
3.2 硬件实现 . 14
3.2.1 双边滤波器的实现 . 14 红外图像细节增强算法研究及FPGA实现:http://www.751com.cn/tongxin/lunwen_10575.html