Learning OpenCV

Exercises

1. Load an image with interesting textures. Smooth the image in several ways using cvSmooth() with smoothtype=CV_GAUSSIAN.

   1. Use a symmetric 3-by-3, 5-by-5, 9-by-9 and 11-by-11 smoothing window size and display the results.

   2. Are the output results nearly the same by smoothing the image twice with a 5-by-5 Gaussian filter as when you smooth once with two 11-by-11 filters? Why or why not?

2. Display the filter, creating a 100-by-100 single-channel image. Clear it and set the center pixel equal to 255.

   1. Smooth this image with a 5-by-5 Gaussian filter and display the results. What did you find?

   2. Do this again but now with a 9-by-9 Gaussian filter.

   3. What does it look like if you start over and smooth the image twice with the 5-by-5 filter? Compare this with the 9-by-9 results. Are they nearly the same? Why or why not?

3. Load an interesting image. Again, blur it with cvSmooth() using a Gaussian filter.

   1. Set param1=param2=9. Try several settings of param3 (e.g., 1, 4, and 6). Display the results.

   2. This time, set param1=param2=0 before setting param3 to 1, 4, and 6. Display the results. Are they different? Why?

   3. Again use param1=param2=0 but now set param3=1 and param4=9. Smooth the picture and display the results.

   4. Repeat part c but with param3=9 and param4=1. Display the results.

   5. Now smooth the image once with the settings of part c and once with the settings of part d. Display the results.

   6. Compare the results in part e with smoothings that use param3=param4=9 and param3=param4=0 (i.e., a 9-by-9 filter). ...