Digital watermarking has been widely used in copyright protection for digital images, but most of the watermarking algorithm can't resist print-and-scan process. Print-and-scan attack is a challenging problem for most of digital watermarks. A watermarking algorithm against print-and-scan attack based on PSO (Particle Swarm Optimization) is proposed in this paper. The watermark information is em...

The key to medical image denoising technique is to remove the noise while preserving important features. Non-local mean filtering and bilateral filtering are commonly used procedures for medical image denoising. In this paper analysis and comparison of spatial as well as frequency domain methods including bilateral filtering , non-local mean filtering, wavelet thresholding, contourlet threshold...

A new robust adaptive fusion method for double-modality medical image PET/CT is proposed according to the Piella framework. The algorithm consists of following three steps. Firstly, registered PET and CT images are decomposed using nonsubsampled contourlet transform (NSCT). Secondly, in order highlight lesions low-frequency image, components fused by pulse-coupled neural network (PCNN) that has...

Contourlet is a new image representation method, which can efficiently represent contours and textures in images. In this paper, we analyze the distribution of significant contourlet coefficients in different subbands and propose a contourlet image coding algorithm by constructing a virtual low frequency subband and adjusting coding method of SPIHT (Set Partitioning in Hierarchical Trees) algor...

Medical image fusion plays an important role in diagnosis and treatment of diseases such as image-guided radiotherapy and surgery. The modified local contrast information is proposed to fuse multimodal medical images. Firstly, the adaptive manifold filter is introduced into filtering source images as the low-frequency part in the modified local contrast. Secondly, the modified spatial frequency...

This paper presents a parallel implementation of color image segmentation algorithm using multiresolution technique. The idea is to achieve the complete and significant objects in the image using contourlet transform based image segmentation and to explore current multi-core architectures present in commercial processors in order to speed up the segmentation process for large size images. The a...

The authors propose a new hybrid watermarking scheme for copyright protection of color images using contourlet transform and singular value decomposition. The host color image and color watermark images are decomposed into directional sub-bands using contourlet transform and then applied Singular value decomposition to mid frequency sub-band

We propose a new method for image de-noising based on the contourlet transform, which has been recently introduced. Image de-noising by means of the contourlet transform introduces many visual artifacts due to the Gibbs-like phenomena. Due to the lack of translation invariance of the contourlet transform, we employ a cycle-spinning-based technique to develop translation invariant contourlet de-...

This paper presents a novel non-blind watermarking algorithm using contourlet transform. The contourlet transform is preferred for watermarking because of its ability to capture the directional edges and contours superior to other transforms such as cosine transform, wavelet transform, etc. Watermark is encrypted and embedded into high frequency directional subband, which is obtained by perform...

Since interference noise and limited imaging algorithm etc caused low-quality images, continuous contour information on targets was difficult to extract, and ISAR imaging on aerial targets wasn’t ideal. On this basis, a new method of image processing is proposed to achieve clearer continuous contour features on targets. The method combines denoising technique based on Contourlet transform with ...