Domande teoriche esame parziale

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Parziale Immagini 1) Contour extraction (6 points) a) You want to extrct the contour of a specific object in an image by applying the Laplacian method. Represent the block schema of all the needed steps with a short description for each of them. b) Report an example of a possible application of the method c) Write how to implement the method in Matlab code and explain it 2) Consider the matrix A and the correspondent grayscale image. (Tot points 7) a) Build the histogram of the image. Report and define all parameters on it. b) Provide the definition of the histogram of an image. How is it constructed? c) Re-map the image so to obtain the inverse one. Write the Matlab function which performs this task and build the histogram of the new image you have obtained. d) The image is corrupted by salt and pepper noise. Suggest a strategy for the removal of this noise. Calculate the SNR. 3) X-Rays (tot 5 points). a) Draw a simple schema of X-ray imaging system and explain its functioning. Define all components in the system and their role. b) Which is the source of contrast in X-rays imaging? Define the law that describes the intensity of X-rays as they travel in body tissues. Report a clinical application. Parziale segnali 1) A biological signal (whose spectrum is indicated in fig.1 together with the main noise at 50 Hz) has to be A/D converted. The real physiological information is in the range of frequencies 0.5-30 Hz, as indicated in the figure. The student indicate the correct A/D procedure to be carried out for correctly reproducing the information and eliminating the main noise. 2) The student describe step-by-step the process of low-pass digital filter design through the “windowing method”, by providing variable values of his/her choice. 3) The student explain the…