Files You Need for This Lab

You will need to download the following files:

• image.h
• image.cc
• Makefile
• imagefft.h - Header file for ComplexFFTImage class, which has a built-in FFT function.
• imagefft.cc - Related source file.
• lab3-skeleton.cc - Outline for the source file for all parts of this lab.

You will need the following image files.

• top_student.png - a photo of the best student in ECE 418 Spring 2004.
• cat_thoughts.png - undeniable proof that cats are conspiring to conquer the world.

Getting Started

Use the following instructions to get started.

1. Download the needed files and enter the directory where you saved them.
2. Make three copies of lab3_skeleton.cc, naming them lab3a.cc, lab3b.cc, and lab3c.cc.
   • In lab3a.cc and lab3b.cc you will be implementing part 1 of this lab (with zero-order hold and bilinear interpolation respectively).
   • In lab3c.cc you will implement all of part 2 of this lab.
3. Edit these files to do the three parts of this lab.

Important Notes

In this lab, you will be using the ComplexFFTImage class. This is almost identical to the ComplexImage class, except it has a built-in FFT function. For example, if you want to transform the ComplexFFTImage image you only need to type in:

And to reverse the transformation, you only need to type in:

Running

Syntax for image interpolation. User specifies coordinates of top_left_row and top_left_column of rectangular region to be enlarged. Suggested command line usage:

• ./lab3a top_student.png out_3a.png top_left_row top_left_column
• ./lab3b top_student.png out_3b.png top_left_row top_left_column

For Image decimation, the suggestion is that you set up your program to use the following syntax:

• ./lab3c input.png small_output.png restored.png difference.png filter_flag decimation_factor