CS 194-26: Project 3

Fun with Frequencies and Gradients!

Louis Leung, CS194-26-afb

Part 1: Frequency Domain

Part 1.1: Warmup

Here, we used the sharpening technique learned in class where you create an image using the following formula: sharpened_image = im + (im - gaussian blurred im) * alpha. The alpha value can be tuned -- sharpening too much can make the picture look oversaturated.

Original
alpha = 3
alpha = 10

Part 1.2: Hybrid Images

These hybrid images are created using a high pass version of one image overlayed with a low pass version of another image. Choosing the sigma and kernel size variables for each of these filtered passes was a lot of trial and error.

Derek & Nutmeg
Derek
Nutmeg

Henry
Guy Fieri
Guy Henrieri

FFT Henry
FFT Guy Fieri
FFT Henry Low Pass
FFT Guy Fieri High Pass
FFT Hybrid



Failures(-ish). These didn't work out so well because the low pass images are a slight side profile while the high pass images are straight on.

Pass the Juul Bro
"Where's my hug at"
Hybrid

Benches your deadlift, his dad owns your dad
Disciple of the Blade
Hybrid

Part 1.3: Gaussian and Laplacian Stacks

Gaussian stacks were created by continuously applying blurring to a photo.
Laplacian stacks were created by taking the difference of im[n] - blurred(im[n]) at level n
The last layer of the Laplacian stack is the last Gaussian blur image.





Part 1.4: Multiresolution Blending

Here, we use a gaussian blurred mask to take varying ratios of different levels of the laplacian stacks for two images and then combine them to create a more smooth, blended combined image.


Orange
Apple
Oraple

Beach
Galaxy
Galaxy Beach
Beach Mask
Here's one of my favorite blended creations with an irregular mask.

Jesus
Toast
Jesus Toast
Mask

Part 2: Gradient Domain Fushion

Here, we take a look into how we can cut and paste part of an image into another image or scene as seamlessly as possible. What makes this combination of a source image into a target background look good is if the source image has its gradients preserved.
This can be mapped by the following minimization equation:

Part 2.1: Toy Example

Here, we do a toy version of the problem by trying to reconstruct an image based on simple gradient calculations -- the difference in intensity of one pixel to its right neighbor and below neighbor.

Toy Example Picture
Toy Example Recreation