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Vincent DeVito Computer Systems Lab 2009-2010. The goal of my project is to take an image input, artificially blur it using a known blur kernel, then.

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Presentation on theme: "Vincent DeVito Computer Systems Lab 2009-2010. The goal of my project is to take an image input, artificially blur it using a known blur kernel, then."— Presentation transcript:

1 Vincent DeVito Computer Systems Lab 2009-2010

2 The goal of my project is to take an image input, artificially blur it using a known blur kernel, then using deconvolution to deblur and restore the image, then run a last step to reduce the noise of the image. The goal is to have the input and output images be identical with a blurry intermediate image. The final step is then to estimate the blur kernel of an image with an unknown blur kernel.

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4  Running goal for image processors and photo editors  Many methods of deconvolution exist  Many utilize the Fourier Transform  Current progress focused on blur kernel estimation  Better kernel  more accurate, clear output image

5  The group of Lu Yuan, et al. designed project with blurry/noisy image pairs  Blurry image intensity + noisy image sharpness + deconvolution = sharp, deblurred output image  The group of Rob Fergus, et al. designed project to estimate blur kernel from naturally blurred image  A few inputs + kernel estimation algorithm + deconvolution = deblurred output image with few artifacts

6  Photography  Improve image quality  Restore image

7  Machine Vision  Requires input images to be of good clarity  Blur could ruin techniques such as edge detection  Intermediate step

8  Convert image to frequency domain using the 2D Discrete Fourier Transform and the FFT.   Utilize the formula e θ i = cos θ + i sin θ  Usually display the magnitude, since DFT produces complex number (a + b i ). Magnitude = (a 2 + b 2 ) 1/2  Scale to 0-255 range  O(n 2 )

9  Separate sums   1D DFT in one direction (vertical/horizontal), then in the other  O(nlog 2 n)

10  Converting image back to spatial domain with Inverse Fourier Transform   Also possible to separate  Need full complex number from DFT or FFT Original Picture Magnitude Only Phase Only

11  First step: get FFT and IFFT to work in conjunction  convolution  Test with various types of blue kernels  Second step: reverse process and deconvolute  Noise Reduction as a follow up step  Blur kernel estimation


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