Search - frequency levels of image

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[Special Effects] medicalcengshu DL : 0: ：根据小波低频子带图像的轮廓模糊度和高频子带图像的细节信息量随小波分解层数增多而增多的规律，从图像熵出发，提出了一种基于低频子带图像熵差的最佳小波分解层数选择法, 该方法通过计算不同分解层数下各低频子带的图像熵差，选择最接近原始图像熵差的分解层数作为最佳分解层数。用多种基于小波变换的图像融合法分别对两组医学图像进行仿真实验，结果表明根据该分解层数选择法得到的融合图像目视效果最好，与相关系数、峰值信噪比、模糊Chebyshev 距离值等客观评价指标保持了很好的一致性。 -Abstract：According to the law that the contour fuzziness of the low-frequency sub-band and the detail information of the high-frequency sub-band increase with the growth of the wavelet decomposition levels, an effect selection method of the optimal decomposition level is proposed. Firstly, the difference of original image entropy is calculated. Then, the differences of the low-frequency sub-image entropy based on different decomposition level are calculated. Finally, the decomposition level which makes the difference of the low-frequency sub-image entropy closest to the difference of original image entropy is found. This level is the optimal decomposition level. To fuse two groups of medical images, simulation experiments are done by use of the wavelet transform and the PCA transform based on wavelet. The experimental result indicates that the fusion image used by the proposed method has the best subjective feeling of human being, and it has very good compatibility to objective
Date : 2025-12-28 Size : 157kb User : 杨颜华
[Special Effects] wavelet-image DL : 0: 二维图像信号的去噪步骤：（1）二维图像信号的小波分解。选择合适的小波与恰当的分解层次N，并对待压缩的二维图像信号进行N层分解计算。（2）对分解后的每一层高频系数，选择一个恰当的阈值，并对该层高频系数进行软阈值量化处理。（3）二维图像信号的小波重构。用小波分解后的第N层近似（低频系数）和经过阈值量化处理后的各层细节（高频系数），对二维信号进行小波重构。-Two-dimensional image signal denoising steps: (1) two-dimensional image signal wavelet decomposition. Select the appropriate wavelet decomposition level and the appropriate N, and treatment of compressed N-layer two-dimensional image signal decomposition calculations. (2) of the decomposition of high-frequency coefficients of each layer, select an appropriate threshold, and high-frequency coefficients of the layer of soft threshold quantification. (3) Wavelet two-dimensional image reconstruction. Wavelet decomposition of the first N-layer approximation (low frequency factor) and through the quantification of threshold levels after the details (high frequency coefficients), two-dimensional wavelet reconstruction signal.
Date : 2025-12-28 Size : 4kb User : lujun
[Special Effects] zhifangtu DL : 0: 通过统计视频图像各帧图像某像素在不同灰度级区间内的频数来提取背景图像-STATS video image each frame image of a certain pixel in a frequency within the interval of the different gray levels to extract a background image
Date : 2025-12-28 Size : 1kb User : 袁阳
[Special Effects] guidinghua DL : 0: 利用MATLAB，求图像的各级像素、频率，绘制图形直方图、规定化直方图，进行分析-Use MATLAB, seeking all levels of image pixels, frequency, graphing histograms, histogram provisions for analysis
Date : 2025-12-28 Size : 1kb User : 南志强