Digital Image Processing COL 783

Assignment 3: Seam Carving

Due Date: Nov 14, 2023


Part A: Seam Carving

This assignment deals with Seam Carving of images as discussed in the class and extends to Object Carving. Seam Carving is a method of re-sizing an image which is in a sense context aware. The re-sizing is not just a scaling operation. The method is described in the paper by Avidan and Shamir [1]. The main idea of re-sizing is to identify a seam connecting from top to bottom (vertical seam) and/or left to right (horizontal seam) pixels with minimum energy. The energy can be defined in terms of gradient function in DCT domain as described in [2]. Finding seam with minimum energy can be implemented using dynamic programming [3]. This method is based on the observation that one can compute the minimum-energy seams (e.g. vertical) going through all pixels in current row i by knowing the minimum-energy seams through all pixels in the previous row i-1. One can define Cumulative Minimum Energy (CME) of a path going through some pixel (i,j) as the energy at (i,j) plus the minimum of the energies at vertical and diagonal adjacent pixels i.e. at (i-1,j-1), (i-1,j), and (i-1,j+1). The cost of the globally-minimum-energy path is then just the lowest CME found at the last row.

The results should include

Part B: Learning Based Seam Carving

Follow the details given here

Note:

References

  1. Seam Carving for Content Aware Image Resizing SIGGRAPH 2007.
  2. Image Retargeting in Compressed Domain
  3. Seam Carving in Wikipedia.