HW 6, EECS 203A

Problem 5.27, Digital Image Processing, 2nd edition by Gonzalez, Woods.

Nasser Abbasi, UCI. Fall 2004

Question

A certain Xray imaging geometry produces a blurring degradation that can be modeled as the convolution of the sensed image with the spatial, circularly symmetric function MATH where $r^{2}=x^{2}+y^{2}$. Show that the degradation in the frequency domain is given by MATH

Solution

In general, MATH

Since we are told what the model is (no noise involved), then the model is MATH

Here MATH is the sensed image, and MATH is the degraded, produced image and $h$ is the impulse response.

This means if the input image is an impulse, then the output image will be $h\left( r\right) $ or $h(x,y)$ since $r$ is a function of $x,y$

So a degraded output image can be considered to be $h(x,y)$ convolved with impulse. Since the Fourier transform of an impulse is 1, then in the frequency domain, the fourier transform of a degraded output image is the fourier transform of $h$ times 1.

i.e. in frequency domain, degraded output image transform MATH

But MATH

MATH

=MATH

MATH

But

MATH

but from tables, we know that MATH

MATH

MATH

MATH

Hence we get MATH

$....$ do not know what I am doing wrong, can't get the exact expression needed, getting very close...