七夕祭りへようこそ!! (Activity # 5)

Applied Physics 186 class isn't an image processing class for nothing. Of course, its students are EXPECTED to have lots of images in their activity blogs.. xD

5 - A:

Part A of Activity 5 focuses on the familiarization with the discrete FFT. We have two sample images, a circle and a letter 'A'. All we needed to do is apply a discrete FFT2() on the image, give it an FFTSHIFT(), and apply an FFT2() again to get an inverted image of the original. The images above are chronologically-ordered to give the viewer an idea of the process.

5-B:

Part B is all about the simulation of an imaging device. This part makes use of a concept known as Convolution, which is a linear operation for linear transformations as long as they follow the Convolution theorem. The basic gist is that we are imaging an image (VIP), through various apertures (circle, circle2, circle3). The image above displays the original 'VIP', along with the images projected from 100%, 50% and 10% of the circular aperture respectively.

5-C:

Part C worked with Correlation through Template Matching. For the image, we used 'THE RAIN IN SPAIN STAYS MAINLY IN THE PLAIN' which is quite known (although unknown to me. xD). We used another image for the letter A, the trick being it had to be of the same size and font as the one in the previous image, and ta daa.. We obtained an image wherein all the 'A's are highlighted. Pretty nifty for looking for patterns in a large image.

5-D:


Finally, Part D was about detecting edges with the use of the convolution integral. All that was needed was a 3x3 matrix pattern such that the total sum is zero. I used a horizontal, vertical, diagonal and a spot pattern to obtain the images above.

I think I deserve a 10 for the activity for finishing it earlier than expected along with Neil. It's easy because it's a demonstration activity, aside from the fact that the stuff needed is readily available.