煤矿井下压缩感知图像处理算法

针对煤矿井下无线传感网络因信息传输量大而导致传感节点能量消耗快、设备寿命缩减的问题,提出一种基于小波变换的压缩感知图像处理算法。该算法采用sym8小波基对图像进行稀疏化分块处理,经测量矩阵自适应采样测量,最后通过OMP算法和小波逆变换重构图像。实验结果表明,与传统的压缩感知算法相比,该算法能够以更低的采样率获得高质量的重构图像。     

一种煤矿井下监控视频图像预处理方法

针对煤矿井下照度低、粉尘大、强光干扰多而导致监控视频图像模糊、容易出现目标检测失误等问题,提出了一种煤矿井下监控视频图像预处理方法。引入直方图均衡化算法将灰度值从集中在某段灰度级区域的非均匀分布状态变换为均匀分布状态,扩展像素灰度值的动态范围;采用多特征判断法即通过灰度阈值、差分阈值、尺寸阈值3个方面判断检测到的目标是否为光斑。实验结果表明,该方法能有效增强图像对比度,改善图像质量,识别并滤除光斑,从而提高目标检测的有效性。     

一种煤矿井下图像增强算法

针对煤矿井下监控图像对比度低、视觉效果差等问题,采用一种基于引导滤波的单尺度Retinex算法进行煤矿井下图像增强。该算法采用具有保边平滑功能的引导滤波进行照度估计,并与原图像进行卷积运算,获得反映自身属性的反射分量,然后针对经反对数变换的反射分量,采用改进的局部对比度增强方法提高图像暗区的对比度,最后得到增强图像。实验结果表明,该算法在对比度提升、细节增强、消噪方面取得了较好的效果。     

贝叶斯小波图像压缩感知方法

现有小波图像压缩感知方法大多利用父子小波系数的相关性来提高重构精度, 很少考虑同一尺度兄弟小波系数间的相关性关系. 鉴于此, 提出一种基于贝叶斯模型的高频系数联合重构小波图像压缩感知方法. 该算法将同一尺度水平、垂直和对角三个方向高频系数分别压缩感知采样, 然后设计分层贝叶斯模型, 充分利用此三个方向兄弟小波系数的相关性来重构图像. 实验结果表明本文提出的方法比传统的多尺度压缩感知有更高的图像重构质量.     

一种基于小波变换的图像压缩方法与实现

提出了一种先去噪再利用小波变换的图像压缩方法,用Matlab软件编程实现算法。实验仿真结果显示,图像在具有高压缩比的同时,重构图像的质量也较优;使用不同的小波基函数,效果不同。     

一种基于三维小波变换的视频图像编码方法

In this paper,We propose an in:proved zerotree coding scheme based on three dimensionalwavelet transform. The wavelet coefficients are quantized with different quantization matrices using hu-man visual system(HVS),and then are encoded with an improved zerotree coding algorithm. Experi-ments prove that this method is very efficient.     

一种低码率的动态图像压缩

进行动态图像压缩时如何兼顾较高的编码速度与较低的码率成为编码的关键。该文采用基于DCT的编码,并对DCT变换进行了一定优化以提高编码速度。在解码的后处理部分,文章采用拉格朗日n次插值算法对图像进行扩张,使得图像获得更大的显示区域并有较好的显示效果。     

一种新型的量化方法与基于小波变换的指纹图像压缩

针对矢量量化和标量量化各有优劣的现状，一种简单，有效的新型量佛方法被提出来了。本文把应用于基于小波变换的指纹压缩，改进了ＥＢＩ的ＷＳＱ算法，大大降低了量化计算复杂度。即获得较高的压缩比，又有较好的主客观质量，并与ＪＰＥＧ标准进行了对比。     

一种新型的小波图像压缩编码

在借鉴前人研究成果的基础上,对SPIHT算法进行改进并提出一种新型的小波图像压缩编码。利用人眼视觉特性对小波系数进行加权,更加注重人的主观因素对图像压缩的影响;高频子带引入最大值表,系数扫描时只需将最大值内相应数据同阈值进行比较。实验结果表明,改进算法较原算法在重构图像的主观效果和峰值信噪比上都得到了提高。     

一种煤矿井下低照度图像增强算法

针对多尺度Retinex算法在处理煤矿井下低照度图像时存在细节增强不足和耗时等问题,提出了一种基于光照校正的快速多尺度Retinex算法对煤矿井下低照度图像进行增强。该算法通过计算高斯模糊后图像的每个像素点的亮度值,将图像划分为暗调区域和高光区域,并对不同区域进行光照校正,从而降低高光区域的亮度,保证不过分曝光,同时提升较暗区域的亮度,凸显更多细节信息;利用三次快速均值滤波代替高斯滤波来估计光照强度,减少算法耗时。实验结果表明,该算法能有效提高图像的亮度和对比度,增强图像中暗调区域和高光区域的细节,具有较快的处理速度。     

An efficient lossy cartoon image compression method

Multimedia Tools and Applications - This paper introduces a new lossy approach for compression of cartoon images. The image is firstly partitioned into regions of roughly the same colour. The chain...     

An encoding method for both image compression and data lossless information hiding

Reversible image data hiding technology means the cover image can be totally recovered after the embedded secret data is extracted. In this paper, we propose a reversible image data hiding scheme based on vector quantization (VQ) compressed images. The secret bits are embedded into the VQ index table by modifying the index value according to the difference of neighboring indices. The data hiding capacity and the size of the final codestream (embedded result) are a trade-off, and it can be decided by users. In other words, the proposed scheme has flexible hiding capacity ability. To estimate the performance, the proposed scheme was compared with the scheme proposed by Wang and Lu (2009). The results of the comparison showed that our proposed scheme is superior to the scheme proposed by Wang and Lu in both data hiding capacity and bit rate.     

United coding method for compound image compression

This paper proposes a compound image coding method named united coding (UC). In UC, several lossless coding tools such as dictionary-entropy coders, run-length encoding (RLE), Hextile, and a few filters used in portable network graphics (PNG) format are united into H.264 like intraframe hybrid video coding. The basic coding unit (BCU) has a size typically between 16?×?16 pixels to 64?×?64 pixels. All coders in UC are used to code each BCU. Then, the lossless coder that generates minimum bit-rate (R) is chosen as the optimal lossless coder. Finally, the final optimal coder is chosen from the lossy intraframe hybrid coder and the optimal lossless coder using R-D cost based optimization criterion. Moreover, the data coded by one lossless coder can be used as the dictionary of other lossless coders. Experimental results demonstrate that compared with H.264, UC achieves up to 20 dB PSNR improvement and better visual picture quality for compound images with mixed text, graphics and natural picture. Compared with lossless coders such as gzip and PNG, UC can achieve 2–5 times higher compression ratio with just a minor loss and keep partial-lossless picture quality. The partial-lossless nature of UC is indispensable for some typical applications, such as cloud computing and rendering, cloudlet-screen computing and remote desktop, where lossless coding of partial image regions is demanded. On the other hand, the implementation complexity and cost increment of UC is moderate, typically less than 25 % of a traditional hybrid coder such as H.264.     

一种新型煤矿视频监控图像滤波算法

针对煤矿视频监控图像存在噪声强度高且对比度低等问题,提出了一种新型煤矿视频监控图像滤波算法。该算法首先采用自适应Canny算子对图像进行边缘检测,实现边缘图像和非边缘图像的有效分离;然后对边缘图像引入直方图均衡化算法进行处理,以突出图像边缘信息,提高图像对比度;从滤波器的构建、结构元素的设计方面对经典数学形态学滤波算法进行改进,将其应用于非边缘图像的滤波;最后对处理后的边缘图像和非边缘图像引入图像融合机制进行加权融合。实验结果表明,与小波阈值法、经典数学形态学滤波算法相比,该算法具有较好的滤波效果。     

An image compression method based on the multi-resolution characteristics of BEMD

This paper presents a BEMD based image compression method based on the multi-resolution characteristics of BIMF. First, an image pyramid of an original image is formed by the down-sampling technique, and then a cascade feedback compression framework is constructed based on the spatial similarity property of the BIMFs at different resolutions. The image compression scheme is implemented by coding the decomposition result at the lowest resolution level. Experimental results show the effectiveness of the proposed method.     

一种矿井巷道图像边缘检测算法

针对传统的Canny算法在处理模糊的矿井巷道图像时存在边缘提取效果较差的问题,提出了一种基于小波变换和Canny算法的矿井巷道图像边缘检测算法。该算法首先对矿井巷道原始图像做小波分解,获得低频图像和高频图像,从而避免模糊图像对边缘检测效果的影响;然后采用Canny算法计算低频图像和高频图像的一阶差分,获得低频图像和高频图像的梯度图,通过计算局部梯度最大值,获得高频图像和低频图像的边缘图;当高频图像的边缘图上出现间断点时,在低频图像的边缘图中检测该点的8点邻域,寻找连接点,即可得到完整的矿井巷道边缘检测图。实验结果表明,与传统的Canny算法相比,该算法能够检测到较多的图像边缘点,具有较好的边缘连接效果。