project image

Fun with Filters and Frequencies!

Part 1: Fun with Filters

1.1 Finite Difference Operator

The above images show (in order) the convolution of the cameraman image with D_x, D_y, the gradient magnitude and the application of a threshold of 0.25 to the grayscale image.

1.2 Derivative of Gaussian (DoG) filter

The above images show the original cameraman image and the blurred cameraman image with a 3x3 gaussian kernel with a sigma of 1.

The above images show the effects of 1.1 with a blurred cameraman image shown above.

The above images show the effects of the single convolution on the blurred image shown above.

1.3 Image Straightening

The best rotation was at an angle of -2 degrees (the implementation searched from -20 to 20 degrees with a step of -2 degrees)

I took an image of Stonehenge and rotated it by 10 degrees. Then, the algorithm found the best rotation to be at an angle of 8 degrees.

I took an image of the leaning tower of Pisa and the algorithm found the best rotation to be at an angle of -4 degrees.

The above image fails because the tower is not in the middle. The algorithm finds the optimum angle to be at 0 degrees of rotation.

2.1 Image Sharpening

2.2 Hybrid Images

2.4 Multiresolution Blending