2009 16th IEEE International Conference on Image Processing (ICIP)

This paper proposes a computationally efficient approach of adaptive directional wavelet transform (AD WT). The AD WT is based on lifting implementation of WT, and it is able to transform an image along diagonal orientations as well as traditional horizontal and vertical directions. The AD WT sacrifices computational speed for its good image coding performance. We present an alternative method to ... View full abstract»

JPEG-XR is a new image compression standard that aims at achieving state-of-the-art image compression, while simultaneously keeping the encoder and decoder complexities as low as possible. JPEG-XR is based on Microsoft technology known as HDPHOTO and makes use of a block-transform. This transform, known as Lapped Biorthogonal Transform (LBT), requires only a small memory footprint while providing ... View full abstract»

We propose an iterative method for the optimization of a set of 2-D separable transforms for a given training data set. The method outputs orthonormal transforms, each one being optimal for a subset of the data with respect to a sparsity-based objective function. The vertical and horizontal directions of the transform may be different, thus allowing directional-adapted transforms (in contrast to t... View full abstract»

Intra-predictive transforms are a kind of block-based transforms that can exploit both the intra- and inter-block correlations. This paper analyzes the coding gains of intra-predictive transforms for the Gaussian process. The tight upper bound of the coding gain is derived, which is shown to be better than both the discrete cosine transform and the Karhunen Loe¿ve transform. The optimal intra-pre... View full abstract»

In this report, we propose a reversible two dimensional (2D) discrete wavelet transform (DWT) compatible to the irreversible 9-7 DWT for lossy coding in the JPEG 2000. All the filters and scalings are factorized into lifting steps, and signals are rounded into integers, so that the proposed DWT becomes reversible and applicable to lossless coding. Furthermore, we factorize the separable 2D transfe... View full abstract»

Transform coding is a essential tool for picture coding applications, and coding schemes that can achieve high energy compaction are essential. In terms of energy compaction, Karhunen-Loeve transform (KLT) is known to be optimal. The energy compaction provided by KLT depends on the statistical property of the input signal and the dimensionality of KLT. However, the quantitative effect of KLT dimen... View full abstract»

The paper presents a dictionary construction method for spatial texture prediction based on sparse approximations. Sparse approximations have been recently considered for image prediction using static dictionaries such as a DCT or DFT dictionary. These approaches rely on the assumption that the texture is periodic, hence the use of a static dictionary formed by pre-defined waveforms. However, in r... View full abstract»

This paper proposes an image coding method based on adaptive downsampling which not only uses the pixel redundancy but also considers visual redundancy. At the encoder side, codec adaptively chooses some smooth regions of the original image to downsample, and then overlapped transform with selectivity, block DCT and adaptive-shape DCT (SA-DCT) are used against the image after being downsampled. Fo... View full abstract»

In this work, we elaborate on a rather intuitive hypothesis: face recognition of low-resolution faces can be improved if the processes of reconstruction and recognition are considered simultaneously, instead of sequentially, without feedback or any interaction. Given a high-resolution training set, matching low-resolution probe images with good accuracy is an open problem. We have recently introdu... View full abstract»

We propose to utilize micro features, namely facial marks (e.g., freckles, moles, and scars) to improve face recognition and retrieval performance. Facial marks can be used in three ways: i) to supplement the features in an existing face matcher, ii) to enable fast retrieval from a large database using facial mark based queries, and iii) to enable matching or retrieval from a partial or profile fa... View full abstract»

This work focuses on performance assessment of software applications designed to evaluate the compliance of a face image to the ISO/ICAO standards for machine readable travel documents. In this paper we describe the new large database (of compliant and non-compliant images) we gathered, the associated testing protocol and the preliminary results measured on some existing algorithms. View full abstract»

Patch-based approaches have become popular in many computer vision applications over recent years. An intrinsic flaw of this framework, missing of the spatial information, however, restricts its usage in face related applications where the spatial configuration is relatively settled. In this paper, we introduce a new patch feature representation, namely spatial Gaussian mixture models (SGMM), whic... View full abstract»

In this paper, we present a novel method for 3D face recognition using adaboosted geodesic distance features. Firstly, a generic model is finely conformed to each face model contained within a 3D face dataset. Secondly, the geodesic distance between anatomical point pairs are computed across each conformed generic model. Adaboost then generates a strong-classifier based on a collection of geodesic... View full abstract»

Facial appearances change with increase in age. While generic growth patterns that are characteristic of different age groups can be identified, facial growth is also observed to be influenced by individual-specific attributes such as one's gender, ethnicity, life-style etc. In this paper, we propose a facial growth model that comprises of transformation models for facial shape and texture. We col... View full abstract»

This paper proposes a new method for removing specularity from face images so that albedo (diffuse reflectivity) can be accurately estimated. Our method utilizes common structural properties of face images to estimate the Lambertian component (including shadows) without using albedo, then specularity is separated as the positive component of the difference between the estimated Lambertian componen... View full abstract»

Unconstrained face recognition is the problem of deciding if an image pair is showing the same individual or not, without having class specific training material or knowing anything about the image conditions. In this paper, an approach of learning suited similarity measurements is introduced. For this the image is partitioned into several parts, to extract image region based histograms of gradien... View full abstract»

In this paper a new general methodology is introduced for the determination of the method of construction of prehistoric wall-paintings. The approach consists of algorithms that perform a) preprocessing of the contours of the figures appearing in the wall-paintings, b) determination of pattern repetitions in the contours of the depicted entities, c) classification of these repeated patterns into p... View full abstract»