【数字图像处理】期末复习资料及期末模拟试卷(含答案)(DOC).doc

Digital Image Processing Examination
1. Fourier Transform problem.
For an image given by the function f(x,y)=(x+y)3 where x,y are continuous varibales; evaluate f(x,y)δ(x-1,y-2) and f(x,y)* δ(x-1,y-2),whereδ is the Dorac Delta function.
For the optical imaging system shoen below,consisting of an image scaling and two forward Fourier transforms show that the output image is a scale and inverted replica of the original image f(x,y).
f(x,y)
Scaling
f(ax,by)
F
F
g(x,y)_
3) three binary images (with value 1 on black areas and value 0 elsewhere) are shown below. Sketch the continuous 2D FT of these images(don’t do this mathematically, try to use instead the convolution theorem and knowledge of FTs of common functions)
2. The rate distortion function of a zero memory Gaussian source of arbitary mean and variance σ2 with respect to the mean-square error criterion is
Plot this function
What is Dmax
If a distortion of no mor than 75% of the source’s variance is allowed, what is the maximum compression that can be achieved?
3. The PDF of an image is given by Pr(r) as shown below. Find the transform to
convert the image's PDF to Pr(z). Assume continuity, and find the transform in terms of r and z. Explain the transformation.
4. A certain inspection application gathers black & white images of parts as they travel along a conveyor belt. It is necessary to sort the parts into two categories: parts with holes and parts with-out holes. An example of an image that might be taken by the inspection camera is shown at the right.
Propose a method to identify and locate the objects of each category in the image so that they can be picked up by a robotic system and placed in different bins. Assume that the imaging system knows where each image pixel is located on the conveyor belt at every point in time.
Provide an annotated flow chart of the algorithm you propose.
5. In a given application, an averaging mask is applied to input images to reduce no