Wyniki wyszukiwania - BazTech

1

FPGA-based secure and noiseless image transmission using lea and optimized bilateral filter

Hebbale Sunil B., Akula V.S. Giridhar, Baraki Parashuram

Computer Science

|

2022

|

T. 23 (4)

451--466

EN

In today’s world, the transmission of secured and noiseless images is a difficult task. Therefore, effective strategies are important for securing data or secret images from attackers. Besides, denoising approaches are important for obtaining noise-free images. For this, an effective crypto-steganography method that is based on a lightweight encryption algorithm (LEA) and the modified least significant bit (MLSB) method for secured transmission is proposed. Moreover, a bilateral filter-based whale optimization algorithm (WOA) is used for image denoising. Before the image transmission, a secret image is encrypted by the LEA algorithm and embedded into the cover image using discrete wavelet transform (DWT) and MLSB techniques. After the image transmission, an extraction process is performed in order to recover the secret image. Finally, a bilateral WOA filter is used to remove the noise from the secret image. The Verilog code for the proposed model is designed and simulated in Xilinx software. Finally, the simulation results show that the proposed filtering technique results in performance that is superior to conventional bilateral and Gaussian filters in terms of the peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM).

2

A homomorphic non-subsampled contourlet transform based ultrasound image despeckling by novel thresholding function and self-organizing map

Singh Prabhishek, Diwakar Manoj, Singh Shilpi, Kumar Sarvesh, Tripathi Amrendra, Shankar Achyut

Biocybernetics and Biomedical Engineering

|

2022

|

Vol. 42, no. 2

512--528

EN

The speckle noise leaves an adverse effect on ultrasound images due to which loss of information occurs. Hence this paper proposes a homomorphic Non-Subsampled Contourlet Transform (NSCT) based ultrasound image despeckling technique using a novel thresholding function, bilateral filter, and self-organizing map (SOM). The bilateral filter is utilized over the low-pass NSCT sub-band for speckle component removal and sharp features. To get better noise suppression and edge preservation, a novel thresholding function is proposed and performed over the high-pass NSCT sub-band. In the proposed method, Kohonen’s SOM is implemented as a post-processing step for deblurring purposes. The significance of the proposed scheme is also tested where it was found that using Kohonen’s SOM as post-processing works better than without post-processing. Experimental outcomes were also evaluated on real speckled ultrasound images and synthetic added speckled noisy images. The results are evaluated and compared using visual analysis and performance metrics using with and without reference images. For more critical analysis, intensity profile along a line and experts observation were also evaluated to find the performance analysis of the proposed methodology. From all experimental and comparative evaluations, it was found that the proposed approach gives better outcomes compared to similar and recent methods.

3

A multistep approach for micro tomography obtained medical image segmentation

Buczkowski M., Saeed K.

Journal of Medical Informatics & Technologies

|

2014

|

Vol. 23

69--76

EN

This paper presents a multistep approach for segmentation of micro tomography images. Various images of porous structures were studied. Proper segmentation of that images is necessary to create 3D models of these structures. The introduced algorithm concerns finding the proper way of image filtering before the use of Canny-Deriche edge detection to obtain the best possible segmentation.

4

Eliminacja zakłóceń przy zachowaniu ostrości krawędzi obiektów w obrazach cyfrowych

Bieda R.

Zeszyty Naukowe. Automatyka / Politechnika Śląska

|

2006

|

z. 146

105-128

PL

W artykule przedstawiona została propozycja nowego filtra dolno-przepustowego, zachowującego wyrazistość brzegów obiektów w scenie obrazowej. Wyniki filtracji porównane zostały z efektami działania innych algorytmów filtracji zastosowanych do obrazów zakłóconych szumem typu gaussowskiego i impulsowego. Prezentowany algorytm filtracji może być używany jako etap wstępny w obróbce obrazów przed dalszym procesem detekcji krawędzi obiektów w obrazie.

EN

In this paper a novel low-pass edge preserving filter is presented. The new algorithm is based on modification of weighted function used in the Gauss filter. The efficiency of the new filter is compared under a variety of performance criteria with the commonly used filters, such as the vector median and the anisotropic diffusion schemes. It is shown that, compared to existing techniques, the new technique are better able to suppress impulsive, Gaussian as well as mixed type noise. The presented filtering scheme can be used as a preliminary stage of edge detection algorithms.