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1.
IEEE Trans Pattern Anal Mach Intell ; 43(12): 4272-4290, 2021 12.
Article En | MEDLINE | ID: mdl-32750769

What is the current state-of-the-art for image restoration and enhancement applied to degraded images acquired under less than ideal circumstances? Can the application of such algorithms as a pre-processing step improve image interpretability for manual analysis or automatic visual recognition to classify scene content? While there have been important advances in the area of computational photography to restore or enhance the visual quality of an image, the capabilities of such techniques have not always translated in a useful way to visual recognition tasks. Consequently, there is a pressing need for the development of algorithms that are designed for the joint problem of improving visual appearance and recognition, which will be an enabling factor for the deployment of visual recognition tools in many real-world scenarios. To address this, we introduce the UG 2 dataset as a large-scale benchmark composed of video imagery captured under challenging conditions, and two enhancement tasks designed to test algorithmic impact on visual quality and automatic object recognition. Furthermore, we propose a set of metrics to evaluate the joint improvement of such tasks as well as individual algorithmic advances, including a novel psychophysics-based evaluation regime for human assessment and a realistic set of quantitative measures for object recognition performance. We introduce six new algorithms for image restoration or enhancement, which were created as part of the IARPA sponsored UG 2 Challenge workshop held at CVPR 2018. Under the proposed evaluation regime, we present an in-depth analysis of these algorithms and a host of deep learning-based and classic baseline approaches. From the observed results, it is evident that we are in the early days of building a bridge between computational photography and visual recognition, leaving many opportunities for innovation in this area.

2.
IEEE Trans Pattern Anal Mach Intell ; 34(10): 2071-7, 2012 Oct.
Article En | MEDLINE | ID: mdl-22585096

We address the problem of motion deblurring using coded exposure. This approach allows for accurate estimation of a sharp latent image via well-posed deconvolution and avoids lost image content that cannot be recovered from images acquired with a traditional shutter. Previous work in this area has used either manual user input or alpha matting approaches to estimate the coded exposure Point Spread Function (PSF) from the captured image. In order to automate deblurring and to avoid the limitations of matting approaches, we propose a Fourier-domain statistical approach to coded exposure PSF estimation that allows us to estimate the latent image in cases of constant velocity, constant acceleration, and harmonic motion. We further demonstrate that previously used criteria to choose a coded exposure PSF do not produce one with optimal reconstruction error, and that an additional 30 percent reduction in Root Mean Squared Error (RMSE) of the latent image estimate can be achieved by incorporating natural image statistics.

3.
IEEE Trans Pattern Anal Mach Intell ; 33(3): 647-54, 2011 Mar.
Article En | MEDLINE | ID: mdl-21252401

This paper examines large partial occlusions in an image which occur near depth discontinuities when the foreground object is severely out of focus. We model these partial occlusions using matting, with the alpha value determined by the convolution of the blur kernel with a pinhole projection of the occluder. The main contribution is a method for removing the image contribution of the foreground occluder in regions of partial occlusion, which improves the visibility of the background scene. The method consists of three steps. First, the region of complete occlusion is estimated using a curve evolution method. Second, the alpha value at each pixel in the partly occluded region is estimated. Third, the intensity contribution of the foreground occluder is removed in regions of partial occlusion. Experiments demonstrate the method's ability to remove the effects of partial occlusion in single images with minimal user input.


Algorithms , Image Interpretation, Computer-Assisted/instrumentation , Imaging, Three-Dimensional/instrumentation , Pattern Recognition, Automated/methods , Artificial Intelligence , Image Enhancement/methods , Sensitivity and Specificity , Subtraction Technique
5.
Hematol Oncol ; 26(2): 73-81, 2008 Jun.
Article En | MEDLINE | ID: mdl-18324639

Many cellular processes converge on the proteasome, and its key regulatory role is increasingly being recognized. Proteasome inhibition allows the manipulation of many cellular pathways including apoptotic and cell cycle mechanisms. The proteasome inhibitor bortezomib has enhanced responses in newly diagnosed patients with myeloma and provides a new line of therapy in relapsed and refractory patients. Malignant cells are more sensitive to proteasome inhibition than normal haematopoietic cells. Proteasome inhibition enhances many conventional therapies and its role in leukaemia is promising.


Gene Expression Regulation, Leukemic , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/therapy , Leukemia/metabolism , Leukemia/therapy , Proteasome Endopeptidase Complex/metabolism , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Apoptosis , Boronic Acids/therapeutic use , Bortezomib , Cell Cycle , Clinical Trials as Topic , Humans , Medical Oncology/methods , Models, Biological , Protease Inhibitors/therapeutic use , Proteasome Endopeptidase Complex/chemistry , Pyrazines/therapeutic use , Recurrence
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