Project 3: Fun with Frequencies and Gradients

By Seunghwan Choi(cs194-26-acf)

Warm up 1.1

I used unsharp technique taught in class to sharpen this image. The equation I used is original + (origina - blurred) * alpha where alpha is 0.5

Original, Sharpened

Part 1.2

Hybrid images are created by combining high frequencies of one picture to low frequencies of another picture.

panda, lincoln, hybrid

Fourier Analysis

input, input, high freq, low freq, hybrid

dog, mona lisa, hybrid

tiger, eagle, hybrid(failed)

Part 1.3

Gaussian Stacks are made by filtering the image with gaussian filter with 2, 4, 8, 16 ... sigma values. Then Laplacian stack is made by difference of neigboring Gaussian stacks

Part 1.4

Multiresolution Blending is done by computing a gentle seam between the two images seperately at each band of image frequencies, resulting in a much smoother seam.

image1 + image2 = blended

Visualizing Laplacian stack for Multiresolution Blending

Part 2.1

For toy problem, I set up the equation so that it becomes Av = b where A is a sparse matrix, b is a kwown value, and v is the variable aka the image we want to reconstruct. Then I used built-in least square to find v.

Part 2.2

Reflection

This was a fun project. I got to merge images, blend images that I want without using photoshop. I was pretty proud of myself. The project itself was pretty challenging. The most important thing I learned from this project is that merging two images HAVE its limitation no matter what.