Fun with frequencies and gradients!

In this project we played with high pass and low pass filters to blend images on top of each other and into each other. We used Gaussian filters for low pass and to build Laplacian filters for high pass, while toying with the sigma value to achieve effective results. We then attempted to seamlessly blend together different images using different blending techniques such as multiresolution blending and poisson blending.

Sharpening an image

The first image is before sharpening, the following image is after sharpening. The sharpened image was generated by taking:

original_image + alpha*[original_image - gausssian(original_image)] where sigma=5 and alpha=1

Hybrid Images

I decided to overlap the face of an old women over the face of a young girl.

This the the best result I achieved by running a low pass filter over the young girl and a high pass filter over the old woman. The lowpass frequency signal was set to sigma=2 and the high pass frequency signal was set to sigma=4.

We can see both the young girl and the old woman by observing the hybrid image at different sizes. At smaller sizes, the image appears to be of the young girl, but at a bigger size the image shows an old woman's face.

Here is the following frequency analysis conducted on the original images, filtered images, and final image.

Here are some other images and their hybrid combinations.

This particular combination failed because the features of the faces couldn't be aligned properly no matter what since the perspectives of the faces don't match

Multiresolution Blending

I attempted to blend together two images using the Laplacian pyramid and masking technique in this paper. Below are two images I blended together by using a vertical mask.

Here is the result:

Here are the laplacian layers I combined to blend these two images at various depths.

depth 1

depth 2

depth 3

depth 4

depth 5

Favorite Image

The seasons image is my favorite blended image because the original images were captured in the same exact location with the same composition. The blending really makes it seamlessly look like the same place is in two different seasons. The mask is simply split perfect down the center since the original images were perfectly symmetrical. Pyramids were built and stacked together at depth=5

Here it is without and with the blend: