For Programmers: Free Programming Magazines  


Home > Archive > Compression > January 2006 > JPEG2000 a Simple Doubt about Size of Code Blok Plz Help...









You are viewing an archived Text-only version of the thread. To view this thread in it's original format and/or if you want to reply to this thread please [click here]

 

Author JPEG2000 a Simple Doubt about Size of Code Blok Plz Help...
Dunce

2006-01-16, 9:55 pm

hi all,
I am student need to impliment JPEG2000, EBCOT encoder for my project.
I have a doubt about the contents of code block outside the subband.
if i use 64*64 code block, and suppse my sub band size is (88*72)R*C
the I will have
only one code block of (64*64) and rest will be
(64*64) (64*24)
(8*64) (8*24)

please advise me how to tackle this problem, if i make all code block
of 64*64 the I have a lot of
empty spaces, if i put like shown above then is it right or not ? if
right then how to terminate??

plz advie me,

thanks in advance,

attiq

Ramnath

2006-01-18, 3:55 am

The codeblocks need not be aligned to fit the subband boundaries - that
is a codeblock can extend into the adjacent subband if it doesn't fit
in the current subband.
At the image boundaries just code the codeblock (whatever size it is) -
Don't make it 64*64 by padding with zeros.

Ramnath

Dunce wrote:
> hi all,
> I am student need to impliment JPEG2000, EBCOT encoder for my project.
> I have a doubt about the contents of code block outside the subband.
> if i use 64*64 code block, and suppse my sub band size is (88*72)R*C
> the I will have
> only one code block of (64*64) and rest will be
> (64*64) (64*24)
> (8*64) (8*24)
>
> please advise me how to tackle this problem, if i make all code block
> of 64*64 the I have a lot of
> empty spaces, if i put like shown above then is it right or not ? if
> right then how to terminate??
>
> plz advie me,
>
> thanks in advance,
>
> attiq


Thomas Richter

2006-01-18, 3:55 am

Hi,

> The codeblocks need not be aligned to fit the subband boundaries - that
> is a codeblock can extend into the adjacent subband if it doesn't fit
> in the current subband.


Sorry, but this is incorrect. A codeblock carries only data from one
single band. If the codeblock does not fit into the boundaries of the
current band, it has to be clipped into the band boundaries. "Out of
band" coefficients are not part of the codeblock.

So long,
Thomas
Ramnath

2006-01-18, 7:55 am

Hi
Thomas is right - "A codeblock carries only data from one single band"
I apologize for the error I made.
Thanks for pointing out
Ramnath

Thomas Richter wrote:
> Hi,
>
>
> Sorry, but this is incorrect. A codeblock carries only data from one
> single band. If the codeblock does not fit into the boundaries of the
> current band, it has to be clipped into the band boundaries. "Out of
> band" coefficients are not part of the codeblock.
>
> So long,
> Thomas


Sponsored Links







Also available: Server administration forum archive | Web Design forum archive | Software forum archive | Hardware reviews archive

Copyright 2008 codecomments.com