Testing DCT input and output

[davyzhu]

Hi all,

I am new to DCT and now testing my FDCT and IDCT program.
I found some of my high frequency DCT part is higher than low frequency DCT part.
And I don't know whether it is correct.

Where can I find example of 8*8 DCT input and output to test my code，thanks!

BTW,
my code's DCT input:
55 60 58 55 60 58 55 60
58 55 60 58 55 60 58 55
60 58 55 60 58 55 60 58
55 60 58 55 60 58 55 60
58 55 60 58 55 60 58 55
60 58 55 60 58 55 60 58
55 60 58 55 60 58 55 60
58 55 60 58 55 60 58 55
my code's DCT output:
461 0 -1 0 -1 -1 1 0
0 0 0 0 0 -2 0 0
-1 0 -1 0 -2 -1 2 0
0 0 0 0 0 -2 -1 0
-1 0 -2 0 -3 -3 4 0
1 -2 1 -2 3 -11 -3 1
1 0 2 1 4 3 -5 0
0 0 0 0 0 1 0 0

Any suggestions will be appreciated!
All the best,
Davy

 

[tofinhk]

Simple DCT problem

What programming language you are using to write this program?

If you are using something other than Matlab, you may use Matlab with DCT function to test your result.

HTH

 

[davyzhu]

Simple DCT problem

Hi tofinhk,

I use dct(dct(x')'), and all ok!

All the best,
Davy