Project 2

Hybrid Images
Evan Shimizu (eshimizu)


This project creates hybrid images, detailed in this paper, from images of our choice.

I created the low-pass images using a simple gaussian filter, generated by MATLAB's fspecial function, and high-pass images by taking the difference between the original image and a gaussian filtered image. Cutoff frequency was determined by fspecial's sigma parameter, and some hand tweaking to make the images look good. The kernel for the fspecial function was set to 25 in both directions.


Bran and Robb

While it might be more thematically appropriate to blend Robb's face with a wolf, these pictures lined up more nicely. These pictures are promotional portraits for the third season of Game of Thrones. The two characters are Robb and Bran. Robb was used as the high frequency image and Bran was used as the low frequency image. Cutoff frequencies were 30 for the high, 12 for the low. The filtered images are averaged together at the end.

Bran - Source
Robb - Source
Bran - FFT Source
Robb - FFT Source
Bran - Filtered
Robb - Filtered
Bran - Filtered FFT
Robb - Filtered FFT

Bran's FFT shows a bit of blockiness. This could be due to the way the image is arranged or due to a gaussian kernel that's not big enough for the image. It seems to not have a huge impact on the final image.

Final Image | Uncompressed

Final Image - FFT

Toothless and a Cat

Because Toothless practically is a cat. Cutoff frequencies were 30 for high, 20 for low.

Cat - Source
Toothless - Source

Final Image | Uncompressed

Final Image - FFT

Dragon and a Bird - Failure Case

This did not work well at all. I think it's because the outline of the dragon and bird didn't really line up well, and the color contrast between the images are too strong to hide the outline of the dragon. Cutoffs were 30 for high and 16 for low.

Bird - Source
Dragon - Source

Final Image | Uncompressed

Bells and Whistles


Color use on the Game of Thrones portraits worked really well, especially when the color on the side of the faces were aligned. I suspect most of the color comes from the low frequency image, which is why color being on the same side of the face matters for these images. I used color on both source images to make the following.

The Hound - Source
Arya - Source

Arya and the Hound - Final Image | Uncompressed

Bran and Robb - Color | Uncompressed

Laplacian and Gaussian Pyramids

Generated for Bran and Robb.

Bran and Robb - Gaussian Pyramid | Full Size

Bran and Robb - Laplacian Pyramid | Full Size