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1.
In this paper, we provide a super-resolution image reconstruction algorithm based on wavelet transform. Wavelet transform can separate high frequency and low frequency information of image. The more high frequency information can be obtained by using wavelet transform and the technique of image fusion. Meanwhile, reconstructed super-resolution image is produced by the iterative method. In iteration process, noise of image can be suppressed by applying method of wavelet threshold de-noising. The experiment results show that the algorithm can overcome the disadvantage of the classical interpolation method and effectively improve the resolution and PSNR of the image.  相似文献   

2.
A new image fusion scheme based on local accumulated gradient and PCA transform is presented. The image fusion process begins by taking the Dual tree complex wavelet transform of the source images. Then, the fused local detailed coefficients are chosen according to local accumulated gradient rule, and the fused approximate coefficients are acquired by selection or averaging rule based on PCA. Finally, the fused image can be obtained by taking the inverse dual tree complex wavelet transform of the fused composite coefficients. The experimental results show that the proposed method is an efficient approach to image fusion.  相似文献   

3.
The conventional discrete wavelet transform (DWT) introduces artifacts during denoising of images containing smooth curves. Finite ridgelet transform (FRIT) solved this problem by mapping the curves in terms of small curved ridges. However, blind application of FRIT all over an image is computationally heavy. Finite curvelet transform (FCT) selectively applies FRIT only to the tiles containing small portions of a curve. In this work, a novel curvelet transform named as 4-quadrant finite curvelet transform (4QFCT) based on a new concept of 4-quadrant finite ridgelet transform (4QFRIT) has been proposed. An image is band pass filtered and the high frequency bands are divided into small non-overlapping square tiles. The 4QFRIT is applied to the tiles containing at least one curve element. Unlike FRIT, the 4QFRIT takes 4 sets of radon projections in all the 4 quadrants and then averages them in time and frequency domains after denoising. The proposed algorithm is extensively tested and benchmarked for denoising of images with Gaussian noise using mean squared error (MSE) and peak signal to noise ratio (PSNR). The results confirm that 4QFCT yields consistently better denoising performance quantitatively and visually.  相似文献   

4.
A construction method of two channels non-separable wavelets filter bank which dilation matrix is [1, 1; 1,-1] and its application in the fusion of multi-spectral image are presented. Many 4×4 filter banks are designed. The multi-spectral image fusion algorithm based on this kind of wavelet is proposed. Using this filter bank, multi-resolution wavelet decomposition of the intensity of multi-spectral image and panchromatic image is performed, and the two low-frequency components of the intensity and the panchromatic image are merged by using a tradeoff parameter. The experiment results show that this method is good in the preservation of spectral quality and high spatial resolution information. Its performance in preserving spectral quality and high spatial information is better than the fusion method based on DWFT and IHS. When the parameter t is closed to 1, the fused image can obtain rich spectral information from the original MS image. The amount of computation reduced to only half of the fusion method based on four channels wavelet transform.  相似文献   

5.
孙韶杰  吴琼  李国辉 《自动化学报》2009,35(12):1564-1567
Nowadays, digital images can be easily tampered due to the availability of powerful image processing software. As digital cameras continue to replace their analog counterparts, the importance of authenticating digital images, identifying their sources, and detecting forgeries is increasing. Blind image forensics is used to analyze an image in the complete absence of any digital watermark or signature. Image compositing is the most common form of digital tampering. Assuming that image compositing operations affect the inherent statistics of the image, we propose an image compositing detection method on based on a statistical model for natural image in the wavelet transform domain. The generalized Gaussian model (GGD) is employed to describe the marginal distribution of wavelet coefficients of images, and the parameters of GGD are obtained using maximum-likelihood estimator. The statistical features include GGD parameters, prediction error, mean, variance, skewness, and kurtosis at each wavelet detail subband. Then, these feature vectors are used to discriminate between natural images and composite images using support vector machine (SVM). To evaluate the performance of our proposed method, we carried out tests on the Columbia Uncompressed Image Splicing Detection Dataset and another advanced dataset, and achieved a detection accuracy of 92% and 79%, respectively. The detection performance of our method is better than that of the method using camera response function on the same dataset.  相似文献   

6.
In many various image-debluring methods, Visual Characteristics are not consides. This paper proposes an image-dehluring method based on the frequency and direction characteristics of human visual system by weighting high frequency subband of blured image‘s wavelet transformation, the enhanced blured image in high frequecy is ob-tained through wavelet anti-transformation ,and the blind deblured methed is used to restore image from the enhanced blured image .the restored imat, e is well improved in visual quality.  相似文献   

7.
Digital Image Watermarking Based on Discrete Wavelet Transform   总被引:7,自引:0,他引:7       下载免费PDF全文
This paper aims at digital watermark which is a new popular research topic recently,presents some methods to embed digital watermark based on modifying frequency coefficients in discrete wavelet transform(DWT) domian,Fist,the,the present progress of digital watermark is briefly introduced;after that,starting from Pitas‘s method and discarding his pseudo random number method,the authors use a digital image scrambling technology as preprocessing for digital watermarking ,Then the authors discuss how to embed a 1-bit digital image as watermark in frequency domain.Finally another digital watermarking method is given in which3-D DWT is used to transform a given digtial image .Based on the experimental results ,it is shown that the proposed methods are robust to a large extent.  相似文献   

8.
Single image haze removal via depth-based contrast stretching transform   总被引:1,自引:0,他引:1  
Under the weather of haze, fog, or smoke, outdoor images show poor visibility and low contrast.Low contrast results in the difficulty for carrying out basic local feature(e.g., interest points and edges) detection algorithms, which are necessary procedures in some computer vision applications. Hence, increasing contrast of degraded images is very important since it is helpful in finding more distinct features from haze images.However, few single image haze removal methods can simultaneously achieve clear visibility, sufficiently high contrast, and simplicity. In this paper, we propose an intuitive and effective method, called the depth-based contrast stretching transform(DCST), to simultaneously obtain clear visibility and enhance contrast of a single haze gray image. The DCST stretches the contrast of haze images based on the coarse depth layers of scenes.Our method is simple and almost real time and can be extended to color images. We analyze in detail that the image stretched by the DCST has a higher local contrast than the image recovered via the physical-based model.Experiments demonstrate that images stretched by the DCST have excellent visibility and contrast compared with a few existing algorithms. Compelling performance is also presented by comparing the proposed method with other representative methods in the application of local feature detection.  相似文献   

9.
Digital audio watermarking embeds inaudible information into digital audio data for the purposes of copyright protection, ownership verification, coven communication, and/or auxiliary data carrying. In this paper, we present a novel watermarking scheme to embed a meaningful gray image into digital audio by quantizing the wavelet coefficients (using integer lifting wavelet transform) of audio samples. Our audiodependent watermarking procedure directly exploits temporal and frequency perceptual masking of the human auditory system (HAS) to guarantee that the embedded watermark image is inaudible and robust. The watermark is constructed by utilizing still image compression technique, breaking each audio clip into smaller segments, selecting the perceptually significant audio segments to wavelet transform, and quantizing the perceptually significant wavelet coefficients. The proposed watermarking algorithm can extract the watermark image without the help from the original digital audio signals. We also demonstrate the robustness of that watermarking procedure to audio degradations and distortions, e.g., those that result from noise adding, MPEG compression, low pass filtering, resampling, and requantization.  相似文献   

10.
This paper describes a new scheme for feature extraction from facial images on FPGA. The proposed method is comprised of two stages. The first stage uses the 5/3 DWT to decompose the original face image into LL, LH, HL, and HH wavelet coefficient to reduce the size of the image. In the second stage, PCA is employed to extract the face features from the wavelet coefficients. Here we use the power iteration algorithm to find the eigenvector of the covariance matrix. We present an efficient hardware architecture using combination of parallel processing module and serial processing module. This method can take the benefits of parallel usage advantage of FPGAs and can save hardware resources. Complete hardware implemented on a Stratix II FPGA. The experimental results show that the system works with high processing rate and only 21% of the logic resources an FPGA are consumed by face recognition logic Thus it is very suitable for the low cost implementation of the face recognition system.  相似文献   

11.
基于小波包变换的遥感图象融合   总被引:20,自引:2,他引:20       下载免费PDF全文
为了能够更好地把来自多传感器的图象信息综合起来,以提高对图象信息的分析和提取能力,在研究了小波包图象分析法之后,提出了一种基于小波包变换的图象融合方法,由于小波包变换能对图象进行多层次分解,包括对小波变换没有细分的高频部分也能进行进一步的分解,因此小波包分析能够为图象提供一种比小波多分辨分析更加精细的分析方法,利用此融合算法将由多传感器获得的同一目标不同波段的遥感图象和不同分辨率的遥感图象进行融合后得到的融合图象,能够很好地将源图象的细节融合在一起,通过与该融合图象进行主观与客观的评价比较,证明该融合方法可以获得更好的融合效果。  相似文献   

12.
基于多进制小波的多源遥感影像融合   总被引:14,自引:0,他引:14       下载免费PDF全文
首先介绍了遥感影像融合的一般理论和方法,然后在讨论多进制小波理论和影像特征的基础上,提出了一种基于特征的多进制小波变换的影像融合算法,该算法根据待融合影像分辨率之比来确定采用几进制小波,将待融合的高分辨率影像进行多进制小波变换,然后把高分辨影像经小波变换后获得的低频成分和低分辨率影像依据一定的关系进行相互转换,以形成新的高分辨影像的低频成分,经过多进制小波逆变换获得到融合后的影像,最大限度地利用了待融合影像的信息,防止了影像信息的丢失,通过对具体影像的清晰度和空间分辨率,融合后的影像最大限度地保留了待融合影像的光谱信息,同时提高了待融合影像的清晰度和空间分辨率,给出了SPOT全色影像与SPOT多光谱影像,SPOT全色影像与TM影像的融合结果,并与其他方法进行了比较,从而证明了本方法的优越性和自适应能力。  相似文献   

13.
基于双树复小波变换彩色多聚焦图像融合方法   总被引:2,自引:0,他引:2       下载免费PDF全文
针对离散小波变换图像融合算法在特征表达上存在的不足,将双树复数小波变换引入到彩色多聚焦图像融合中。对彩色图像的三个通道分别进行融合处理,并采用基于多测度的融合策略:各通道小波变换后低频子带采用区域清晰度的方法;高频子带采用区域标准差的方法。融合效果评价除使用传统方法的熵、交叉熵外,还使用了通用的主观与客观相结合的方法。通过对实验结果的主客观性能分析,验证了该方法得到的融合图像效果较好,优于离散小波变换融合算法。  相似文献   

14.
周厚奎 《信息与控制》2012,41(3):278-282
提出了一种基于静态小波变换(SWT)和2代曲波(curvelet)变换的图像融合算法.首先将原图像分别进行SWT变换得到高、低频分量.然后,对低频分量采用基于2代曲波变换的方法进行融合,对高频分量基于绝对值最大的方法进行融合.最后进行SWT逆变换得到最终的融合图像.实验结果表明,该算法具有SWT变换和2代曲波变换二者的优点,主客观评价均优于单独SWT变换和单独2代曲波变换融合算法,也优于离散小波变换(DWT)和曲波变换相结合的融合算法.  相似文献   

15.
IHS变换与小波变换相结合的图像融合新方法*   总被引:1,自引:0,他引:1  
提出了一种IHS变换与小波变换相结合的图像融合新方法。对多光谱(TM)图像的强度分量和全色(PAN)图像分别进行小波分解,根据小波变换高低频分量的不同特点,分别采取不同的高低频融合准则形成新的小波高低频分量,再先后进行小波逆变换和IHS逆变换得到融合后的TM图像。实验结果表明,提出的图像融合算法明显改善了融合图像的客观评价和主观视觉效果。  相似文献   

16.
针对传统NSCT图像融合算法存在的不足,提出一种基于增补小波变换和PCNN的NSCT域图像融合算法。首先对源图像进行NSCT分解,生成一系列低频和高频分量。对低频分量利用二维小波分解,生成一个低频和三个方向分量,对低频分量利用局部区域能量加权方法融合,三个方向分量利用改进的高斯加权SML方法融合;对NSCT分解的高频分量,分为对最高层和其它层的融合,最高层利用改进的高斯加权SML方法融合,其余层利用边缘梯度信息激励PCNN方法融合。最后对NSCT进行逆变换得到融合图像。实验结果证实了所提算法的有效性。  相似文献   

17.
小波包分析将频带进行多层次划分,对小波多分辨分析没有细分的高频部分也进行了进一步的分解。本文在研究了小波包图像分析法后,提出了基于小波包变换的象素级图像融合算法。通过把同一目标的多传感器获得的不同波段的图像数据利用小波包变换进行融合,得到融合图像。这种方法能够很好地将源图像的细节融合在一起,完好地显示了源图像各自的信息。  相似文献   

18.
This paper presents a new wavelet-based algorithm for the fusion of spatially registered infrared and visible images. Wavelet-based image fusion is the most common fusion method, which fuses the information from the source images in the wavelet transform domain according to some fusion rules. We specifically propose new fusion rules for fusion of low and high frequency wavelet coefficients of the source images in the second step of the wavelet-based image fusion algorithm. First, the source images are decomposed using dual-tree discrete wavelet transform (DT-DWT). Then, a fuzzy-based approach is used to fuse high frequency wavelet coefficients of the IR and visible images. Particularly, fuzzy logic is used to integrate the outputs of three different fusion rules (weighted averaging, selection using pixel-based decision map (PDM), and selection using region-based decision map (RDM)), based on a dissimilarity measure of the source images. The objective is to utilize the advantages of previous pixel- and region-based methods in a single scheme. The PDM is obtained based on local activity measurement in the DT-DWT domain of the source images. A new segmentation-based algorithm is also proposed to generate the RDM using the PDM. In addition, a new optimization-based approach using population-based optimization is proposed for the low frequency fusion rule instead of simple averaging. After fusing low and high frequency wavelet coefficients of the source images, the final fused image is obtained using the inverse DT-DWT. This new method provides improved subjective and objectives results as compared to previous image fusion methods.  相似文献   

19.
和小波变换相比较,曲波变换能更好地表示图像的边缘信息.在此基础上给出了一种基于曲波变换的图像融合方法,并将其应用于红外和可见光图像融合.首先,对红外图像和可见光图像分别进行曲波变换,得到两幅图像的低频分量和不同尺度的高频分量.在对源图像的各分量融合时,对低频分量采用平均加权进行融合.对高频分量采用取绝对值较大的方法进行融合,得到融合后的低频分量和不同尺度的高频分量,最后对这些融合后的分量进行重构,得到融合图像.仿真结果表明:和基于小波变换的融合算法相比较,该算法较好地保留了源图像的细节信息,提高了融合的效果.  相似文献   

20.
为了解决折反射成像内外环分辨率低且不均匀的问题,针对互补全景图像的特点,提出了一种基于小波多尺度分解的图像融合方法。首先对两幅互补的源图像分别进行小波多尺度分解,得到不同分辨率、不同方向的分量;其次,按照特定的融合策略,低频采用平均算子进行融合,高频采用逐层互换的融合策略进行融合;最后,通过小波逆变换得到融合图像。实验结果表明,该方法在互补全景图像的融合中简单有效,并且拥有较好的效果。  相似文献   

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