This paper proposes an RST−invariant multi−bit watermarking system based on LPM and DFT. This system embeds the watermark in a rotation and translation invariant domain obtained by first acquiring log−polar mapped DFT (LPM−DFT) magnitudes of an image, and then taking the magnitude of the 1−dimensional DFT along the angular axis of this LPM−DFT magnitudes. Neither the original cover image nor a ...

In this paper, we propose a novel watermarking based on the spatial q-log domain. After decomposing the RGB information of the cover image, we apply the q-log transform to obtain the q-log domain frequency. We embed the watermark into the low-frequency of q-SVD domain in order to achieve the robustness of watermark. We choose in our method the Quantization Index Modulation (QIM) based watermark...

Matching of keypoints across image patches forms the basis of computer vision applications, such as object detection, recognition, and tracking in real-world images. Most of keypoint methods are mainly used to match the high-resolution images, which always utilize an image pyramid for multiscale keypoint detection. In this paper, we propose a novel keypoint method to improve the matching perfor...

This paper evaluates the performance of an image compression system based upon the complex logarithmic conformal mapping. A staple in the robotics and visual systems fields, our attempts were to investigate the application of this algorithm in the field of image compression. The characteristics predisposed to the log sensor include a foveal region centered around the focal point which generates...

Space-variant sensing is the architectural basis of all higher vertebrate visual systems (Schwartz, 1994). One evident motivation for this is that the spacecomplexity of the human visual system is reduced by up to four orders of magnitude (Rojer and Schwartz, 1990) via the use of space-variant architecture (jar a given ratio of field width to maximum resolution). This observation has obvious pr...

Rotation, Shifting, and Translation (RST) invariant image watermarking is a very important research topic. In this letter, we report a new filtering method in the log-polar mapping (LPM), and a novel rectification method that can be used in any RST invariant image watermarking algorithms. We get a log-polar mapping of an image by calculating the Fourier transform of the image and resampling the...

Synthetic aperture radar (SAR) images are mainly denoised by multiplicative speckle noise, which is due to the consistent behavior of scattering phenomenon known as speckle noise. This paper presents the basic concept, role and importance of Discrete Wavelet Transform (DWT) in the field of despeckling SAR images and also offers a study of SAR image quality on applying DWT on the speckled image ...

In order to solve the problem of rotation invariant texture image retrieval, an image retrieval algorithm based on Log-Polar and nonsubsampled contourlet transform (NSCT) is proposed. Log-Polar transform was first applied to texture image to convert the rotation to translation. Then, translation invariant NSCT was employed to decompose the transformed images. Standard deviations, energies and e...

In this paper we expose the development of a CBIR system (Content-based Image Retrieval) that is able to retrieve images from a corpus based upon the image content. In order to obtain such functionality, the system establishes a set of characteristics which will be automatically generated. This allows the system to univocally identify each image from the collection. The sort of characteristics ...

We explored the suitability of the log-Gabor method, a speech analysis method inspired by Ezzat e.a. (2007), for automatic classification of personality and likability traits in speech. The core idea underlying the log-Gabor method is to treat the spectrogram as an image of spectro-temporal information. The image is transformed into Gabor energy values using the twodimensional logarithmic Gabor...