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DTSTAMP:20201015T183000Z
UID:1602682701118@events.msu.edu
CATEGORIES:Conferences / Seminars / Lectures
DTSTART:20201015T183000Z
DTEND:20201015T193000Z
SUMMARY:Math Seminar Series
DESCRIPTION:
 Applied Mathematics\n
 \n
 Reinhard Heckel from the 
 Technical University of Munich will be speaking.\n
 \n
 The 
 presentation is titled "Provable 
 Image Recovery with Untrained Convolutional 
 Neural Networks."\n
 \n
 This is a virtual meeting.\n
 \n
 Contact 
 Olga Turanova (turanova@msu.edu) 
 for more information.\n
 \n
 The abstract is as 
 follows:\n
 \n
 Convolutional Neural Networks are 
 highly successful tools for image recovery 
 and restoration. A major contributing factor 
 to this success is that convolutional networks 
 impose strong prior assumptions about natural 
 images-so strong that they enable image recovery 
 without any training data. A surprising 
 observation that highlights those prior assumptions 
 is that one can remove noise from a 
 corrupted natural image by simply fitting (via 
 gradient descent) a randomly initialized, over-parameterized 
 convolutional generator to 
 the noisy image. In this talk, we discuss a simple 
 un-trained convolutional network, called 
 the deep decoder, that provably enables image 
 denoising and regularization of inverse problems 
 such as compressive sensing with excellent 
 performance. We formally characterize the 
 dynamics of fitting this convolutional network 
 to a noisy signal and to an under-sampled 
 signal, and show that in both cases early-stopped 
 gradient descent provably recovers the 
 clean signal. Finally, we discuss our own numerical 
 results and numerical results from another 
 group demonstrating that un-trained convolutional 
 networks enable magnetic resonance 
 imaging from highly under-sampled measurements, 
 achieving results surprisingly close to trained 
 networks, and outperforming classical untrained 
 methods.\n\n
 Price: free\n
 Sponsor: Department of Mathematics\n
 Sponsor's Homepage: https://www.math.msu.edu/\n
 Contact name: Department of Mathematics\n
 Contact phone: (517) 353-0844\n
 for more info visit the web at:\n 
 https://www.math.msu.edu/Seminars/CalendarView.aspx?month-of=September2016\n
LOCATION:Zoom link provided on Math Seminars page
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