Antonio Cedillo-Hernandez

Transcoding resilient video watermarking scheme based on spatio-temporal HVS and DCT

Video transcoding is a legitimate operation widely used to modify video format in order to access the video content in the end-users devices, which may have some limitations in the spatial and temporal resolutions, bit-rate and video coding standards. In many previous watermarking algorithms the embedded watermark is not able to survive video transcoding, because this operation is a combination of some aggressive attacks, especially when lower bit-rate coding is required in the target device. As a consequence of the transcoding operation, the embedded watermark may be lost. This paper proposes a robust video watermarking scheme against video transcoding performed on base-band domain. In order to obtain the watermark robustness against video transcoding, four criteria based on Human Visual System (HVS) are employed to embed a sufficiently robust watermark while preserving its imperceptibility. The quantization index modulation (QIM) algorithm is used to embed and detect the watermark in 2D-Discrete Cosine Transform (2D-DCT) domain. The watermark imperceptibility is evaluated by conventional peak signal to noise ratio (PSNR) and structural similarity index (SSIM), obtaining sufficiently good visual quality. Computer simulation results show the watermark robustness against video transcoding as well as common signal processing operations and intentional attacks for video sequences.

Improved unseen-visible watermarking for copyrigth protection of digital image

Nowadays consumers of worldwide can capture digital image and video scene using several multimedia devices such as smartphones, tablets and cameras. Thus, the data captured may be easily copied or transmitted without any control and as consequence the intellectual property of the owner can be infringed, causing economic or moral damages. This fact suggests the necessity to develop security tools such as watermarking, to confront problems associated with the copyright protection. In this paper we propose an improved unseen-visible watermarking algorithm for copyright protection of digital color images. Unseen-visible watermarking is a recent approach that takes advantages of the visible and invisible watermarking, such as the readability and imperceptibility respectively, preserving the robustness of both. The design of the proposed method is based on Just Noticeable Difference (JND), Total Variation-based image decomposition and an image enhancement criterion. The watermark can be readable with a naked eye through the manipulation of image enhancement of the display device. Experimental results show that the scheme is effective for digital color images, preserving a high imperceptibility and its computational complexity is low.

Content Based Video Retrival System for Mexican Culture Heritage Based on Object Matching and Local-Global Descriptors

Multimedia data and networking technologies have had a highly growing during the last decade, with these changes users have changed from text to content based video retrieval systems due to its better performance. We propose a fast content-based video retrieval system which involves the combination of a local descriptor obtained from the speeded-up robust feature algorithm together with an effective and fast object matching operation. To save computational time, compressed video data are partially decoded in order to get discrete cosine transform coefficients of key frames, which are used to obtain sub-block coefficients and a down-sampling version of frames. The preliminary results are ranking using an efficient color descriptor based on color correlogram and dominant color descriptors. To measure the performance of the proposed technique the precision and recall metrics are used. The experimental results show the accuracy of the proposed method applied to a database of Mexican Culture Heritage videos.

Digital image ownership authentication via camouflaged unseen-visible watermarking

In recent years, end users can easily capture digital images using several devices, such as smartphones, mobile devices and digital imaging cameras, allowing such images to be easily copied, manipulated, transmitted or format converted without any restrictions. This fact suggests the necessity to develop digital tools, such as digital watermarking, to solve the issues associated with copyright protection and ownership authentication of digital images. To claim the ownership of a digital image, we propose a camouflaged, unseen-visible watermarking technique based on luminance and texture properties in conjunction with an image enhancement criterion. The proposed method has some advantages over invisible and visible watermarking methodologies in terms of readability and imperceptibility of the watermark, respectively. The experimental results demonstrate that the proposed scheme is effective and applicable for digital images on a variety of topics, including natural scenes and man-made objects, both indoors and outdoors. A comparison with previously reported methods based on unseen-visible watermarking techniques is also provided.

A spatiotemporal saliency-modulated JND profile applied to video watermarking

Abstract The just noticeable distortion (JND) has been considered a suitable solution for controlling the watermark strength and generating robust watermarking schemes with distortions that are below the sensitivity threshold. However, JND assumes the same attention level for all image regions, which does not reflect the behavior of an observer. Recently, several models have utilized the modulatory effect of visual attention over JND to improve the efficiency of watermarking schemes. However, most of them have focused on still images. In this paper, we propose a saliency-modulated JND profile for improving video watermarking schemes. Our method aims to adapt the watermark strength to obtain the most robust possible scheme with an imperceptible watermark. Moreover, it has the advantage of fully exploiting the spatiotemporal properties of video to minimize its perceptual redundancies and achieve low computational complexity. Experimental results show the effectiveness of our proposed method and its contributions to video watermarking process.

An Improved Imperceptible Visible Watermarking Algorithm for Auxiliary Information Delivery

An imperceptible visible watermarking (IVW) algorithm is proposed to deliver auxiliary information about the visual contents, including ownership information. The proposed algorithm overcomes several inconveniences presented in previously reported IVW algorithms using the just noticeable difference (JND) criterion, invisible watermarking and binarisation function. The proposed algorithm consists of the visible watermark embedding and the exhibition stages. The JND criterion is used to embed visible watermark pattern in an imperceptible manner by the human visual system, while invisible watermarking based on the discrete cosine transform is used to share crucial parameters between both stages, which makes possible the watermark visualisation without any side information. In the watermark exhibition stage, the imperceptibly embedded visible watermark pattern is exhibited by the binarisation function. The proposed algorithm can be applied to any class of images with different characteristics and several visible watermark patterns can be embedded into an input image. Evaluation results show that performance of the proposed algorithm is better compared with previously reported algorithms from several practical points of view.

An Efficient Content-Based Video Retrieval for Large Databases

Multimedia data grows fast due to advances in information technologies, creating the demand for efficient video indexing and object retrieval techniques. Traditional methods consume significant computational resources such as storage space and processing time. In this paper we propose an efficient content-based video retrieval system that is based on three main stages. The first stage involves computing the DCimage of each I-frame, from which a summarization process to extract key-frames is performed. During the second stage, a segmentation processes is applied to each key-frame in order to isolate the region of interest within it. Local features are extracted from the resulting area and are stored as the descriptor of the frame. The retrieval stage is carried out by computing the Euclidean distance and determines if its content is related with the video database. Experimental results show that the proposed approach is promising in terms of efficiency and effectiveness.

Customer Authentication of Digital Imaging Using Hybrid Watermarking

In this paper, we present a robust and imperceptible hybrid watermarking method in order to be applied to digital color images with the purpose of detecting illegal copies, using a customer robust authentication. In order to improve the robustness of the proposed method against several common signal processing and geometrical attacks, two different algorithms for embedding a unique watermark are used. The watermark is composed by a binary pattern obtained from a cryptographic hash of the customer data. Discrete Fourier Transform (DFT) and a bi-dimensional histogram, both into the YCbCr color model domain, are used to embed the watermark bit sequence. The quality of the watermarked image is measured using the following well-known indices peak signal to noise ratio (PSNR), mean square error (MSE) and structural similarity index (SSIM). Experimental results show the robustness of the proposed method preserving at the same time a high quality on the host image.

Mexican archaeological image retrieval based on object matching and a local descriptor

Content-based image retrieval (CBIR) is a hard task which consists in retrieving similar content from a large multimedia database. In the literature, in order to extract descriptors from the images the CBIR techniques use several low-level features such as color, texture, shape, contours, among others. In the recent years, several local descriptors based on the detection of feature points have been used to retrieve the most similar images with different geometric and photometric characteristics. In this paper we propose a CBIR technique that involves the combination of a local descriptor obtained from the Speeded Up Robust Feature (SURF) algorithm together with an effective and fast object matching operation in order to improve the search speed and the retrieval accuracy related to the Mexican archaeological imaging. In order to reduce the computational complexity of the proposed method, Quarter Common Intermediate Format (QCIF) is used previous of computing the SURF descriptor. To measure the performance of the proposed technique the precision and recall metrics are used. The experimental results show the accuracy of the proposed CBIR technique applied to a data base of Mexican culture images that are captured by several environmental conditions and different acquisition equipment.

Copyright Protection in Video Distribution Systems by Using a Fast and Robust Watermarking Scheme

In this paper we propose a watermarking scheme to ensure copyright protection in video distribution systems. This research is focused on provide a low computational cost solution that allows embedding a robust and imperceptible watermarking signal in the video content, such that the original video transmission rate will not be affected. Our proposal accomplishes this challenge by introducing a fast and effective method based on spatio-temporal Human Visual System properties that allow improving imperceptibility along video sequence and at the same time, enhancing robustness. Extensive experiments were performed to prove that the proposed algorithm satisfies quickness, invisibility and robustness against several real-world video processing issues. The proposed scheme has the advantages of robustness, simplicity and flexibility, allowing it to be considered a good solution in practical situations since it can be adapted to different video distribution systems.