Problem 930. 1D DCT-II transform.

Created by Ryszard Maciol

Difficulty:Rate

Solve Later
Add To GroupÃ‚

Implement a function that calculates 1D Discrete Cosine Transform (DCT-II) for each row of a given input matrix so that the outputs are in columns.

For example:

Input:

[1 0 0 0]

Gives:

mydct([1 0 0 0])
ans =
          0.5
      0.65328
          0.5
       0.2706

Solve

Solution Stats

118 Solutions
19 Solvers

Last Solution submitted on Apr 21, 2023

Last 200 Solutions

Problem Comments

1 Comment

1 Comment

Rafael S.T. Vieira on 22 Oct 2020

A fair warning to the challenger: the requested DCT-II is the orthogonal version, which means it needs to be multiplied by sqrt(2/N) where N is the size of the row, and the first element of the DCT x0 needs to be multiplied by 1/sqrt(2). It took me a while to understand. Wikipedia's formula is almost right, but it is missing those terms, which are mentioned only further below. Look at MATLAB's documentation (DCT-2), https://www.mathworks.com/help/signal/ref/dct.html, to find the proper formula.

Solution Comments

Show comments

ANNOUNCEMENT

Registration Now Open for MathWorks AUTOMOTIVE CONFERENCE 2025

Hello Community, We're excited to announce that registration is now open for the...

Problem Recent Solvers19

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 930. 1D DCT-II transform.

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Registration Now Open for MathWorks AUTOMOTIVE CONFERENCE 2025

Problem Recent Solvers19

Suggested Problems

More from this Author4

Problem Tags

Community Treasure Hunt

Problem 930. 1D DCT-II transform.

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Registration Now Open for MathWorks AUTOMOTIVE CONFERENCE 2025

Problem Recent Solvers19

Suggested Problems

More from this Author4

Problem Tags

Community Treasure Hunt

Players