Towards Benchmarking Scene Background Initialization

Given a set of images of a scene taken at different times, the availability of an initial background model that describes the scene without foreground objects is the prerequisite for a wide range of applications, ranging from video surveillance to computational photography. Even though several methods have been proposed for scene background initialization, the lack of a common groundtruthed dataset and of a common set of metrics makes it difficult to compare their performance. To move first steps towards an easy and fair comparison of these methods, we assembled a dataset of sequences frequently adopted for background initialization, selected or created ground truths for quantitative evaluation through a selected suite of metrics, and compared results obtained by some existing methods, making all the material publicly available.Comment: 6 pages, SBI dataset, SBMI2015 Worksho

A web-based digital analysis interface for image quality assessment

Image processing and transmission systems may introduce some amount of distortion or artefacts in a digital image. This fact usually leads to a visual or statistical image quality assessment (IQA) required in many applications and research studies in order to analyse a product image in terms of deteriorations as well as effects of the processing. There are numerous IQA criteria presented in the literature separately that makes it really difficult both for use in comparative analyses and for educational purposes. In this presented work, a user friendly webbased digital educational interface for full-reference or no-reference image quality assessment using MATLAB builder NE has been developed. In addition to this, developed system performs user-defined optional deteriorations (median noise, Gaussian blur, motion blur, high-pass filter and jpeg compression) on the image and assesses deterioration of the image. It is an extremely easy, fast and economical way of analysing digital images, especially designed for researchers, graduate and postgraduate students who work on digital image processing. Using this webbased tool well contributes to teaching all of the IQA methods and quality effects of systematic distortions on the image as well as establishes a scientific benchmark for researchers

A New DCT Based Watermarking Method Using Luminance Component

The main purpose of the digital watermarking is to provide information security and copyright protection. From this point of view, a robust blind watermarking method based on Discrete Cosine Transform for colour images is proposed in this paper. The proposed method provides hiding a binary watermark in a compressed Digital Colour Image. First, the Digital Color Image is transformed into YCbCr from RGB color space and then the Discrete Cosine Transform middle band of the luminance (Y) component is used for watermarking processes. Each bit of the binary watermark is embedded in a different Discrete Cosine Transform block. Thus, deterioration on the image is minimized achieving high invisibility. The situation is checked whether the watermark is lost after the image saved. If the watermark is lost in any block, the average of some neighbouring Discrete Cosine Transform coefficients is used for embedding the watermark bit. The experimental results show that the proposed method can be safely used when point of interest is binary watermarks. Moreover, extraction processes do not need the cover image and the watermark is recovered completely. Statistical and perceptual quality evaluations show that the proposed method is better than its counterparts

Results of hypofractionated whole brain radiotherapy (2x8 Gy) for patients with brain metastases from lung cancer

WOS: 000292578200006PubMed ID: 21766491Purpose: To evaluate the clinical and radiologic response rates, toxicity and tolerability of 2x8 Gy whole brain radiotherapy (WBRT) in lung cancer patients with brain metastases (BM). Methods: WBRT was delivered to 126 lung cancer patients with BM during 2002-2006. External beam RT was delivered with a fraction dose of 8 Gy on the same day of each consecutive week Tumor and symptom response and toxicity were recorded at every follow-up. Recursive partitioning analysis (RPA) and the new Graded Prognostic Assessment (GPA) were used for analysis of overall survival (OS). Results: Twenty-three patients had small cell (SCLC) and 103 had non small cell lung cancer Pretreatment median Karnofsky performance score (KPS) was 70 (range 20-90). Clinical response rates were as follows: complete 31%; good partial 30.2%; partial 21.4%; stable 7.9%; and progressive 5.6%. Median palliation and survival duration was 57 and 80 days, respectively. Two- and 6-month survival rates (SR) were 59.5% and 25.4%, respectively. According to recursive partitioning analysis (RPA) 6-month SR for groups 1, 2 and 3 were 61.5, 41.6 and 33.9%, respectively (p=0.002). Six-month SR for the new Graded Prognostic Assessment (GPA) were: GPA 0-1, 7%; GPA 1.5-2.5, 34.2%; GPA 3, 25%; and GPA 3.5-4.0, 66.6% (p=0.0003). Conclusion: 2x8 Gy WBRT was found to be feasible. However the late morbidity of this schedule is unknown so its use could be restricted to patients with poor performance status, with a short life expectancy and/or social problems, unlikely to tolerate more protracted radiotherapy regimens