Image lab report - first draft PDF

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1. Title

2. Author(s) Sebastian Sheng Hua He 11688041

3. Abstract 250 words This

4. Introduction

5. Image processing practicals

5.1 Noise removal

5.1.1 Background theory Noise

5.1.2 Actual computer algorithm (operations) First we open up the radiograph of a skull contaminated by salt and pepper noise. Then under the Analyze tab, we use the Histogram tab to display the images grey level histogram, taking note of the large spikes at 0 and 255. Then under the Process tab, we click on the Filters tab and click on Mean and setting the radius at 2. We then note how the histogram changes. We then repeat the process again but now we use a 5 x 5 median mask, by clicking on Median and setting the radius of 2 and note the changes in the histogram and also on how effective it was for removing the noise. We then repeat the whole process again by using a Noisy G skull and note the necessary changes. 5.1.3 Results and discussion

5.2 Band-pass and notch filters

Band-pass filters can be obtained using Process/FFT/Bandpass Filter… Both the low and high frequencies defining the pass band need to be specified, but start with the default values. Band-pass filter axialbrainMRI use various pass bands. Check DisplayFilter to see the filter used in each case.

Open striped lena, and take the fast Fourier transform (Process/FFT/FFT).Using the Paintbrush from the Tools menu, paint the two diagonal spots in the magnitude image that correspond to the diagonal stripes to black, and take the inverse transform (Process/FFT/Inverse FFT). Note how most of the stripes have been removed from the spatial image. There are still remnants close to the periphery of the picture.

Remove these by painting out the streaks that pass through the diagonal spots in the Fourier transform magnitude image. Take the inverse Fourier transform and confirm the removal of the remnants.

5.2.1 Background theory

5.2.2 Actual computer algorithm (operations)

5.2.3 Results and discussion

6. Summary or conclusions

7. Acknowledgement

8. References....