[测][遥感][计] 直方图均衡化
Then, the method of histogram equalization is used to realize the adjustment of the luminance and the contrast.
然后采用直方图均衡的方法实现图像的亮度调整和对比度修正；
Then, in HSI space, the method based on adaptive histogram equalization (AHE) is introduced to adjust the saturation and intensity. And then, the contrast is regulated further.
在HSI空间中，采用自适应直方图均衡（AHE）方法实现了图像饱和度和亮度的调整，并进一步修正了图像的对比度。
Traditional histogram equalization and gray-scale transformation algorithms can't realize the enhancement of the target in the infrared image effectively.
传统的直方图均衡和灰度变换增强算法，不能针对红外图像的目标进行有效地增强。
Satisfied results usually can not be got when processing color images degraded by fog and mist with the conventional enhancement algorithms such as histogram equalization and homomorphic filtering.
对于薄尘雾退化的彩色图像，用直方图均衡和同态滤波等常规增强算法处理往往不能得到满意的效果。
Methods: We adopt methods of image subtraction, grid interpolation and histogram equalization in order to eliminate errors induced by the optical system.
方法：分别采用图像相减，栅格插值及直方图均衡法消除了光学系统所产生的误差。
The histogram equalization can enhance the contrast by redistributing the gray levels, it has the drawback that it reduces the information in the processed image.
直方图均衡可以使图像灰度分布接近均匀，提高图像对比度，但图像的信息量会有一定程度的损失。
The traditional image enhancement approaches include gray-scale transformation, histogram modification, histogram equalization, image smoothing and Wiener filtration.
传统的图像增强方法有灰度变换、直方图修正、直方图均衡、图像平滑和维纳滤波。
This paper mainly tells us the ways of image gray transformation, including linear gray transformation, nonlinear gray transformation and the approach of histogram equalization.
此文主要研究用于增强图像的灰度变换方法，包括线性灰度变换、非线性灰度变换与直方图均衡化方法。
The color image reinforcing which realized by grey statistics histogram equalization method has reduced the need of environment brightness in virtual photographing system.
由灰度统计直方图均衡所实现的彩色增强处理降低了虚拟照相系统对环境照度的要求。
The method of histogram equalization is attempted to used in the sonar image, and the result is analyzed.
在图像增强方面，尝试了直方图均衡化增强方法，并对其处理结果进行了分析。
The image enchancement based on histogram equalization and specification can improve the contrast details and the dynamic range of gray level of the image.
基于直方图均衡化和规定化处理的图像增强技术，能有效地改善图像的对比度和灰度动态范围。
Aiming at this problem, histogram equalization and gray stretch are used to enhance license plate image, and make the image clearer.
针对这一情况，将直方图均衡和灰度拉伸相结合，增强牌照图像，使图像更加清晰。
This pa-per proposed a method which is partially overlapped local histogram equalization based on maximum entropy and brightness preserving(Local BPHEME).
本文提出了基于熵最大化和亮度保持的部分重叠的局部直方图均衡方法（局部BPHEME）。
However, this is not the desirable property in many applications where preserving the original brightness is essential, so a new algorithm of local histogram equalization is proposed.
由于图像增强的很多实际应用需要保持原始图像的亮度，为此提出一种新的局部直方图均衡算法。
This paper puts forward an improved histogram equalization algorithm based on eliminating the gray redundancy.
该文提出一种改进的消除灰度冗余的红外图像直方图均衡算法。
The region histogram equalization is different from traditional histogram modification technology, the idea is based on human vision character and edge effect in image vision.
区域间直方图均衡不同于传统的直方图修正技术，该思想是充分地考虑到人类的视觉特性和边缘在图像视觉中的作用而提出的。
This paper develops an image enhancement algorithm of histogram equalization.
给出了一个改进的直方图均衡化图象增强算法。
In visual quality, the algorithm is better than the traditional unshaped mask method, histogram equalization method.
算法在视觉质量上优于传统的反锐化掩膜法、直方图均衡法。
The image enhanced by traditional histogram equalization is over-bright in the high gray area.
常规直方图均衡化增强后的图像在高灰度区有过亮的感觉。
As the traditional algorithms for local histogram equalization is used to enhance the contrast of an image, the output brightness is always regardless of the input image.
现有的局部直方图均衡算法用于图像的对比度增强时，输出图像的亮度与输入图像无关。
A modified algorithm of histogram equalization to gray image manipulation was discussed and actualized by analyzing principia and deficiency of the traditional algorithm of gray image.
分析了传统灰度图像直方图均衡化算法的不足，讨论并实现了一种改进的直方图均衡化图像增强算法。
In visual quality, the algorithm is better than the traditional unshaped mask method and histogram equalization method.
算法在视觉质量上优于传统的反锐化掩膜法、直方图均衡法。
First, the image histogram equalization of treatment.
首先，对图像进行直方图均衡化处理。
Methods Based on improving of traditional histogram equalization, the proposed method adopts the minimum mean brightness error bi-histogram equalization and an effective intersected point.
方法在改进常规直方图均衡化算法的基础上，以最小灰度平均值误差二元直方图均衡化为基础，引入另一个有效分割点。
Results Through the gray-level histogram equalization, the detail and the edge of medical digital images could be enhanced.
结果通过直方图均衡增强能改善医学灰阶图像的层次感，提高图像细节的可识别性和边缘特征。
The principium, implementation method and simulation results of FPGA -based video format conversion, median filtering and adaptive bidirectional plateau histogram equalization were given.
给出了基于FPGA的视频格式转换、快速中值滤波、自适应平台直方图双向均衡化的原理、实现方法及仿真结果。
直方图均衡化（Histogram Equalization）是一种用于增强图像对比度的数字图像处理技术。其核心思想是通过重新分配图像像素的灰度值，使输出图像的灰度直方图尽可能均匀分布，从而扩大图像的动态范围，改善视觉效果。
灰度直方图
表示图像中每个灰度级出现的频率分布。设图像灰度级范围为 ([0, L-1])，灰度级 (k) 的像素数量为 (n_k)，则其概率密度函数为：
$$ p_r(r_k) = frac{n_k}{N} $$
其中 (N) 为总像素数，(r_k) 为灰度级。
均衡化变换函数
通过累积分布函数（CDF）映射原始灰度级到新灰度级：
$$ s_k = T(rk) = (L-1) sum{j=0}^{k} p_r(r_j) $$
该函数将原始分布拉伸为近似均匀分布，提升对比度。
权威参考文献：
直方图均衡化（Histogram Equalization）是一种用于增强图像对比度的数字图像处理技术。它通过重新分配像素的强度值，使图像的灰度直方图更均匀分布，从而改善整体视觉效果。
直方图概念
图像的直方图表示不同灰度级（0-255）的像素数量分布。低对比度图像的直方图通常集中在狭窄区域，而均衡化后直方图会覆盖更广范围。
映射函数
通过累积分布函数（CDF）将原始灰度值映射到新值。公式为：
$$
s_k = T(rk) = (L-1) sum{j=0}^{k} frac{n_j}{N}
$$
其中：
当处理结果不理想时，可采用自适应直方图均衡化（CLAHE），该方法将图像分块处理并限制对比度增强幅度，从而保留更多细节。
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